The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving ...The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.展开更多
In line with the author’s long-time experience on soil reconnaissance, monitoring and scientific probes, this article expounds the vital significance in systematic build-up of pedological data, protection of arable l...In line with the author’s long-time experience on soil reconnaissance, monitoring and scientific probes, this article expounds the vital significance in systematic build-up of pedological data, protection of arable land, employment and renovation of the farmland soil in accordance with the local edaphic setting in a bid to increase the grain yield.展开更多
基于某公司针对Φ12 mm HRB400E热轧带肋钢筋进行的“提锰降钒”生产实践,参考Mn和V的强化机理,统计并分析了两个时期内轧制该规格钢筋的化学成分及力学性能。结果表明:在HRB400E生产实践中,质量分数为0.001%的V对屈服强度的影响近似相...基于某公司针对Φ12 mm HRB400E热轧带肋钢筋进行的“提锰降钒”生产实践,参考Mn和V的强化机理,统计并分析了两个时期内轧制该规格钢筋的化学成分及力学性能。结果表明:在HRB400E生产实践中,质量分数为0.001%的V对屈服强度的影响近似相等于质量分数为0.020%的Mn对钢材屈服强度的影响。展开更多
A large number of mathematical models were developed for supporting agricultural production structure optimization decisions; however, few of them can address various uncertainties existing in many factors （e.g., eco...A large number of mathematical models were developed for supporting agricultural production structure optimization decisions; however, few of them can address various uncertainties existing in many factors （e.g., eco-social benefit maximization, food security, employment stability and ecosystem balance）. In this study, an interval-probabilistic agricultural production structure optimization model （IPAPSOM） is formulated for tackling uncertainty presented as discrete intervals and/or probability distribution. The developed model improves upon the existing probabilistic programming and inexact optimization approaches. The IPAPSOM considers not only food security policy constraints, but also involves rural households’income increase and eco-environmental conversation, which can effectively reflect various interrelations among different aspects in an agricultural production structure optimization system. Moreover, it can also help examine the reliability of satisfying （or risk of violating） system constraints under uncertainty. The model is applied to a real case of long-term agricultural production structure optimization in Dancheng County, which is located in Henan Province of Central China as one of the major grain producing areas. Interval solutions associated with different risk levels of constraint violation are obtained. The results are useful for generating a range of decision alternatives under various system benefit conditions, and thus helping decision makers to identify the desired agricultural production structure optimization strategy under uncertainty.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the National Key Research and Development Program of China(2017YFD0300203 and 2016YFD0300105)。
文摘The shortage of groundwater resources is a considerable challenge for winter wheat production on the North China Plain.Water-saving technologies and procedures are thus urgently required.To determine the water-saving potential of using micro-sprinkling irrigation(MSI)for winter wheat production,field experiments were conducted from 2012 to 2015.Compared to traditional flooding irrigation(TFI),micro-sprinkling thrice with 90 mm water(MSI1)and micro-sprinkling four times with 120 mm water(MSI2)increased the water use efficiency by 22.5 and 16.2%,respectively,while reducing evapotranspiration by 17.6 and 10.8%.Regardless of the rainfall pattern,MSI(i.e.,MSI1 or MSI2)either stabilized or significantly increased the grain yield,while reducing irrigation water volumes by 20–40%,compared to TFI.Applying the same volumes of irrigation water,MSI(i.e.,MSI3,micro-sprinkling five times with 150 mm water)increased the grain yield and water use efficiency of winter wheat by 4.6 and 11.7%,respectively,compared to TFI.Because MSI could supply irrigation water more frequently in smaller amounts each time,it reduced soil layer compaction,and may have also resulted in a soil water deficit that promoted the spread of roots into the deep soil layer,which is beneficial to photosynthetic production in the critical period.In conclusion,MSI1 or MSI2 either stabilized or significantly increased grain yield while reducing irrigation water volumes by 20–40%compared to TFI,and should provide water-saving technological support in winter wheat production for smallholders on the North China Plain.
文摘In line with the author’s long-time experience on soil reconnaissance, monitoring and scientific probes, this article expounds the vital significance in systematic build-up of pedological data, protection of arable land, employment and renovation of the farmland soil in accordance with the local edaphic setting in a bid to increase the grain yield.
文摘基于某公司针对Φ12 mm HRB400E热轧带肋钢筋进行的“提锰降钒”生产实践,参考Mn和V的强化机理,统计并分析了两个时期内轧制该规格钢筋的化学成分及力学性能。结果表明:在HRB400E生产实践中,质量分数为0.001%的V对屈服强度的影响近似相等于质量分数为0.020%的Mn对钢材屈服强度的影响。
基金funded by the National Natural Science Foundation of China (41130748, 41101162)the Key Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-EW-304)
文摘A large number of mathematical models were developed for supporting agricultural production structure optimization decisions; however, few of them can address various uncertainties existing in many factors （e.g., eco-social benefit maximization, food security, employment stability and ecosystem balance）. In this study, an interval-probabilistic agricultural production structure optimization model （IPAPSOM） is formulated for tackling uncertainty presented as discrete intervals and/or probability distribution. The developed model improves upon the existing probabilistic programming and inexact optimization approaches. The IPAPSOM considers not only food security policy constraints, but also involves rural households’income increase and eco-environmental conversation, which can effectively reflect various interrelations among different aspects in an agricultural production structure optimization system. Moreover, it can also help examine the reliability of satisfying （or risk of violating） system constraints under uncertainty. The model is applied to a real case of long-term agricultural production structure optimization in Dancheng County, which is located in Henan Province of Central China as one of the major grain producing areas. Interval solutions associated with different risk levels of constraint violation are obtained. The results are useful for generating a range of decision alternatives under various system benefit conditions, and thus helping decision makers to identify the desired agricultural production structure optimization strategy under uncertainty.
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.
