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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. 5
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2015, 23(5): 525-534.
doi: 10.13930/j.cnki.cjea.141126
Abstract:
Understanding yield potential and yield gap for major cereal crops is critical for improving crop yield and helping farmers to adopt effective cultivation strategies. Based on 64 recently published classical literatures, this review summarized research advance in yield potential and yield gap for three major cereal crops (wheat, rice and maize) grown around the world. The different methods of measurement of yield potential and yield gap were also compared. The results showed that global yield potential was 6.7 t hm-2 for wheat, 8.1 t hm-2 for rice and 11.2 t hm-2 for maize, and that the average yields of farmers for wheat, rice and maize were respectively 60%, 60% and 53% of the yield potential. Furthermore, it was noted that yield estimation by crop models was one of the most effective methods of quantifying yield potential. The yield potentials based on recorded highest yield and model-estimated yield were highly reasonable. Although yield potential based on experimental yield and best farmers' yield were lower than that based on model-estimated yield, it was still important for exploring potential improvements in yield in short term. Finally, it was advanced that optimized management strategies, such as integrated soil-crop system management, were effective ways for reducing yield gap. There still existed a large potential to increase grain yield for the three major cereal crops of wheat, rice and maize. It was indicated that studies on how to close yield gap, improve grain yield and ensure food security would attract a considerable attention in the future.
Understanding yield potential and yield gap for major cereal crops is critical for improving crop yield and helping farmers to adopt effective cultivation strategies. Based on 64 recently published classical literatures, this review summarized research advance in yield potential and yield gap for three major cereal crops (wheat, rice and maize) grown around the world. The different methods of measurement of yield potential and yield gap were also compared. The results showed that global yield potential was 6.7 t hm-2 for wheat, 8.1 t hm-2 for rice and 11.2 t hm-2 for maize, and that the average yields of farmers for wheat, rice and maize were respectively 60%, 60% and 53% of the yield potential. Furthermore, it was noted that yield estimation by crop models was one of the most effective methods of quantifying yield potential. The yield potentials based on recorded highest yield and model-estimated yield were highly reasonable. Although yield potential based on experimental yield and best farmers' yield were lower than that based on model-estimated yield, it was still important for exploring potential improvements in yield in short term. Finally, it was advanced that optimized management strategies, such as integrated soil-crop system management, were effective ways for reducing yield gap. There still existed a large potential to increase grain yield for the three major cereal crops of wheat, rice and maize. It was indicated that studies on how to close yield gap, improve grain yield and ensure food security would attract a considerable attention in the future.
2015, 23(5): 535-543.
doi: 10.13930/j.cnki.cjea.150215
Abstract:
In order to build a water-saving planting system and control water over-exploitation in the North China Plain, a field experiment was conducted to compare yield, cost-benefit and water use efficiency between spring maize monoculture and winter wheat-summer maize double cropping system under rain-fed conditions. The field experiment was conducted in 2007 2013 under rain-fed conditions at the Luancheng Agro-Ecosystem Experimental Station (LAS) of the Chinese Academy of Sciences (CAS), which is in the northern region of the North China Plain located at the base of Mount Taihang. Winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation is the most commonly used cropping system in the region. There were two treatments in the experiment, one was the winter wheat and summer maize rotation system (T1) and the other one was the single harvest of spring maize cropping system (T2). The winter wheat was grown from the first 10 days or mid-October to mid-June of the following year. Then summer maize was grown from mid-to-late June to early October, while spring maize was grown from mid-to-late May to the first 10 days of September. The varieties of winter wheat and summer maize used were 'Kenong199' and 'Zhengdan 958', respectively. Also the varieties of spring maize used were 'Nongda 108', 'Xundan 20', 'Zhengdan 958' and 'Xianyu335'. No irrigation was adopted in the experiment over the period from September 2007 to June 2013. The results showed that under rain-fed conditions, wheat yield was relatively stable while summer maize and spring maize yields varied with different climate years. Summer maize yield was especially strongly influenced by soil water content at sowing. Maize did not germinate normally in many seasons due to dry soil and little rain after sowing. Delayed summer maize germination decreased maize yield. Although crop yield under T1 treatment was 34.1% higher than that under T2 treatment, cost-benefit of T1 was 279.97 Yuan·hm-2 lower than that of T2 due to higher input of winter wheat. The proportions of agricultural materials and machinery investments were higher while labor input accounted for a small proportion of the inputs for the three crops. Fertilizer input accounted for a significant proportion in the agricultural materials. The input-output ratios of winter wheat, summer maize and spring maize were 1.42, 2.66 and 3.42, respectively. Under rain-fed conditions, input-output ratio of winter wheat was the lowest and that of spring maize the highest. Water consumption analysis suggested that soil water was the largest water source of winter wheat, while rainfall was the dominant source of spring and summer maize. In practice, farmers gradually reduced planting area of winter wheat and enlarged that of spring maize. In view of food security, it was needed to adjust the agricultural cropping system to control over-exploitation of groundwater resources and ensure sustainable development of agriculture in the study area.
In order to build a water-saving planting system and control water over-exploitation in the North China Plain, a field experiment was conducted to compare yield, cost-benefit and water use efficiency between spring maize monoculture and winter wheat-summer maize double cropping system under rain-fed conditions. The field experiment was conducted in 2007 2013 under rain-fed conditions at the Luancheng Agro-Ecosystem Experimental Station (LAS) of the Chinese Academy of Sciences (CAS), which is in the northern region of the North China Plain located at the base of Mount Taihang. Winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation is the most commonly used cropping system in the region. There were two treatments in the experiment, one was the winter wheat and summer maize rotation system (T1) and the other one was the single harvest of spring maize cropping system (T2). The winter wheat was grown from the first 10 days or mid-October to mid-June of the following year. Then summer maize was grown from mid-to-late June to early October, while spring maize was grown from mid-to-late May to the first 10 days of September. The varieties of winter wheat and summer maize used were 'Kenong199' and 'Zhengdan 958', respectively. Also the varieties of spring maize used were 'Nongda 108', 'Xundan 20', 'Zhengdan 958' and 'Xianyu335'. No irrigation was adopted in the experiment over the period from September 2007 to June 2013. The results showed that under rain-fed conditions, wheat yield was relatively stable while summer maize and spring maize yields varied with different climate years. Summer maize yield was especially strongly influenced by soil water content at sowing. Maize did not germinate normally in many seasons due to dry soil and little rain after sowing. Delayed summer maize germination decreased maize yield. Although crop yield under T1 treatment was 34.1% higher than that under T2 treatment, cost-benefit of T1 was 279.97 Yuan·hm-2 lower than that of T2 due to higher input of winter wheat. The proportions of agricultural materials and machinery investments were higher while labor input accounted for a small proportion of the inputs for the three crops. Fertilizer input accounted for a significant proportion in the agricultural materials. The input-output ratios of winter wheat, summer maize and spring maize were 1.42, 2.66 and 3.42, respectively. Under rain-fed conditions, input-output ratio of winter wheat was the lowest and that of spring maize the highest. Water consumption analysis suggested that soil water was the largest water source of winter wheat, while rainfall was the dominant source of spring and summer maize. In practice, farmers gradually reduced planting area of winter wheat and enlarged that of spring maize. In view of food security, it was needed to adjust the agricultural cropping system to control over-exploitation of groundwater resources and ensure sustainable development of agriculture in the study area.
2015, 23(5): 544-553.
doi: 10.13930/j.cnki.cjea.141087
Abstract:
Although market demands for oilseed flax (Linum usitatissimum L.) gradually expanded in recent years, low yields restricted the development of oilseed flax. Lodging is a common problem in oilseed flax production which causes yield loss and quality deterioration. Effective water and fertilizer management is an important measure for improving oilseed flax yields. In order to investigate the effects of irrigation and nitrogen fertilizer application on lodging resistance and yield of oilseed flax, a field experiment was conducted in 2012-2013 with hybrid variety of "Longyaza1" oilseed flax in Yuzhong County, Gansu Province. In the experiment, the main plots were irrigated at 2 700 m3·hm-2 (W1) and 3 300 m3·hm-2 (W2), while the subplots were fertilized with nitrogen (N) at 0 kg·hm-2 (N0 or CK), 37.5 kg·hm -2 (N1), 112.5 kg·hm-2 (N2) and 225 kg·hm-2 (N3). Water meter was used to strictly control irrigation amount, urea was used as N fertilizer, two-thirds as base fertilizer and one-third as top-dresser before budding stage. Then the effects of irrigation and nitrogen fertilization rates on lodging resistance traits (i.e., lodging resistance index, stem strength, stem chemicals contents) and yield of oilseed flax were determined. The results showed that with increasing irrigation, stem strength and lodging resistance index of oilseed flax declined. Then the plant height and gravity center height increased while stem diameter and culm wall thickness decreased. Also while above-ground dry weight increased, below-ground dry weight and the root-shoot ratio decreased with increasing irrigation. The contents of cellulose, lignin, soluble sugars and starch of oilseed flax stem decreased. Also with increasing nitrogen input, oil flax stem strength and lodging resistance index initially increased and then decreased. The height and gravity center height of the plant increased while stem diameter, culm wall thickness, root dry weight and root-shoot ratio initially increased and later decreased. Furthermore, above-ground dry weight increased and stem contents of various biochemical components and yield initially increased and then decreased. Further analysis showed that lodging resistance index of oilseed flax was positively correlated with stem strength, stem diameter, culm wall thickness, root dry weight, root-shoot ratio and then cellulose, lignin, soluble sugar and starch contents. Lodging resistance index of oilseed flax was also negatively correlated with plant height, gravity center height and above-ground dry weight. Compared with high irrigation, low irrigation increased stem strength, lodging resistance index and yield respectively by 30.55%, 41.06% and 0.53%. Thus excessive irrigation was did not enhance lodging resistance of oilseed flax. The highest stem strength and yield occurred under N2 treatment. Compared with CK, N2 treatment increased stem strength and yield respectively by 36.8% and 15.9%. Compared to high nitrogen treatment (N3), N2 treatment increased stem strength and yield respectively by 3.95% and 0.8%. Thus, neither too high nor too low nitrogen fertilization was necessary in oilseed flax cultivation. The appropriate amounts of irrigation and nitrogen fertilizer was very important for preventing lodging, ensuring high production and increasing productivity of oilseed flax. Under the experimental condition in this study, W1N2 treatment (of 2 700 m3·hm-2 irrigation and 112.5 kg·hm-2 pure N) was the proper combination of irrigation and nitrogen fertilizer for high oilseed flax yield.
Although market demands for oilseed flax (Linum usitatissimum L.) gradually expanded in recent years, low yields restricted the development of oilseed flax. Lodging is a common problem in oilseed flax production which causes yield loss and quality deterioration. Effective water and fertilizer management is an important measure for improving oilseed flax yields. In order to investigate the effects of irrigation and nitrogen fertilizer application on lodging resistance and yield of oilseed flax, a field experiment was conducted in 2012-2013 with hybrid variety of "Longyaza1" oilseed flax in Yuzhong County, Gansu Province. In the experiment, the main plots were irrigated at 2 700 m3·hm-2 (W1) and 3 300 m3·hm-2 (W2), while the subplots were fertilized with nitrogen (N) at 0 kg·hm-2 (N0 or CK), 37.5 kg·hm -2 (N1), 112.5 kg·hm-2 (N2) and 225 kg·hm-2 (N3). Water meter was used to strictly control irrigation amount, urea was used as N fertilizer, two-thirds as base fertilizer and one-third as top-dresser before budding stage. Then the effects of irrigation and nitrogen fertilization rates on lodging resistance traits (i.e., lodging resistance index, stem strength, stem chemicals contents) and yield of oilseed flax were determined. The results showed that with increasing irrigation, stem strength and lodging resistance index of oilseed flax declined. Then the plant height and gravity center height increased while stem diameter and culm wall thickness decreased. Also while above-ground dry weight increased, below-ground dry weight and the root-shoot ratio decreased with increasing irrigation. The contents of cellulose, lignin, soluble sugars and starch of oilseed flax stem decreased. Also with increasing nitrogen input, oil flax stem strength and lodging resistance index initially increased and then decreased. The height and gravity center height of the plant increased while stem diameter, culm wall thickness, root dry weight and root-shoot ratio initially increased and later decreased. Furthermore, above-ground dry weight increased and stem contents of various biochemical components and yield initially increased and then decreased. Further analysis showed that lodging resistance index of oilseed flax was positively correlated with stem strength, stem diameter, culm wall thickness, root dry weight, root-shoot ratio and then cellulose, lignin, soluble sugar and starch contents. Lodging resistance index of oilseed flax was also negatively correlated with plant height, gravity center height and above-ground dry weight. Compared with high irrigation, low irrigation increased stem strength, lodging resistance index and yield respectively by 30.55%, 41.06% and 0.53%. Thus excessive irrigation was did not enhance lodging resistance of oilseed flax. The highest stem strength and yield occurred under N2 treatment. Compared with CK, N2 treatment increased stem strength and yield respectively by 36.8% and 15.9%. Compared to high nitrogen treatment (N3), N2 treatment increased stem strength and yield respectively by 3.95% and 0.8%. Thus, neither too high nor too low nitrogen fertilization was necessary in oilseed flax cultivation. The appropriate amounts of irrigation and nitrogen fertilizer was very important for preventing lodging, ensuring high production and increasing productivity of oilseed flax. Under the experimental condition in this study, W1N2 treatment (of 2 700 m3·hm-2 irrigation and 112.5 kg·hm-2 pure N) was the proper combination of irrigation and nitrogen fertilizer for high oilseed flax yield.
2015, 23(5): 554-562.
doi: 10.13930/j.cnki.cjea.141041
Abstract:
In recent years, panicle deformity of rice (Oryza sativa L.) characterized by blank florets/spikelets and distorted lemma and palea has caused significant yield loss of rice grown in uplands reclaimed into paddy lands in Jianghan Plain, Hubei Province, China. Up to now, it remains unclear why rice panicle deformity is prevalent in reclaimed paddy lands from uplands. However, studies have shown that panicle deformity is largely related with soil characteristics. Using old paddy field as control, a pot soil experiment was carried out to investigate the effects of old cotton fields reclaimed into paddy fields and rice straw application on the growth of rice seedlings. The study also analyzed rice mineral elements uptake, soil Eh, and soil available Fe, Mn, Cu and Zn contents. Soil waterlogged incubation test was adopted to study the effects of straw application on dynamic changes of DTPA-Fe, DTPA-Mn, DTPA-Cu and DTPA-Zn contents in the old paddy fields and paddy fields from cotton field. The results showed that rice seedlings in cotton fields reclaimed into paddy fields growth poorly and had symptoms of chlorosis, with dry weight and chlorophyll content of respectively 30% and 20% those of rice seedlings in old paddy fields. While Fe content was significantly lower, Cu and Zn contents were markedly higher in rice plants in cotton fields than in old paddy fields. Eh was significantly higher in soil of cotton field reclaimed into paddy than in old paddy soils. In the pot experiment, when submerged under water for 10 days, DTPA-Cu and DTPA-Zn contents in upland soils were respectively by 1.4-2.5 times and 1.6-1.8 times of those in old paddy soils while DTPA-Fe content was only 7% of that in old paddy soils. With prolonged inundation, DTPA-Fe content in cotton field soils gradually increased while DTPA-Mn, DTPA-Cu and DTPA-Zn contents initially increased and then decreased. Incubation test results showed that after submergence for 28 days, the differences in soil DTPA-Fe, DTPA-Mn, DTPA-Cu and DTPA-Zn between upland soils and old paddy soils diminished. Straw application of upland soils reclaimed into paddy soils reduced soil Eh and soil DTPA-Cu and DTPA-Zn contents but increased soil DTPA-Fe content. This resulted in a significant increase in chlorophyll content of rice seedlings. In conclusion, it was better to sow rice seeds or transplant rice seedlings after one month of flooding old cotton fields reclaimed into paddy fields. This prevented imbalance in soil trace elements that in turn inhibited rice growth. Straw application partly but not completely eliminated inhibiting effects on rice seedlings growth of reclamation of cotton field into paddy.
In recent years, panicle deformity of rice (Oryza sativa L.) characterized by blank florets/spikelets and distorted lemma and palea has caused significant yield loss of rice grown in uplands reclaimed into paddy lands in Jianghan Plain, Hubei Province, China. Up to now, it remains unclear why rice panicle deformity is prevalent in reclaimed paddy lands from uplands. However, studies have shown that panicle deformity is largely related with soil characteristics. Using old paddy field as control, a pot soil experiment was carried out to investigate the effects of old cotton fields reclaimed into paddy fields and rice straw application on the growth of rice seedlings. The study also analyzed rice mineral elements uptake, soil Eh, and soil available Fe, Mn, Cu and Zn contents. Soil waterlogged incubation test was adopted to study the effects of straw application on dynamic changes of DTPA-Fe, DTPA-Mn, DTPA-Cu and DTPA-Zn contents in the old paddy fields and paddy fields from cotton field. The results showed that rice seedlings in cotton fields reclaimed into paddy fields growth poorly and had symptoms of chlorosis, with dry weight and chlorophyll content of respectively 30% and 20% those of rice seedlings in old paddy fields. While Fe content was significantly lower, Cu and Zn contents were markedly higher in rice plants in cotton fields than in old paddy fields. Eh was significantly higher in soil of cotton field reclaimed into paddy than in old paddy soils. In the pot experiment, when submerged under water for 10 days, DTPA-Cu and DTPA-Zn contents in upland soils were respectively by 1.4-2.5 times and 1.6-1.8 times of those in old paddy soils while DTPA-Fe content was only 7% of that in old paddy soils. With prolonged inundation, DTPA-Fe content in cotton field soils gradually increased while DTPA-Mn, DTPA-Cu and DTPA-Zn contents initially increased and then decreased. Incubation test results showed that after submergence for 28 days, the differences in soil DTPA-Fe, DTPA-Mn, DTPA-Cu and DTPA-Zn between upland soils and old paddy soils diminished. Straw application of upland soils reclaimed into paddy soils reduced soil Eh and soil DTPA-Cu and DTPA-Zn contents but increased soil DTPA-Fe content. This resulted in a significant increase in chlorophyll content of rice seedlings. In conclusion, it was better to sow rice seeds or transplant rice seedlings after one month of flooding old cotton fields reclaimed into paddy fields. This prevented imbalance in soil trace elements that in turn inhibited rice growth. Straw application partly but not completely eliminated inhibiting effects on rice seedlings growth of reclamation of cotton field into paddy.
2015, 23(5): 563-570.
doi: 10.13930/j.cnki.cjea.140994
Abstract:
Soil structure, which is decided by the stability of soil aggregates to a great extent, significantly influences soil environment. Soil aggregates are secondary particles formed through the combination of particulate minerals with organic and inorganic substances. Soil organic carbon is critical for enhancing soil quality and sustainable production. Even a slight increase in soil organic carbon content could induce a substantial sequestration of excess atmospheric CO2. Cold waterlogged paddy field is one form of low-productivity paddy fields in the central China. This type of paddy field is especially common in the middle and lower reaches of Yangtze River Basin. In recent years, large areas of cold waterlogged paddy fields have been abandoned due to high labor costs and low returns. Due to long-term floods, cold waterlogged paddy fields have very poor soil structures that are often described as mushy soils. Not only is the composition of aggregate proportions and organic carbon of marshy soils are vastly different from that of ordinary paddy fields, the aggregate sizes and organic carbon stability of marshy soils are unclear. It is also not clear how soil structure and organic carbon changed after cold waterlogged paddy field was abandoned. In this study, we investigated the effects of land abandonment on soil total organic carbon, soil aggregation fractions and organic carbon content in cold waterlogged paddy fields under continuous rice cultivation (CWC), abandoned for three years (CWA3) and abandoned for six years (CWA6). The results showed that the aggregate compositions were dominated by <53 μm particles, accounting for over 40% of the soil in cold waterlogged paddy fields. Then >250 μm particles accounted for over 35% and 53 250 μm particles accounted for less than 20% of the 0-25 cm soil layer in cold waterlogged paddy fields. Land abandonment significantly increased the <53 μm aggregate fraction and decreased the 53-250 μm aggregate fraction in the 0-25 cm soil layer. Also land abandonment improved labile organic carbon pool Ⅰ index (LIc-Ⅰ) of the <53 μm and >250 μm soil aggregates, decreased labile organic carbon pool Ⅱ index (LIc-Ⅱ) in the 53-250 μm and >250 μm soil aggregates, and reduced recalcitrant organic carbon index (RIc) in the <53 μm and 53-250 μm soil aggregates. Soil total organic carbon increased with increasing length of period of land abandonment.
Soil structure, which is decided by the stability of soil aggregates to a great extent, significantly influences soil environment. Soil aggregates are secondary particles formed through the combination of particulate minerals with organic and inorganic substances. Soil organic carbon is critical for enhancing soil quality and sustainable production. Even a slight increase in soil organic carbon content could induce a substantial sequestration of excess atmospheric CO2. Cold waterlogged paddy field is one form of low-productivity paddy fields in the central China. This type of paddy field is especially common in the middle and lower reaches of Yangtze River Basin. In recent years, large areas of cold waterlogged paddy fields have been abandoned due to high labor costs and low returns. Due to long-term floods, cold waterlogged paddy fields have very poor soil structures that are often described as mushy soils. Not only is the composition of aggregate proportions and organic carbon of marshy soils are vastly different from that of ordinary paddy fields, the aggregate sizes and organic carbon stability of marshy soils are unclear. It is also not clear how soil structure and organic carbon changed after cold waterlogged paddy field was abandoned. In this study, we investigated the effects of land abandonment on soil total organic carbon, soil aggregation fractions and organic carbon content in cold waterlogged paddy fields under continuous rice cultivation (CWC), abandoned for three years (CWA3) and abandoned for six years (CWA6). The results showed that the aggregate compositions were dominated by <53 μm particles, accounting for over 40% of the soil in cold waterlogged paddy fields. Then >250 μm particles accounted for over 35% and 53 250 μm particles accounted for less than 20% of the 0-25 cm soil layer in cold waterlogged paddy fields. Land abandonment significantly increased the <53 μm aggregate fraction and decreased the 53-250 μm aggregate fraction in the 0-25 cm soil layer. Also land abandonment improved labile organic carbon pool Ⅰ index (LIc-Ⅰ) of the <53 μm and >250 μm soil aggregates, decreased labile organic carbon pool Ⅱ index (LIc-Ⅱ) in the 53-250 μm and >250 μm soil aggregates, and reduced recalcitrant organic carbon index (RIc) in the <53 μm and 53-250 μm soil aggregates. Soil total organic carbon increased with increasing length of period of land abandonment.
2015, 23(5): 571-578.
doi: 10.13930/j.cnki.cjea.141405
Abstract:
Cold-waterlogged paddy fields across Jiangnan rice-growing regions belong to low-yield paddy fields. The main characteristics of these paddy fields include low soil temperature, high reducing agents and bad soil structure. However, the fields have the potential to significantly increase paddy rice yields. A 30-year stony open deep-narrow drainage ditch system in Shunchang County, Fujian Province, was investigated for its effects on groundwater level, soil chemical characteristics and rice grain quality in cold-waterlogged paddy fields using a consecutive 3-year monitoring. The results showed that soil conditions in paddy fields 75 m, 25 m, 15 m and 5 m from the ditches were deep-foot mud, shallow-foot mud, blue mud and blue-bottom mud, respectively. The groundwater levels in paddy fields 75 m, 25 m, 15 m and 5 m from the drainage ditches were 5.0 cm, 8.3 cm, 5.4 cm and 16.7 cm, respectively. The highest variation in groundwater level (from 62 cm to 13 cm) was in paddy field 5 m from the drainage ditches. The closer the distance to the drainage ditches, the lower the reducing agents and the higher the contents of available N, P and K. Compared with the field 75 m from the drainage ditches (CK), soil reducing agents content at the field 5 m from the drainage ditches decreased by 62.6% while available N, P and K contents increased respectively by 40.7%, 38.8% and 184.5%. At closer distances to the drainage ditches (e.g., 5 m, 15 m and 25 m sites), amino acids content of rice grain were significantly higher than that of CK. Amino acids content of rice grain was significantly negatively correlated with soil reducing agents content, but positively correlated with soil available N and P contents. Starch content of rice grain was also significantly negatively correlated with soil reducing agents content. Soil physiochemical properties and rice amino acids content were improved by long-term drainage of stony open deep-narrow drainage ditches. Soil improving effect was obvious in paddy fields within 15 m distance from stony open deep-narrow drainage ditches.
Cold-waterlogged paddy fields across Jiangnan rice-growing regions belong to low-yield paddy fields. The main characteristics of these paddy fields include low soil temperature, high reducing agents and bad soil structure. However, the fields have the potential to significantly increase paddy rice yields. A 30-year stony open deep-narrow drainage ditch system in Shunchang County, Fujian Province, was investigated for its effects on groundwater level, soil chemical characteristics and rice grain quality in cold-waterlogged paddy fields using a consecutive 3-year monitoring. The results showed that soil conditions in paddy fields 75 m, 25 m, 15 m and 5 m from the ditches were deep-foot mud, shallow-foot mud, blue mud and blue-bottom mud, respectively. The groundwater levels in paddy fields 75 m, 25 m, 15 m and 5 m from the drainage ditches were 5.0 cm, 8.3 cm, 5.4 cm and 16.7 cm, respectively. The highest variation in groundwater level (from 62 cm to 13 cm) was in paddy field 5 m from the drainage ditches. The closer the distance to the drainage ditches, the lower the reducing agents and the higher the contents of available N, P and K. Compared with the field 75 m from the drainage ditches (CK), soil reducing agents content at the field 5 m from the drainage ditches decreased by 62.6% while available N, P and K contents increased respectively by 40.7%, 38.8% and 184.5%. At closer distances to the drainage ditches (e.g., 5 m, 15 m and 25 m sites), amino acids content of rice grain were significantly higher than that of CK. Amino acids content of rice grain was significantly negatively correlated with soil reducing agents content, but positively correlated with soil available N and P contents. Starch content of rice grain was also significantly negatively correlated with soil reducing agents content. Soil physiochemical properties and rice amino acids content were improved by long-term drainage of stony open deep-narrow drainage ditches. Soil improving effect was obvious in paddy fields within 15 m distance from stony open deep-narrow drainage ditches.
2015, 23(5): 579-588.
doi: 10.13930/j.cnki.cjea.141321
Abstract:
To clarify photosynthetic characteristics and their relationship with soil water conditions of Bothriochloa ischaemum (L.) Keng intercropped with Lespedeza davurica (Laxm.) Schindl. in the loess hilly-gully region, a pot experiment was conducted in the weather enclosure of the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau. B. ischaemum (B) was intercropped with L. davurica (D) in six mixture sowing ratios of 2︰10, 4︰8, 6︰6, 8︰4, 10︰2, 12︰0), and these combinations were marked as B2D10, B4D6, B6D6, B8D4, B10D2 and B12D0, respectively. Three soil water conditions were set in the experiment, which were high water (80% field capacity, HW), middle water (60% field capacity, MW) and low water (40% field capacity, LW). Additionally, during the elongation stage of B. ischaemum, soil water content was improved separately from MW to HW, LW to HW and MW, respectively, i.e. middle water to high water (MHW), low water to high water (LHW) and middle water (LMW). Altogether, there were 36 treatments in the experiment, and each was replicated three times. Photosynthetic characteristics, net photosynthetic rate (Pn), transpirationrate (Tr), stomatal conductance (Gs), water use efficiency (WUE) of B. ischaemum were measured after soil was rewatered. Results showed that under relative stable water conditions (i.e. HW, MW, and LW), photosynthetic parameters of B. ischaemum were significantly highest under HW treatment, and significantly lowest under LW treatment for all mixture sowing ratios, indicating water was the key factor affecting B. ischaemum photosynthesis. After re-watering, the largest and smallest increases of photosynthetic parameters of B. ischaemum appeared under LHW and LMW respectively. For all mixture sowing ratios, photosynthetic activity of B. ischaemum under MHW recovered to stable level in the shortest time, suggesting that higher water content in early stage and higher rewatering level benefited B. ischaemum photosynthesis improvement. B. ischaemum presented not only higherPn, lower Tr and higher WUE under B10D2 and B8D4 treatment, but also greater increase in Pn and WUE and smaller increase in Tr after rewatered, implying that the two mixture sowing ratios were beneficial for improving the photosynthesis efficiency of B. ischaemum. The research results suggested that photo-physiological activities of B. ischaemum was recovered after re-watering from short-term drought stress, and the recovery speed and level were correlated with mixture sowing ratio with L. davurica and soil water content before re-watering.
To clarify photosynthetic characteristics and their relationship with soil water conditions of Bothriochloa ischaemum (L.) Keng intercropped with Lespedeza davurica (Laxm.) Schindl. in the loess hilly-gully region, a pot experiment was conducted in the weather enclosure of the State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau. B. ischaemum (B) was intercropped with L. davurica (D) in six mixture sowing ratios of 2︰10, 4︰8, 6︰6, 8︰4, 10︰2, 12︰0), and these combinations were marked as B2D10, B4D6, B6D6, B8D4, B10D2 and B12D0, respectively. Three soil water conditions were set in the experiment, which were high water (80% field capacity, HW), middle water (60% field capacity, MW) and low water (40% field capacity, LW). Additionally, during the elongation stage of B. ischaemum, soil water content was improved separately from MW to HW, LW to HW and MW, respectively, i.e. middle water to high water (MHW), low water to high water (LHW) and middle water (LMW). Altogether, there were 36 treatments in the experiment, and each was replicated three times. Photosynthetic characteristics, net photosynthetic rate (Pn), transpirationrate (Tr), stomatal conductance (Gs), water use efficiency (WUE) of B. ischaemum were measured after soil was rewatered. Results showed that under relative stable water conditions (i.e. HW, MW, and LW), photosynthetic parameters of B. ischaemum were significantly highest under HW treatment, and significantly lowest under LW treatment for all mixture sowing ratios, indicating water was the key factor affecting B. ischaemum photosynthesis. After re-watering, the largest and smallest increases of photosynthetic parameters of B. ischaemum appeared under LHW and LMW respectively. For all mixture sowing ratios, photosynthetic activity of B. ischaemum under MHW recovered to stable level in the shortest time, suggesting that higher water content in early stage and higher rewatering level benefited B. ischaemum photosynthesis improvement. B. ischaemum presented not only higherPn, lower Tr and higher WUE under B10D2 and B8D4 treatment, but also greater increase in Pn and WUE and smaller increase in Tr after rewatered, implying that the two mixture sowing ratios were beneficial for improving the photosynthesis efficiency of B. ischaemum. The research results suggested that photo-physiological activities of B. ischaemum was recovered after re-watering from short-term drought stress, and the recovery speed and level were correlated with mixture sowing ratio with L. davurica and soil water content before re-watering.
2015, 23(5): 589-596.
doi: 10.13930/j.cnki.cjea.140888
Abstract:
Alternative cropping (0 year of potato cultivation), and 2, 4, 6, 10 years of continuous monoculture of potato were studied to explain the mechanism of continuous cropping obstacles by using combined BIOLOG and morphological identification techniques of arbuscular mycorrhizal fungi (AMF). The results showed that soil nutrients contents decreased with increasing number of continuous potato cropping years after 4 years continuous cropping. Compared with 4 years continuous potato cropping, 10 years continuous potato cropping decreased soil total phosphorus, available phosphorus, available potassium and available nitrogen respectively by 61.32%, 26.86%, 26.87% and 17.24%. However, no obvious nutrient deficiency or imbalance was noted in the experiment. Soil microbial community structure also changed significantly. The amounts of actinomyces and fungi increased in the first few years and later dropped significantly. The amount of bacteria gradually decreased with increasing number of years of continuous potato cropping, but no significantly changed. Microbial functional diversity of soil microbial community was still strong under 4 6 years of continuous potato cropping. Compared with alternative cropping (0 years), average well color development (AWCD) increased by 3.89% under 6 years of continuous potato cropping. The metabolism ability of soil microbial community using carbohydrate and amino acids as sources of carbon obviously decreased, but metabolism ability diversity tended to unanimous with the extension of continuous potato cropping years. The dominant AMF species changed from Glomus deserticola under alternative cropping (0 years) to G. delhiense and G. formosanum under 2 years of continuous potato cropping, and to G. globiferum under 10 years of continuous potato cropping. Multivariate analysis showed that the diversity of soil microbial structure and function, and AMF diversity were affected by soil pH, total phosphorus, amounts of actynomycetes and bacteria, and soil microbial groups using carbohydrate and amino acids as sources of carbon substrate. It was therefore concluded that continuous potato cropping decreased not only fungi and actinomycetes population but also AMF diversity. The dominant AMF species also changed and soil microbial structure diversity performance was inconsistent with function diversity. There was functional and structural disorder of soil microbial communities under continuous potato cropping.
Alternative cropping (0 year of potato cultivation), and 2, 4, 6, 10 years of continuous monoculture of potato were studied to explain the mechanism of continuous cropping obstacles by using combined BIOLOG and morphological identification techniques of arbuscular mycorrhizal fungi (AMF). The results showed that soil nutrients contents decreased with increasing number of continuous potato cropping years after 4 years continuous cropping. Compared with 4 years continuous potato cropping, 10 years continuous potato cropping decreased soil total phosphorus, available phosphorus, available potassium and available nitrogen respectively by 61.32%, 26.86%, 26.87% and 17.24%. However, no obvious nutrient deficiency or imbalance was noted in the experiment. Soil microbial community structure also changed significantly. The amounts of actinomyces and fungi increased in the first few years and later dropped significantly. The amount of bacteria gradually decreased with increasing number of years of continuous potato cropping, but no significantly changed. Microbial functional diversity of soil microbial community was still strong under 4 6 years of continuous potato cropping. Compared with alternative cropping (0 years), average well color development (AWCD) increased by 3.89% under 6 years of continuous potato cropping. The metabolism ability of soil microbial community using carbohydrate and amino acids as sources of carbon obviously decreased, but metabolism ability diversity tended to unanimous with the extension of continuous potato cropping years. The dominant AMF species changed from Glomus deserticola under alternative cropping (0 years) to G. delhiense and G. formosanum under 2 years of continuous potato cropping, and to G. globiferum under 10 years of continuous potato cropping. Multivariate analysis showed that the diversity of soil microbial structure and function, and AMF diversity were affected by soil pH, total phosphorus, amounts of actynomycetes and bacteria, and soil microbial groups using carbohydrate and amino acids as sources of carbon substrate. It was therefore concluded that continuous potato cropping decreased not only fungi and actinomycetes population but also AMF diversity. The dominant AMF species also changed and soil microbial structure diversity performance was inconsistent with function diversity. There was functional and structural disorder of soil microbial communities under continuous potato cropping.
2015, 23(5): 597-604.
doi: 10.13930/j.cnki.cjea.150001
Abstract:
To determine the effects of cracks on soil characteristics and crop growth in subsided coal mining areas, field investigation and laboratory analysis were conducted for the contents of soil water and available nitrogen, soil microbial characteristics and physiological properties of crops at points with different distances from soil cracks. The results showed that soil cracks conduced to the loss of soil water and nitrogen. The closer the sampling site was to the soil cracks, the lower were the contents of soil water and available nitrogen. The cracks had no effect on the contents of soil water and available nitrogen at sampling sites beyond 120 cm from the cracks. The change in the contents of soil water and available nitrogen led to changes in soil microbial characteristics. The closer sampling site was to a soil crack, the lower were the activities of soil enzymes (urease and sucrase) and soil respiration rate. The crack had no effect on soil microbial characteristics at distances beyond 90 cm from the cracks. The crack had significant effect on chlorophyll content and photosynthetic rate of wheat, but had no effect on chlorophyll content of wheat at distances beyond 60 cm from the cracks. At jointing stage, the cracks showed a significant effect on wheat leaf photosynthetic rate within 0 60 cm from the cracks. The cracks had no effect on wheat leaf photosynthetic rate at distances beyond 60 cm from the cracks. However, at flowering stage, the crack had no effect on wheat leaf photosynthetic rate at distances beyond 90 cm from the cracks. The cracks had different effects on yield traits of winter wheat. The cracks had significant effect on plant height, unit stem weight and grain number per ear of wheat within 0 60 cm from soil cracks. The crack had no effect on yield traits of wheat at distances beyond 90 cm from the cracks. The crack reduced spike number and yield of wheat. The closer the sampling site was to the cracks, the higher was the reduction in spike number and yield of wheat. Compared with the distance of 120 cm from the cracks, spike number and yield of wheat within 0 30 cm from the cracks dropped by 43.7% and 53.3%, respectively. Thus soil cracks caused loss of soil water and nitrogen that in turn decreased soil quality and crop yield.
To determine the effects of cracks on soil characteristics and crop growth in subsided coal mining areas, field investigation and laboratory analysis were conducted for the contents of soil water and available nitrogen, soil microbial characteristics and physiological properties of crops at points with different distances from soil cracks. The results showed that soil cracks conduced to the loss of soil water and nitrogen. The closer the sampling site was to the soil cracks, the lower were the contents of soil water and available nitrogen. The cracks had no effect on the contents of soil water and available nitrogen at sampling sites beyond 120 cm from the cracks. The change in the contents of soil water and available nitrogen led to changes in soil microbial characteristics. The closer sampling site was to a soil crack, the lower were the activities of soil enzymes (urease and sucrase) and soil respiration rate. The crack had no effect on soil microbial characteristics at distances beyond 90 cm from the cracks. The crack had significant effect on chlorophyll content and photosynthetic rate of wheat, but had no effect on chlorophyll content of wheat at distances beyond 60 cm from the cracks. At jointing stage, the cracks showed a significant effect on wheat leaf photosynthetic rate within 0 60 cm from the cracks. The cracks had no effect on wheat leaf photosynthetic rate at distances beyond 60 cm from the cracks. However, at flowering stage, the crack had no effect on wheat leaf photosynthetic rate at distances beyond 90 cm from the cracks. The cracks had different effects on yield traits of winter wheat. The cracks had significant effect on plant height, unit stem weight and grain number per ear of wheat within 0 60 cm from soil cracks. The crack had no effect on yield traits of wheat at distances beyond 90 cm from the cracks. The crack reduced spike number and yield of wheat. The closer the sampling site was to the cracks, the higher was the reduction in spike number and yield of wheat. Compared with the distance of 120 cm from the cracks, spike number and yield of wheat within 0 30 cm from the cracks dropped by 43.7% and 53.3%, respectively. Thus soil cracks caused loss of soil water and nitrogen that in turn decreased soil quality and crop yield.
2015, 23(5): 605-613.
doi: 10.13930/j.cnki.cjea.141152
Abstract:
C4-phosphoenolpyruvate carboxylase (PEPC) gene (C4-pepc) plays a key role in C4 photosynthesis by catalyzing initial fixation of CO2 in C4 plants. To determine whether adenosine triphosphate (ATP) limits photosynthetic rate of transgenic rice plant with over-expressing maize C4-pepc, the second upper leaves of non-transgenic rice (WT) and transgenic rice with over-expressing maizeC4-pepc (PC) were sprayed with 2 mmol·L-1 NaHSO3, 100 umol·L-1 3-(3 ,4 -dichlorophenyl)-1,1-dimethylurea (DCMU) and 10 umol·L-1 oligomycin at 5 6 leaf blade seedling stage under 20% (m/v) polyethylene glycol 6000 (PEG-6000) treatment. Then the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), PEPC activity, ATP content and ΦPS? of PC and WT rice plants measured in the next morning. The results showed that 2 mmol·L-1 NaHSO3 enhanced Pn of the upper leaves of PC and WT rice seedlings without PEG-6000 treatment. However, the 100 umol·L-1 DCMU and 10 umol·L-1 oligomycin decreased Pn of the upper leaves of PC and WT rice seedlings without PEG-6000 treatment. Treatment with 2 mmol·L-1 NaHSO3 increased Gs and Ci of WT rice leaves but decreased Gs and Ci of PC rice leaves. While treatment with 100 umol·L-1 DCMU increased Ci of PC and WT rice leaves, it decreased Gs of PC and WT rice leaves. PEG-6000 treatment decreased Pn of the upper leaves in PC and WT plants under different treatments. However, PEG-6000 treatment combined with 2 mmol·L-1 NaHSO3 solution spray retarded the decrease in Pn. Then PEG-6000 treatment combined with DCMU and oligomycin sprays increased the rate of Pn decline. After 8 hours of 20% PEG-6000 treatment combined with different solutions, Gs of PC rice leaves remained unchanged while Pn of PC rice leaves changed obviously. The results further showed that ATP content, PEPC activity and ΦPS? content in rice leaves changed obviously under different treatments. While DCMU treatment accelerated the decrease in ATP content, PEPC activity and ΦPS? of PC and WT leaves, NaHSO3 retarded the rates of decrease in these elements. Although oligomycin decreased ATP content in rice leaves, it had no effect on ΦPSII in rice leaves. It was therefore concluded that PC maintained high levels of PS? activity and Pn stability by inducing more ATP in rice leaves compared with WT plants under drought stress.
C4-phosphoenolpyruvate carboxylase (PEPC) gene (C4-pepc) plays a key role in C4 photosynthesis by catalyzing initial fixation of CO2 in C4 plants. To determine whether adenosine triphosphate (ATP) limits photosynthetic rate of transgenic rice plant with over-expressing maize C4-pepc, the second upper leaves of non-transgenic rice (WT) and transgenic rice with over-expressing maizeC4-pepc (PC) were sprayed with 2 mmol·L-1 NaHSO3, 100 umol·L-1 3-(3 ,4 -dichlorophenyl)-1,1-dimethylurea (DCMU) and 10 umol·L-1 oligomycin at 5 6 leaf blade seedling stage under 20% (m/v) polyethylene glycol 6000 (PEG-6000) treatment. Then the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), PEPC activity, ATP content and ΦPS? of PC and WT rice plants measured in the next morning. The results showed that 2 mmol·L-1 NaHSO3 enhanced Pn of the upper leaves of PC and WT rice seedlings without PEG-6000 treatment. However, the 100 umol·L-1 DCMU and 10 umol·L-1 oligomycin decreased Pn of the upper leaves of PC and WT rice seedlings without PEG-6000 treatment. Treatment with 2 mmol·L-1 NaHSO3 increased Gs and Ci of WT rice leaves but decreased Gs and Ci of PC rice leaves. While treatment with 100 umol·L-1 DCMU increased Ci of PC and WT rice leaves, it decreased Gs of PC and WT rice leaves. PEG-6000 treatment decreased Pn of the upper leaves in PC and WT plants under different treatments. However, PEG-6000 treatment combined with 2 mmol·L-1 NaHSO3 solution spray retarded the decrease in Pn. Then PEG-6000 treatment combined with DCMU and oligomycin sprays increased the rate of Pn decline. After 8 hours of 20% PEG-6000 treatment combined with different solutions, Gs of PC rice leaves remained unchanged while Pn of PC rice leaves changed obviously. The results further showed that ATP content, PEPC activity and ΦPS? content in rice leaves changed obviously under different treatments. While DCMU treatment accelerated the decrease in ATP content, PEPC activity and ΦPS? of PC and WT leaves, NaHSO3 retarded the rates of decrease in these elements. Although oligomycin decreased ATP content in rice leaves, it had no effect on ΦPSII in rice leaves. It was therefore concluded that PC maintained high levels of PS? activity and Pn stability by inducing more ATP in rice leaves compared with WT plants under drought stress.
2015, 23(5): 614-619.
doi: 10.13930/j.cnki.cjea.141228
Abstract:
The Songnen Plain is one of the largest saline-sodic soil regions in not only China but whole World. The saline-sodic soils in the plain have high spatial variability in soil salinity and sodicity. This heterogeneity has made it very difficult to use the saline-sodic soils for large scale paddy rice production in the region. The objective of this study was to investigate the degree of spatial variability and structural variance of soil apparent electrical conductivity in the plain. The study also determined the relationships between soil apparent electrical conductivity and soil-water extract electrical conductivity (EC1︰5) and then soil sodicity (ESP) using Pearson regression analysis. Soil salinity and spatial variability were measured using EM38 (electromagnetic induction) and GPS (global position system) systems in saline-sodic paddy soils in the plain. The data were then analyzed using classical statistical and geo-statistical techniques. Classical statistical analysis suggested that ECh (soil apparent electrical conductivity in the horizontal direction) and ECv (soil apparent electrical conductivity in the vertical direction) had moderate spatial variation with normal distribution curves. However, geo-statistical analysis showed that ECh and ECv had strongly spatial auto-correlation due to compound impact of structural factors. The optimal model of empirical semivariograms used to simulate ECh and ECv was the exponential model. The spatial distribution maps interpolated with Kriging apparently showed similar spatial distributions of ECh and ECv. Based on Pearson correlation, it was noted that soil EC1︰5 and ESP were significantly correlated with ECh and ECv, with coefficients of correlation greater than 0.8. Regression analysis showed exponential function relations between ECh and ECv and between EC1︰5 and ESP, with coefficients of determination greater than 0.76. Comparison of soil apparent electrical conductivity in the vertical and horizontal directions suggested that the correlation coefficients and determination coefficients between ECh, EC1︰5 and ESP were greater than those between ECv, EC1︰5 and ESP. This suggested that ECh better reflected the degree of soil salinity and was more appropriate for saline-sodic soil studies in the region. The results of the study provided the theoretical basis for the integration of salinity spatial variability theory with soil improvement practices. It also provided data support for homogenous in situ reclamation of saline-sodic soils to reduce soil salinity for rice production.
The Songnen Plain is one of the largest saline-sodic soil regions in not only China but whole World. The saline-sodic soils in the plain have high spatial variability in soil salinity and sodicity. This heterogeneity has made it very difficult to use the saline-sodic soils for large scale paddy rice production in the region. The objective of this study was to investigate the degree of spatial variability and structural variance of soil apparent electrical conductivity in the plain. The study also determined the relationships between soil apparent electrical conductivity and soil-water extract electrical conductivity (EC1︰5) and then soil sodicity (ESP) using Pearson regression analysis. Soil salinity and spatial variability were measured using EM38 (electromagnetic induction) and GPS (global position system) systems in saline-sodic paddy soils in the plain. The data were then analyzed using classical statistical and geo-statistical techniques. Classical statistical analysis suggested that ECh (soil apparent electrical conductivity in the horizontal direction) and ECv (soil apparent electrical conductivity in the vertical direction) had moderate spatial variation with normal distribution curves. However, geo-statistical analysis showed that ECh and ECv had strongly spatial auto-correlation due to compound impact of structural factors. The optimal model of empirical semivariograms used to simulate ECh and ECv was the exponential model. The spatial distribution maps interpolated with Kriging apparently showed similar spatial distributions of ECh and ECv. Based on Pearson correlation, it was noted that soil EC1︰5 and ESP were significantly correlated with ECh and ECv, with coefficients of correlation greater than 0.8. Regression analysis showed exponential function relations between ECh and ECv and between EC1︰5 and ESP, with coefficients of determination greater than 0.76. Comparison of soil apparent electrical conductivity in the vertical and horizontal directions suggested that the correlation coefficients and determination coefficients between ECh, EC1︰5 and ESP were greater than those between ECv, EC1︰5 and ESP. This suggested that ECh better reflected the degree of soil salinity and was more appropriate for saline-sodic soil studies in the region. The results of the study provided the theoretical basis for the integration of salinity spatial variability theory with soil improvement practices. It also provided data support for homogenous in situ reclamation of saline-sodic soils to reduce soil salinity for rice production.
2015, 23(5): 620-627.
doi: 10.13930/j.cnki.cjea.141306
Abstract:
Soil salinization and alkalinization frequently co-occur in nature. The interactive effects of salt and alkali stress on plants are more complex and serious, greatly limiting crop production. However, the comprehensive effect of salt and alkali stress on crops remains largely unclear. Screening and cultivating salt-tolerant plants are the most efficient way of exploiting saline-alkaline soils. Jerusalem artichoke (Helianthus tuberosus L.) has long been considered as a highly promising biological energy material with a considerable tolerance to saline-alkaline soils. The objective of this study was to explore the response of 16 Jerusalem artichoke accessions to saline-alkaline stress at seedling stage, and to screen salt-tolerant accessions for cultivation of saline-alkaline lands and provide critical guidance for the management of saline-alkaline soils. To that end, two neutral salts (NaCl and Na2SO4) and two alkali salts (NaHCO3 and Na2CO3) were mixed with mole ratio of 5︰23︰9︰5 to simulate typical saline-alkaline stress. The 16 Jerusalem artichoke accessions were cultivated in plastic pots in a controlled environment chamber. The half-strength Hoagland solution without exogenous saline-alkaline was used as the control. The half-strength Hoagland solution supplemented with 150 mmol·L 1 saline-alkaline mixture was as the treatment. The shoot fresh and dry weight, root fresh and dry weight, SOD activity, and MDA and proline contents were measured after 7 days treatment. The saline-alkaline resistance of different Jerusalem artichoke accessions was evaluated by the fuzzy mathematics method of membership function, principal component analysis (PCA) and clustering analysis (CA). PCA showed that shoot fresh weight, plant dry weight and proline content were the most significant factors, and recommended as the main indexes for identifying saline-alkaline tolerance of Jerusalem artichoke at seedling stage. The degrees of salt-tolerance of 16 Jerusalem artichoke accessions were different. The 16 Jerusalem artichoke accessions were sorted into four groups based on clustering analysis. Jerusalem artichoke accessions of ZH-2 and ZH-3 were strongly tolerant to saline-alkaline stress. Jerusalem artichoke accessions ZH-4, Taiyangdao and Qingyu001 had medium tolerance. Then the remaining 10 Jerusalem artichoke accessions (e.g., ZH-5, ZH-6 and ZH-10) had lower tolerance. Of all 16 Jerusalem artichoke accessions, ZH-9 was the most sensitive to saline-alkaline stress.
Soil salinization and alkalinization frequently co-occur in nature. The interactive effects of salt and alkali stress on plants are more complex and serious, greatly limiting crop production. However, the comprehensive effect of salt and alkali stress on crops remains largely unclear. Screening and cultivating salt-tolerant plants are the most efficient way of exploiting saline-alkaline soils. Jerusalem artichoke (Helianthus tuberosus L.) has long been considered as a highly promising biological energy material with a considerable tolerance to saline-alkaline soils. The objective of this study was to explore the response of 16 Jerusalem artichoke accessions to saline-alkaline stress at seedling stage, and to screen salt-tolerant accessions for cultivation of saline-alkaline lands and provide critical guidance for the management of saline-alkaline soils. To that end, two neutral salts (NaCl and Na2SO4) and two alkali salts (NaHCO3 and Na2CO3) were mixed with mole ratio of 5︰23︰9︰5 to simulate typical saline-alkaline stress. The 16 Jerusalem artichoke accessions were cultivated in plastic pots in a controlled environment chamber. The half-strength Hoagland solution without exogenous saline-alkaline was used as the control. The half-strength Hoagland solution supplemented with 150 mmol·L 1 saline-alkaline mixture was as the treatment. The shoot fresh and dry weight, root fresh and dry weight, SOD activity, and MDA and proline contents were measured after 7 days treatment. The saline-alkaline resistance of different Jerusalem artichoke accessions was evaluated by the fuzzy mathematics method of membership function, principal component analysis (PCA) and clustering analysis (CA). PCA showed that shoot fresh weight, plant dry weight and proline content were the most significant factors, and recommended as the main indexes for identifying saline-alkaline tolerance of Jerusalem artichoke at seedling stage. The degrees of salt-tolerance of 16 Jerusalem artichoke accessions were different. The 16 Jerusalem artichoke accessions were sorted into four groups based on clustering analysis. Jerusalem artichoke accessions of ZH-2 and ZH-3 were strongly tolerant to saline-alkaline stress. Jerusalem artichoke accessions ZH-4, Taiyangdao and Qingyu001 had medium tolerance. Then the remaining 10 Jerusalem artichoke accessions (e.g., ZH-5, ZH-6 and ZH-10) had lower tolerance. Of all 16 Jerusalem artichoke accessions, ZH-9 was the most sensitive to saline-alkaline stress.
2015, 23(5): 628-633.
doi: 10.13930/j.cnki.cjea.141280
Abstract:
NaCl is always considered as a stress factor and as the main cause of salt stress in plants. However, it has been proved that low concentrations of NaCl have no harmful effect on plant growth. In fact, studies have shown that low concentrations of NaCl actually promote plant growth and quality. As a new mode of cultivation, hydroponic culture has been a suitable solution to control Chinese chive diseases caused by Chinese chive maggot. To explore the effect of low concentrations of NaCl on the growth, quality and production of Chinese chive, 0 mmol·L-1 (CK), 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl were respectively added to nutrient solutions in the experiment. The results showed that plant height, pseudo-stem diameter and leaf length were highest under 20 mmol·L-1 NaCl treatment. Leaf number of Chinese chive treated with NaCl increased compared with that of CK. However, leaf width decreased with increasing concentration of NaCl. The contents of photosynthetic pigments increased after treated with low concentrations of NaCl. Chlorophyll a, chlorophyll b, carotenoid and chlorophyll a+b contents were highest under 10 mmol·L-1 NaCl treatment. NaCl treatment decreased nitrate accumulation and nitrate content decreased by 12.42%, 13.17%, 15.16% and 26.76% respectively under 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl treatments compared with that under CK. Vitamin C content increased by 12.2%, 12.8% and 5.1% and 15.4% under 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl, respectively, compared with that of the control. The contents of soluble sugar, crude fibers and yield of Chinese chive were highest under 10 mmol·L-1 NaCl. Yield increased respectively by 6.7%, 6.6%, 6.9% and 6.7% in the first harvest, second harvest, third harvest and 3 combined harvests under 10 mmol·L-1 NaCl over CK. Comprehensive analysis showed that adding 10 mmol·L-1 NaCl to nutrient solution enhanced growth performance, decreased nitrate content, improved quality and increased production of Chinese chives.
NaCl is always considered as a stress factor and as the main cause of salt stress in plants. However, it has been proved that low concentrations of NaCl have no harmful effect on plant growth. In fact, studies have shown that low concentrations of NaCl actually promote plant growth and quality. As a new mode of cultivation, hydroponic culture has been a suitable solution to control Chinese chive diseases caused by Chinese chive maggot. To explore the effect of low concentrations of NaCl on the growth, quality and production of Chinese chive, 0 mmol·L-1 (CK), 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl were respectively added to nutrient solutions in the experiment. The results showed that plant height, pseudo-stem diameter and leaf length were highest under 20 mmol·L-1 NaCl treatment. Leaf number of Chinese chive treated with NaCl increased compared with that of CK. However, leaf width decreased with increasing concentration of NaCl. The contents of photosynthetic pigments increased after treated with low concentrations of NaCl. Chlorophyll a, chlorophyll b, carotenoid and chlorophyll a+b contents were highest under 10 mmol·L-1 NaCl treatment. NaCl treatment decreased nitrate accumulation and nitrate content decreased by 12.42%, 13.17%, 15.16% and 26.76% respectively under 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl treatments compared with that under CK. Vitamin C content increased by 12.2%, 12.8% and 5.1% and 15.4% under 5 mmol·L-1, 10 mmol·L-1, 20 mmol·L-1 and 30 mmol·L-1 NaCl, respectively, compared with that of the control. The contents of soluble sugar, crude fibers and yield of Chinese chive were highest under 10 mmol·L-1 NaCl. Yield increased respectively by 6.7%, 6.6%, 6.9% and 6.7% in the first harvest, second harvest, third harvest and 3 combined harvests under 10 mmol·L-1 NaCl over CK. Comprehensive analysis showed that adding 10 mmol·L-1 NaCl to nutrient solution enhanced growth performance, decreased nitrate content, improved quality and increased production of Chinese chives.
2015, 23(5): 634-641.
doi: 10.13930/j.cnki.cjea.141249
Abstract:
The western flower thrips, Frankliniella occidentalis (Pergande), is one of the pests with most adverse effects on global crop production. F. occidentalis is also a key invasive pest of vegetables, fruits and the wider horticultural and/or ornamental plants in China. It causes direct damage through feeding and ovipositioning, but also significant indirect losses by transmitting plant viruses. Significant plant damage by F. occidentalis has been observed in recent years with the degree of damage differing with plant species. This has made it extremely difficult to fully understand the differences in damage as a lot of factors relating with plants and insect pests. So far, there has been little research on F. occidentalis damages to horticultural host plants. In order to verify the effect of different horticultural host plants on the development of F. occidentalis, the development and survival of F. occidentalis on flowers of five horticultural plants (Rosa chinensis, Dianthus caryophyllus, Lilium brownie, Pelargonium hortorum/ and Pharbitis nil) were studied. The research also studied the relationships of F. occidentalis development with the contents of nutriments (soluble protein and soluble sugar) and secondary compounds (tannin, flavone and phenolic) of flowers of five horticultural plants. The results showed that the shortest time for F. occidentalis to complete one generation was on R. chinensis (11.02 days) and the longest was on P. nil (13.21 days). The survival rates of F. occidentalis at different stages were different on different flowers. In short, the highest generation survival rate was on L. brownie (84%) and the lowest was on P. hortorum (76%). There were also significant differences in the contents of nutriments and secondary compounds among the five host flowers. The highest content of soluble protein was in R. chinensis (12.39 mg·g-1), significantly higher than that in the other host flowers, while the lowest was in P. nil (4.57 mg·g-1). Soluble sugar content decreased in the order of L. brownie (6.83 mg·g-1), D. caryophyllus (6.15 mg·g-1), P. hortorum (4.26 mg·g-1), R. chinensis (3.38 mg·g 1) and P. nil (2.25 mg·g 1). Tannin content increased in the order of R. chinensis, D. caryophyllus, L. brownie, P. hortorum and P. nil. Both flavone and phenolic contents were highest in P. hortorum (respectively 6.01 mg·g 1 and 2.45 mg·g-1) and lowest in R. chinensis (respectively 2.88 mg·g-1 and 0.64 mg·g-1). Correlation analysis showed that while the developmental velocity of F. occidentalis was significantly positively correlated with the content of soluble protein (R = 0.896, P = 0.040), it was negatively correlated with the contents of tannin (R = 0.917, P = 0.01), flavone (R = 0.921, P = 0.014) and phenolic (R = 0.905, P = 0.013) of host flowers. There was no correlation between the rate of development of F. occidentalis and the content of soluble sugar of host flowers (R = 0.40, P = 0.505). Also the rate of survival of F. occidentalis had no significant correlation with any of the chemical compounds tested. It was therefore concluded that some of the chemical compounds of the host flowers had significant effect on the development of F. occidentalis. The higher the content of soluble protein, the more favorable the development of F. occidentalis. However, the higher the contents of tannin, flavone and phenolic, the less favorable the development of F. occidentalis.
The western flower thrips, Frankliniella occidentalis (Pergande), is one of the pests with most adverse effects on global crop production. F. occidentalis is also a key invasive pest of vegetables, fruits and the wider horticultural and/or ornamental plants in China. It causes direct damage through feeding and ovipositioning, but also significant indirect losses by transmitting plant viruses. Significant plant damage by F. occidentalis has been observed in recent years with the degree of damage differing with plant species. This has made it extremely difficult to fully understand the differences in damage as a lot of factors relating with plants and insect pests. So far, there has been little research on F. occidentalis damages to horticultural host plants. In order to verify the effect of different horticultural host plants on the development of F. occidentalis, the development and survival of F. occidentalis on flowers of five horticultural plants (Rosa chinensis, Dianthus caryophyllus, Lilium brownie, Pelargonium hortorum/ and Pharbitis nil) were studied. The research also studied the relationships of F. occidentalis development with the contents of nutriments (soluble protein and soluble sugar) and secondary compounds (tannin, flavone and phenolic) of flowers of five horticultural plants. The results showed that the shortest time for F. occidentalis to complete one generation was on R. chinensis (11.02 days) and the longest was on P. nil (13.21 days). The survival rates of F. occidentalis at different stages were different on different flowers. In short, the highest generation survival rate was on L. brownie (84%) and the lowest was on P. hortorum (76%). There were also significant differences in the contents of nutriments and secondary compounds among the five host flowers. The highest content of soluble protein was in R. chinensis (12.39 mg·g-1), significantly higher than that in the other host flowers, while the lowest was in P. nil (4.57 mg·g-1). Soluble sugar content decreased in the order of L. brownie (6.83 mg·g-1), D. caryophyllus (6.15 mg·g-1), P. hortorum (4.26 mg·g-1), R. chinensis (3.38 mg·g 1) and P. nil (2.25 mg·g 1). Tannin content increased in the order of R. chinensis, D. caryophyllus, L. brownie, P. hortorum and P. nil. Both flavone and phenolic contents were highest in P. hortorum (respectively 6.01 mg·g 1 and 2.45 mg·g-1) and lowest in R. chinensis (respectively 2.88 mg·g-1 and 0.64 mg·g-1). Correlation analysis showed that while the developmental velocity of F. occidentalis was significantly positively correlated with the content of soluble protein (R = 0.896, P = 0.040), it was negatively correlated with the contents of tannin (R = 0.917, P = 0.01), flavone (R = 0.921, P = 0.014) and phenolic (R = 0.905, P = 0.013) of host flowers. There was no correlation between the rate of development of F. occidentalis and the content of soluble sugar of host flowers (R = 0.40, P = 0.505). Also the rate of survival of F. occidentalis had no significant correlation with any of the chemical compounds tested. It was therefore concluded that some of the chemical compounds of the host flowers had significant effect on the development of F. occidentalis. The higher the content of soluble protein, the more favorable the development of F. occidentalis. However, the higher the contents of tannin, flavone and phenolic, the less favorable the development of F. occidentalis.
Quantitative evaluation of soil conservation in 2000 2010 in Heilongjiang Province using RUSLE model
2015, 23(5): 642-649.
doi: 10.13930/j.cnki.cjea.141320
Abstract:
Soil erosion is a major cause of global land degradation. From the 19th century to date, domestic and foreign scholars have carried out extensive researches on the estimation of the amount of soil erosion. This article conducted a simulation analysis of soil conservation quantity of Heilongjiang Province in 2000 2010 using dates of rainfall, soil properties, elevation and other meteorological data. Then the study used the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) to quantify soil conservation in Heilongjiang Province. All the factors of the RUSLE model were precisely determined, including rainfall erosion power (R), soil erosion value (K), terrain factors [including slope length factor (L) and gradient factor (S)] and water/soil conservation measures (P). The study evaluated soil conservation amount and analyzed its distribution and dynamics in Heilongjiang Province for the period 2000 2010. The results showed an increasing trend in the amount of soil conservation in Heilongjiang Province in 2000 2010. Soil conservation quantity in Heilongjiang Province increased on average by 41.95×106 t (a rate of increase of 5.34%) in the 10-year period from 2000 to 2010. The amount of soil maintenance in different areas of Heilongjiang Province increased obviously, except in Mudanjiang and Harbin. In particular, the increase in soil maintenance was highest (over 20%) in Shuangyashan City and Heihe City, lowest (less than 9%) in Suihua City and Yichun City while it increased by less than 10% in Mudanjiang and Harbin. The per unit area soil conservation quantity for various land use types were highest (3 384.36 t·km-2·a-1) for forests and lowest (177.17 t·km-2·a-1) for bare land. Moreover, the amount of soil conservation of forests was 1.32 times, 6.36 times, 7.42 times, 9.80 times, 10.29 times, 19.10 times higher than that of thicket, grassland, wetland, farmland, cities and bare land. Over the past decade, the trend in soil conservation quantity in various land use types increased. In 2000 2010, the quantity of soil conservation in Heilongjiang Province was at the low state. It, however, gradually improved with enhanced transformation of the low-level into high-level of soil conservation quantity. The area of low-level transformed into high-level soil conservation quantity was 1 055.76 km2 and that of high-level transformed into low-level was 37.76 km2. To ensure stable and sustainable development of the ecosystem in Heilongjiang Province, it was needed to increase the amount of transformation of low-level into high-level of soil conservation quantity in Songnen Plain and Sanjiang Plain in Heilongjiang Province. There was also the need to enforce agricultural protection, continuous regional integration in Heilongjiang Province, and to promote vigorous forest growth and control land use. Future efforts should also limit intensified urban ecosystems destruction, ensure comprehensive, coordinated and sustainable development and reduce soil erosion issues in the region.
Soil erosion is a major cause of global land degradation. From the 19th century to date, domestic and foreign scholars have carried out extensive researches on the estimation of the amount of soil erosion. This article conducted a simulation analysis of soil conservation quantity of Heilongjiang Province in 2000 2010 using dates of rainfall, soil properties, elevation and other meteorological data. Then the study used the Revised Universal Soil Loss Equation (RUSLE) model and Geographic Information System (GIS) to quantify soil conservation in Heilongjiang Province. All the factors of the RUSLE model were precisely determined, including rainfall erosion power (R), soil erosion value (K), terrain factors [including slope length factor (L) and gradient factor (S)] and water/soil conservation measures (P). The study evaluated soil conservation amount and analyzed its distribution and dynamics in Heilongjiang Province for the period 2000 2010. The results showed an increasing trend in the amount of soil conservation in Heilongjiang Province in 2000 2010. Soil conservation quantity in Heilongjiang Province increased on average by 41.95×106 t (a rate of increase of 5.34%) in the 10-year period from 2000 to 2010. The amount of soil maintenance in different areas of Heilongjiang Province increased obviously, except in Mudanjiang and Harbin. In particular, the increase in soil maintenance was highest (over 20%) in Shuangyashan City and Heihe City, lowest (less than 9%) in Suihua City and Yichun City while it increased by less than 10% in Mudanjiang and Harbin. The per unit area soil conservation quantity for various land use types were highest (3 384.36 t·km-2·a-1) for forests and lowest (177.17 t·km-2·a-1) for bare land. Moreover, the amount of soil conservation of forests was 1.32 times, 6.36 times, 7.42 times, 9.80 times, 10.29 times, 19.10 times higher than that of thicket, grassland, wetland, farmland, cities and bare land. Over the past decade, the trend in soil conservation quantity in various land use types increased. In 2000 2010, the quantity of soil conservation in Heilongjiang Province was at the low state. It, however, gradually improved with enhanced transformation of the low-level into high-level of soil conservation quantity. The area of low-level transformed into high-level soil conservation quantity was 1 055.76 km2 and that of high-level transformed into low-level was 37.76 km2. To ensure stable and sustainable development of the ecosystem in Heilongjiang Province, it was needed to increase the amount of transformation of low-level into high-level of soil conservation quantity in Songnen Plain and Sanjiang Plain in Heilongjiang Province. There was also the need to enforce agricultural protection, continuous regional integration in Heilongjiang Province, and to promote vigorous forest growth and control land use. Future efforts should also limit intensified urban ecosystems destruction, ensure comprehensive, coordinated and sustainable development and reduce soil erosion issues in the region.
2015, 23(5): 650-658.
doi: 10.13930/j.cnki.cjea.141312
Abstract:
Water footprint, proposed by professor Hoekstra, is a new indicator of water consumption, which includes both direct and indirect water use. Water footprint of crop production is the volume of water consumed in producing per kilogram of crop. It not only reflects water use efficiency, but also the real water occupation in the process of agricultural production. This paper calculated both green and blue water footprints of crop production. For crop production, green water footprint reflects how much green water is consumed by producing per kilogram of crop, and blue water footprint is water consumed from sources such as surface water or groundwater. Quantification of crop water footprint will contribute to our knowledge of determining water utilization conditions in agricultural production and provide theoretical basis for improving water use efficiency by optimizing cropping patterns in relation to local water resources endowment. Using Shaanxi Province as the study area, this paper calculated water footprint of crop production (WFP) using a modified method that took into account water evaporation loss during transmission and distribution processes of water in crop fields. The paper then used the (blue) water stress indexes βt (βb) to determine the relationship between water resources and total/blue water footprints. Finally, the temporal and spatial distributions of WFP,βt and βb in Shaanxi Province were analyzed. The results showed large differences in WFP among crops and crop production areas, with a general declining trend in WFP. Water footprint of integrated crop production (IWFP) in Shaanxi Province dropped from 1.132 m3·kg-1 to 0.931 m3·kg-1 from 2000 to 2012. While Xi'an City had the lowest average IWFP (0.849 m3·kg-1), Yulin City had the highest one (1.730 m3·kg-1). The average annual total crop water footprint (WF) of Shaanxi Province was 127.39×108 m3, with green water footprint (GWF) proportion of 50.22%. With similar spatial distribution characteristics of water footprint of crop production, crop water footprint varied significantly from 3.47×108 m3 in Tongchuan City to 24.19×108 m3 in Weinan City. The multi-year averages of βt and βb in Shaanxi Province were 0.255 and 0.187, respectively. Also βt and βb values for Weinan City and Xianyang City were 0.610 and 1.200, respectively. Weinan City and Xianyang City had the most severe water scarcity in Shaanxi Province. Apart from the southern area of Shaanxi Province, water unsustainable development challenges were noted in each of the districts in Shaanxi Province.
Water footprint, proposed by professor Hoekstra, is a new indicator of water consumption, which includes both direct and indirect water use. Water footprint of crop production is the volume of water consumed in producing per kilogram of crop. It not only reflects water use efficiency, but also the real water occupation in the process of agricultural production. This paper calculated both green and blue water footprints of crop production. For crop production, green water footprint reflects how much green water is consumed by producing per kilogram of crop, and blue water footprint is water consumed from sources such as surface water or groundwater. Quantification of crop water footprint will contribute to our knowledge of determining water utilization conditions in agricultural production and provide theoretical basis for improving water use efficiency by optimizing cropping patterns in relation to local water resources endowment. Using Shaanxi Province as the study area, this paper calculated water footprint of crop production (WFP) using a modified method that took into account water evaporation loss during transmission and distribution processes of water in crop fields. The paper then used the (blue) water stress indexes βt (βb) to determine the relationship between water resources and total/blue water footprints. Finally, the temporal and spatial distributions of WFP,βt and βb in Shaanxi Province were analyzed. The results showed large differences in WFP among crops and crop production areas, with a general declining trend in WFP. Water footprint of integrated crop production (IWFP) in Shaanxi Province dropped from 1.132 m3·kg-1 to 0.931 m3·kg-1 from 2000 to 2012. While Xi'an City had the lowest average IWFP (0.849 m3·kg-1), Yulin City had the highest one (1.730 m3·kg-1). The average annual total crop water footprint (WF) of Shaanxi Province was 127.39×108 m3, with green water footprint (GWF) proportion of 50.22%. With similar spatial distribution characteristics of water footprint of crop production, crop water footprint varied significantly from 3.47×108 m3 in Tongchuan City to 24.19×108 m3 in Weinan City. The multi-year averages of βt and βb in Shaanxi Province were 0.255 and 0.187, respectively. Also βt and βb values for Weinan City and Xianyang City were 0.610 and 1.200, respectively. Weinan City and Xianyang City had the most severe water scarcity in Shaanxi Province. Apart from the southern area of Shaanxi Province, water unsustainable development challenges were noted in each of the districts in Shaanxi Province.
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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