The calculation method of potential evapotranspiration（PET） was improved by adopting a more reliable PET estimate based on the Penman-Monteith equation into the standardized precipitation evapotranspiration index（S...The calculation method of potential evapotranspiration（PET） was improved by adopting a more reliable PET estimate based on the Penman-Monteith equation into the standardized precipitation evapotranspiration index（SPEI） in this study（SPEI PM）. This improvement increased the applicability of SPEI in North China Plain（NCP）. The historic meteorological data during 1962–2011 were used to calculate SPEI PM. The detrended yields of maize from Hebei, Henan, Shandong, Beijing, and Tianjin provinces/cities of NCP were obtained by linear sliding average method. Then regression analysis was made to study the relationships between detrended yields and SPEI values. Different time scales were applied, and thus SPEI PM was mentioned as SPEI PMk-j（k=time scale, 1, 2, 3, 4,…, 24 mon; j=month, 1, 2, 3,..., 12）, among which SPEI PM3-8 reflected the water condition from June to August, a period of heavy precipitation and vigorous growth of maize in NCP. SPEI PM3-8 was highly correlated with detrended yield in this region, which can effectively evaluate the effect of drought on maize yield. Additionally, this relationship becomes more significant in recent 20 yr. The regression model based on the SPEI series explained 64.8% of the variability of the annual detrended yield in Beijing, 45.2% in Henan, 58.6% in Shandong, and 54.6% in Hebei. Moreover, when SPEI PM3-8 is in the range of –0.6 to 1.1, –0.9 to 0.8 and –0.8 to 2.3, the detrended yield increases in Shandong, Henan and Beijing. The yield increasing range was during normal water condition in Shandong and Henan, where precipitation was abundant. It indicated that the field management matched well with local water condition and thus allowed stable and high yield. Maize yield increase in these two provinces in the future can be realized by further improving water use efficiency and enhancing the stress resistance as well as yield stability. In Hebei and Beijing, the precipitation is less and thus the normal water condition cannot meet the high yield target. Increasing of water input and improving water use efficiency are both strategies for future yield increase. As global climate change became stronger and yield demands increased, the relationship between drought and maize yield became much closer in NCP too. The research of drought monitoring method and strategies for yield increase should be enhanced in the future, so as to provide strong supports for food security and agricultural sustainable development in China.展开更多
Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,...Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,to evaluate the effects of five different combined doses of standard fertilizer practice and Si fertilizer on growth,yield and yield components,as well as nutrient uptake of rice.The treatments consisted of the recommended dose of fertilizer(RDF,110 kg/hm^2 N + 90 kg/hm^2 P_2O_5 + 80 kg/hm^2 K_2O) as the control,RDF + 100 kg/hm^2 SiO_2,RDF + 200 kg/hm^2 SiO_2,RDF + 300 kg/hm^2 SiO_2 and RDF + 400 kg/hm^2 SiO_2.The results showed that the growth,grain and straw yields as well as yield components(number of grains per panicle,seed-setting rate and 1000-grain weight) were significantly affected by Si application.The highest grain yield of 3 705 kg/hm^2 was obtained with the highest level of Si fertilizer in combination with RDF(RDF + 400 kg/hm^2 SiO_2),however,it was statistically at par with the yields obtained with RDF + 300 kg/hm^2 SiO_2(3 664 kg/hm^2) and RDF + 200 kg/hm^2 SiO_2(3 621 kg/hm^2).The optimum dose of Si fertilizer with maximized grain yield(3 716 kg/hm^2) was 329 kg/hm^2 SiO_2.The nutrient(Si,N,P and K) uptakes of rice were also significantly enhanced by Si application.Si application at the level of 329 kg/hm^2 along with RDF would help in the sustainable production of rice in the tropical zone of Vietnam.展开更多
基金supported by the Chinese National Public Scientific Research (201203031)the Chinese National Corn Industry Technology System (CARS-02-26)the Chinese Postdoctoral Science Foundation Project funded on the surface (2013M 541092)
文摘The calculation method of potential evapotranspiration（PET） was improved by adopting a more reliable PET estimate based on the Penman-Monteith equation into the standardized precipitation evapotranspiration index（SPEI） in this study（SPEI PM）. This improvement increased the applicability of SPEI in North China Plain（NCP）. The historic meteorological data during 1962–2011 were used to calculate SPEI PM. The detrended yields of maize from Hebei, Henan, Shandong, Beijing, and Tianjin provinces/cities of NCP were obtained by linear sliding average method. Then regression analysis was made to study the relationships between detrended yields and SPEI values. Different time scales were applied, and thus SPEI PM was mentioned as SPEI PMk-j（k=time scale, 1, 2, 3, 4,…, 24 mon; j=month, 1, 2, 3,..., 12）, among which SPEI PM3-8 reflected the water condition from June to August, a period of heavy precipitation and vigorous growth of maize in NCP. SPEI PM3-8 was highly correlated with detrended yield in this region, which can effectively evaluate the effect of drought on maize yield. Additionally, this relationship becomes more significant in recent 20 yr. The regression model based on the SPEI series explained 64.8% of the variability of the annual detrended yield in Beijing, 45.2% in Henan, 58.6% in Shandong, and 54.6% in Hebei. Moreover, when SPEI PM3-8 is in the range of –0.6 to 1.1, –0.9 to 0.8 and –0.8 to 2.3, the detrended yield increases in Shandong, Henan and Beijing. The yield increasing range was during normal water condition in Shandong and Henan, where precipitation was abundant. It indicated that the field management matched well with local water condition and thus allowed stable and high yield. Maize yield increase in these two provinces in the future can be realized by further improving water use efficiency and enhancing the stress resistance as well as yield stability. In Hebei and Beijing, the precipitation is less and thus the normal water condition cannot meet the high yield target. Increasing of water input and improving water use efficiency are both strategies for future yield increase. As global climate change became stronger and yield demands increased, the relationship between drought and maize yield became much closer in NCP too. The research of drought monitoring method and strategies for yield increase should be enhanced in the future, so as to provide strong supports for food security and agricultural sustainable development in China.
基金the Project of Netherlands Organization for Cooperation in Higher Education(NUFFIC)/The Netherlands Initiative for Capacity development in Higher Education(NICHE)/Vietnam 105(VNM 105)Supporting the integration in Agricultural Curricula of Climate Change concerns at Universities of Agriculture:Hanoi University of Agriculture,Hong Duc University and Hue University of Agriculture and Forestry(ACCCU)-Wageningen University and the Asian Institute of Technology,Thailand,for funding the work
文摘Application of silicon(Si) could greatly boost rice yield and mitigate abiotic stress,especially drought.A field experiment was conducted during 2015 at the research farm of Hong Duc University,Thanh Hoa City,Vietnam,to evaluate the effects of five different combined doses of standard fertilizer practice and Si fertilizer on growth,yield and yield components,as well as nutrient uptake of rice.The treatments consisted of the recommended dose of fertilizer(RDF,110 kg/hm^2 N + 90 kg/hm^2 P_2O_5 + 80 kg/hm^2 K_2O) as the control,RDF + 100 kg/hm^2 SiO_2,RDF + 200 kg/hm^2 SiO_2,RDF + 300 kg/hm^2 SiO_2 and RDF + 400 kg/hm^2 SiO_2.The results showed that the growth,grain and straw yields as well as yield components(number of grains per panicle,seed-setting rate and 1000-grain weight) were significantly affected by Si application.The highest grain yield of 3 705 kg/hm^2 was obtained with the highest level of Si fertilizer in combination with RDF(RDF + 400 kg/hm^2 SiO_2),however,it was statistically at par with the yields obtained with RDF + 300 kg/hm^2 SiO_2(3 664 kg/hm^2) and RDF + 200 kg/hm^2 SiO_2(3 621 kg/hm^2).The optimum dose of Si fertilizer with maximized grain yield(3 716 kg/hm^2) was 329 kg/hm^2 SiO_2.The nutrient(Si,N,P and K) uptakes of rice were also significantly enhanced by Si application.Si application at the level of 329 kg/hm^2 along with RDF would help in the sustainable production of rice in the tropical zone of Vietnam.
