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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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2016 Vol. 24, No. 6
Display Method:
2016, 24(6): 695-703.
Abstract:
Phthalic acid esters (PAEs) are classified as environmental hormone organic compounds, commonly contained in plastic, resin and rubber, accounting for 20%60%, as plasticizers with potentially hazardous impacts on the environment and human health. In soils, the main anthropogenic sources of PAEs are agricultural chemicals, sewage water irrigation and atmospheric precipitation. PAEs can abundantly accumulate in the soil and be transported to different environmental systems via a series of environmental, geochemical processes such as volatilization, leaching, adsorption, biodegradation, plant uptake and food chain. This article combined the results of domestic and international studies to summarize the state of soil PAEs pollution in China. Anthropogenic activities and land use changes were the main factors responsible for seasonal and spatial distributions of PAEs. The contents of PAEs in soils in most regions of China reached dozens milligram per kilogram, which obviously exceeded the standards for the US and the European countries. Di-n-butyl phthalate (DnBP) and di (2-ethylhexyl) phthalate (DEHP) were the dominant PAEs in soils, similar to those observed in other countries. Also the environmental behavior of PAEs in soil-gas interface (volatilization and atmospheric precipitation), soil-plant system (phytoremediation and plant uptake) and soil-water interface (sediment adsorption and desorption) were analyzed to determine the causes of soil PAEs transfer between air, water, sediments and plants. There were significant differences in the characteristics of PAEs absorption, accumulation, distribution and transformation among the different interfaces. Because of the widespread application of PAEs and its occurrence in most common daily chemicals, humans are exposed to PAEs through foods contaminated during crop growth in soil or during packaging. Humans are also at risk through exposure to air (for breathing or absorption by skin), causing severely ecological and health risks in many regions of China. It was recommended that future soil PAEs research should focus on regional soil pollution and environmental behavior, PAEs transmission and evolution regularity in space and time, medium migration mechanisms, risk reduction and remediation measure research. There was need to use knowledge about the environmental fate and health risks of PAEs in soils to improve the regulation of organic pollution transformation in soils. This knowledge was also necessary for providing theoretical basis for the protection of ecological environments and soil health.
Phthalic acid esters (PAEs) are classified as environmental hormone organic compounds, commonly contained in plastic, resin and rubber, accounting for 20%60%, as plasticizers with potentially hazardous impacts on the environment and human health. In soils, the main anthropogenic sources of PAEs are agricultural chemicals, sewage water irrigation and atmospheric precipitation. PAEs can abundantly accumulate in the soil and be transported to different environmental systems via a series of environmental, geochemical processes such as volatilization, leaching, adsorption, biodegradation, plant uptake and food chain. This article combined the results of domestic and international studies to summarize the state of soil PAEs pollution in China. Anthropogenic activities and land use changes were the main factors responsible for seasonal and spatial distributions of PAEs. The contents of PAEs in soils in most regions of China reached dozens milligram per kilogram, which obviously exceeded the standards for the US and the European countries. Di-n-butyl phthalate (DnBP) and di (2-ethylhexyl) phthalate (DEHP) were the dominant PAEs in soils, similar to those observed in other countries. Also the environmental behavior of PAEs in soil-gas interface (volatilization and atmospheric precipitation), soil-plant system (phytoremediation and plant uptake) and soil-water interface (sediment adsorption and desorption) were analyzed to determine the causes of soil PAEs transfer between air, water, sediments and plants. There were significant differences in the characteristics of PAEs absorption, accumulation, distribution and transformation among the different interfaces. Because of the widespread application of PAEs and its occurrence in most common daily chemicals, humans are exposed to PAEs through foods contaminated during crop growth in soil or during packaging. Humans are also at risk through exposure to air (for breathing or absorption by skin), causing severely ecological and health risks in many regions of China. It was recommended that future soil PAEs research should focus on regional soil pollution and environmental behavior, PAEs transmission and evolution regularity in space and time, medium migration mechanisms, risk reduction and remediation measure research. There was need to use knowledge about the environmental fate and health risks of PAEs in soils to improve the regulation of organic pollution transformation in soils. This knowledge was also necessary for providing theoretical basis for the protection of ecological environments and soil health.
2016, 24(6): 704-715.
Abstract:
Studies on the emissions of greenhouse gases and global warming potential (GWP) under different tillage systems have benefited scientific research on the effects of agricultural management on mitigating greenhouse gas emission and reducing global warming. Such studies have also laid the theoretical basis for establishing measures to reduce global greenhouse gas emissions. Long term tillage and straw return to soil experiments were set up in 2001 at the Luancheng Agro-ecosystem Experimental Station (LAES) of Chinese Academy of Sciences. The experiments included 5 treatments — no-tillage with whole maize residue mulching (M1), no-tillage with chopped maize residue mulching (M2), rotary tillage with chopped maize residue incorporation (X), mouldboard ploughing with chopped maize residue incorporation (F) and mouldboard ploughing with maize residue remove (CK, representing conventional tillage method). The experiment monitored N2O, CO2 and CH4 fluxes in wheat-maize rotation fields using the static chamber method / gas chromatography technique for the period from October 2008 to September 2010. Total greenhouse gas emissions and GWP were also estimated. Meanwhile, during the experimental period, the amount of fuel consumed by farm machines and power consumed during irrigation and fertilizer application were recorded and transformed to carbon equivalent using a transformation coefficient. In the study, crop yield and aboveground biomasses were measured and carbon sequestration calculated. The total GWP under the 5 tillage treatments were estimated based on the identified parameters of greenhouse effect. The results indicated that wheat-maize rotation fields served as the source of N2O and CO2, and also the sink of CH4. In M1, M2, X, F and CK treatments, total N2O emissions from soil were 2.06 kg(N2O-N)?hm2?a1, 2.28 kg(N2O-N).hm-2.a-1, 2.54 kg(N2O-N).hm-2.a-1, 3.87 kg(N2O-N).hm-2.a-1 and 2.29 kg(N2O-N).hm-2.a-1; total CO2 emissions from soil of 6 904 kg(CO2-C).hm-2.a-1, 7 351 kg(CO2-C).hm-2.a-1, 8 873 kg(CO2-C).hm-2.a-1, 9 065 kg(CO2-C).hm-2.a-1 and 7 425 kg(CO2-C).hm-2.a-1; and total CH4 sink of 2.50 kg(CH4-C).hm-2.a-1, 1.77 kg(CH4-C).hm-2.a-1, 1.33 kg(CH4-C).hm-2.a-1, 1.38 kg(CH4-C).hm-2.a-1 and 1.57 kg(CH4-C).hm-2.a-1, respectively. GWPs in M1 and M2 treatments were negative, which indicated that farmland ecosystems under no-tillage with straw served as carbon sink, with annual carbon retention of 947–1 070 kg(C).hm-2 after subtracting directly or indirectly carbon equivalent emitted from the system. GWPs for other treatments were positive, with GWPs for CK, F and X of 3 364 kg(C).hm-2, 989 kg(C).hm-2 and 343 kg(C).hm-2, respectively. This suggested that for wheat-maize rotation system in the North China, chopped crop residue incorporation with rotary tillage was optimal tillage practice with relatively lower greenhouse effects and higher grain yield.
Studies on the emissions of greenhouse gases and global warming potential (GWP) under different tillage systems have benefited scientific research on the effects of agricultural management on mitigating greenhouse gas emission and reducing global warming. Such studies have also laid the theoretical basis for establishing measures to reduce global greenhouse gas emissions. Long term tillage and straw return to soil experiments were set up in 2001 at the Luancheng Agro-ecosystem Experimental Station (LAES) of Chinese Academy of Sciences. The experiments included 5 treatments — no-tillage with whole maize residue mulching (M1), no-tillage with chopped maize residue mulching (M2), rotary tillage with chopped maize residue incorporation (X), mouldboard ploughing with chopped maize residue incorporation (F) and mouldboard ploughing with maize residue remove (CK, representing conventional tillage method). The experiment monitored N2O, CO2 and CH4 fluxes in wheat-maize rotation fields using the static chamber method / gas chromatography technique for the period from October 2008 to September 2010. Total greenhouse gas emissions and GWP were also estimated. Meanwhile, during the experimental period, the amount of fuel consumed by farm machines and power consumed during irrigation and fertilizer application were recorded and transformed to carbon equivalent using a transformation coefficient. In the study, crop yield and aboveground biomasses were measured and carbon sequestration calculated. The total GWP under the 5 tillage treatments were estimated based on the identified parameters of greenhouse effect. The results indicated that wheat-maize rotation fields served as the source of N2O and CO2, and also the sink of CH4. In M1, M2, X, F and CK treatments, total N2O emissions from soil were 2.06 kg(N2O-N)?hm2?a1, 2.28 kg(N2O-N).hm-2.a-1, 2.54 kg(N2O-N).hm-2.a-1, 3.87 kg(N2O-N).hm-2.a-1 and 2.29 kg(N2O-N).hm-2.a-1; total CO2 emissions from soil of 6 904 kg(CO2-C).hm-2.a-1, 7 351 kg(CO2-C).hm-2.a-1, 8 873 kg(CO2-C).hm-2.a-1, 9 065 kg(CO2-C).hm-2.a-1 and 7 425 kg(CO2-C).hm-2.a-1; and total CH4 sink of 2.50 kg(CH4-C).hm-2.a-1, 1.77 kg(CH4-C).hm-2.a-1, 1.33 kg(CH4-C).hm-2.a-1, 1.38 kg(CH4-C).hm-2.a-1 and 1.57 kg(CH4-C).hm-2.a-1, respectively. GWPs in M1 and M2 treatments were negative, which indicated that farmland ecosystems under no-tillage with straw served as carbon sink, with annual carbon retention of 947–1 070 kg(C).hm-2 after subtracting directly or indirectly carbon equivalent emitted from the system. GWPs for other treatments were positive, with GWPs for CK, F and X of 3 364 kg(C).hm-2, 989 kg(C).hm-2 and 343 kg(C).hm-2, respectively. This suggested that for wheat-maize rotation system in the North China, chopped crop residue incorporation with rotary tillage was optimal tillage practice with relatively lower greenhouse effects and higher grain yield.
2016, 24(6): 716-724.
Abstract:
In conventional crop production, high yield has always meant high carbon emissions. It has therefore become urgent to develop theoretical and practical strategies for high yield with low carbon emissions in modern agriculture. In this study, a field experiment was conducted in a typical oasis irrigation region to determine the integrated response of carbon emission in wheat-maize intercropping systems under different straw-return (straw standing, straw mulching and no-mulching), plastic film mulching (mulching for one year and two years), cropping (wheat-maize intercropping, monoculture of wheat and maize) and tillage (no-tillage, conventional tillage) patterns. The results showed that intercropping significantly decreased soil carbon emissions in farmlands. Compared with monoculture wheat and maize under conventional tillage management, the averaged total soil CO2 emissions in wheat-maize intercropping systems reduced by a range of 279–876 kg·hm-2, the equivalent of 5.1%–16.0%. No tillage with straw-return and plastic film mulching for 2-year reduced soil carbon emissions in the next year. No-tillage in combination with straw-return to soil decreased total soil CO2 emissions by 648–966 kg·hm-2, the equivalent of 21.3%31.8%, than conventional tillage without straw-return to soil in mono-cropped wheat field. Plastic film mulching for two years reduced total soil CO2 emissions by 632 kg·hm-2 compared with that of conventional tillage in mono-cropped maize. In particular, wheat-maize intercropping in combination with straw-return to soil and 2-year plastic film mulching further reduced the carbon emissions. Compared with conventional intercropping with plastic film mulching for 1-year and conventional tillage (CTI1), wheat-maize intercropping with 25–30 cm of standing straw, 2-year plastic film mulching and no-tillage (NTSSI2) and wheat-maize intercropping with 25–30 cm straw mulching on the soil and 2-year plastic film mulching and no-tillage (NTSI2) reduced total soil CO2 emissions by 471 kg·hm-2 and 518 kg·hm-2, the equivalent of 9.2% and 10.1%, respectively. The carbon sequestration potential (ratio of total plant carbon fixation to total soil carbon emission, i.e., NPPC/Ras) were 13.7 and 14.0, respectively, in NTSSI2 and NTSI2 treatments, they were higher by 19.1% and 21.5% than that of CTI1, respectively. This indicated that NTSI2 had a more prominent potential for reducing carbon emissions and enhancing carbon sequestration. Thus, NTSI2 was recommended as the best farming pattern due to its high-efficiency of carbon emission reduction and carbon sequestration in irrigated arid oasis regions.
In conventional crop production, high yield has always meant high carbon emissions. It has therefore become urgent to develop theoretical and practical strategies for high yield with low carbon emissions in modern agriculture. In this study, a field experiment was conducted in a typical oasis irrigation region to determine the integrated response of carbon emission in wheat-maize intercropping systems under different straw-return (straw standing, straw mulching and no-mulching), plastic film mulching (mulching for one year and two years), cropping (wheat-maize intercropping, monoculture of wheat and maize) and tillage (no-tillage, conventional tillage) patterns. The results showed that intercropping significantly decreased soil carbon emissions in farmlands. Compared with monoculture wheat and maize under conventional tillage management, the averaged total soil CO2 emissions in wheat-maize intercropping systems reduced by a range of 279–876 kg·hm-2, the equivalent of 5.1%–16.0%. No tillage with straw-return and plastic film mulching for 2-year reduced soil carbon emissions in the next year. No-tillage in combination with straw-return to soil decreased total soil CO2 emissions by 648–966 kg·hm-2, the equivalent of 21.3%31.8%, than conventional tillage without straw-return to soil in mono-cropped wheat field. Plastic film mulching for two years reduced total soil CO2 emissions by 632 kg·hm-2 compared with that of conventional tillage in mono-cropped maize. In particular, wheat-maize intercropping in combination with straw-return to soil and 2-year plastic film mulching further reduced the carbon emissions. Compared with conventional intercropping with plastic film mulching for 1-year and conventional tillage (CTI1), wheat-maize intercropping with 25–30 cm of standing straw, 2-year plastic film mulching and no-tillage (NTSSI2) and wheat-maize intercropping with 25–30 cm straw mulching on the soil and 2-year plastic film mulching and no-tillage (NTSI2) reduced total soil CO2 emissions by 471 kg·hm-2 and 518 kg·hm-2, the equivalent of 9.2% and 10.1%, respectively. The carbon sequestration potential (ratio of total plant carbon fixation to total soil carbon emission, i.e., NPPC/Ras) were 13.7 and 14.0, respectively, in NTSSI2 and NTSI2 treatments, they were higher by 19.1% and 21.5% than that of CTI1, respectively. This indicated that NTSI2 had a more prominent potential for reducing carbon emissions and enhancing carbon sequestration. Thus, NTSI2 was recommended as the best farming pattern due to its high-efficiency of carbon emission reduction and carbon sequestration in irrigated arid oasis regions.
2016, 24(6): 725-735.
Abstract:
In order to explore the benefits of combined application of silicon and phosphate on maize production, a field plot experiment was conducted from 2014 to 2015. The effects of different rates of phosphate and silicon fertilizers application on leaf area index, net photosynthetic rate and transpiration rate at jointing and silking stages, dry matter accumulation in different organs at jointing, silking, grain-filling and maturity stages, and grain yield and yield components of spring maize were investigated using maize varieties ‘ZH2’ and ‘ZH115’ in low phosphorus soils. Compared with control plot (P0Si0), net photosynthetic rate and leaf area index at jointing and silking stages increased significantly under application of phosphorus, silicon fertilizers and the combined application of both fertilizers. Also dry matter accumulation at jointing, silking, grain-filling and maturity stages, dry grain weight ratio at grain-filling and maturity stages, and grains per ear, spike length, 1000-kernel weight and gain yield increased under the above three fertilization treatments. However, dry weight ratio of leaf at filling and maturity stage, dry weight ratio of stem and sheath at grain-filling stage and bare top length decreased. Specifically for phosphorus fertilization treatment, the increases or reductions in the above mentioned parameters were more obvious than those for silicon fertilization treatment. The largest changes were found in the combined application of phosphorus and silicon fertilizers. There was a significantly synergic effect on the investigated parameters between phosphorus fertilizer and silicon fertilizer. Furthermore, grain yield of corn was positively related with dry matter accumulation at jointing stage, silking stage, grain-filling stage and maturity stage in 2014–2015. Compared with phosphorus fertilizer treatment, grain yield increased by 1 288.57 kg·hm-2 (in 2014) and 1 313.61 kg·hm-2 (in 2015) under combined phosphorus and silicon fertilization treatment. This indicated that there was a sustainable increase in yield due to the combined application of phosphorus and silicon fertilizers. In summary, dry matter accumulation and photosynthesis improved during the early growth stage, dry matter distribution rate in each plant part was optimized during the later growth stage, and maize yield eventually increased by the combined application of phosphorus and silicon fertilizers in low available phosphorus soils in the hilly uplands of Sichuan Basin.
In order to explore the benefits of combined application of silicon and phosphate on maize production, a field plot experiment was conducted from 2014 to 2015. The effects of different rates of phosphate and silicon fertilizers application on leaf area index, net photosynthetic rate and transpiration rate at jointing and silking stages, dry matter accumulation in different organs at jointing, silking, grain-filling and maturity stages, and grain yield and yield components of spring maize were investigated using maize varieties ‘ZH2’ and ‘ZH115’ in low phosphorus soils. Compared with control plot (P0Si0), net photosynthetic rate and leaf area index at jointing and silking stages increased significantly under application of phosphorus, silicon fertilizers and the combined application of both fertilizers. Also dry matter accumulation at jointing, silking, grain-filling and maturity stages, dry grain weight ratio at grain-filling and maturity stages, and grains per ear, spike length, 1000-kernel weight and gain yield increased under the above three fertilization treatments. However, dry weight ratio of leaf at filling and maturity stage, dry weight ratio of stem and sheath at grain-filling stage and bare top length decreased. Specifically for phosphorus fertilization treatment, the increases or reductions in the above mentioned parameters were more obvious than those for silicon fertilization treatment. The largest changes were found in the combined application of phosphorus and silicon fertilizers. There was a significantly synergic effect on the investigated parameters between phosphorus fertilizer and silicon fertilizer. Furthermore, grain yield of corn was positively related with dry matter accumulation at jointing stage, silking stage, grain-filling stage and maturity stage in 2014–2015. Compared with phosphorus fertilizer treatment, grain yield increased by 1 288.57 kg·hm-2 (in 2014) and 1 313.61 kg·hm-2 (in 2015) under combined phosphorus and silicon fertilization treatment. This indicated that there was a sustainable increase in yield due to the combined application of phosphorus and silicon fertilizers. In summary, dry matter accumulation and photosynthesis improved during the early growth stage, dry matter distribution rate in each plant part was optimized during the later growth stage, and maize yield eventually increased by the combined application of phosphorus and silicon fertilizers in low available phosphorus soils in the hilly uplands of Sichuan Basin.
2016, 24(6): 736-743.
Abstract:
Biochar application was considered as an effective way of carbon sequestration of soil. It has been known to improve both soil water and nutrient holding capacity. As a key indicator of soil fertility, microorganism plays an important role in soil ecosystem. It was necessary to understand the influence of biochar application on microbial community and functional diversity in calcareous cinnamon soils for rational utilization of biochar in cinnamon soils. A pot experiment with five biochar application levels [0 g.kg-1 (as control), 5 g.kg-1, 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1] was conducted to investigate the response of soil microbial activity and diversity, using Biolog analysis and high-throughput sequestration (HiSeq). The results showed that the average rate of color change (AWCD) decreased with increasing biochar application level, and the AWCD values were in the order of 5 g.kg-1 control > 10 g.kg-1 > 30 g.kg-1 > 60 g.kg-1 treatments. There was no significant difference between control and 5 g.kg-1 treatments in terms of AWCD. The soil microbial community diversity index (H′) and richness index (S) also decreased, but evenness index (E) increased with increasing biochar application level. Compared with the control, biochar application rates at 5 g.kg-1, 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 increased H′ by 0.16%, 0.88%, 3.14% and 11.09%; increased S by 2.82%, 11.27%, 18.31% and 47.89%; and increased E by 1.14%, 3.00%, 3.73% and 13.76%; respectively. Principal component analysis showed that carbon substrate utilization of soil microbial community was significantly affected by 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 biochar application. HiSeq analysis showed that soil bacterial OTU enhanced significantly by 1.09%, 5.26% and 24.42%, respectively, in 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 biochar treatments, meanwhile, the richness index (Chao1) was increased by 5.73%, 10.21% and 37.68%, respectively, compared with that of control. Biochar enhanced the abundance of bacteria and decreased the evenness of soil bacterial distribution. Proteobacteria abundance was significantly increased by 32.3%, 21.1% and 16.7%, respectively, under 10 g.kg-1, 30g.kg-1, 60 g.kg-1 biochar treatment, while Bacteroidetes abundance decreased obviously by 22.1%, 55.3%, 66.8% and 50.5%, respectively, compared with those of control. The results indicated that the rational dosage of biochar application was not more than 5g.kg-1 (soil dry) in calcareous cinnamon soil to maintain the microbial community structure and activity.
Biochar application was considered as an effective way of carbon sequestration of soil. It has been known to improve both soil water and nutrient holding capacity. As a key indicator of soil fertility, microorganism plays an important role in soil ecosystem. It was necessary to understand the influence of biochar application on microbial community and functional diversity in calcareous cinnamon soils for rational utilization of biochar in cinnamon soils. A pot experiment with five biochar application levels [0 g.kg-1 (as control), 5 g.kg-1, 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1] was conducted to investigate the response of soil microbial activity and diversity, using Biolog analysis and high-throughput sequestration (HiSeq). The results showed that the average rate of color change (AWCD) decreased with increasing biochar application level, and the AWCD values were in the order of 5 g.kg-1 control > 10 g.kg-1 > 30 g.kg-1 > 60 g.kg-1 treatments. There was no significant difference between control and 5 g.kg-1 treatments in terms of AWCD. The soil microbial community diversity index (H′) and richness index (S) also decreased, but evenness index (E) increased with increasing biochar application level. Compared with the control, biochar application rates at 5 g.kg-1, 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 increased H′ by 0.16%, 0.88%, 3.14% and 11.09%; increased S by 2.82%, 11.27%, 18.31% and 47.89%; and increased E by 1.14%, 3.00%, 3.73% and 13.76%; respectively. Principal component analysis showed that carbon substrate utilization of soil microbial community was significantly affected by 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 biochar application. HiSeq analysis showed that soil bacterial OTU enhanced significantly by 1.09%, 5.26% and 24.42%, respectively, in 10 g.kg-1, 30 g.kg-1 and 60 g.kg-1 biochar treatments, meanwhile, the richness index (Chao1) was increased by 5.73%, 10.21% and 37.68%, respectively, compared with that of control. Biochar enhanced the abundance of bacteria and decreased the evenness of soil bacterial distribution. Proteobacteria abundance was significantly increased by 32.3%, 21.1% and 16.7%, respectively, under 10 g.kg-1, 30g.kg-1, 60 g.kg-1 biochar treatment, while Bacteroidetes abundance decreased obviously by 22.1%, 55.3%, 66.8% and 50.5%, respectively, compared with those of control. The results indicated that the rational dosage of biochar application was not more than 5g.kg-1 (soil dry) in calcareous cinnamon soil to maintain the microbial community structure and activity.
2016, 24(6): 744-752.
Abstract:
In order to optimize farming practice, plastic film recycling and water use efficiency of intercropping farming systems, a field experiment was conducted on maize-pea intercropping field at Hexi Corridor in Gansu Province. The experiment investigated the effect of three mulching patterns (NT: single plastic mulching for 2 years; CT: no tillage in fall with mulching and tillage in the next spring; CT: traditional mulching and tillage) on crop total water consumption and soil evaporation under high (7 200 m3.hm-2), intermediate (6 450 m3.hm-2) and low (5 700 m3.hm-2) irrigation levels. The results showed that the level of water supply had a significant effect on the soil evaporation. The soil evaporation increased with increasing irrigation level, but there was no significant difference among different mulching patterns under the same irrigation level. There was a significant difference in soil evaporation between maize strip and pea strip during harvest period of pea in all the treatments. Soil evaporation in pea strip was 68.51% and 69.30% higher than in maize strip before and after pea harvest, respectively. In addition, pea strip was an important factor driving water consumption in the intercropping farming system. The maize strip, which occupied some 60% of the farmland, only accounted for 44.47% of soil evaporation. Then the pea strip, which occupied some 40% of the farmland accounted for 55.53% of the total soil evaporation. Moreover, the evaporation in maize-pea intercropping field was mainly occurred after pea harvest, as only 26.98% of the soil evaporation occurred before pea harvest. NT treatment significantly increased the benefits of cubic meter water. The mean of water benefit per cubic meter under different irrigation levels were 7.39% and 31.33% higher for NT than for RT and CT, respectively. In addition, the highest water benefit per cubic meter reached 2.51 Yuan.m-3, which was observed under NT plus medium irrigation. In conclusion, NT reduced soil evaporation and non-productive water loss common under traditional mulching. Soil evaporation and total water consumption were positive correlated with irrigation level, with the highest water benefit per cubic meter under NT at moderate irrigation.
In order to optimize farming practice, plastic film recycling and water use efficiency of intercropping farming systems, a field experiment was conducted on maize-pea intercropping field at Hexi Corridor in Gansu Province. The experiment investigated the effect of three mulching patterns (NT: single plastic mulching for 2 years; CT: no tillage in fall with mulching and tillage in the next spring; CT: traditional mulching and tillage) on crop total water consumption and soil evaporation under high (7 200 m3.hm-2), intermediate (6 450 m3.hm-2) and low (5 700 m3.hm-2) irrigation levels. The results showed that the level of water supply had a significant effect on the soil evaporation. The soil evaporation increased with increasing irrigation level, but there was no significant difference among different mulching patterns under the same irrigation level. There was a significant difference in soil evaporation between maize strip and pea strip during harvest period of pea in all the treatments. Soil evaporation in pea strip was 68.51% and 69.30% higher than in maize strip before and after pea harvest, respectively. In addition, pea strip was an important factor driving water consumption in the intercropping farming system. The maize strip, which occupied some 60% of the farmland, only accounted for 44.47% of soil evaporation. Then the pea strip, which occupied some 40% of the farmland accounted for 55.53% of the total soil evaporation. Moreover, the evaporation in maize-pea intercropping field was mainly occurred after pea harvest, as only 26.98% of the soil evaporation occurred before pea harvest. NT treatment significantly increased the benefits of cubic meter water. The mean of water benefit per cubic meter under different irrigation levels were 7.39% and 31.33% higher for NT than for RT and CT, respectively. In addition, the highest water benefit per cubic meter reached 2.51 Yuan.m-3, which was observed under NT plus medium irrigation. In conclusion, NT reduced soil evaporation and non-productive water loss common under traditional mulching. Soil evaporation and total water consumption were positive correlated with irrigation level, with the highest water benefit per cubic meter under NT at moderate irrigation.
ZHANG Wen,
XIE Hui,
ZHANG Ping,
ZHONG Haixia,
ZHANG Fuchun,
ZHUANG Hongmei,
YANG Lei,
XU Yeting,
GONG Peng,
LU Chunsheng
2016, 24(6): 753-761.
Abstract:
Intercropping of fruit trees and cereals is one of the major cropping patterns in South Xinjiang. As trees age and canopy volumes increase in intercropping systems, low-light stress due to tree canopy effect becomes the main drive behind dramatic reduction in yield. However, given the fragile ecological environment of South Xinjiang and food security, this system has continued for a long time now. In this study, the relationship between canopy structure and light condition in intercropping systems was determined in order to provide theoretical basis for choosing canopy structures suitable for optimal production. Almond tree (10 a) and winter wheat intercropping system was used to study the effects of 4 canopy structures (delayed open-central shape, open-center shape, high-stem shape and semicircle small-canopy shape) on radiation intensity of various wavebands, spectral composition and diurnal variations of photosynthetically active radiation (PAR) during wheat filling stage, with monoculture winter wheat as the control. The results showed that: 1) In terms of quality of light condition in intercropping systems, the order from high to low was semicircle small-canopy shape, high-stem shape, open-center shape and delayed open-central shape. The averages of radiation intensity under the 4 canopy shapes were respectively 55.63%, 46.54%, 37.87% and 28.76% of the control. Correspondingly, PAR intensities were 55.84%, 44.57%, 35.52% and 26.40% of the control. 2) Compared with the control, radiation intensity of each waveband decreased at various degrees. Reductions in PAR, blue-violet, yellow-green and red-orange light radiations were larger than average reduction in total radiation. However, reductions in ultraviolet, near infrared and far infrared light radiation were smaller than average reduction in total radiation. For example, in the eastern region under delayed open-central shape canopy, total radiation decreased to 11.37% of the control. Then blue-violet light, yellow-green light, red-orange light and PAR decreased respectively to 7.98%, 8.42%, 8.62% and 8.30% while ultraviolet light, near infrared light, far infrared light decreased to 12.30%, 15.94% and 23.00% of the control. 3) For all the light quality parameters, the ratio of red-orange light to far infrared light was most sensitive to canopy structure (CV = 23.34%). It can be used as a major indicator for light conditions in intercropping systems. 4) Canopy structure characteristics (e.g., canopy width, stem height, tree height and whether center stem) existed or had little effect on diurnal variation in PAR in intercropping systems, especially for regions east of the tree. Based on the above analysis, light conditions in intercropping systems can be improved by tree pruning such as canopy limitation, trunk height increase and head cut. Among the four canopy structures, semicircle small-canopy shape produced the best light conditions.
Intercropping of fruit trees and cereals is one of the major cropping patterns in South Xinjiang. As trees age and canopy volumes increase in intercropping systems, low-light stress due to tree canopy effect becomes the main drive behind dramatic reduction in yield. However, given the fragile ecological environment of South Xinjiang and food security, this system has continued for a long time now. In this study, the relationship between canopy structure and light condition in intercropping systems was determined in order to provide theoretical basis for choosing canopy structures suitable for optimal production. Almond tree (10 a) and winter wheat intercropping system was used to study the effects of 4 canopy structures (delayed open-central shape, open-center shape, high-stem shape and semicircle small-canopy shape) on radiation intensity of various wavebands, spectral composition and diurnal variations of photosynthetically active radiation (PAR) during wheat filling stage, with monoculture winter wheat as the control. The results showed that: 1) In terms of quality of light condition in intercropping systems, the order from high to low was semicircle small-canopy shape, high-stem shape, open-center shape and delayed open-central shape. The averages of radiation intensity under the 4 canopy shapes were respectively 55.63%, 46.54%, 37.87% and 28.76% of the control. Correspondingly, PAR intensities were 55.84%, 44.57%, 35.52% and 26.40% of the control. 2) Compared with the control, radiation intensity of each waveband decreased at various degrees. Reductions in PAR, blue-violet, yellow-green and red-orange light radiations were larger than average reduction in total radiation. However, reductions in ultraviolet, near infrared and far infrared light radiation were smaller than average reduction in total radiation. For example, in the eastern region under delayed open-central shape canopy, total radiation decreased to 11.37% of the control. Then blue-violet light, yellow-green light, red-orange light and PAR decreased respectively to 7.98%, 8.42%, 8.62% and 8.30% while ultraviolet light, near infrared light, far infrared light decreased to 12.30%, 15.94% and 23.00% of the control. 3) For all the light quality parameters, the ratio of red-orange light to far infrared light was most sensitive to canopy structure (CV = 23.34%). It can be used as a major indicator for light conditions in intercropping systems. 4) Canopy structure characteristics (e.g., canopy width, stem height, tree height and whether center stem) existed or had little effect on diurnal variation in PAR in intercropping systems, especially for regions east of the tree. Based on the above analysis, light conditions in intercropping systems can be improved by tree pruning such as canopy limitation, trunk height increase and head cut. Among the four canopy structures, semicircle small-canopy shape produced the best light conditions.
2016, 24(6): 762-769.
Abstract:
Global atmospheric CO2 concentration has increased from around 280 μmol·mol-1 in pre-industrial times to the present 400 μmol·mol-1, and will continue to increase in the future if the emission scenario remains unchanged. As CO2 is an essential substrate for plant photosynthesis, then, the rising CO2 has a significant effect on rice production. The late growth stage of rice, from flowering to maturity, is the critical period of yield formation. The source-sink relationship during this reproductive stage plays a crucial role in rice yield formation. Although a lot of research work has been done on regulating the source-sink on rice yield, there are few reports on rice yield response to high CO2 concentration under regulated sink-source balance. In order to understand how the effect of elevated CO2 concentration (ambient+200 μmol·mol-1) on rice yield was influenced by source-sink relationship, we conducted a field experiment in 2014 using a hybrid rice ‘Y Liangyou 2’ and Free Air CO2 Enrichment (FACE) facility at Yangzhou (119°42′0″E, 32°35′5″N), China. Rice plants were grown under two levels of CO2 concentration (ambient and elevated) from tillering until maturity. Source-sink manipulation was achieved through cutting off the whole flag leaf (LC1), the top three leaves (LC3) or half of the spikelets at heading (SR, spikelets remove, remove every other primary branch of panicle). Grain yield and its components were investigated. The results showed that under CK conditions (plant intact with no leaf or spikelet cutting), elevated CO2 concentration increased average rice grain yield by 12% (P < 0.01). This was mainly attributed to slight increase in spikelet number per panicle and grain filling ability. On average, CO2 elevation increased grain yield by 26% (P < 0.05) and 57% (P < 0.01) for LC1 and LC3 crops, respectively. This response was mainly attributed to the drastic increase in percent grain-filling (LC1: 14%, P < 0.1; LC3: 47%, P = 0.16) and average grain weight (LC1: 11%, P < 0.05; LC3: 24%, P < 0.05). Under SR crops, yield response to elevated CO2 concentration (+15%, P = 0.01) was similar to that of CK crops. Compared with CK, grain yield under LC1 and LC3 treatments decreased, respectively by 17% (P < 0.01) and 52% (P < 0.01) at heading stage. This decline was mainly due to the decrease in percent grain-filling and average grain weight. Although grain-filling capacity was enhanced by SR treatment, grain yield declined significantly (29%) due to the halved total spikelet number. The response of grain yield to elevated CO2 concentration was positively correlated with that of percent grain-filling and average grain weight. The results indicated that source-sink manipulation (especially leaf removal) could change the response of grain yield to the elevated CO2 concentration by affecting rice grain-filling capability at heading stage.
Global atmospheric CO2 concentration has increased from around 280 μmol·mol-1 in pre-industrial times to the present 400 μmol·mol-1, and will continue to increase in the future if the emission scenario remains unchanged. As CO2 is an essential substrate for plant photosynthesis, then, the rising CO2 has a significant effect on rice production. The late growth stage of rice, from flowering to maturity, is the critical period of yield formation. The source-sink relationship during this reproductive stage plays a crucial role in rice yield formation. Although a lot of research work has been done on regulating the source-sink on rice yield, there are few reports on rice yield response to high CO2 concentration under regulated sink-source balance. In order to understand how the effect of elevated CO2 concentration (ambient+200 μmol·mol-1) on rice yield was influenced by source-sink relationship, we conducted a field experiment in 2014 using a hybrid rice ‘Y Liangyou 2’ and Free Air CO2 Enrichment (FACE) facility at Yangzhou (119°42′0″E, 32°35′5″N), China. Rice plants were grown under two levels of CO2 concentration (ambient and elevated) from tillering until maturity. Source-sink manipulation was achieved through cutting off the whole flag leaf (LC1), the top three leaves (LC3) or half of the spikelets at heading (SR, spikelets remove, remove every other primary branch of panicle). Grain yield and its components were investigated. The results showed that under CK conditions (plant intact with no leaf or spikelet cutting), elevated CO2 concentration increased average rice grain yield by 12% (P < 0.01). This was mainly attributed to slight increase in spikelet number per panicle and grain filling ability. On average, CO2 elevation increased grain yield by 26% (P < 0.05) and 57% (P < 0.01) for LC1 and LC3 crops, respectively. This response was mainly attributed to the drastic increase in percent grain-filling (LC1: 14%, P < 0.1; LC3: 47%, P = 0.16) and average grain weight (LC1: 11%, P < 0.05; LC3: 24%, P < 0.05). Under SR crops, yield response to elevated CO2 concentration (+15%, P = 0.01) was similar to that of CK crops. Compared with CK, grain yield under LC1 and LC3 treatments decreased, respectively by 17% (P < 0.01) and 52% (P < 0.01) at heading stage. This decline was mainly due to the decrease in percent grain-filling and average grain weight. Although grain-filling capacity was enhanced by SR treatment, grain yield declined significantly (29%) due to the halved total spikelet number. The response of grain yield to elevated CO2 concentration was positively correlated with that of percent grain-filling and average grain weight. The results indicated that source-sink manipulation (especially leaf removal) could change the response of grain yield to the elevated CO2 concentration by affecting rice grain-filling capability at heading stage.
2016, 24(6): 770-779.
Abstract:
UV-B radiation has a profound effect on plant morphogenesis, inevitably affecting potato cultivation, especially with enhanced UV-B radiation on the earth’s surface. Compared with rice, wheat, corn and other crops, the total effect of UV-B radiation on potato is still not conclusive, especially the morphological response of potato to UV-B radiation. In this study, the effect of enhanced UV-B radiation on plant height, internode length, leaf area, root to shoot ratio (R/T) and other morphological indices of 7 potato varieties (lines) were analyzed and compared. The determination of the inter-variety variations in response was critical for the evaluation of the effect of UV-B radiation on potato. It was also important for providing further understanding on the tolerance and sensitivity of different varieties of potato to enhanced UV-B radiation. An outdoor pot culture experiment was conducted to evaluate the sensitivity of 7 potato varieties (lines), 3 colored-tuber and 4 achromatic-tuber, to a range of UV-B radiation levels. Three biologically effective UV-B radiation treatments — 0 (control), 2.5 kJm-2d-1 (T1) and 5.0 kJm-2d-1 (T2) — were imposed on the potato varieties for 50 d when seedlings were over 20 cm high. Aboveground morphological indices were measured after 15 d, 30 d and 45 d of treatment, respectively. Response index (RI) and cumulative stress response index (CSRI) were eventually used to evaluate the sensitivity of the different varieties (lines) of potato to the UV-B radiations. The results showed that plant height, internode and leaf area of most of the treated varieties (lines) decreased consistently under enhanced UV-B radiation. The inhibitory effect of UV-B radiation on potato was more obvious under higher UV-B dose with longer duration. While a significant variability of morphological response was observed, the degree of sensitivity to UV-B radiation also varied among the potato varieties. Compared with colored-tuber varieties (lines), achromatic-tuber varieties (lines) were inhibited more severe under elevated UV-B radiation, with more evident reduction in aboveground biomass. For example, the shoot fresh weight response index of ‘Hezuo 88’ was 60.28 and 70.44 (negative), respectively, while that of colored-tuber ‘Zhuanxinwu’ was 107.75 and 21.4 (positive) under T1 and T2, respectively. Due to the negative effect of enhanced UV-B radiation on aboveground biomass, root biomass also dropped significantly for most of the potato varieties (lines). Compared with belowground root and tuber, the inhibition of aboveground biomass increased with increasing exposure to enhanced UV-B radiation. Thus, R/T of all the potato varieties (lines) obviously increased, especially at high UV-B radiation (T2). Based on the calculated CSRI, achromatic-tube varieties (lines) (‘Hezuo 88’ and ‘Lishu 6’) were sensitive to UV-B radiation, while colored-tube varieties (‘Zhuanxinwu’ and ‘21-1’) more tolerant to UV-B radiation. The results suggested that the biomass of both shoot and root and tuber color were important indicators in selecting or developing UV-B radiation tolerant potato varieties.
UV-B radiation has a profound effect on plant morphogenesis, inevitably affecting potato cultivation, especially with enhanced UV-B radiation on the earth’s surface. Compared with rice, wheat, corn and other crops, the total effect of UV-B radiation on potato is still not conclusive, especially the morphological response of potato to UV-B radiation. In this study, the effect of enhanced UV-B radiation on plant height, internode length, leaf area, root to shoot ratio (R/T) and other morphological indices of 7 potato varieties (lines) were analyzed and compared. The determination of the inter-variety variations in response was critical for the evaluation of the effect of UV-B radiation on potato. It was also important for providing further understanding on the tolerance and sensitivity of different varieties of potato to enhanced UV-B radiation. An outdoor pot culture experiment was conducted to evaluate the sensitivity of 7 potato varieties (lines), 3 colored-tuber and 4 achromatic-tuber, to a range of UV-B radiation levels. Three biologically effective UV-B radiation treatments — 0 (control), 2.5 kJm-2d-1 (T1) and 5.0 kJm-2d-1 (T2) — were imposed on the potato varieties for 50 d when seedlings were over 20 cm high. Aboveground morphological indices were measured after 15 d, 30 d and 45 d of treatment, respectively. Response index (RI) and cumulative stress response index (CSRI) were eventually used to evaluate the sensitivity of the different varieties (lines) of potato to the UV-B radiations. The results showed that plant height, internode and leaf area of most of the treated varieties (lines) decreased consistently under enhanced UV-B radiation. The inhibitory effect of UV-B radiation on potato was more obvious under higher UV-B dose with longer duration. While a significant variability of morphological response was observed, the degree of sensitivity to UV-B radiation also varied among the potato varieties. Compared with colored-tuber varieties (lines), achromatic-tuber varieties (lines) were inhibited more severe under elevated UV-B radiation, with more evident reduction in aboveground biomass. For example, the shoot fresh weight response index of ‘Hezuo 88’ was 60.28 and 70.44 (negative), respectively, while that of colored-tuber ‘Zhuanxinwu’ was 107.75 and 21.4 (positive) under T1 and T2, respectively. Due to the negative effect of enhanced UV-B radiation on aboveground biomass, root biomass also dropped significantly for most of the potato varieties (lines). Compared with belowground root and tuber, the inhibition of aboveground biomass increased with increasing exposure to enhanced UV-B radiation. Thus, R/T of all the potato varieties (lines) obviously increased, especially at high UV-B radiation (T2). Based on the calculated CSRI, achromatic-tube varieties (lines) (‘Hezuo 88’ and ‘Lishu 6’) were sensitive to UV-B radiation, while colored-tube varieties (‘Zhuanxinwu’ and ‘21-1’) more tolerant to UV-B radiation. The results suggested that the biomass of both shoot and root and tuber color were important indicators in selecting or developing UV-B radiation tolerant potato varieties.
2016, 24(6): 780-789.
Abstract:
Nitrogen is the most critical input limiting rice productivity. Due to increasing fertilizer costs and environmental concerns, nitrogen use efficiency (NUE) is hotly debated in the scientific community. To explore the absorption, utilization and main traits distribution patter of nitrogen in recombinant inbred lines (RILs), a field experiment was conducted to evaluate potential NUE of rice (Oryza sativa L.). The split-plot experiment had two treatments (one without nitrogen fertilizer and the other with 150 kg.hm-2 of nitrogen) for populations of RILs, the parents and the check line Q149. The relationship between NUE and the main agronomic characteristics of RILs population was determined using statistical correlation, clustering, principal component analyses. The results showed that the variation coefficient of NUE was larger under 150 kg.hm-2 nitrogen treatment than under non-nitrogen treatment. Proper increase in nitrogen fertilization was beneficial to nitrogen content in rice panicle, stem and leaf, and to total dry matter weight of single plant. Significantly positive correlations were noted between dry matter production efficiency and plant high, panicle length, stem weight per plant, total dry matter weight of single plant under two nitrogen treatments. Also under both treatments, significantly negative correlations were noted between dry matter production efficiency and the contents of nitrogen in rice stem, leaf and panicle. There were positive correlations between grain production efficiency and grain weight per plant, seed setting rate, thousand-seed weight, total number of grains per panicle, and spike length. Equally, there were negative correlations between grain production efficiency and stem weight per plant, leaf nitrogen content, leaf weight per plant and total amount of nitrogen per plant. Stepwise regression analysis indicated that nitrogen content in stem and panicle, and stem weight per plant had significant effects on dry matter NUE. However, the effects of number of panicles per plant, number of grains per panicle and seed setting rate on grain NUE were more significant in the two treatments. Principal component analysis showed that the nitrogen content in rice plant, especially in stem, decreased with increasing of NUE. Therefore, in low-nitrogen field, it was necessary to select heavy-panicle type variety that was high in stem weight (including long panicle length, more grains per panicle and high seed-setting rate) in breeding programs. Furthermore, lower nitrogen content in stem and panicle (especially in stem) benefited the breeding for high NUE. Based on the study, 7 rice lines with high NUE (e.g., Q149) and 6 lines with low NUE (e.g., Q114) were selected for special germplasm in rice breeding projects.
Nitrogen is the most critical input limiting rice productivity. Due to increasing fertilizer costs and environmental concerns, nitrogen use efficiency (NUE) is hotly debated in the scientific community. To explore the absorption, utilization and main traits distribution patter of nitrogen in recombinant inbred lines (RILs), a field experiment was conducted to evaluate potential NUE of rice (Oryza sativa L.). The split-plot experiment had two treatments (one without nitrogen fertilizer and the other with 150 kg.hm-2 of nitrogen) for populations of RILs, the parents and the check line Q149. The relationship between NUE and the main agronomic characteristics of RILs population was determined using statistical correlation, clustering, principal component analyses. The results showed that the variation coefficient of NUE was larger under 150 kg.hm-2 nitrogen treatment than under non-nitrogen treatment. Proper increase in nitrogen fertilization was beneficial to nitrogen content in rice panicle, stem and leaf, and to total dry matter weight of single plant. Significantly positive correlations were noted between dry matter production efficiency and plant high, panicle length, stem weight per plant, total dry matter weight of single plant under two nitrogen treatments. Also under both treatments, significantly negative correlations were noted between dry matter production efficiency and the contents of nitrogen in rice stem, leaf and panicle. There were positive correlations between grain production efficiency and grain weight per plant, seed setting rate, thousand-seed weight, total number of grains per panicle, and spike length. Equally, there were negative correlations between grain production efficiency and stem weight per plant, leaf nitrogen content, leaf weight per plant and total amount of nitrogen per plant. Stepwise regression analysis indicated that nitrogen content in stem and panicle, and stem weight per plant had significant effects on dry matter NUE. However, the effects of number of panicles per plant, number of grains per panicle and seed setting rate on grain NUE were more significant in the two treatments. Principal component analysis showed that the nitrogen content in rice plant, especially in stem, decreased with increasing of NUE. Therefore, in low-nitrogen field, it was necessary to select heavy-panicle type variety that was high in stem weight (including long panicle length, more grains per panicle and high seed-setting rate) in breeding programs. Furthermore, lower nitrogen content in stem and panicle (especially in stem) benefited the breeding for high NUE. Based on the study, 7 rice lines with high NUE (e.g., Q149) and 6 lines with low NUE (e.g., Q114) were selected for special germplasm in rice breeding projects.
2016, 24(6): 790-800.
Abstract:
Knowledge on yield stability of sugarcane varieties and representativeness of test sites during national regional trials of sugarcane varieties is critical for rationally regional distribution and guiding sugarcane breeding. Additive main effects and multiplicative interaction (AMMI) and heritability adjusted GGE (HA-GGE) biplot models are the two widely used statistical methods in analyzing data on crop variety trials. Using experimental data from regional trials, the interactions between crop genotype and environment can be analyzed to determine yield potential of tested varieties and representativeness of pilots. In order to assess the representativeness and discrimination ability of 13 test locations of sugarcane variety trail, the AMMI model was used in combination with HA-GGE bipliot to analyze cane and sugar yields of 11 sugarcane varieties planted at 10 national regional trial sites of sugarcane varieties in China. The results showed that cane and sugar yields were significantly different for different varieties and test sites. There was significant interaction effect between variety and test site. The ‘FN40’ sugarcane variety had the best performance, with high yield, good productivity and high stability of cane yield and sugar yield. The yield of ‘YZ08-2060’ sugarcane variety was slightly lower than that of ‘FN40’, while the stability of its cane and sugar yields was slightly higher than that of ‘FN40’. Compared with ‘ROC22’ variety, ‘YG43’, ‘YG46’ and ‘MT02-205’ had higher cane and sugar yields, but had lower stability. ‘FN40’, ‘YG43’, ‘YG46’ and ‘YZ08-2060’ had stronger adaptability, and were recommended for cultivation at suitable planting sites. The result further indicated that three test locations, Suixi of Guangdong Province, Kaiyuan of Yunnan Province and Fuzhou of Fujian Province, had higher discrimination and better representativeness based on comprehensive analysis of AMMI and HA-GGE biplot models. Here, two sugarcane varieties (‘FN40’ and ‘YZ08-2060’), both with high yield and good stability, were recommended for commercial production in all sugarcane planting areas in China. In conclusion, the combined used of AMMI and GGE biplot model provided more accurate assessment for the productivity, stability and adaptability of sugarcane varieties. It was also very reliable in terms of demonstration of discrimination and representativeness of test sites. This study provided valuable reference base for the identification and promotion of new sugarcane varieties.
Knowledge on yield stability of sugarcane varieties and representativeness of test sites during national regional trials of sugarcane varieties is critical for rationally regional distribution and guiding sugarcane breeding. Additive main effects and multiplicative interaction (AMMI) and heritability adjusted GGE (HA-GGE) biplot models are the two widely used statistical methods in analyzing data on crop variety trials. Using experimental data from regional trials, the interactions between crop genotype and environment can be analyzed to determine yield potential of tested varieties and representativeness of pilots. In order to assess the representativeness and discrimination ability of 13 test locations of sugarcane variety trail, the AMMI model was used in combination with HA-GGE bipliot to analyze cane and sugar yields of 11 sugarcane varieties planted at 10 national regional trial sites of sugarcane varieties in China. The results showed that cane and sugar yields were significantly different for different varieties and test sites. There was significant interaction effect between variety and test site. The ‘FN40’ sugarcane variety had the best performance, with high yield, good productivity and high stability of cane yield and sugar yield. The yield of ‘YZ08-2060’ sugarcane variety was slightly lower than that of ‘FN40’, while the stability of its cane and sugar yields was slightly higher than that of ‘FN40’. Compared with ‘ROC22’ variety, ‘YG43’, ‘YG46’ and ‘MT02-205’ had higher cane and sugar yields, but had lower stability. ‘FN40’, ‘YG43’, ‘YG46’ and ‘YZ08-2060’ had stronger adaptability, and were recommended for cultivation at suitable planting sites. The result further indicated that three test locations, Suixi of Guangdong Province, Kaiyuan of Yunnan Province and Fuzhou of Fujian Province, had higher discrimination and better representativeness based on comprehensive analysis of AMMI and HA-GGE biplot models. Here, two sugarcane varieties (‘FN40’ and ‘YZ08-2060’), both with high yield and good stability, were recommended for commercial production in all sugarcane planting areas in China. In conclusion, the combined used of AMMI and GGE biplot model provided more accurate assessment for the productivity, stability and adaptability of sugarcane varieties. It was also very reliable in terms of demonstration of discrimination and representativeness of test sites. This study provided valuable reference base for the identification and promotion of new sugarcane varieties.
2016, 24(6): 801-810.
Abstract:
In order to explore the effects of habitat change driven by land use change on functional groups of ant, ant co- mmunities in secondary natural forests, eucalyptus plantations, lac insect plantations, rubber plantations, lac insect-corn agroforests, drylands and farmlands were investigated by pitfall traps and Winkler in Lüchun County, Yunnan Province. A total of 37 891 individual ants were collected, belonging to 137 species, 52 genera and 8 sub-families of Formicidae. The 52 ant genera were divided into 7 functional groups based on competitive interactions, habitat requirements, behavioral dominance, and response to environment stress and disturbance. They were Dominant Dolichoderinae, Subordinate Camponotini, Generalised Myrmicinae, Opportunities, Cryptic Species, Climate Specialists and Specialist Predators. Species richness of different functional groups was in the order of Opportunists (10 genera 32 species) > Climate Specialists (15 genera 29 species) > Generalized Myrmicinae (3 genera 24 species) > Cryptic Species (14 genera 21 species) > Subordinate Camponotini (2 genera 16 species) > Specialist Predators (6 genera 14 species) > Dominant Dolichoderinae (2 genera 2 species). Subordinate Camponotini, Climate Specialists and Cryptic Species had higher abundance in secondary natural forests, eucalyptus plantations and lac insect plantations. Dominant Dolichoderinae had higher abundance in farmlands with high disturbances. Dominant Dolichoderinae had only 2 genera 2 species while most other functional groups had higher species richness in secondary natural forests, eucalyptus plantations, lac insect plantations and lac insect-corn agroforests. There was less difference in species richness of specialist predators among different habitats. Community structures of ant functional groups in eucalyptus plantations and lac insect plantations had high similarities with those in secondary natural forests. The community structures of ant functional groups in rubber plantations and lac insect-corn agroforests had high similarities with those in drylands. Changes in species composition of Climate Specialists, Generalized Myrmicinae, Opportunitists and Subordinate Camponotini among different habitats were larger than those in the other samples. The changes in ant communities of Generalized Myrmicinae, Opportunitists and Subordinate Camponotini were significant in different habitats. This showed that ant communities in eucalyptus plantations, lac insect plantations and secondary natural forests were in high dissimilation with those in drylands and farmlands. Ant communities of Cryptic Species and Climate Specialists in eucalyptus plantations had high similarities with those in lac insect plantations. There were no significant changes in Specialist Predator ant communities among the different habitats. Ant functional groups were good indicators for habitat change, especially Generalized Myrmicinae, Subordinate Camponotini and Opportunitists were better indicators than the other ant functional groups. The most essential attribute was ant abundance, while community compositions within each functional group had different responses to disturbances and changes in available resources with land use change.
In order to explore the effects of habitat change driven by land use change on functional groups of ant, ant co- mmunities in secondary natural forests, eucalyptus plantations, lac insect plantations, rubber plantations, lac insect-corn agroforests, drylands and farmlands were investigated by pitfall traps and Winkler in Lüchun County, Yunnan Province. A total of 37 891 individual ants were collected, belonging to 137 species, 52 genera and 8 sub-families of Formicidae. The 52 ant genera were divided into 7 functional groups based on competitive interactions, habitat requirements, behavioral dominance, and response to environment stress and disturbance. They were Dominant Dolichoderinae, Subordinate Camponotini, Generalised Myrmicinae, Opportunities, Cryptic Species, Climate Specialists and Specialist Predators. Species richness of different functional groups was in the order of Opportunists (10 genera 32 species) > Climate Specialists (15 genera 29 species) > Generalized Myrmicinae (3 genera 24 species) > Cryptic Species (14 genera 21 species) > Subordinate Camponotini (2 genera 16 species) > Specialist Predators (6 genera 14 species) > Dominant Dolichoderinae (2 genera 2 species). Subordinate Camponotini, Climate Specialists and Cryptic Species had higher abundance in secondary natural forests, eucalyptus plantations and lac insect plantations. Dominant Dolichoderinae had higher abundance in farmlands with high disturbances. Dominant Dolichoderinae had only 2 genera 2 species while most other functional groups had higher species richness in secondary natural forests, eucalyptus plantations, lac insect plantations and lac insect-corn agroforests. There was less difference in species richness of specialist predators among different habitats. Community structures of ant functional groups in eucalyptus plantations and lac insect plantations had high similarities with those in secondary natural forests. The community structures of ant functional groups in rubber plantations and lac insect-corn agroforests had high similarities with those in drylands. Changes in species composition of Climate Specialists, Generalized Myrmicinae, Opportunitists and Subordinate Camponotini among different habitats were larger than those in the other samples. The changes in ant communities of Generalized Myrmicinae, Opportunitists and Subordinate Camponotini were significant in different habitats. This showed that ant communities in eucalyptus plantations, lac insect plantations and secondary natural forests were in high dissimilation with those in drylands and farmlands. Ant communities of Cryptic Species and Climate Specialists in eucalyptus plantations had high similarities with those in lac insect plantations. There were no significant changes in Specialist Predator ant communities among the different habitats. Ant functional groups were good indicators for habitat change, especially Generalized Myrmicinae, Subordinate Camponotini and Opportunitists were better indicators than the other ant functional groups. The most essential attribute was ant abundance, while community compositions within each functional group had different responses to disturbances and changes in available resources with land use change.
2016, 24(6): 811-818.
Abstract:
Correct calculations of livestock pollutants discharges are required for determination of the impact of livestock on water environment. The existing estimation methods of livestock pollutants discharges are insufficient and confusing in terms of definition of discharge coefficients, and therefore induce mistakes in breeding cycle calculations and livestock elimination rate. Aiming to meet these problems, the paper established calibration methods for calculating production coefficient and discharge coefficient of pollutants, and breeding cycle of livestock, based on livestock breeding data and pollution control methods of Chongqing City of China. And the producing and discharging amounts of livestock in Chongqing City were estimated with the methods. According to ecological function of five functional areas of Chongqing City and discharge characteristics of chemical oxygen demand (CODCr), total nitrogen (TN) and total phosphorus (TP), the equiscalar pollution loading ratio and comprehensive pollution index were used to investigate regional distribution of livestock manure and water environment response and to identify the main pollutants and polluted areas in Chongqing. The results provided the needed decision support for industrial development and environmental protection. Results showed that the breeding cycles of pig, dairy cattle, beef cattle, laying hens and broilers were 122, 365, 365, 52 and 365 days, respectively. The corresponding discharge coefficients for CODCr were 0.049, 0.626, 0.170, 0.002 and 0.001 kg·head-1·d-1, respectively. Also the corresponding discharge coefficients for TN were 0.013, 0.081, 0.048, 0.001 and 0 kg·head-1·d-1, respectively. Then the corresponding discharge coefficients for TP were 0.012, 0.024, 0.030, 0.001 and 0.003 kg·head-1·d-1, respectively. A total of 411.81×104 equivalent pig heads were raised in 2013 in Chongqing City, and 2.27×106 tons manure, 1.66×106 tons urine and were discharged containing respectively 3.03×104 t, 0.72×104 t and 1.87×104 tons of CODCr, TN and TP. Based on pollution evaluation, the main contaminated areas were urban development area and northeast ecological conservation development area, with TP as the main pollutant. The synthetic index of water potential quality range was 0.22–4.12. The results also showed that the development of livestock breeding was significantly correlated with function regionalization. Water pollution was not the main environmental problem in urban core function area, which was the center of politics, economy and culture defined some sections as “forbidden region for raising livestock”. Urban development area was the main polluted region, where implement industrial planting was promoted in order to solve the contradictions between economic progress and environmental protection. The northeast ecological conservation development area was another main polluted region, where the ecological red lines were needed to build to restrict project implementation and protect the Three Gorges Reservoir.
Correct calculations of livestock pollutants discharges are required for determination of the impact of livestock on water environment. The existing estimation methods of livestock pollutants discharges are insufficient and confusing in terms of definition of discharge coefficients, and therefore induce mistakes in breeding cycle calculations and livestock elimination rate. Aiming to meet these problems, the paper established calibration methods for calculating production coefficient and discharge coefficient of pollutants, and breeding cycle of livestock, based on livestock breeding data and pollution control methods of Chongqing City of China. And the producing and discharging amounts of livestock in Chongqing City were estimated with the methods. According to ecological function of five functional areas of Chongqing City and discharge characteristics of chemical oxygen demand (CODCr), total nitrogen (TN) and total phosphorus (TP), the equiscalar pollution loading ratio and comprehensive pollution index were used to investigate regional distribution of livestock manure and water environment response and to identify the main pollutants and polluted areas in Chongqing. The results provided the needed decision support for industrial development and environmental protection. Results showed that the breeding cycles of pig, dairy cattle, beef cattle, laying hens and broilers were 122, 365, 365, 52 and 365 days, respectively. The corresponding discharge coefficients for CODCr were 0.049, 0.626, 0.170, 0.002 and 0.001 kg·head-1·d-1, respectively. Also the corresponding discharge coefficients for TN were 0.013, 0.081, 0.048, 0.001 and 0 kg·head-1·d-1, respectively. Then the corresponding discharge coefficients for TP were 0.012, 0.024, 0.030, 0.001 and 0.003 kg·head-1·d-1, respectively. A total of 411.81×104 equivalent pig heads were raised in 2013 in Chongqing City, and 2.27×106 tons manure, 1.66×106 tons urine and were discharged containing respectively 3.03×104 t, 0.72×104 t and 1.87×104 tons of CODCr, TN and TP. Based on pollution evaluation, the main contaminated areas were urban development area and northeast ecological conservation development area, with TP as the main pollutant. The synthetic index of water potential quality range was 0.22–4.12. The results also showed that the development of livestock breeding was significantly correlated with function regionalization. Water pollution was not the main environmental problem in urban core function area, which was the center of politics, economy and culture defined some sections as “forbidden region for raising livestock”. Urban development area was the main polluted region, where implement industrial planting was promoted in order to solve the contradictions between economic progress and environmental protection. The northeast ecological conservation development area was another main polluted region, where the ecological red lines were needed to build to restrict project implementation and protect the Three Gorges Reservoir.
2016, 24(6): 819-828.
Abstract:
Xinjiang region has relatively abundant unused land resources that can be rationally developed and used. This is beneficial to ease the increasingly worsening conflict between people and land and ensure regional food security to a certain extent. This paper chose Fukang City in Northern Tianshan Mountain Economic Belt as the research area and used twelve factors to build up an evaluation index system for Fukang City. The twelve factors included soil salinity, soil depth, soil texture, organic matter content, landform, forest cover rate, irrigation rate, soil erosion module, cumulative temperature ≥10 ℃, distance from stream, runoff volume of watershed and annual precipitation. The ecological niche model was used to evaluate the suitability of unused lands converted into arable lands in the study area. The results showed that unused lands (including highly suitable and basically suitable) most suitable for conversion into arable lands accounted for 22.21% of total unused lands in the region. Such lands located in the lower part of piedmont alluvial fans and in relatively flat terrains. Reluctantly suitable unused lands only accounted for 16.36% of total unused lands and were mainly located at the edge of the northern desert and in the upper parts of southern piedmont alluvial fans. Unused lands unsuitable for development accounted for 61.43% and mainly distributed in the southern slopes, the edge of piedmont alluvial fans and the fringe zone close to the northern desert. On the basis of the evaluation results, the paper chose potential index, potential increase in arable land, unused land area in town and sub-town, unused arable land development area, unused arable land proportion, average patch area and patch fragmentation index to build a development potential matrix of unused lands in the study area. Cluster analysis was also used to regionalize unused lands. Based on the research, the study area was divided into five potential zones. Grade I potential zone covered an area of 21 000.97 hm-2 with potential additional arable land area of 15 222.92 hm-2. Grade II potential zone was 12 875.69 hm-2 with potential additional arable land of 10 155.41 hm-2. Grade III potential zone was 5 008.84 hm-2 with potential additional arable land of 4 165.35 hm-2. Also grade IV potential zone was 878.67 hm-2 with potential additional arable land of 753.78 hm-2. Then grade V potential zone of unused lands was unsuitable for exploitation. The regionalization of the unused lands provided the theoretical basis for the development and utilization of unused lands in Fukang City both in time and space scales. It also had some practical significance in terms of future pattern of differential development and utilization of unused lands.
Xinjiang region has relatively abundant unused land resources that can be rationally developed and used. This is beneficial to ease the increasingly worsening conflict between people and land and ensure regional food security to a certain extent. This paper chose Fukang City in Northern Tianshan Mountain Economic Belt as the research area and used twelve factors to build up an evaluation index system for Fukang City. The twelve factors included soil salinity, soil depth, soil texture, organic matter content, landform, forest cover rate, irrigation rate, soil erosion module, cumulative temperature ≥10 ℃, distance from stream, runoff volume of watershed and annual precipitation. The ecological niche model was used to evaluate the suitability of unused lands converted into arable lands in the study area. The results showed that unused lands (including highly suitable and basically suitable) most suitable for conversion into arable lands accounted for 22.21% of total unused lands in the region. Such lands located in the lower part of piedmont alluvial fans and in relatively flat terrains. Reluctantly suitable unused lands only accounted for 16.36% of total unused lands and were mainly located at the edge of the northern desert and in the upper parts of southern piedmont alluvial fans. Unused lands unsuitable for development accounted for 61.43% and mainly distributed in the southern slopes, the edge of piedmont alluvial fans and the fringe zone close to the northern desert. On the basis of the evaluation results, the paper chose potential index, potential increase in arable land, unused land area in town and sub-town, unused arable land development area, unused arable land proportion, average patch area and patch fragmentation index to build a development potential matrix of unused lands in the study area. Cluster analysis was also used to regionalize unused lands. Based on the research, the study area was divided into five potential zones. Grade I potential zone covered an area of 21 000.97 hm-2 with potential additional arable land area of 15 222.92 hm-2. Grade II potential zone was 12 875.69 hm-2 with potential additional arable land of 10 155.41 hm-2. Grade III potential zone was 5 008.84 hm-2 with potential additional arable land of 4 165.35 hm-2. Also grade IV potential zone was 878.67 hm-2 with potential additional arable land of 753.78 hm-2. Then grade V potential zone of unused lands was unsuitable for exploitation. The regionalization of the unused lands provided the theoretical basis for the development and utilization of unused lands in Fukang City both in time and space scales. It also had some practical significance in terms of future pattern of differential development and utilization of unused lands.
2016, 24(6): 829-836.
Abstract:
Well water is the main source of drinking water in subtropical agricultural regions in China, and its quality is critical for human health. In this paper, we carried out a geostatistical analysis to investigate the seasonal changes and spatial variability in the concentrations of ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), total nitrogen (TN) and total phosphorus (TP) in domestic well water in a typical agricultural catchment in southern China. Our results showed that the average concentrations of NH4+-N, NO3--N, TN and TP in spring, summer, autumn and winter of 2013–2014 were in the ranges of 0.050.10 mg(N)·L-1, 3.04.9 mg(N)·L-1, 3.45.1 mg(N)·L-1 and 0.030.17 mg(P)·L-1, respectively. The observed concentrations of NH4+-N, NO3--N, TN and TP exceeded the national standards in terms of frequency by 2.3%, 10.4%, 9.5% and 7.9%, respectively. Temporally, NO3--N, TN and TP were significantly (P < 0.05) higher in summer and lower in spring, mainly resulting from paddy rice fertilization and precipitation. On the contrary, there was no significant difference in seasonal concentrations for NH4+-N, mainly due to soil retention. In terms of spatial variability, these four variables were strongly auto-correlated in space and with different spatial ranges for different seasons. In terms of spatial distribution, the high NH4+-N, NO3--N, TN and TP concentrations were distributed as patches, even though their locations, sizes and shapes varied from one another. The concentrations of NO3--N and TN were high in the southeast and southwest of the catchment, where rice was cultivated in the low topography. But the concentrations of NO3--N and TN were low in the north, where there was forest plantation on the high topography. This result suggested that the spatial distribution of NO3--N and TN in well water were related to topography and land use type in the catchment. The spatial coefficients of variation of NH4+-N and TP were higher than those of NO3--N and TN. This was mainly attributed to the strong adsorption and immobilization of NH4+-N and phosphate in the soil matrix, resulting in the differences in NH4+-N and TP concentrations at different locations. The main factors affecting the seasonal change and spatial variability of well water quality in subtropical agriculture region were topography, regional hydrological and climatic conditions, soil types, land use types and agricultural fertilization.
Well water is the main source of drinking water in subtropical agricultural regions in China, and its quality is critical for human health. In this paper, we carried out a geostatistical analysis to investigate the seasonal changes and spatial variability in the concentrations of ammonium nitrogen (NH4+-N), nitrate nitrogen (NO3--N), total nitrogen (TN) and total phosphorus (TP) in domestic well water in a typical agricultural catchment in southern China. Our results showed that the average concentrations of NH4+-N, NO3--N, TN and TP in spring, summer, autumn and winter of 2013–2014 were in the ranges of 0.050.10 mg(N)·L-1, 3.04.9 mg(N)·L-1, 3.45.1 mg(N)·L-1 and 0.030.17 mg(P)·L-1, respectively. The observed concentrations of NH4+-N, NO3--N, TN and TP exceeded the national standards in terms of frequency by 2.3%, 10.4%, 9.5% and 7.9%, respectively. Temporally, NO3--N, TN and TP were significantly (P < 0.05) higher in summer and lower in spring, mainly resulting from paddy rice fertilization and precipitation. On the contrary, there was no significant difference in seasonal concentrations for NH4+-N, mainly due to soil retention. In terms of spatial variability, these four variables were strongly auto-correlated in space and with different spatial ranges for different seasons. In terms of spatial distribution, the high NH4+-N, NO3--N, TN and TP concentrations were distributed as patches, even though their locations, sizes and shapes varied from one another. The concentrations of NO3--N and TN were high in the southeast and southwest of the catchment, where rice was cultivated in the low topography. But the concentrations of NO3--N and TN were low in the north, where there was forest plantation on the high topography. This result suggested that the spatial distribution of NO3--N and TN in well water were related to topography and land use type in the catchment. The spatial coefficients of variation of NH4+-N and TP were higher than those of NO3--N and TN. This was mainly attributed to the strong adsorption and immobilization of NH4+-N and phosphate in the soil matrix, resulting in the differences in NH4+-N and TP concentrations at different locations. The main factors affecting the seasonal change and spatial variability of well water quality in subtropical agriculture region were topography, regional hydrological and climatic conditions, soil types, land use types and agricultural fertilization.
2016, 24(6): 837-844.
Abstract:
Soil moisture is an important component of the hydrologic cycle in terrestrial ecosystems and it is critical for predicting and understanding various hydrological processes, including changes in weather conditions, precipitation patterns, runoff generation and irrigation scheduling. Soil moisture is a function of the total effect of environmental factors. The Mongolia Plateau is an ideal area for studying the interaction between soil moisture and environmental factors, because of its arid and semi-arid location and its high ecological fragility and sensitivity to global climate change. Therefore, it was necessary to study the response of soil moisture to environmental factors, which was favorable to monitor and predict droughts, adjust agricultural production structures and improve regional eco-environment in the Mongolia Plateau. A soil moisture retrieval model for the Mongolia Plateau was built using microwave radiance transfer function and Qp model based on AMSR-2 brightness temperature and SPOT normalized difference vegetation index (NDVI) data. Soil moisture was retrieved, and the retrieval precision was verified during vegetation growth period from April to October 2013 in the Mongolia Plateau. Combination with TRMM 3B43 precipitation and air temperature data acquired by meteorological stations, the study explored response characteristics between soil moisture, meteorological factors and vegetation. The results showed that 1) the coefficient of determination (r) between retrieved and ground-based soil moisture was 0.680 6, with a root-mean square error (RMSE) of 0.031 6 cm3.cm-3. The retrieval result was much better than soil moisture product data of JAXA (RMSE = 0.044 1 cm3.cm-3). 2) The developed model had a high accuracy and was applicable in surface soil moisture estimation. The regression coefficient of the linear fit of the TRMM 3B43 precipitation measure (rainfall) was 0.859 8 and with a slope line of 0.941 5, which suggested that TRMM 3B43 data were applicable in the Mongolia Plateau. 3) Total precipitation, mean NDVI and soil moisture during the growing season decreased gradually from north to south and from northeast to southwest. In the arid region of the study area, soil moisture was significantly and positively correlated with temperature, followed by precipitation and vegetation. In the semi-arid region of the study area, vegetation was the key factor driving soil moisture, and the effects of temperature and precipitation on soil moisture showed seasonal variations. The response of soil moisture to the three factors was in the order of vegetation > precipitation > temperature in the semi-humid region of the study area. In conclusion, the response of soil moisture to both environmental factors and vegetation could provide scientific basis for constructing healthy regional eco-environments with reducing disasters risk.
Soil moisture is an important component of the hydrologic cycle in terrestrial ecosystems and it is critical for predicting and understanding various hydrological processes, including changes in weather conditions, precipitation patterns, runoff generation and irrigation scheduling. Soil moisture is a function of the total effect of environmental factors. The Mongolia Plateau is an ideal area for studying the interaction between soil moisture and environmental factors, because of its arid and semi-arid location and its high ecological fragility and sensitivity to global climate change. Therefore, it was necessary to study the response of soil moisture to environmental factors, which was favorable to monitor and predict droughts, adjust agricultural production structures and improve regional eco-environment in the Mongolia Plateau. A soil moisture retrieval model for the Mongolia Plateau was built using microwave radiance transfer function and Qp model based on AMSR-2 brightness temperature and SPOT normalized difference vegetation index (NDVI) data. Soil moisture was retrieved, and the retrieval precision was verified during vegetation growth period from April to October 2013 in the Mongolia Plateau. Combination with TRMM 3B43 precipitation and air temperature data acquired by meteorological stations, the study explored response characteristics between soil moisture, meteorological factors and vegetation. The results showed that 1) the coefficient of determination (r) between retrieved and ground-based soil moisture was 0.680 6, with a root-mean square error (RMSE) of 0.031 6 cm3.cm-3. The retrieval result was much better than soil moisture product data of JAXA (RMSE = 0.044 1 cm3.cm-3). 2) The developed model had a high accuracy and was applicable in surface soil moisture estimation. The regression coefficient of the linear fit of the TRMM 3B43 precipitation measure (rainfall) was 0.859 8 and with a slope line of 0.941 5, which suggested that TRMM 3B43 data were applicable in the Mongolia Plateau. 3) Total precipitation, mean NDVI and soil moisture during the growing season decreased gradually from north to south and from northeast to southwest. In the arid region of the study area, soil moisture was significantly and positively correlated with temperature, followed by precipitation and vegetation. In the semi-arid region of the study area, vegetation was the key factor driving soil moisture, and the effects of temperature and precipitation on soil moisture showed seasonal variations. The response of soil moisture to the three factors was in the order of vegetation > precipitation > temperature in the semi-humid region of the study area. In conclusion, the response of soil moisture to both environmental factors and vegetation could provide scientific basis for constructing healthy regional eco-environments with reducing disasters risk.
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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