The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment ...The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.展开更多
The European Federation of Food, Agriculture, and Tourism Trade Unions (EFFAT) called for the immediate ban on glyphosate in the 2022 renewal process, promoting the use of natural herbicides and recommending against t...The European Federation of Food, Agriculture, and Tourism Trade Unions (EFFAT) called for the immediate ban on glyphosate in the 2022 renewal process, promoting the use of natural herbicides and recommending against the use of other harmful or hazardous chemicals. The new chemical testing and selection research agendas should consider the hormetic effects of individual natural herbicides, and their potential mixtures, on targeted and non-targeted organisms to avoid stimulation of pests and negative effects on non-targeted organisms. New scientific research programs are needed to study the effects of mixtures of natural pesticides on soils, plants, animals, and microorganisms within the context of agroforestry.展开更多
From the view of current condition and developing trend of the debt scale in Chinese local government,if it could not be controlled by an effective way,the debt crisis will explode in the near future.According to the ...From the view of current condition and developing trend of the debt scale in Chinese local government,if it could not be controlled by an effective way,the debt crisis will explode in the near future.According to the regional distribution in our country,except for Beijing,Shanghai,Tianjin and Hainan,the debt risk mainly concentrates in the western region.In a further step,it can be seen that this risk of debt is resulted by the imbalanced relationship among“power,responsibility and interests”which contains none-accordance of debt power(such as debt financing power),confusion of debt responsibility(such as debt management responsibility)and distortion of debt interests(such as the private benefit and the public interests).If we want to correct this problem,the keynote is to prevent the local government’s debt to be used by the purpose of reaching the private interests.Actually,it should play a role that the local debt financing takes to the“faithful”service for the social interests.For realizing this purpose,it should keep eyes on the relationship among“power,responsibility and interests”,which is the most important factor as for setting up the control system of debt risk about our local governments.Particularly,it includes the following aspects.First of all,it should find the right time to empower the local government with the debt power.Secondly,on the basis of both positive and negative sides,it should design a system to restrict the debt responsibility in the local government,in order to solve the problems such as new debt,invalid debt and overdue debt expansion.Thirdly,it should propose the guidance mechanism to realize the convergence from the private benefit to the social interests on the local debt.展开更多
基金National Key Research and Development Program(2019YFC0408803)Basic Public Welfare Research Project of Zhejiang Province(LGN20E090001)+2 种基金Major scientific and technological projects of Zhejiang Provincial Department of water resources(RA1913)Water conservancy science and technology in Zhejiang Province(RC1918,RC2029),National Natural Science Foundation of China(52009044)High-level Talent Research Project of North China University of Water Resources and Electric Power(201705017).
文摘The flooding caused by heavy rainfall in rice irrigation area and the drought caused by the drop of groundwater level are the research focus in the field of irrigation and drainage.Based on the comparative experiment and farmland water level control technology,this paper studied the average soil temperature under different soil layers(TM),the daily temperature change(TDC),the photosynthetic accumulation of single leaf and canopy in rice,and response of photothermal energy to rice root characteristics and growth factors in the paddy field under drought conditions.The results showed that the peak soil temperature under drought treatment was basically synchronous with the conventional irrigation,and the it was delayed by 2–6 h under flooding treatment compared to the drought treatment.Under different water gradients,the temperature decreased according to T_(L)>T_(CK)>T_(H)(L,H and CK represented water flooding,drought and control treatments),and the TDC was opposite.In addition to milky stage,the daily photosynthetic(Pn)accumulation of single leaf and canopy in the flooding and drought treated paddy fields were lower than conventional irrigation,and had a negative impact on leaf area index(LAI)and yield(YR),but did not form fatal damage.The root characteristic factors,RL(root length),RW(root weight),R-CR(root-canopy ratio)were promoted with drought,and YR under light drought was slightly higher than that under heavy drought.There was a strong positive correlation between TM and R-CR in all rice growth stages,while TDC-5 was negatively correlated with effective panicle number,TDC and R-CR in 20 cm soil layer were positively correlated.The correlation between daily Pn accumulation and YR was low,and the correlation between Pn and YR factors was negative or weak positive or negative.The total Pn was positively correlated with yield factors,and the correlation coefficient was higher than that of daily Pn.
基金This study was supported by The Startup Foundation for Introducing Talent of Nanjing University of Information Science&Technology(NUIST),Nanjing,China(Grant No.003080)the Jiangsu Distinguished Professor Program of the People’s Government of Jiangsu Province.
文摘The European Federation of Food, Agriculture, and Tourism Trade Unions (EFFAT) called for the immediate ban on glyphosate in the 2022 renewal process, promoting the use of natural herbicides and recommending against the use of other harmful or hazardous chemicals. The new chemical testing and selection research agendas should consider the hormetic effects of individual natural herbicides, and their potential mixtures, on targeted and non-targeted organisms to avoid stimulation of pests and negative effects on non-targeted organisms. New scientific research programs are needed to study the effects of mixtures of natural pesticides on soils, plants, animals, and microorganisms within the context of agroforestry.
文摘From the view of current condition and developing trend of the debt scale in Chinese local government,if it could not be controlled by an effective way,the debt crisis will explode in the near future.According to the regional distribution in our country,except for Beijing,Shanghai,Tianjin and Hainan,the debt risk mainly concentrates in the western region.In a further step,it can be seen that this risk of debt is resulted by the imbalanced relationship among“power,responsibility and interests”which contains none-accordance of debt power(such as debt financing power),confusion of debt responsibility(such as debt management responsibility)and distortion of debt interests(such as the private benefit and the public interests).If we want to correct this problem,the keynote is to prevent the local government’s debt to be used by the purpose of reaching the private interests.Actually,it should play a role that the local debt financing takes to the“faithful”service for the social interests.For realizing this purpose,it should keep eyes on the relationship among“power,responsibility and interests”,which is the most important factor as for setting up the control system of debt risk about our local governments.Particularly,it includes the following aspects.First of all,it should find the right time to empower the local government with the debt power.Secondly,on the basis of both positive and negative sides,it should design a system to restrict the debt responsibility in the local government,in order to solve the problems such as new debt,invalid debt and overdue debt expansion.Thirdly,it should propose the guidance mechanism to realize the convergence from the private benefit to the social interests on the local debt.
