Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse stud...Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse study was conducted to examine the effects of four N rates on the competitive ability ofEchinochloa colona and Amaranthus viridis grown together with direct-seeded rice. Rice and each weed species were grown in a replacement series design at added N rates of 0, 50, 100, and 150 kg ha1. Replacement series diagrams for relative yield showed that competitive ability ofE. colona increased with added soil N. Values of weed aggressivity index for E. colona also significantly increased with the addition of N in the soil. In the absence of added N, A. viridis was more competitive than rice but this relationship slightly changed as N was added. However, values of weed aggressivity index of were statistically similar at all N rates. The results suggest that the competitiveness ofE. colona increased with added soil N, and A. viridis unchanged by soil N levels. Both weed species were different in their response to higher N levels. Information gained in this study could be used to demonstrate the importance of effective weed and fertilizer management.展开更多
Chinese water resource management （CWRM） has passed through four stages： infancy, initial development, rapid development, and formation. In the last of these stages some problems persist and will affect management ...Chinese water resource management （CWRM） has passed through four stages： infancy, initial development, rapid development, and formation. In the last of these stages some problems persist and will affect management performance. CWRM was a decentralised, imperfectly codified and weakly implemented system that lacked a sound market policy, rational water prices, water conservation awareness, technical support and a performance appraisal system. The government of China proposed two new strategies in 2009： the Three Red Lines and the Interconnected River System Network （IRSN）. This paper analyses these two strategies and reflects on new CWRM concepts. Both strategies strive for the sustainable utilisation of water resources and human-water harmony. The concepts, quantification method and application of harmony theory to water resources management is discussed. Applications of harmony theory to water resources management include （i） harmony between humans and nature; （ii） a harmony strategy for water resources management; （iii） a rational allocation model for water resources among different areas and departments based on harmony theory; （iv） harmony-based water allocation issues associated with transboundary rivers; （v） harmony-based interbasin water transfer problems; and （vi） harmony-based control of pollution discharge. We conclude by discussing how harmony theory and its applications provide an appropriate pathway for water resource management in China.展开更多
文摘Information on weed competitiveness responses to added nitrogen （N） is required to assist with the development of appropriate fertilizer management strategies where weed competition is anticipated. A greenhouse study was conducted to examine the effects of four N rates on the competitive ability ofEchinochloa colona and Amaranthus viridis grown together with direct-seeded rice. Rice and each weed species were grown in a replacement series design at added N rates of 0, 50, 100, and 150 kg ha1. Replacement series diagrams for relative yield showed that competitive ability ofE. colona increased with added soil N. Values of weed aggressivity index for E. colona also significantly increased with the addition of N in the soil. In the absence of added N, A. viridis was more competitive than rice but this relationship slightly changed as N was added. However, values of weed aggressivity index of were statistically similar at all N rates. The results suggest that the competitiveness ofE. colona increased with added soil N, and A. viridis unchanged by soil N levels. Both weed species were different in their response to higher N levels. Information gained in this study could be used to demonstrate the importance of effective weed and fertilizer management.
基金National Social Science Fund Project (No. 12&ZD215)National Natural Science Foundation of China (No.51279183 andNo.51079132)Program for Innovative Research Team (in Science and Technology) in University of Henan Province (No.2013)
文摘Chinese water resource management （CWRM） has passed through four stages： infancy, initial development, rapid development, and formation. In the last of these stages some problems persist and will affect management performance. CWRM was a decentralised, imperfectly codified and weakly implemented system that lacked a sound market policy, rational water prices, water conservation awareness, technical support and a performance appraisal system. The government of China proposed two new strategies in 2009： the Three Red Lines and the Interconnected River System Network （IRSN）. This paper analyses these two strategies and reflects on new CWRM concepts. Both strategies strive for the sustainable utilisation of water resources and human-water harmony. The concepts, quantification method and application of harmony theory to water resources management is discussed. Applications of harmony theory to water resources management include （i） harmony between humans and nature; （ii） a harmony strategy for water resources management; （iii） a rational allocation model for water resources among different areas and departments based on harmony theory; （iv） harmony-based water allocation issues associated with transboundary rivers; （v） harmony-based interbasin water transfer problems; and （vi） harmony-based control of pollution discharge. We conclude by discussing how harmony theory and its applications provide an appropriate pathway for water resource management in China.
