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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2015 Vol. 23, No. 10
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2015, 23(10): 1215-1219.
doi: 10.13930/j.cnki.cjea.150276
Abstract:
China has the largest population and is also the largest agro-based country in the world. As such, agricultural modernization is critical for national modernization. To this end, food security should be the ultimate goal of agricultural modernization in China. Based on China’s modernization development progress, the importance ranking of agricultural modernization in national modernization has been determined by food security at different historical stages. With small population in the 1950s, there was not big problem for food supply. Thus agricultural modernization was ranked the second among the four modernization types. Then with the acute shortage and huge demand for food in “Three Years of Natural Disasters” in the 1960s, agricultural modernization was ranked first among the four modernization types. At the beginning of the 21st century, China was completely self-sufficient in food and even slight surpluses. Then, agricultural modernization did not appear in the five modernization types documented in the 17th National Congress Report of the Communist Party of China (CPC). But by 2012, food import rapidly increased along with increasing population in China. Then, agricultural modernization ranked the fourth in the four modernization types in the 18th National Congress Report of CPC. Food security ranked the first in 2014 because of the large amount of food import in recent years. Because of the huge population, weak foundation of agricultural modernization, resource and environment conflicts, food security was strongly emphasized in China. It was stressed that ensuring food security was China’s internal issue. Agricultural modernization was identified as China’s long-term mission. At present and also in the future, it was proposed to continuously increase food security via agricultural mechanization, high water use efficiency and biotechnology-based agriculture in China. This was concluded to maintain sustainable development of agricultural modernization and to realize the ultimate goal of food security in China.
China has the largest population and is also the largest agro-based country in the world. As such, agricultural modernization is critical for national modernization. To this end, food security should be the ultimate goal of agricultural modernization in China. Based on China’s modernization development progress, the importance ranking of agricultural modernization in national modernization has been determined by food security at different historical stages. With small population in the 1950s, there was not big problem for food supply. Thus agricultural modernization was ranked the second among the four modernization types. Then with the acute shortage and huge demand for food in “Three Years of Natural Disasters” in the 1960s, agricultural modernization was ranked first among the four modernization types. At the beginning of the 21st century, China was completely self-sufficient in food and even slight surpluses. Then, agricultural modernization did not appear in the five modernization types documented in the 17th National Congress Report of the Communist Party of China (CPC). But by 2012, food import rapidly increased along with increasing population in China. Then, agricultural modernization ranked the fourth in the four modernization types in the 18th National Congress Report of CPC. Food security ranked the first in 2014 because of the large amount of food import in recent years. Because of the huge population, weak foundation of agricultural modernization, resource and environment conflicts, food security was strongly emphasized in China. It was stressed that ensuring food security was China’s internal issue. Agricultural modernization was identified as China’s long-term mission. At present and also in the future, it was proposed to continuously increase food security via agricultural mechanization, high water use efficiency and biotechnology-based agriculture in China. This was concluded to maintain sustainable development of agricultural modernization and to realize the ultimate goal of food security in China.
2015, 23(10): 1220-1227.
doi: 10.13930/j.cnki.cjea.150103
Abstract:
Arbuscular mycorrhizal fungi (AMF) promotes growth of plants and increases utilization of phosphorus (P) and other nutrients of plants. Intercropping is an effective way promoting use efficiency of resources in both time and space. As the shortage of soil phosphate in different regions around the world worsens, more researches have focused on intercropping or mycorrhizal technology to strengthen soil P utilization and increase crop yield. Irrespectively, little has remained known about the effects of combined AMF inoculation and intercropping on plant growth and P utilization in sloping soils in Dianchi watershed. Plant growth and P utilization of maize (Zea mays L.) intercropped with soybean (Glycine max L.) or monocultured in red soils were investigated through the addition of different amounts of P to compartment chamber and different treatments of AMF inoculation in a root growth chamber. Three different P additions [no P (P0), organic P (soy lecithin, OP50) and inorganic P (potassium dihydrogen phosphate, IOP50) with 50 mg(P)kg-1 of soil, respectively] and two AMF treatments [no AMF (NM) and Glomus mosseae inoculation (GM)] were set up. The results showed that among the composite treatments, both the shortest root length and largest shoot biomass of maize occurred under the GM-IOP50 intercropping treatment. For OP50 treatment, AMF infection rate of intercropped maize was significantly higher than that of monocultured maize. Regardless of P addition under intercropping, maize shoot biomass was obviously higher for GM treatment than for NM treatment. Then maize root biomass and plant height were significantly higher under GM treatment than under NM treatment. Root biomass was also highest under GM-OP50 intercropping treatment. For GM inoculation treatment, biomass for P0, IOP50 and OP50 intercropping treatments increased respectively by 45.98%, 111.33% and 33.56% over that of the corresponding mono-cropping treatments. With or without the addition of P under mono-cropping, P content in maize shoot was significantly higher for GM treatment than for NM treatment. Also irrespective of the mode of planting and addition of P, P content in maize root was significantly higher for GM treatment than for NM treatment. Regardless of P addition treatment, P uptake of maize shoot under intercropping with GM inoculation treatment was higher than that of the other treatments. Then shoot P uptake under IOP50 treatment was significantly higher than that under OP50 treatment. Under GM intercropping treatment, the specific absorption rate of P by maize root was significantly higher for IOP50 intercropping treatment than for OP50 intercropping treatment. Thus AMF inoculation, P application and intercropping modes respectively promoted plant growth to a certain extent. GM-IOP50 intercropping treatment performed best in terms of shoot growth and P uptake, which effectively strengthened P use in red soils in Dianchi Lake Basin.
Arbuscular mycorrhizal fungi (AMF) promotes growth of plants and increases utilization of phosphorus (P) and other nutrients of plants. Intercropping is an effective way promoting use efficiency of resources in both time and space. As the shortage of soil phosphate in different regions around the world worsens, more researches have focused on intercropping or mycorrhizal technology to strengthen soil P utilization and increase crop yield. Irrespectively, little has remained known about the effects of combined AMF inoculation and intercropping on plant growth and P utilization in sloping soils in Dianchi watershed. Plant growth and P utilization of maize (Zea mays L.) intercropped with soybean (Glycine max L.) or monocultured in red soils were investigated through the addition of different amounts of P to compartment chamber and different treatments of AMF inoculation in a root growth chamber. Three different P additions [no P (P0), organic P (soy lecithin, OP50) and inorganic P (potassium dihydrogen phosphate, IOP50) with 50 mg(P)kg-1 of soil, respectively] and two AMF treatments [no AMF (NM) and Glomus mosseae inoculation (GM)] were set up. The results showed that among the composite treatments, both the shortest root length and largest shoot biomass of maize occurred under the GM-IOP50 intercropping treatment. For OP50 treatment, AMF infection rate of intercropped maize was significantly higher than that of monocultured maize. Regardless of P addition under intercropping, maize shoot biomass was obviously higher for GM treatment than for NM treatment. Then maize root biomass and plant height were significantly higher under GM treatment than under NM treatment. Root biomass was also highest under GM-OP50 intercropping treatment. For GM inoculation treatment, biomass for P0, IOP50 and OP50 intercropping treatments increased respectively by 45.98%, 111.33% and 33.56% over that of the corresponding mono-cropping treatments. With or without the addition of P under mono-cropping, P content in maize shoot was significantly higher for GM treatment than for NM treatment. Also irrespective of the mode of planting and addition of P, P content in maize root was significantly higher for GM treatment than for NM treatment. Regardless of P addition treatment, P uptake of maize shoot under intercropping with GM inoculation treatment was higher than that of the other treatments. Then shoot P uptake under IOP50 treatment was significantly higher than that under OP50 treatment. Under GM intercropping treatment, the specific absorption rate of P by maize root was significantly higher for IOP50 intercropping treatment than for OP50 intercropping treatment. Thus AMF inoculation, P application and intercropping modes respectively promoted plant growth to a certain extent. GM-IOP50 intercropping treatment performed best in terms of shoot growth and P uptake, which effectively strengthened P use in red soils in Dianchi Lake Basin.
2015, 23(10): 1228-1235.
doi: 10.13930/j.cnki.cjea.150546
Abstract:
With poor physical properties and low organic matter content, lime concretion black soil is one of the lowest productive soils and is widely distributed in the Huang-Huai-Hai Plain in China. Although the physical and chemical properties of lime concretion black soil influenced by exogenous organic matter have been widely reported, few studies have focused on the effects of synchronous application of organic materials with different stabilities in lime concretion black soil. Thus a two-year pot experiment was conducted at the State Experimental Station of Agro-Ecosystem in Fengqiu to evaluate the effects of organic materials with different stabilities (biochar, organic fertilizer and straw) on the physico-chemical properties of lime concretion black soil and maize yield. Eight treatments were designed based on applications of different organic materials with the same inputs of carbon and nitrogen, which were CK (no fertilizer), straw (S), organic manure (M), biochar (C), 1/2 straw + 1/2 organic manure (SM), 1/2 biochar + 1/2 straw (CS), 1/2 biochar + 1/2 organic manure (CM), and 1/3 biochar + 1/3 organic fertilizer + 1/3 straw (CSM). Compared with CK, the application of different organic materials decreased soil bulk density by 19.60%32.23% and increased saturated soil moisture, field capacity and total porosity by 7.91%28.99%, 10.47%30.76% and 10.36%28.21%, respectively. There were significant differences in total organic matter and labile organic matter contents of soil between CK and organic materials application treatments. The trends of increase in different components of organic matter were similar. On the other hand, the variation range of high labile organic matter was obviously greater than that of total organic matter. The high labile organic matter content increased by 39.22%8.83%, whereas that of total organic matter increased by 11.00%37.00% under organic materials treatments. Bulk density of CSM (1.28 gcm-1) was lower than those of C (1.30 gcm-1) and S (1.36 gcm-1). Total porosity of CSM was highest (58.53%) among all treatments. Total porosity under CS, SM, S, C and M treatments was 56.90%, 54.38%, 55.62%, 53.18% and 50.38%, respectively. Total organic matter content of CS, CM, CSM, C and S was 30.76 gkg-1, 32.99 gkg-1, 31.45 gkg-1, 25.36 gkg-1 and 26.16 gkg-1, respectively. Maize yield for different treatments were similar in trend to that of total organic matter content. Grain yield for CS, SM and CSM was respectively 463.67 gpot-1, 376.31 gpot-1 and 471.77 gpot-1; higher than that of C, S and M. Overall, mixed application of biochar, straw and organic fertilizer was by far better than the application of sole organic material in terms of improving soil physico-chemical properties and maize yield.
With poor physical properties and low organic matter content, lime concretion black soil is one of the lowest productive soils and is widely distributed in the Huang-Huai-Hai Plain in China. Although the physical and chemical properties of lime concretion black soil influenced by exogenous organic matter have been widely reported, few studies have focused on the effects of synchronous application of organic materials with different stabilities in lime concretion black soil. Thus a two-year pot experiment was conducted at the State Experimental Station of Agro-Ecosystem in Fengqiu to evaluate the effects of organic materials with different stabilities (biochar, organic fertilizer and straw) on the physico-chemical properties of lime concretion black soil and maize yield. Eight treatments were designed based on applications of different organic materials with the same inputs of carbon and nitrogen, which were CK (no fertilizer), straw (S), organic manure (M), biochar (C), 1/2 straw + 1/2 organic manure (SM), 1/2 biochar + 1/2 straw (CS), 1/2 biochar + 1/2 organic manure (CM), and 1/3 biochar + 1/3 organic fertilizer + 1/3 straw (CSM). Compared with CK, the application of different organic materials decreased soil bulk density by 19.60%32.23% and increased saturated soil moisture, field capacity and total porosity by 7.91%28.99%, 10.47%30.76% and 10.36%28.21%, respectively. There were significant differences in total organic matter and labile organic matter contents of soil between CK and organic materials application treatments. The trends of increase in different components of organic matter were similar. On the other hand, the variation range of high labile organic matter was obviously greater than that of total organic matter. The high labile organic matter content increased by 39.22%8.83%, whereas that of total organic matter increased by 11.00%37.00% under organic materials treatments. Bulk density of CSM (1.28 gcm-1) was lower than those of C (1.30 gcm-1) and S (1.36 gcm-1). Total porosity of CSM was highest (58.53%) among all treatments. Total porosity under CS, SM, S, C and M treatments was 56.90%, 54.38%, 55.62%, 53.18% and 50.38%, respectively. Total organic matter content of CS, CM, CSM, C and S was 30.76 gkg-1, 32.99 gkg-1, 31.45 gkg-1, 25.36 gkg-1 and 26.16 gkg-1, respectively. Maize yield for different treatments were similar in trend to that of total organic matter content. Grain yield for CS, SM and CSM was respectively 463.67 gpot-1, 376.31 gpot-1 and 471.77 gpot-1; higher than that of C, S and M. Overall, mixed application of biochar, straw and organic fertilizer was by far better than the application of sole organic material in terms of improving soil physico-chemical properties and maize yield.
2015, 23(10): 1236-1243.
doi: 10.13930/j.cnki.cjea.150126
Abstract:
Radiation use efficiency (RUE) is critical for improving crop yield. It is not only related to crop canopy intercepted radiation, but also to the distribution of radiation within the canopy. The characteristics and forming processes of crop canopy are affected by genetic characteristics, management practices and other related factors. Various canopy characteristics have different end-effects on crop RUE. Winter wheat is a major crop grown in the North China Plain (NCP), accounting for about 50% of wheat production in China. Thus keeping high yields and improving resources use efficiency of winter wheat are critical in the NCP region. To explore the effects of varieties, water and nitrogen supplies on RUE of winter wheat, a field experiment was conducted at Luancheng Agro-Ecosystems Experimental Station, Chinese Academy of Sciences in the winter wheat growing season from 2012 to 2013. Three winter wheat varieties (‘Jimai585’, ‘Kenong199’ and ‘Shixin828’) were used in the experiment — the main wheat varieties grown in the study area. Three water supply levels [70 mm irrigation in jointing stage (serious deficit irrigation), total 140 mm irrigations in jointing and booting stages (moderate deficit irrigation) and total 210 mm irrigations in jointing, booting and grain-filling stages (normal irrigation)] were applied, and three nitrogen supply levels [135 kg(N)·hm-2, 180 kg(N)·hm-2 and 225 kg(N)·hm-2] used as fertilizer management in the study. Biomass, leaf area index and photosynthetically active radiation (PAR) were measured every 7 days. RUE was calculated using biomass and intercepted radiation during the respective growth periods of winter wheat. The results showed that RUE was significantly different for different wheat varieties. RUE was 2.10 g·MJ-1 for ‘Jimai585’, 2.05 g·MJ-1 for ‘Kenong199’ and 1.93 g·MJ-1 for ‘Shixin828’. RUE under different water and nitrogen levels was also different, and ranged within 1.802.20 g·MJ-1. RUE increased with increasing nitrogen supply. However, RUE was higher for moderate water deficit irrigation than others treatments. There was no significant difference in RUE for water and nitrogen interaction. This suggested that genetic characteristics, water and nitrogen supplies significantly influenced wheat RUE. Although increasing RUE obviously increased biomass, winter wheat yield did not significantly increase after a certain increase in biomass due to lower dry matter transfer rate. The results also showed a significantly relationship between RUE and air temperature for the period from stem-elongation to grain-filling. Given the above, it was concluded that the appropriate nitrogen and water supply for winter wheat was beneficial for dry matter accumulation and improvement of RUE, eventually resulting in high winter wheat yield.
Radiation use efficiency (RUE) is critical for improving crop yield. It is not only related to crop canopy intercepted radiation, but also to the distribution of radiation within the canopy. The characteristics and forming processes of crop canopy are affected by genetic characteristics, management practices and other related factors. Various canopy characteristics have different end-effects on crop RUE. Winter wheat is a major crop grown in the North China Plain (NCP), accounting for about 50% of wheat production in China. Thus keeping high yields and improving resources use efficiency of winter wheat are critical in the NCP region. To explore the effects of varieties, water and nitrogen supplies on RUE of winter wheat, a field experiment was conducted at Luancheng Agro-Ecosystems Experimental Station, Chinese Academy of Sciences in the winter wheat growing season from 2012 to 2013. Three winter wheat varieties (‘Jimai585’, ‘Kenong199’ and ‘Shixin828’) were used in the experiment — the main wheat varieties grown in the study area. Three water supply levels [70 mm irrigation in jointing stage (serious deficit irrigation), total 140 mm irrigations in jointing and booting stages (moderate deficit irrigation) and total 210 mm irrigations in jointing, booting and grain-filling stages (normal irrigation)] were applied, and three nitrogen supply levels [135 kg(N)·hm-2, 180 kg(N)·hm-2 and 225 kg(N)·hm-2] used as fertilizer management in the study. Biomass, leaf area index and photosynthetically active radiation (PAR) were measured every 7 days. RUE was calculated using biomass and intercepted radiation during the respective growth periods of winter wheat. The results showed that RUE was significantly different for different wheat varieties. RUE was 2.10 g·MJ-1 for ‘Jimai585’, 2.05 g·MJ-1 for ‘Kenong199’ and 1.93 g·MJ-1 for ‘Shixin828’. RUE under different water and nitrogen levels was also different, and ranged within 1.802.20 g·MJ-1. RUE increased with increasing nitrogen supply. However, RUE was higher for moderate water deficit irrigation than others treatments. There was no significant difference in RUE for water and nitrogen interaction. This suggested that genetic characteristics, water and nitrogen supplies significantly influenced wheat RUE. Although increasing RUE obviously increased biomass, winter wheat yield did not significantly increase after a certain increase in biomass due to lower dry matter transfer rate. The results also showed a significantly relationship between RUE and air temperature for the period from stem-elongation to grain-filling. Given the above, it was concluded that the appropriate nitrogen and water supply for winter wheat was beneficial for dry matter accumulation and improvement of RUE, eventually resulting in high winter wheat yield.
2015, 23(10): 1244-1252.
doi: 10.13930/j.cnki.cjea.150263
Abstract:
Phosphorus is one of the main nutrient elements needed by plant growth. Because phosphate fertilizer is difficult to move under traditional soil culture, there is a significant gap between applied phosphorus fertilize and available phosphorus of plant. Under hydroponic conditions, however, phosphate fertilizer is evenly dissolved in nutrient solutions. This is not only beneficial for nutrient uptake of plant, but also critical for accurately and quantitatively analyzing the effect of phosphorus on plant. To determine the effect of phosphorus level on lettuce growth, quality and dynamic absorption of mineral elements, 0.2 mmol·L-1, 0.4 mmol·L-1, 0.6 mmol·L-1, 0.8 mmol·L-1 and 1.0 mmol·L-1 of NaH2PO4 were separately added to a nutrient solution. The growth, yield, quality and dynamic mineral absorption of lettuce were measured and quantitatively analyzed. The results showed that the quality of lettuce was best under 0.4 mmol·L-1 NaH2PO4. In 0.6 mmol·L-1 of NaH2PO4 solution, the yield of lettuce hit peak amount, and the total absorption of N, P, K, Ca and Mg during the whole growth period reached highest point (691.26 mg·plant-1) with the corresponding proportions of absorption of 1︰0.20︰1.34︰0.80︰0.24. The differences in nitrogen absorption were not significant under different phosphorus levels. However, the uptake of phosphorus increased with increasing level of phosphorus. In other words, there was luxury absorption of phosphorus with increasing levels of phosphorus dosage. The absorption of nitrogen and phosphorus was mainly concentrated in 2030 days after planting, the absorption amounts at this period, respectively, accounted for 79.86% and 59.25% of the total absorptions during the whole growth period. The absorption of potassium apparently increased with time, reached its maximum in the last 10 days, with absorption amount of 47.68% of total absorption during the whole growth period. The absorption of calcium and magnesium did not change significantly during the whole growth period, while absorption of calcium was mainly concentrated in 1030 days after planting, that of magnesium was mainly concentrated in the last 30 days of lettuce growth. During full growth period, potassium absorption proportion was the largest among nutrient elements, followed by nitrogen and calcium. Under higher phosphorus level, the proportion of phosphorus absorption was higher than that of magnesium, while under low phosphorus level, it was lower than that of magnesium. Phosphorus use efficiency decreased with increasing phosphorus level applied. Low phosphorus level enhanced the use efficiency of mineral elements.
Phosphorus is one of the main nutrient elements needed by plant growth. Because phosphate fertilizer is difficult to move under traditional soil culture, there is a significant gap between applied phosphorus fertilize and available phosphorus of plant. Under hydroponic conditions, however, phosphate fertilizer is evenly dissolved in nutrient solutions. This is not only beneficial for nutrient uptake of plant, but also critical for accurately and quantitatively analyzing the effect of phosphorus on plant. To determine the effect of phosphorus level on lettuce growth, quality and dynamic absorption of mineral elements, 0.2 mmol·L-1, 0.4 mmol·L-1, 0.6 mmol·L-1, 0.8 mmol·L-1 and 1.0 mmol·L-1 of NaH2PO4 were separately added to a nutrient solution. The growth, yield, quality and dynamic mineral absorption of lettuce were measured and quantitatively analyzed. The results showed that the quality of lettuce was best under 0.4 mmol·L-1 NaH2PO4. In 0.6 mmol·L-1 of NaH2PO4 solution, the yield of lettuce hit peak amount, and the total absorption of N, P, K, Ca and Mg during the whole growth period reached highest point (691.26 mg·plant-1) with the corresponding proportions of absorption of 1︰0.20︰1.34︰0.80︰0.24. The differences in nitrogen absorption were not significant under different phosphorus levels. However, the uptake of phosphorus increased with increasing level of phosphorus. In other words, there was luxury absorption of phosphorus with increasing levels of phosphorus dosage. The absorption of nitrogen and phosphorus was mainly concentrated in 2030 days after planting, the absorption amounts at this period, respectively, accounted for 79.86% and 59.25% of the total absorptions during the whole growth period. The absorption of potassium apparently increased with time, reached its maximum in the last 10 days, with absorption amount of 47.68% of total absorption during the whole growth period. The absorption of calcium and magnesium did not change significantly during the whole growth period, while absorption of calcium was mainly concentrated in 1030 days after planting, that of magnesium was mainly concentrated in the last 30 days of lettuce growth. During full growth period, potassium absorption proportion was the largest among nutrient elements, followed by nitrogen and calcium. Under higher phosphorus level, the proportion of phosphorus absorption was higher than that of magnesium, while under low phosphorus level, it was lower than that of magnesium. Phosphorus use efficiency decreased with increasing phosphorus level applied. Low phosphorus level enhanced the use efficiency of mineral elements.
2015, 23(10): 1253-1259.
doi: 10.13930/j.cnki.cjea.141429
Abstract:
Scarcity of freshwater resources is an important factor that limits crop yield in the Bohai Rim in Hebei Province. Appropriate fertilization increases crop water use efficiency and meets demand for nutrient of crops. A pot experiment was conducted to study the effects nitrogen and water on winter wheat in Nanpi Agro-Ecosystem Experimental Station, Chinese Academy of Sciences (11640′E, 3800′N, altitude 1.0 m). Three water levels [50% (W0), 65% (W1) and 80% (W2) of field capacity], four nitrogen levels [0 g(N)·kg-1 (N0), 0.10 g(N)·kg-1 (N1), 0.20 g(N)·kg-1 (N2) and 0.29 g(N)·kg-1 (N3)] were respectively set in the pot experiment, and the combinations assessed in a total of 12 experiment treatments. Each treatment was repeated 10 times. The variations in dry matter accumulation and distribution and photosynthetic parameters of winter wheat ‘Xiaoyan 60’ were analyzed. As expected, water and nitrogen significantly increased biomass, grain yield, leaf chlorophyll, leaf water potential, leaf photosynthetic rate and water use efficiency (WUE) of ‘Xiaoyan 60’. The effect of water on winter wheat yield was greater than that of nitrogen. Compared with water and nitrogen deficit (W1N1) treatment, yield increased by 66.03% for the treatment with appropriate water and nitrogen (W2N2). Yield under W1N1 was 153.30% higher than that under severe water and nitrogen deficiency (W0N0). At the same water level, SPAD increased with increasing nitrogen dose. Then at the same nitrogen level, SPAD was lower under severe water stress (W0) and suitable water (W2) treatments than under mild water stress (W1) treatment. Water had a positive effect on leaf water potential, which significantly increased from W0 to W1 but with not obviously increased from W1 to W2. Photosynthetic rate (Pn), transpiration rate (Tr) and instantaneous water use efficiency (WUEi) increased with increasing N dose. Pn and Tr improved and WUEi decreased with increasing soil moisture. Yield and yield water use efficiency (WUEy) increased with increasing water content from W0 to W1 and then remained unchanged from W1 to W2 under N1 or N0 conditions. WUEy of winter wheat under N2 and N3 conditions increased with increasing water content. In conclusion, 1) proper management of water and nitrogen maintained ‘Xiaoyan 60’ grain yield and water use efficiency (WUE) at high levels. Excessive water and nitrogen use decreased grain yield and WUE. 2) Grain yield, WUE and leaf photosynthetic rate were positively correlated with water and nitrogen. 3) ‘Xiaoyan 60’ was more suitable for production at low water and medium fertilizer conditions in the Bohai Rim of Hebei Province.
Scarcity of freshwater resources is an important factor that limits crop yield in the Bohai Rim in Hebei Province. Appropriate fertilization increases crop water use efficiency and meets demand for nutrient of crops. A pot experiment was conducted to study the effects nitrogen and water on winter wheat in Nanpi Agro-Ecosystem Experimental Station, Chinese Academy of Sciences (11640′E, 3800′N, altitude 1.0 m). Three water levels [50% (W0), 65% (W1) and 80% (W2) of field capacity], four nitrogen levels [0 g(N)·kg-1 (N0), 0.10 g(N)·kg-1 (N1), 0.20 g(N)·kg-1 (N2) and 0.29 g(N)·kg-1 (N3)] were respectively set in the pot experiment, and the combinations assessed in a total of 12 experiment treatments. Each treatment was repeated 10 times. The variations in dry matter accumulation and distribution and photosynthetic parameters of winter wheat ‘Xiaoyan 60’ were analyzed. As expected, water and nitrogen significantly increased biomass, grain yield, leaf chlorophyll, leaf water potential, leaf photosynthetic rate and water use efficiency (WUE) of ‘Xiaoyan 60’. The effect of water on winter wheat yield was greater than that of nitrogen. Compared with water and nitrogen deficit (W1N1) treatment, yield increased by 66.03% for the treatment with appropriate water and nitrogen (W2N2). Yield under W1N1 was 153.30% higher than that under severe water and nitrogen deficiency (W0N0). At the same water level, SPAD increased with increasing nitrogen dose. Then at the same nitrogen level, SPAD was lower under severe water stress (W0) and suitable water (W2) treatments than under mild water stress (W1) treatment. Water had a positive effect on leaf water potential, which significantly increased from W0 to W1 but with not obviously increased from W1 to W2. Photosynthetic rate (Pn), transpiration rate (Tr) and instantaneous water use efficiency (WUEi) increased with increasing N dose. Pn and Tr improved and WUEi decreased with increasing soil moisture. Yield and yield water use efficiency (WUEy) increased with increasing water content from W0 to W1 and then remained unchanged from W1 to W2 under N1 or N0 conditions. WUEy of winter wheat under N2 and N3 conditions increased with increasing water content. In conclusion, 1) proper management of water and nitrogen maintained ‘Xiaoyan 60’ grain yield and water use efficiency (WUE) at high levels. Excessive water and nitrogen use decreased grain yield and WUE. 2) Grain yield, WUE and leaf photosynthetic rate were positively correlated with water and nitrogen. 3) ‘Xiaoyan 60’ was more suitable for production at low water and medium fertilizer conditions in the Bohai Rim of Hebei Province.
2015, 23(10): 1260-1267.
doi: 10.13930/j.cnki.cjea.150542
Abstract:
Canopy carbon flux was continuously measured in 2003–2013 using the eddy covariance system in a winter wheat field in Yucheng station, Shandong Province, to explore the effect of extreme heat on winter wheat canopy carbon assimilation. The extreme heat (EH) threshold was determined as the 95th percentile of daily maximum temperature (Ta_max), which was 30.58 ℃ during grain-filling stage in 2003–2013 in the study area. Two typical couples of EH and non-EH days in 2004 and 2012 were selected and compared to determine the characteristics and mechanism of the effects of EH on net ecosystem productivity (NEP, daytime), which was used to denote winter wheat canopy carbon assimilation rate. The results showed that Ta_max in the EH days were 3.10 ℃ and 3.17 ℃ higher than those in the non-EH days respectively in 2004 and 2012. Then total amounts of daytime NEP in EH days decreased by 3.25 mg(CO2)m-2s-12)m-2s-1 (with decreasing rate of 19.17%), respectively, compared with that in non-EH days in 2004 and 2012. NEP had a significant quadratic curve correlation with PAR, but no significant when PAR was greater than 1 000 μmolm-2s-1, at that time NEP accounted for over 52.31% of total daytime NEP for both EH and non-EH days. The difference in NEP between EH and non-EH days increased with increasing PAR, especially when PAR was greater than 1 000 μmolm-2s-1. There were no significant correlations between relative humidity of atmosphere (RH) and NEP, whether during whole day or when PAR was more than 1 000 μmolm-2s-1. In the four observed days, 020 cm soil water content (SWC) was about 80% of field capacity. This was the appropriate soil water content at grain-filling stage of winter wheat, which had no negative effect on NEP. For the whole days, NEP had no significant correlation with air temperature (Ta) in both EH and non-EH days. However, during the daytime with PAR > 1 000 μmolm-2s-1, NEP had significant negative correlation with Ta. NEP decreased by 7.28%9.53% in 2004 and by 6.94%10.42% in 2012 with every 1 ℃ increase in Ta. In conclusion, NEP was largely restrained by Ta when Ta was above 30.58 ℃ at the grain-filling process of winter wheat in the North China Plain. While the contribution of Ta to daytime NEP inhibition was 59%83%, total NEP decreased by 6.05%6.37% with 1 ℃ increase in Ta for EH days.
Canopy carbon flux was continuously measured in 2003–2013 using the eddy covariance system in a winter wheat field in Yucheng station, Shandong Province, to explore the effect of extreme heat on winter wheat canopy carbon assimilation. The extreme heat (EH) threshold was determined as the 95th percentile of daily maximum temperature (Ta_max), which was 30.58 ℃ during grain-filling stage in 2003–2013 in the study area. Two typical couples of EH and non-EH days in 2004 and 2012 were selected and compared to determine the characteristics and mechanism of the effects of EH on net ecosystem productivity (NEP, daytime), which was used to denote winter wheat canopy carbon assimilation rate. The results showed that Ta_max in the EH days were 3.10 ℃ and 3.17 ℃ higher than those in the non-EH days respectively in 2004 and 2012. Then total amounts of daytime NEP in EH days decreased by 3.25 mg(CO2)m-2s-12)m-2s-1 (with decreasing rate of 19.17%), respectively, compared with that in non-EH days in 2004 and 2012. NEP had a significant quadratic curve correlation with PAR, but no significant when PAR was greater than 1 000 μmolm-2s-1, at that time NEP accounted for over 52.31% of total daytime NEP for both EH and non-EH days. The difference in NEP between EH and non-EH days increased with increasing PAR, especially when PAR was greater than 1 000 μmolm-2s-1. There were no significant correlations between relative humidity of atmosphere (RH) and NEP, whether during whole day or when PAR was more than 1 000 μmolm-2s-1. In the four observed days, 020 cm soil water content (SWC) was about 80% of field capacity. This was the appropriate soil water content at grain-filling stage of winter wheat, which had no negative effect on NEP. For the whole days, NEP had no significant correlation with air temperature (Ta) in both EH and non-EH days. However, during the daytime with PAR > 1 000 μmolm-2s-1, NEP had significant negative correlation with Ta. NEP decreased by 7.28%9.53% in 2004 and by 6.94%10.42% in 2012 with every 1 ℃ increase in Ta. In conclusion, NEP was largely restrained by Ta when Ta was above 30.58 ℃ at the grain-filling process of winter wheat in the North China Plain. While the contribution of Ta to daytime NEP inhibition was 59%83%, total NEP decreased by 6.05%6.37% with 1 ℃ increase in Ta for EH days.
2015, 23(10): 1268-1276.
doi: 10.13930/j.cnki.cjea.150293
Abstract:
Tobacco alkaloids and nitrite are the main precursors of tobacco-specific nitrosamines (TSNA). Nitrite is formed by nitrate reduction reaction in tobacco leaves. Nicotine, nornicotine, anatabine and anabasine react with nitrous acid to form 4-(N-methyl nitrosamines)-1-(3-pyridyl)-1-butyl ketone (NNK), N-nitrosonornicotine (NNN), N-nitroso new nicotine (NAT) and N-nitroso false horsetail alkali (NAB), 4 main forms of TSNAs. Nicotine is the main tobacco alkaloid. Although nornicotine content is usually very low, the transformation of nicotine to nornicotine can occur through tobacco gene mutation, which activates and greatly increases the contents of nornicotine, NNN and total TSNA. The conversion of nicotine to nornicotine and nitrite reduction reactions occur during the processes of tobacco curing and storage. This is especially the case for the formation and accumulation of TSNA during the period of curing. In order to further clarify effects of tobacco types and varieties, curing methods on TSNA, TSNA contents and nicotine variations during curing were analyzed. The study used split-plot experimental design involving 4 tobacco types (burley, Maryland tobacco, flue-cured tobacco and sun-cured tobacco) and 8 varieties (lines) [B37LC (low nicotine conversion line) and B37HC (high nicotine conversion line) of burley; Md609LC (low nicotine conversion line) and Md609HC (high nicotine conversion line) of Maryland tobacco; ‘Yunyan87’ and ‘K326’ of flue-cured tobacco varieties; ‘dark sun cured tobacco’ and ‘light colored sun cured tobacco’ of sun-cured tobacco varieties] with 3 curing methods (flue-curing, air-curing and sun-curing) as secondary treatments. Then the 4 TSNA and alkaloid contents in leaves under both the main and secondary treatments were investigated. The results showed that tobacco varieties (lines) were the main factor influencing alkaloid content, nicotine conversion rate and contents of 4 kinds of TSNA. Nornicotine contents and nicotine conversion rates of HC lines of Maryland tobacco and burley tobacco were highest, and those of HC lines was lowest. NNN was the main TSNA in all the tobacco types, accounting for 54.35%?97.36% of total TSNA. It was followed by NAT (2.33%?38.46%), NNK (0.17%?5.47%) and NAB (0.14%?5.92%). Comparison of different tobacco types in terms of proportions of four forms of TSNA showed that NNN was highest in HC lines of burley tobacco and Mayland tobacco, accounting for 93.93% and 96.99% of total TSNA content. Compared with HC lines, LC lines fell by 90.93% and 91.54% in NNN contents, respectively, in burley and Maryland tobacco. The contents of NNK, NAT and NAB in HC lines were higher than in LC lines, although the difference was smaller than that of NNN. Comparison of 3 curing methods showed that nicotine content of flue-cured tobacco was greater than that of sun-cured which was in turn greater than that of air-cured tobacco. The nornicotine content and conversion rate of nicotine were highest for air-cured tobacco, followed by sun-cured tobacco and then flue-cured tobacco. Except NAB, the contents of NNN, NNK, NAT and total TSNA in flue-cured tobacco were significantly higher than those of air-cured tobacco, which were in turn significantly higher than those of sun-cured tobacco. Also while total TSNA content of air-cured tobacco was 41.85% higher than that of flue-cured tobacco, NNN content of air-cured tobacco was 45.45% higher than that of flue-cured tobacco. Curing method had greatest impact on HC lines and minimal impact on LC lines of burley tobacco and Maryland tobacco. It was beneficial to decrease TSNA content and promote tobacco safety to plant low nicotine conversion varieties of burley tobacco and Maryland tobacco and improve curing conditions.
Tobacco alkaloids and nitrite are the main precursors of tobacco-specific nitrosamines (TSNA). Nitrite is formed by nitrate reduction reaction in tobacco leaves. Nicotine, nornicotine, anatabine and anabasine react with nitrous acid to form 4-(N-methyl nitrosamines)-1-(3-pyridyl)-1-butyl ketone (NNK), N-nitrosonornicotine (NNN), N-nitroso new nicotine (NAT) and N-nitroso false horsetail alkali (NAB), 4 main forms of TSNAs. Nicotine is the main tobacco alkaloid. Although nornicotine content is usually very low, the transformation of nicotine to nornicotine can occur through tobacco gene mutation, which activates and greatly increases the contents of nornicotine, NNN and total TSNA. The conversion of nicotine to nornicotine and nitrite reduction reactions occur during the processes of tobacco curing and storage. This is especially the case for the formation and accumulation of TSNA during the period of curing. In order to further clarify effects of tobacco types and varieties, curing methods on TSNA, TSNA contents and nicotine variations during curing were analyzed. The study used split-plot experimental design involving 4 tobacco types (burley, Maryland tobacco, flue-cured tobacco and sun-cured tobacco) and 8 varieties (lines) [B37LC (low nicotine conversion line) and B37HC (high nicotine conversion line) of burley; Md609LC (low nicotine conversion line) and Md609HC (high nicotine conversion line) of Maryland tobacco; ‘Yunyan87’ and ‘K326’ of flue-cured tobacco varieties; ‘dark sun cured tobacco’ and ‘light colored sun cured tobacco’ of sun-cured tobacco varieties] with 3 curing methods (flue-curing, air-curing and sun-curing) as secondary treatments. Then the 4 TSNA and alkaloid contents in leaves under both the main and secondary treatments were investigated. The results showed that tobacco varieties (lines) were the main factor influencing alkaloid content, nicotine conversion rate and contents of 4 kinds of TSNA. Nornicotine contents and nicotine conversion rates of HC lines of Maryland tobacco and burley tobacco were highest, and those of HC lines was lowest. NNN was the main TSNA in all the tobacco types, accounting for 54.35%?97.36% of total TSNA. It was followed by NAT (2.33%?38.46%), NNK (0.17%?5.47%) and NAB (0.14%?5.92%). Comparison of different tobacco types in terms of proportions of four forms of TSNA showed that NNN was highest in HC lines of burley tobacco and Mayland tobacco, accounting for 93.93% and 96.99% of total TSNA content. Compared with HC lines, LC lines fell by 90.93% and 91.54% in NNN contents, respectively, in burley and Maryland tobacco. The contents of NNK, NAT and NAB in HC lines were higher than in LC lines, although the difference was smaller than that of NNN. Comparison of 3 curing methods showed that nicotine content of flue-cured tobacco was greater than that of sun-cured which was in turn greater than that of air-cured tobacco. The nornicotine content and conversion rate of nicotine were highest for air-cured tobacco, followed by sun-cured tobacco and then flue-cured tobacco. Except NAB, the contents of NNN, NNK, NAT and total TSNA in flue-cured tobacco were significantly higher than those of air-cured tobacco, which were in turn significantly higher than those of sun-cured tobacco. Also while total TSNA content of air-cured tobacco was 41.85% higher than that of flue-cured tobacco, NNN content of air-cured tobacco was 45.45% higher than that of flue-cured tobacco. Curing method had greatest impact on HC lines and minimal impact on LC lines of burley tobacco and Maryland tobacco. It was beneficial to decrease TSNA content and promote tobacco safety to plant low nicotine conversion varieties of burley tobacco and Maryland tobacco and improve curing conditions.
2015, 23(10): 1277-1284.
doi: 10.13930/j.cnki.cjea.150433
Abstract:
To understand the characteristics of organic carbon in the 38°N ecological transect of Hebei Province, 35 sampling plots with different land use patterns in 3 regions (low hilly area, piedmont plain of Taihang Mountain and low coastal plain) in the 38°N ecological transect of Hebei Province from west to east were set and soil samples were collected in the 010 cm, 1020 cm, 2040 cm, 4060 cm and 60100 cm layers from September to October in 2011 for soil organic carbon content analysis. The results suggested that the soil organic carbon density was higher in the low hilly area than in the piedmont plain, which was in turn higher than in the low coastal plain. The corresponding soil organic carbon density was respectively 9.03 kgm-2, 4.26 kgm-2 and 3.51 kgm-2. The difference in organic carbon content of the low hilly area from that of other two regions was partly due to the high organic carbon content in scrublands in the low hilly area. Furthermore, organic carbon content in the 040 cm soil in forestland and farmland in the low hilly area was higher than those in the other two regions. The order of soil organic carbon content in forestland and farmland was low hilly area > piedmont plain > low coastal plain. Organic carbon content in 040 cm soil in forestlands was 19.45 gkg-1 (low hilly area), 7.89 gkg-1 (piedmont plain) and 7.55 gkg-1 (low coastal plain). Also soil organic carbon content in farmland was 7.70 gkg-1 (low hilly area), 7.09 gkg-1 (piedmont plain) and 6.00 gkg-1 (low coastal plain). Soil organic carbon content decreased with soil depth and there was some difference among different land use patterns. The sequence of variation in soil organic carbon content with soil depth (from top to bottom) was higher in the low hilly area than in the piedmont plain, which was in turn higher than in the low coastal plain. In the low hilly area, the variation range of soil organic carbon content with soil depth was higher in scrubland than in forest, and it was lowest in farmland. In the piedmont plain, the range of variation in soil organic carbon content with soil depth in farmland was a slight bigger than that in forest land. In the low coastal plain, the range of variation in soil organic carbon content with soil depth was higher in forest land than in abandoned land, it was lowest in farmland. In consideration of carbon sequestration and economic benefits, 3 suggestions were put forward as follows: 1) forest products and tourism should be developed in the low hilly area; 2) the piedmont plain should emphasize the development of grain production; and 3) the low coastal plain should be improved in soil salinization and cotton cultivation.
To understand the characteristics of organic carbon in the 38°N ecological transect of Hebei Province, 35 sampling plots with different land use patterns in 3 regions (low hilly area, piedmont plain of Taihang Mountain and low coastal plain) in the 38°N ecological transect of Hebei Province from west to east were set and soil samples were collected in the 010 cm, 1020 cm, 2040 cm, 4060 cm and 60100 cm layers from September to October in 2011 for soil organic carbon content analysis. The results suggested that the soil organic carbon density was higher in the low hilly area than in the piedmont plain, which was in turn higher than in the low coastal plain. The corresponding soil organic carbon density was respectively 9.03 kgm-2, 4.26 kgm-2 and 3.51 kgm-2. The difference in organic carbon content of the low hilly area from that of other two regions was partly due to the high organic carbon content in scrublands in the low hilly area. Furthermore, organic carbon content in the 040 cm soil in forestland and farmland in the low hilly area was higher than those in the other two regions. The order of soil organic carbon content in forestland and farmland was low hilly area > piedmont plain > low coastal plain. Organic carbon content in 040 cm soil in forestlands was 19.45 gkg-1 (low hilly area), 7.89 gkg-1 (piedmont plain) and 7.55 gkg-1 (low coastal plain). Also soil organic carbon content in farmland was 7.70 gkg-1 (low hilly area), 7.09 gkg-1 (piedmont plain) and 6.00 gkg-1 (low coastal plain). Soil organic carbon content decreased with soil depth and there was some difference among different land use patterns. The sequence of variation in soil organic carbon content with soil depth (from top to bottom) was higher in the low hilly area than in the piedmont plain, which was in turn higher than in the low coastal plain. In the low hilly area, the variation range of soil organic carbon content with soil depth was higher in scrubland than in forest, and it was lowest in farmland. In the piedmont plain, the range of variation in soil organic carbon content with soil depth in farmland was a slight bigger than that in forest land. In the low coastal plain, the range of variation in soil organic carbon content with soil depth was higher in forest land than in abandoned land, it was lowest in farmland. In consideration of carbon sequestration and economic benefits, 3 suggestions were put forward as follows: 1) forest products and tourism should be developed in the low hilly area; 2) the piedmont plain should emphasize the development of grain production; and 3) the low coastal plain should be improved in soil salinization and cotton cultivation.
2015, 23(10): 1285-1292.
doi: 10.13930/j.cnki.cjea.150206
Abstract:
Soil is extremely important for plant growth and land productivity. A good understanding of the soil fertility quality is helpful to clearly learn soil environment condition, and it also contributes to effectively and rationally use of land resources. Currently, there are many methods evaluating soil fertility quality and assessing the condition of soil environment. However, due to subjective experience influencing on indicator weight decision, the results of these evaluation methods are more or less deviation from actual situation. And the results are usually not visualized. In this study, a new method — entire-array-polygon graphical representation and indicator method, a method used in eco-city evaluation, was used to evaluate soil fertility quality. The feasibility of the entire-array-polygon indicator method was also verified. A black soil in Jilin Province was used to establish both the evaluation indicator system and classification standard from three aspects — soil nutrient, soil structure and soil environment. The study evaluated a representative test data taken from 13 field sampling points in black soil fields in Jilin Province. The evaluation results of the entire-array-polygon indicator method were compared with the results of extenic method and improved artificial neural network method. The results clearly showed that soil fertility quality at the 13 sampling points in the study area was level III and the soil quality belonged to moderate grade. The study also advanced soil improvement measures based on the limiting factors of different sampling points. Sampling points G3, G7 and G8 needed more phosphor fertilizer, points G4, G10 and G14 needed more attention in terms of cropping systems and improvement of soil structure. The results of comparison with other evaluation methods indicated that the entire-array-polygon method was feasible for evaluating soil fertility quality. The evaluation results were highly consistent with those of other methods, with different evaluation results for only 1 to 3 sampling points. The entire-array-polygon indicator method was visual and easy to understand and convenient to quantify in terms of programming evaluation factors and avoiding subjective and arbitrary. It proved to be a new and useful method for evaluating soil fertility quality and provided a reference for application in other regions or soil types for assessing soil fertility quality.
Soil is extremely important for plant growth and land productivity. A good understanding of the soil fertility quality is helpful to clearly learn soil environment condition, and it also contributes to effectively and rationally use of land resources. Currently, there are many methods evaluating soil fertility quality and assessing the condition of soil environment. However, due to subjective experience influencing on indicator weight decision, the results of these evaluation methods are more or less deviation from actual situation. And the results are usually not visualized. In this study, a new method — entire-array-polygon graphical representation and indicator method, a method used in eco-city evaluation, was used to evaluate soil fertility quality. The feasibility of the entire-array-polygon indicator method was also verified. A black soil in Jilin Province was used to establish both the evaluation indicator system and classification standard from three aspects — soil nutrient, soil structure and soil environment. The study evaluated a representative test data taken from 13 field sampling points in black soil fields in Jilin Province. The evaluation results of the entire-array-polygon indicator method were compared with the results of extenic method and improved artificial neural network method. The results clearly showed that soil fertility quality at the 13 sampling points in the study area was level III and the soil quality belonged to moderate grade. The study also advanced soil improvement measures based on the limiting factors of different sampling points. Sampling points G3, G7 and G8 needed more phosphor fertilizer, points G4, G10 and G14 needed more attention in terms of cropping systems and improvement of soil structure. The results of comparison with other evaluation methods indicated that the entire-array-polygon method was feasible for evaluating soil fertility quality. The evaluation results were highly consistent with those of other methods, with different evaluation results for only 1 to 3 sampling points. The entire-array-polygon indicator method was visual and easy to understand and convenient to quantify in terms of programming evaluation factors and avoiding subjective and arbitrary. It proved to be a new and useful method for evaluating soil fertility quality and provided a reference for application in other regions or soil types for assessing soil fertility quality.
2015, 23(10): 1293-1301.
doi: 10.13930/j.cnki.cjea.150228
Abstract:
In order to explore the differences in metabolic functional diversity of soil microbial communities under different cultivation patterns of maize, a fixed-point experiment was carried out and the field investigation and Biolog analysis used to study metabolic activity and functional diversity of soil microbial community under 4 cultivation patterns of maize. The investigated cultivation patterns included annual rotation of 4 rows maize with potato (R4), 4 rows maize continuous cropping (C4), annual rotation of 8 rows maize with potato (R8) and 8 rows maize continuous cropping (C8). A total of 4 growth stages of maize (pre-planting, jointing, heading and harvest stages) were studied. The results showed that both metabolic activity and functional diversity of soil microbial communities were lower at pre-planting stage, and higher at heading stage of maize. Metabolic activity and functional diversity of soil microbial community under rotation cropping were higher than those under continuous cropping at pre-planting stage of maize. The Shannon-Wiener index of soil microbial under R8 and R4 was 22.93% and 11.42% higher than that under C8 and C4, respectively. Meanwhile the Shannon-Wiener index of soil microbial under R4 was 3.17% lower than that under R8. However, the Shannon-Wiener index of soil microbial under C4 was 6.83% higher than that under C8. The functional diversities of soil microbial communities at jointing, heading and harvest stages of maize under continuous cropping patterns were slightly higher than those under rotation cropping patterns, and higher under C4 than under C8, though the differences were not significantly. Before planting, the overall utilization degree of 6 categories of carbon sources by soil microbial communities under 4 planting patterns was low. The main microbial populations impacted by planting patterns were those decomposing carbohydrates, carboxylic acids and polymers before maize planting. With the growth of maize, the ability of microbial communities to metabolize 6 categories carbon substrate gradually increased, and peaked at heading stage. Also characteristic carbon resources at jointing, heading and harvest stages were similar. Differences in the utilization of polymers by soil microbial communities under different planting patterns were insignificant. PLS-EDA analysis showed that the ability of soil microbial communities to utilize carbon source was significantly different under different cultivation patterns. Before planting, soil microbial communities under R8 and C4 were similar in terms of carbon utilization. However, Soil microbial communities under 4 different cultivation patterns had distinctly different modes of utilization of carbon sources after planting of maize. Especially, carbon utilization of soil microbial communities under C4 was significantly different from that of the other three cultivation patterns at jointing and harvest stages of maize. It showed that continuous cropping of maize influenced the functionality of soil microbial community and reduced soil microbial species richness. This resulted in structures disorder and functions loss of soil microbial community.
In order to explore the differences in metabolic functional diversity of soil microbial communities under different cultivation patterns of maize, a fixed-point experiment was carried out and the field investigation and Biolog analysis used to study metabolic activity and functional diversity of soil microbial community under 4 cultivation patterns of maize. The investigated cultivation patterns included annual rotation of 4 rows maize with potato (R4), 4 rows maize continuous cropping (C4), annual rotation of 8 rows maize with potato (R8) and 8 rows maize continuous cropping (C8). A total of 4 growth stages of maize (pre-planting, jointing, heading and harvest stages) were studied. The results showed that both metabolic activity and functional diversity of soil microbial communities were lower at pre-planting stage, and higher at heading stage of maize. Metabolic activity and functional diversity of soil microbial community under rotation cropping were higher than those under continuous cropping at pre-planting stage of maize. The Shannon-Wiener index of soil microbial under R8 and R4 was 22.93% and 11.42% higher than that under C8 and C4, respectively. Meanwhile the Shannon-Wiener index of soil microbial under R4 was 3.17% lower than that under R8. However, the Shannon-Wiener index of soil microbial under C4 was 6.83% higher than that under C8. The functional diversities of soil microbial communities at jointing, heading and harvest stages of maize under continuous cropping patterns were slightly higher than those under rotation cropping patterns, and higher under C4 than under C8, though the differences were not significantly. Before planting, the overall utilization degree of 6 categories of carbon sources by soil microbial communities under 4 planting patterns was low. The main microbial populations impacted by planting patterns were those decomposing carbohydrates, carboxylic acids and polymers before maize planting. With the growth of maize, the ability of microbial communities to metabolize 6 categories carbon substrate gradually increased, and peaked at heading stage. Also characteristic carbon resources at jointing, heading and harvest stages were similar. Differences in the utilization of polymers by soil microbial communities under different planting patterns were insignificant. PLS-EDA analysis showed that the ability of soil microbial communities to utilize carbon source was significantly different under different cultivation patterns. Before planting, soil microbial communities under R8 and C4 were similar in terms of carbon utilization. However, Soil microbial communities under 4 different cultivation patterns had distinctly different modes of utilization of carbon sources after planting of maize. Especially, carbon utilization of soil microbial communities under C4 was significantly different from that of the other three cultivation patterns at jointing and harvest stages of maize. It showed that continuous cropping of maize influenced the functionality of soil microbial community and reduced soil microbial species richness. This resulted in structures disorder and functions loss of soil microbial community.
2015, 23(10): 1302-1311.
doi: 10.13930/j.cnki.cjea.150267
Abstract:
Soil bacteria are important drivers of nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformation processes in the soil. Thus knowledge about the shift of microbial community structure and diversity following different agricultural management practices could improve our understanding of soil processes and help us to develop agricultural management strategies. Because most soil bacteria are nonculturable, and traditional molecular biology methods, such as DGGE, are partial, the researches on soil bacterial are limited. High-throughput sequencing technology provides an effective tool for microbial molecular biology research. In this study, the technology of high-throughput sequencing on Illumina MiSeq platform was adopted to investigate the effects of fertilization and straw residue incorporation on bacterial communities in lime concretion black soils. The 16S rRNA genes of topsoil bacteria in lime concretion black soil were sequenced by high-throughput sequencing on Illumina MiSeq platform and related biological analysis conducted to investigate the changes in soil bacterial composition, diversity and structure under 4 different fertilization practices at wheat tillering stage. Soil samples were collected in lime concretion black soils in Mengcheng, Anhui Province, China with 3 treatments (CK: no fertilization, no straw return; F: chemical fertilization without straw return; W: straw return without chemical fertilization). The results showed that 173 323 reads of 14 873 OTUs (operational taxonomic unit) were generated at 3% cutoff level under all treatments with an average length of 439 bp. Bacterial OTUs were classified into 19 different known phyla and 41 classes. Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the dominant phyla (with relative abundance > 10%) in lime concretion black soils. Then Alphaproteobacteria, Betaproteobacteria, Sphingobacteriia, Acidobacteria and Gammaproteobacteria were the dominant classes (with relative abundance > 10%). The total number of dominant genera (with relative abundance > 1%) in all 3 treatments was 47, of which 21 genera were found in all treatments, and the largest number (39) of dominant genera occurred under F treatment. The dominant phylum, class and genus with the highest relative abundances were Proteobacteria (38.7%?43.1%), Alphaproteobacteria (14.5%?18.1%) and Sphingomonas (4.6%?7.7%) in all 3 treatments. The richness indexes (Chao1 and ACE indexes) were significantly lower for F treatment than for CK and W treatments. ACE index decreased by 22.8% under F treatment compared with CK. The richness indexes (Chao1 and ACE indexes) of CK and W treatments were not significantly different from each other. The Shannon index of W treatment was significantly higher than that of CK and F treatments, it increased by 4.1% compared with CK. Then the Shannon indexes of CK and F treatments were also not significantly different from each other. The Simpson index of F treatment was significantly higher than that of CK and W treatments. The Simpson index of F treatment increased by 38.1% compared with CK treatment. The Simpson index of W treatment was lowest among 3 treatments, decreasing by 23.8% compared with CK treatment. Hierarchical cluster analysis showed that CK and W treatments were in the same cluster group, while F was in a different cluster group. All the above findings suggested that chemical fertilization had a stronger effect on the composition, relative abundance of the dominant bacterial group and bacterial structure in soils than incorporation of straw residue. While chemical fertilization decreased soil bacterial richness, it increased bacterial predominance. On the contrary, straw residue incorporation increased soil bacterial diversity, but decreased bacterial predominance.
Soil bacteria are important drivers of nearly all biogeochemical cycles in terrestrial ecosystems and participate in most nutrient transformation processes in the soil. Thus knowledge about the shift of microbial community structure and diversity following different agricultural management practices could improve our understanding of soil processes and help us to develop agricultural management strategies. Because most soil bacteria are nonculturable, and traditional molecular biology methods, such as DGGE, are partial, the researches on soil bacterial are limited. High-throughput sequencing technology provides an effective tool for microbial molecular biology research. In this study, the technology of high-throughput sequencing on Illumina MiSeq platform was adopted to investigate the effects of fertilization and straw residue incorporation on bacterial communities in lime concretion black soils. The 16S rRNA genes of topsoil bacteria in lime concretion black soil were sequenced by high-throughput sequencing on Illumina MiSeq platform and related biological analysis conducted to investigate the changes in soil bacterial composition, diversity and structure under 4 different fertilization practices at wheat tillering stage. Soil samples were collected in lime concretion black soils in Mengcheng, Anhui Province, China with 3 treatments (CK: no fertilization, no straw return; F: chemical fertilization without straw return; W: straw return without chemical fertilization). The results showed that 173 323 reads of 14 873 OTUs (operational taxonomic unit) were generated at 3% cutoff level under all treatments with an average length of 439 bp. Bacterial OTUs were classified into 19 different known phyla and 41 classes. Proteobacteria, Acidobacteria, Actinobacteria and Bacteroidetes were the dominant phyla (with relative abundance > 10%) in lime concretion black soils. Then Alphaproteobacteria, Betaproteobacteria, Sphingobacteriia, Acidobacteria and Gammaproteobacteria were the dominant classes (with relative abundance > 10%). The total number of dominant genera (with relative abundance > 1%) in all 3 treatments was 47, of which 21 genera were found in all treatments, and the largest number (39) of dominant genera occurred under F treatment. The dominant phylum, class and genus with the highest relative abundances were Proteobacteria (38.7%?43.1%), Alphaproteobacteria (14.5%?18.1%) and Sphingomonas (4.6%?7.7%) in all 3 treatments. The richness indexes (Chao1 and ACE indexes) were significantly lower for F treatment than for CK and W treatments. ACE index decreased by 22.8% under F treatment compared with CK. The richness indexes (Chao1 and ACE indexes) of CK and W treatments were not significantly different from each other. The Shannon index of W treatment was significantly higher than that of CK and F treatments, it increased by 4.1% compared with CK. Then the Shannon indexes of CK and F treatments were also not significantly different from each other. The Simpson index of F treatment was significantly higher than that of CK and W treatments. The Simpson index of F treatment increased by 38.1% compared with CK treatment. The Simpson index of W treatment was lowest among 3 treatments, decreasing by 23.8% compared with CK treatment. Hierarchical cluster analysis showed that CK and W treatments were in the same cluster group, while F was in a different cluster group. All the above findings suggested that chemical fertilization had a stronger effect on the composition, relative abundance of the dominant bacterial group and bacterial structure in soils than incorporation of straw residue. While chemical fertilization decreased soil bacterial richness, it increased bacterial predominance. On the contrary, straw residue incorporation increased soil bacterial diversity, but decreased bacterial predominance.
2015, 23(10): 1312-1319.
doi: 10.13930/j.cnki.cjea.150515
Abstract:
Phosphorus (P) is a key nutrient which influences the growth, development and yield of crops. P availability can regulate soil microbial community structure and diversity by altering the quantity and components of root exudates. Whether P addition increases carbon resources utilization and functional diversity of soil microorganisms remains highly debatable. Also how P addition affects carbon resources utilization and functional diversity of soil microorganisms is not fully understood. In this study, a pot soil culture experiment with 2 P application treatments [low P of 5.7 mg(P)kg-1(soil) and high P of 200 mg(P)kg-1(soil)] was carried out to investigate the effect of P on carbon resources utilization and functional diversity of microorganisms in maize rhizosphere soil. After 35 d of growth, maize rhizosphere soil was collected using the nylon mesh method under 2 P treatments. The Biolog microplate technique was used to examine the color change of micro-well solutions containing 31 carbon sources every 24 h for consecutively 240 h. The results showed that with prolonged culture time, the utilization of 31 types of carbon sources by soil microorganisms obviously increased until the carbon sources in the micro-well solution were exhausted. High P treatment significantly increased average well color development (AWCD) and improved the utilization of carbohydrate carbon and its derivatives, amino acids and metabolites, but not affected the utilization of fatty acids and lipids. Functional diversity of soil microorganisms in maize rhizosphere soil was regulated by P availability, which depended largely on culturing time. During 72 h cultivation, high P treatment significantly increased the diversity index, dominance index and evenness index of soil microorganisms. However, after 72 h of cultivation, high P treatment had no significant effect on soil microorganism diversity. Based on principal component analysis (PCA), extracted first 3 components explained 75.15% of carbon sources utilization and separated 2 categories based on P treatments. A total of 23 carbon sources was correlated with PC1, 8 correlated with PC2 and 3 correlated with PC3. Multivariate analysis showed that the pattern of carbon sources utilization of soil microorganisms under high P supply was significantly different from that under low P supply (Hotelling trace = 2.485, F = 62.95, P < 0.001). In conclusion, carbohydrate and the derivatives, amino acids and metabolites were the major carbon sources utilized by soil microorganisms in maize rhizosphere soil. P addition significantly increased carbon sources utilization by soil microorganisms. To some extent, it also improved soil microbial functional diversity in maize rhizosphere soil.
Phosphorus (P) is a key nutrient which influences the growth, development and yield of crops. P availability can regulate soil microbial community structure and diversity by altering the quantity and components of root exudates. Whether P addition increases carbon resources utilization and functional diversity of soil microorganisms remains highly debatable. Also how P addition affects carbon resources utilization and functional diversity of soil microorganisms is not fully understood. In this study, a pot soil culture experiment with 2 P application treatments [low P of 5.7 mg(P)kg-1(soil) and high P of 200 mg(P)kg-1(soil)] was carried out to investigate the effect of P on carbon resources utilization and functional diversity of microorganisms in maize rhizosphere soil. After 35 d of growth, maize rhizosphere soil was collected using the nylon mesh method under 2 P treatments. The Biolog microplate technique was used to examine the color change of micro-well solutions containing 31 carbon sources every 24 h for consecutively 240 h. The results showed that with prolonged culture time, the utilization of 31 types of carbon sources by soil microorganisms obviously increased until the carbon sources in the micro-well solution were exhausted. High P treatment significantly increased average well color development (AWCD) and improved the utilization of carbohydrate carbon and its derivatives, amino acids and metabolites, but not affected the utilization of fatty acids and lipids. Functional diversity of soil microorganisms in maize rhizosphere soil was regulated by P availability, which depended largely on culturing time. During 72 h cultivation, high P treatment significantly increased the diversity index, dominance index and evenness index of soil microorganisms. However, after 72 h of cultivation, high P treatment had no significant effect on soil microorganism diversity. Based on principal component analysis (PCA), extracted first 3 components explained 75.15% of carbon sources utilization and separated 2 categories based on P treatments. A total of 23 carbon sources was correlated with PC1, 8 correlated with PC2 and 3 correlated with PC3. Multivariate analysis showed that the pattern of carbon sources utilization of soil microorganisms under high P supply was significantly different from that under low P supply (Hotelling trace = 2.485, F = 62.95, P < 0.001). In conclusion, carbohydrate and the derivatives, amino acids and metabolites were the major carbon sources utilized by soil microorganisms in maize rhizosphere soil. P addition significantly increased carbon sources utilization by soil microorganisms. To some extent, it also improved soil microbial functional diversity in maize rhizosphere soil.
2015, 23(10): 1320-1328.
doi: 10.13930/j.cnki.cjea.150229
Abstract:
Crop growth simulation model provides a new method for water resources analysis of farmland and optimization of management measures for water use efficiency improvement in crop production. The characteristics of annual variation of simulated yield, evapotranspiration (ET), plant transpiration (EP), soil evaporation (ES), and water productivity (WP) of winter wheat in Cangzhou area in the North China Plain during 19812014 were analyzed using a calibrated CERES-Wheat model. The calibration of CERES-Wheat model was done using a two-years’ field experiment with 4 irrigation treatments conducted in Wuqiao County of Cangzhou City, Hebei Province. The irrigation treatments included T0 (no irrigation during wheat growth period), T1 (75 mm irrigation at jointing stage), T2 (75 mm irrigation at jointing stage and anthesis stage, respectively), T3 (75 mm irrigation at regrowing stage, booting stage and anthesis stage, respectively), with a preplanting irrigation of 75 mm for all treatments. The winter wheat cultivar ‘Shijiazhuang 8’ was taken and the cultivar coefficients of the model was obtained by a program of genotype coefficient calculator (GENCALC) combined the method of ‘trial and error’. The calibrated model was proved that it adapted for predicting yield and ET of winter wheat and could be used in this district. Based on the calibrated CERES-Wheat model, the annual yield, ET, EP, ES, and WP of winter wheat were simulated using the meteorological data during 19812014 by the method of scene simulation. The quantitative relationship model between ET and WP was built according to the simulated data, and the calculated economic ET was 435 mm when WP got the maximum value. Subtracting the average rainfall from the average ET during 19812014, the average water demand mainly including irrigation water and soil water during winter wheat growth period was 189 mm (T0), 264 mm (T1), 298 mm (T2) or 319 mm (T3), and the corresponding average yield for the 4 irrigation treatments was 4 144 kghm-2, 7 293 kghm-2, 7 301 kghm-2 and 8 245 kghm-2, respectively. Deducting the ES by taking proper cultivation management measures like plastic film mulching, 80 mm (T0), 71 mm (T1), 71 mm (T2) or 70 mm (T3) of water could be saved during winter wheat growth period, and if the average rainfall was deducted from the average EP under this condition, the average water demand for the 4 irrigation treatments was 109 mm (T0), 193 mm (T1), 227 mm (T2) and 249 mm (T3), respectively. These conclusions can be used to develop quantitative water management measures for winter wheat planting in Cangzhou area in the North China Plain.
Crop growth simulation model provides a new method for water resources analysis of farmland and optimization of management measures for water use efficiency improvement in crop production. The characteristics of annual variation of simulated yield, evapotranspiration (ET), plant transpiration (EP), soil evaporation (ES), and water productivity (WP) of winter wheat in Cangzhou area in the North China Plain during 19812014 were analyzed using a calibrated CERES-Wheat model. The calibration of CERES-Wheat model was done using a two-years’ field experiment with 4 irrigation treatments conducted in Wuqiao County of Cangzhou City, Hebei Province. The irrigation treatments included T0 (no irrigation during wheat growth period), T1 (75 mm irrigation at jointing stage), T2 (75 mm irrigation at jointing stage and anthesis stage, respectively), T3 (75 mm irrigation at regrowing stage, booting stage and anthesis stage, respectively), with a preplanting irrigation of 75 mm for all treatments. The winter wheat cultivar ‘Shijiazhuang 8’ was taken and the cultivar coefficients of the model was obtained by a program of genotype coefficient calculator (GENCALC) combined the method of ‘trial and error’. The calibrated model was proved that it adapted for predicting yield and ET of winter wheat and could be used in this district. Based on the calibrated CERES-Wheat model, the annual yield, ET, EP, ES, and WP of winter wheat were simulated using the meteorological data during 19812014 by the method of scene simulation. The quantitative relationship model between ET and WP was built according to the simulated data, and the calculated economic ET was 435 mm when WP got the maximum value. Subtracting the average rainfall from the average ET during 19812014, the average water demand mainly including irrigation water and soil water during winter wheat growth period was 189 mm (T0), 264 mm (T1), 298 mm (T2) or 319 mm (T3), and the corresponding average yield for the 4 irrigation treatments was 4 144 kghm-2, 7 293 kghm-2, 7 301 kghm-2 and 8 245 kghm-2, respectively. Deducting the ES by taking proper cultivation management measures like plastic film mulching, 80 mm (T0), 71 mm (T1), 71 mm (T2) or 70 mm (T3) of water could be saved during winter wheat growth period, and if the average rainfall was deducted from the average EP under this condition, the average water demand for the 4 irrigation treatments was 109 mm (T0), 193 mm (T1), 227 mm (T2) and 249 mm (T3), respectively. These conclusions can be used to develop quantitative water management measures for winter wheat planting in Cangzhou area in the North China Plain.
2015, 23(10): 1329-1338.
doi: 10.13930/j.cnki.cjea.150552
Abstract:
This paper mainly analyzed climate trend during growth and crucial growth periods of naked barley in the Tibetan Plateau from 1965 to 2013. The study used average temperature, precipitation, sunshine duration and other meteorological data from 106 meteorological stations allocated in the Tibetan Plateau for the past 50 years. In the paper, tendency analysis, Thornthwaite Memorial model, geographical information system (GIS), statistical product and service solution (SPSS) techniques were used to analyze potential climate productivity of naked barley. Then the features of temporal and spatial variations and the effects of climate change on the development and yield of naked barley as well as the effects of various meteorological factors on the climate potential productivity of naked barley in the Tibetan Plateau in the past 50 years were analyzed. The results showed, 1) there was an increasing trend in temperature (0.53 ℃10a-1) and precipitation (7.8 mm10a-1) in the Tibetan Plateau in the past 50 years. While temperature increased significantly, the increase in precipitation was not significant. Also there was an obvious decrease in sunshine duration (16.9 h10a-1). 2) While temperature (0.4 ℃10a-1) and precipitation (7.2 mm10a-1) increased during naked barley growth period in the Tibetan Plateau, sunshine duration (15 h10a-1) significantly decreased during naked barley growing season. There was an obvious warming tendency in the northern zone of the Tibetan Plateau, significant increase in precipitation in the central region of the Tibetan Plateau and then an obvious decline in sunshine duration in the northeast part of the Tibetan Plateau. 3) Climate potential productivity of naked barley increased in the Tibetan Plateau (136.7 kghm-210a-1) from 1965 to 2013. The magnitude of increase was larger for the central region than for other regions of the Tibetan Plateau. However, there was a decreasing trend in climate potential productivity of naked barley in the southeastern edge of the plateau, the northern part of Qaidam Basin in Qinghai Province and the northwestern region of Tibet. 4) Precipitation and temperature had significantly positive correlation with climate potential productivity of naked barley. Conversely, sunshine duration was negatively correlated with climate potential productivity of naked barley. Precipitation was the most critical factor affecting climate potential productivity of naked barley during the growing season and the key growth stages, followed by temperature. Finally, the study proposed measures to use of climatic factors to enhance climate potential productivity of naked barley.
This paper mainly analyzed climate trend during growth and crucial growth periods of naked barley in the Tibetan Plateau from 1965 to 2013. The study used average temperature, precipitation, sunshine duration and other meteorological data from 106 meteorological stations allocated in the Tibetan Plateau for the past 50 years. In the paper, tendency analysis, Thornthwaite Memorial model, geographical information system (GIS), statistical product and service solution (SPSS) techniques were used to analyze potential climate productivity of naked barley. Then the features of temporal and spatial variations and the effects of climate change on the development and yield of naked barley as well as the effects of various meteorological factors on the climate potential productivity of naked barley in the Tibetan Plateau in the past 50 years were analyzed. The results showed, 1) there was an increasing trend in temperature (0.53 ℃10a-1) and precipitation (7.8 mm10a-1) in the Tibetan Plateau in the past 50 years. While temperature increased significantly, the increase in precipitation was not significant. Also there was an obvious decrease in sunshine duration (16.9 h10a-1). 2) While temperature (0.4 ℃10a-1) and precipitation (7.2 mm10a-1) increased during naked barley growth period in the Tibetan Plateau, sunshine duration (15 h10a-1) significantly decreased during naked barley growing season. There was an obvious warming tendency in the northern zone of the Tibetan Plateau, significant increase in precipitation in the central region of the Tibetan Plateau and then an obvious decline in sunshine duration in the northeast part of the Tibetan Plateau. 3) Climate potential productivity of naked barley increased in the Tibetan Plateau (136.7 kghm-210a-1) from 1965 to 2013. The magnitude of increase was larger for the central region than for other regions of the Tibetan Plateau. However, there was a decreasing trend in climate potential productivity of naked barley in the southeastern edge of the plateau, the northern part of Qaidam Basin in Qinghai Province and the northwestern region of Tibet. 4) Precipitation and temperature had significantly positive correlation with climate potential productivity of naked barley. Conversely, sunshine duration was negatively correlated with climate potential productivity of naked barley. Precipitation was the most critical factor affecting climate potential productivity of naked barley during the growing season and the key growth stages, followed by temperature. Finally, the study proposed measures to use of climatic factors to enhance climate potential productivity of naked barley.
2015, 23(10): 1339-1347.
doi: 10.13930/j.cnki.cjea.150252
Abstract:
Evapotranspiration (ET) is an vital element of the hydrological cycle and energy budget, and it is closely related to plant/crop growth. Accurate estimation and spatio-temporal distribution of ET in different vegetation types in river basins are critical for water resources research and sustainable water resources management. Distributed hydrological models are among the promising approaches to the simulation and estimation of actual ET in river basins. However, distributed models are limited in the estimation accuracy of the spatio-temporal distribution of ET in different vegetation types. The Hydro-Informatic Modelling System (HIMS), a modular framework for distributed hydrological models, has proven very efficient in simulating streamflow. It has a simple structure and has been successfully used in China and Australia. To improve the ability to estimate actual ET using HIMS, we modified daily ET module in HIMS by demanding detailed description of evapotranspiration processes and adopting recent findings about filed ET observations. The spatial distribution and seasonal variations in land cover in the investigated basin and the effects of irrigation on actual ET were considered in the modified module. In the modified ET module, vegetation types were classified and actual ET derived as the residual sum of each vegetation type. Then ET for each vegetation type was calculated using the single crop coefficient method. Next, leaf area index calculated by the crop model was applied to separately estimate soil evaporation and plant transpiration. Vadose zone was divided into two (root zone and transition zone) and root zone soil water used to calculate soil water stress coefficient. The relationship between root and transition zone soil water storage was modeled through a linear function. Seepage from the root zone to transition zone was considered in the soil moisture calculation module. The modified ET module was validated and applied in Haihe River Basin. The results suggested that the modified module improved the precise estimation of ET. The relative error of annual mean actual ET between the improved module simulation and water budget estimation was 3.4%. The relative error was 12.6% for the original HIMS model estimation, which was 3.4% for the modified HIMS model. Compared with the original HIMS module, the modified module improved capacities of simulation of actual ET of forest and grassland, total field ET for rational wheat-maize fields, and separation of soil evaporation and crop transpiration. The modified ET module quantified actual ET and accurately characterized temporal and spatial variations in ET. This was critical for the accurate management of ET in Haihe River Basin.
Evapotranspiration (ET) is an vital element of the hydrological cycle and energy budget, and it is closely related to plant/crop growth. Accurate estimation and spatio-temporal distribution of ET in different vegetation types in river basins are critical for water resources research and sustainable water resources management. Distributed hydrological models are among the promising approaches to the simulation and estimation of actual ET in river basins. However, distributed models are limited in the estimation accuracy of the spatio-temporal distribution of ET in different vegetation types. The Hydro-Informatic Modelling System (HIMS), a modular framework for distributed hydrological models, has proven very efficient in simulating streamflow. It has a simple structure and has been successfully used in China and Australia. To improve the ability to estimate actual ET using HIMS, we modified daily ET module in HIMS by demanding detailed description of evapotranspiration processes and adopting recent findings about filed ET observations. The spatial distribution and seasonal variations in land cover in the investigated basin and the effects of irrigation on actual ET were considered in the modified module. In the modified ET module, vegetation types were classified and actual ET derived as the residual sum of each vegetation type. Then ET for each vegetation type was calculated using the single crop coefficient method. Next, leaf area index calculated by the crop model was applied to separately estimate soil evaporation and plant transpiration. Vadose zone was divided into two (root zone and transition zone) and root zone soil water used to calculate soil water stress coefficient. The relationship between root and transition zone soil water storage was modeled through a linear function. Seepage from the root zone to transition zone was considered in the soil moisture calculation module. The modified ET module was validated and applied in Haihe River Basin. The results suggested that the modified module improved the precise estimation of ET. The relative error of annual mean actual ET between the improved module simulation and water budget estimation was 3.4%. The relative error was 12.6% for the original HIMS model estimation, which was 3.4% for the modified HIMS model. Compared with the original HIMS module, the modified module improved capacities of simulation of actual ET of forest and grassland, total field ET for rational wheat-maize fields, and separation of soil evaporation and crop transpiration. The modified ET module quantified actual ET and accurately characterized temporal and spatial variations in ET. This was critical for the accurate management of ET in Haihe River Basin.
Editor-in-chief：LIU Changming
Competent Authorities：Chinese Academy of Sciences
Sponsored by：Institute of Genetics and Developmental Biology, Chinese Academy of Sciences; China Ecological Economics Society
Organizer：Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
ISSN 2096-6237
CN 13-1432/S
- Chinese core periodicals
- Core Chinese Sci-Tech Periodicals
- China's Top Science and Technology Periodicals
- Covered by Chinese Science Citation Database (CSCD)
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