Annual ryegrass(Lolium multiflorum Lam.), a non-leguminous winter cover crop, has been adopted to absorb soil native N to minimize N loss from an intensive double rice cropping system in southern China, but a little...Annual ryegrass(Lolium multiflorum Lam.), a non-leguminous winter cover crop, has been adopted to absorb soil native N to minimize N loss from an intensive double rice cropping system in southern China, but a little is known about its effects on rice grain yield and rice N use efficiency. In this study, effects of ryegrass on double rice yield, N uptake and use efficiency were measured under different fertilizer N rates. A 3-year(2009–2011) field experiment arranged in a split-plot design was undertaken. Main plots were ryegrass(RG) as a winter cover crop and winter fallow(WF) without weed. Subplots were three N treatments for each rice season: 0(N_0), 100(N_(100)) and 200 kg N ha–1(N_(200)). In the 3-year experiment, RG reduced grain yield and plant N uptake for early rice(0.4–1.7 t ha–1 for grain yield and 4.6–20.3 kg ha–1 for N uptake) and double rice(0.6–2.0 t ha–1 for grain yield and 6.3–27.0 kg ha–1 for N uptake) when compared with WF among different N rates. Yield and N uptake decrease due to RG was smaller in N_(100) and N_(200) plots than in N_0 plots. The reduction in early rice grain yield in RG plots was associated with decrease number of panicles. Agronomic N use efficiency and fertilizer N recovery efficiency were higher in RG plots than winter fallow for early rice and double rice among different N rates and experimental years. RG tended to have little effect on grain yield, N uptake, agronomic N use efficiency, and fertilizer N recovery efficiency in the late rice season. These results suggest that ryegrass may reduce grain yield while it improves rice N use efficiency in a double rice cropping system.展开更多
The system of rice intensification (SRI) is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of mo...The system of rice intensification (SRI) is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons (2009-2011).In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting (CT) and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44) were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure (FYM);T 3,10 t/hm2 FYM+ 60 kg/hm2 N;T 4,5 t/hm2 FYM+ 90 kg/hm2 N;T 5,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.5 kg/hm2 blue green algae (BGA);T 6,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 (control,no NPK application) to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2-3 cm) was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management (INM) resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.展开更多
The increasing demand for fresh sweet maize (Zea mays L. saccharata) in southern China has prioritized the need to find solutions to the environmental pollution caused by its continuous production and high inputs of...The increasing demand for fresh sweet maize (Zea mays L. saccharata) in southern China has prioritized the need to find solutions to the environmental pollution caused by its continuous production and high inputs of chemical nitrogen fertilizers. A promising method for improving crop production and environmental conditions is to intercrop sweet maize with legumes. Here, a three-year field experiment was conducted to assess the influence of four different cropping systems (sole sweet maize (SS), sole soybean (SB), two rows sweet maize-three rows soybean (S2B3) intercropping, and two rows sweet maize-four rows soybean (S2B4) intercropping), together with two rates of N fertilizer application (300 and 360 kg N ha-1) on grain yield, residual soil mineral N, and soil N2O emissions in southern China. Results showed that in most case, inter- cropping achieved yield advantages (total land equivalent ratio (TLER=0.87-1.25) was above one). Moreover, intercropping resulted in 39.8% less soil mineral N than SS at the time of crop harvest, averaged over six seasons (spring and autumn in each of the three years of the field experiment). Generally, intercropping and reduced-N application (300 kg N ha-1) produced lower cumulative soil N20 and yield-scaled soil N20 emissions than SS and conventionaI-N application (360 kg N ha-l), respectively. $2B4 intercropping with reduced-N rate (300 kg N ha-~) showed the lowest cumulative soil N20 (mean value=0.61 kg ha-1) and yield-scaled soil N20 (mean value=0.04 kg t-1) emissions. Overall, intercropping with reduced-N rate maintained sweet maize production, while also reducing environmental impacts. The system of S2B4 intercropping with reduced-N rate may be the most sustainable and environmentally friendly cropping system.展开更多
In 1996,China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types.Today,approximately 80 super rice varieties have been released and some of them ...In 1996,China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types.Today,approximately 80 super rice varieties have been released and some of them show high grain yields of 12-21 t/hm2 in field experiments.The main reasons for the high yields of super rice varieties,compared with those of conventional varieties,can be summarized as follows:more spikelets per panicle and larger sink size (number of spikelets per square meter);larger leaf area index,longer duration of green leaf,greater photosynthetic rate,higher lodging resistance,greater dry matter accumulation before the heading stage,greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period;and larger root system and greater root activity.However,there are two main problems in super rice production:poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets),and low and unstable seed-setting rate.Here,we review recent research advances in the crop physiology of super rice,focusing on biological features,formation of yield components,and population quality.Finally,we suggest further research on crop physiology of super rice.展开更多
The potential of yield increase in the North China Plain is about 30 billion kg by ameliorating the low yield and medium low yield farmlands and 4 billion kg by reclaiming unused land. Water shortage will be the main ...The potential of yield increase in the North China Plain is about 30 billion kg by ameliorating the low yield and medium low yield farmlands and 4 billion kg by reclaiming unused land. Water shortage will be the main limitation to the further increase of grain crop yield. The amount of water shortage is 8 200 million m3 at present, and will be 17 720 million m3 in 2 000. Yield increase can not be realized by using more water in the future. Other factors such as decrease of the area of cultivated land and the grain crop growing area, deterioration of environment and destruction of resources will also affect the development of grain production. Some suggestions have been proposed in the paper for attaining sustainable increase of yield in the plain.展开更多
基金supported by the National Natural Science Foundation of China(31501274,31171509,30671222,31270488)the Special Fund for Agro-scientific Research in the Public Interest,China(201103001)the National Key Technologies R&D Program of China during the 12th Five-Year Plan period(2011BAD16B15)
文摘Annual ryegrass(Lolium multiflorum Lam.), a non-leguminous winter cover crop, has been adopted to absorb soil native N to minimize N loss from an intensive double rice cropping system in southern China, but a little is known about its effects on rice grain yield and rice N use efficiency. In this study, effects of ryegrass on double rice yield, N uptake and use efficiency were measured under different fertilizer N rates. A 3-year(2009–2011) field experiment arranged in a split-plot design was undertaken. Main plots were ryegrass(RG) as a winter cover crop and winter fallow(WF) without weed. Subplots were three N treatments for each rice season: 0(N_0), 100(N_(100)) and 200 kg N ha–1(N_(200)). In the 3-year experiment, RG reduced grain yield and plant N uptake for early rice(0.4–1.7 t ha–1 for grain yield and 4.6–20.3 kg ha–1 for N uptake) and double rice(0.6–2.0 t ha–1 for grain yield and 6.3–27.0 kg ha–1 for N uptake) when compared with WF among different N rates. Yield and N uptake decrease due to RG was smaller in N_(100) and N_(200) plots than in N_0 plots. The reduction in early rice grain yield in RG plots was associated with decrease number of panicles. Agronomic N use efficiency and fertilizer N recovery efficiency were higher in RG plots than winter fallow for early rice and double rice among different N rates and experimental years. RG tended to have little effect on grain yield, N uptake, agronomic N use efficiency, and fertilizer N recovery efficiency in the late rice season. These results suggest that ryegrass may reduce grain yield while it improves rice N use efficiency in a double rice cropping system.
文摘The system of rice intensification (SRI) is reported to have advantages like lower seed requirement,less pest attack,shorter crop duration,higher water use efficiency and the ability to withstand higher degree of moisture stress than traditional method of rice cultivation.With this background,SRI was compared with traditional transplanting technique at Indian Agricultural Research Institute,New Delhi,India during two wet seasons (2009-2011).In the experiment laid out in a factorial randomized block design,two methods of rice cultivation [conventional transplanting (CT) and SRI] and two rice varieties (Pusa Basmati 1 and Pusa 44) were used under seven crop nutrition treatments,viz.T 1,120 kg/hm2 N,26.2 kg/hm2 P and 33 kg/hm2 K;T 2,20 t/hm2 farmyard manure (FYM);T 3,10 t/hm2 FYM+ 60 kg/hm2 N;T 4,5 t/hm2 FYM+ 90 kg/hm2 N;T 5,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.5 kg/hm2 blue green algae (BGA);T 6,5 t/hm2 FYM+ 60 kg/hm2 N+ 1.0 t/hm2 Azolla,and T 7,N 0 P 0 K 0 (control,no NPK application) to study the effect on seed quality,yield and water use.In SRI,soil was kept at saturated moisture condition throughout vegetative phase and thin layer of water (2-3 cm) was maintained during the reproductive phase of rice,however,in CT,standing water was maintained in crop growing season.Results revealed that CT and SRI gave statistically at par grain yield but straw yield was significantly higher in CT as compared to SRI.Seed quality was superior in SRI as compared to CT.Integrated nutrient management (INM) resulted in higher plant height with longer leaves than chemical fertilizer alone in both the rice varieties.Grain yield attributes such as number of effective tillers per hill,panicle length and panicle weight of rice in both the varieties were significantly higher in INM as compared to chemical fertilizer alone.Grain yields of both the varieties were the highest in INM followed by the recommended doses of chemical fertilizer.The grain yield and its attributes of Pusa 44 were significantly higher than those of Pusa Basmati 1.The seed quality parameters like germination rate and vigor index as well as N uptake and soil organic carbon content were higher in INM than those in chemical fertilizer alone.CT rice used higher amount of water than SRI,with water saving of 37.6% to 34.5% in SRI.Significantly higher water productivity was recorded in SRI as compared to CT rice.
基金supported by the Key Technologies R&D Program of China during the 12th Five-year Plan period(2012BAD14B16-04)the Science and Technology Development Program of Guangdong,China(2012A020100003 and 2015B090903077)
文摘The increasing demand for fresh sweet maize (Zea mays L. saccharata) in southern China has prioritized the need to find solutions to the environmental pollution caused by its continuous production and high inputs of chemical nitrogen fertilizers. A promising method for improving crop production and environmental conditions is to intercrop sweet maize with legumes. Here, a three-year field experiment was conducted to assess the influence of four different cropping systems (sole sweet maize (SS), sole soybean (SB), two rows sweet maize-three rows soybean (S2B3) intercropping, and two rows sweet maize-four rows soybean (S2B4) intercropping), together with two rates of N fertilizer application (300 and 360 kg N ha-1) on grain yield, residual soil mineral N, and soil N2O emissions in southern China. Results showed that in most case, inter- cropping achieved yield advantages (total land equivalent ratio (TLER=0.87-1.25) was above one). Moreover, intercropping resulted in 39.8% less soil mineral N than SS at the time of crop harvest, averaged over six seasons (spring and autumn in each of the three years of the field experiment). Generally, intercropping and reduced-N application (300 kg N ha-1) produced lower cumulative soil N20 and yield-scaled soil N20 emissions than SS and conventionaI-N application (360 kg N ha-l), respectively. $2B4 intercropping with reduced-N rate (300 kg N ha-~) showed the lowest cumulative soil N20 (mean value=0.61 kg ha-1) and yield-scaled soil N20 (mean value=0.04 kg t-1) emissions. Overall, intercropping with reduced-N rate maintained sweet maize production, while also reducing environmental impacts. The system of S2B4 intercropping with reduced-N rate may be the most sustainable and environmentally friendly cropping system.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.31061140457 and 31071360)the National Basic Research Program(Grant Nos.2009CB118603 and 2012CB114306)+1 种基金the National Key Technology Support Program of China(Grant No.2011BAD16B14)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK2009-005)
文摘In 1996,China launched a program to breed super rice or super hybrid rice by combining intersubspecific heterosis with ideal plant types.Today,approximately 80 super rice varieties have been released and some of them show high grain yields of 12-21 t/hm2 in field experiments.The main reasons for the high yields of super rice varieties,compared with those of conventional varieties,can be summarized as follows:more spikelets per panicle and larger sink size (number of spikelets per square meter);larger leaf area index,longer duration of green leaf,greater photosynthetic rate,higher lodging resistance,greater dry matter accumulation before the heading stage,greater remobilization of pre-stored carbohydrates from stems and leaves to grains during the grain-filling period;and larger root system and greater root activity.However,there are two main problems in super rice production:poor grain-filling of the later-flowering inferior spikelets (in contrast to earlier-flowering superior spikelets),and low and unstable seed-setting rate.Here,we review recent research advances in the crop physiology of super rice,focusing on biological features,formation of yield components,and population quality.Finally,we suggest further research on crop physiology of super rice.
文摘The potential of yield increase in the North China Plain is about 30 billion kg by ameliorating the low yield and medium low yield farmlands and 4 billion kg by reclaiming unused land. Water shortage will be the main limitation to the further increase of grain crop yield. The amount of water shortage is 8 200 million m3 at present, and will be 17 720 million m3 in 2 000. Yield increase can not be realized by using more water in the future. Other factors such as decrease of the area of cultivated land and the grain crop growing area, deterioration of environment and destruction of resources will also affect the development of grain production. Some suggestions have been proposed in the paper for attaining sustainable increase of yield in the plain.