Phosphorus （P） and zinc （Zn） deficiencies are the major problems that decrease crop productivity under rice-wheat cropping system. Field experiments were conducted to investigate impacts of P （0, 40, 80 and 120 k...Phosphorus （P） and zinc （Zn） deficiencies are the major problems that decrease crop productivity under rice-wheat cropping system. Field experiments were conducted to investigate impacts of P （0, 40, 80 and 120 kg/hm^2） and Zn levels （0, 5, 10 and 15 kg/hm^2） on dry matter （DM） accumulation and partitioning, and harvest index of three rice genotypes ＇fine （Bamati-385） vs. coarse （F-Malakand and Pukhraj）＇ at various growth stages （tiliering, heading and physiological maturity）. The experiments were conducted at farmers＇ field at Batkhela in Northwestern Pakistan for two years in summer 2011 and 2012. The two year pooled data reveled that there were no differences in percent of DM partitioning into leaves and culms with application of different P and Zn levels, and genotypes at tillering. The highest P level （120 kg/hm^2） partitioned more DM into panicles than leaves and culms at heading and physiological maturity stages. The highest Zn level （15 kg/hm^2） accumulated more DM and partitioned more DM into panicles than leaves and culms at heading and physiological maturity stages. The hybrid rice （Pukhraj） produced and partitioned more DM into panicles than F-Malakand and Bamati-385 at heading and physiological maturity stages. Higher DM accumulation and greater amounts of partitioning into panicles at heading and physiological maturity stages was noticed with increase in P and Zn levels, and the increase was significantly higher in the coarse rice genotypes than fine. We concluded that the growing hybrid rice with application of 120 kg/hm^2 P ＋ 15 kg/hm^2 Zn not only increases total DM accumulation and partitioned greater amounts into the reproductive plant parts （panicles） but also results in higher harvest index.展开更多
Using Moderate Resolution Imaging Spectroradiometer(MODIS) data from the dry season during 2010–2012 over the whole Yunnan Province, an improved temperature vegetation dryness index(iTVDI), in which a parabolic dry-e...Using Moderate Resolution Imaging Spectroradiometer(MODIS) data from the dry season during 2010–2012 over the whole Yunnan Province, an improved temperature vegetation dryness index(iTVDI), in which a parabolic dry-edge equation replaces the traditional linear dry-edge equation, was developed, to reveal the regional drought regime in the dry season. After calculating the correlation coefficient, root-mean-square error, and standard deviation between the iTVDI and observed topsoil moisture at 10 and 20 cm for seven sites, the effectiveness of the new index in depicting topsoil moisture conditions was verified. The drought area indicated by iTVDI mapping was then compared with the drought-affected area reported by the local government. The results indicated that the iTVDI can monitor drought more accurately than the traditional TVDI during the dry season in Yunnan Province. Using iTVDI facilitates drought warning and irrigation scheduling, and the expectation is that this new index can be broadly applied in other areas.展开更多
文摘Phosphorus （P） and zinc （Zn） deficiencies are the major problems that decrease crop productivity under rice-wheat cropping system. Field experiments were conducted to investigate impacts of P （0, 40, 80 and 120 kg/hm^2） and Zn levels （0, 5, 10 and 15 kg/hm^2） on dry matter （DM） accumulation and partitioning, and harvest index of three rice genotypes ＇fine （Bamati-385） vs. coarse （F-Malakand and Pukhraj）＇ at various growth stages （tiliering, heading and physiological maturity）. The experiments were conducted at farmers＇ field at Batkhela in Northwestern Pakistan for two years in summer 2011 and 2012. The two year pooled data reveled that there were no differences in percent of DM partitioning into leaves and culms with application of different P and Zn levels, and genotypes at tillering. The highest P level （120 kg/hm^2） partitioned more DM into panicles than leaves and culms at heading and physiological maturity stages. The highest Zn level （15 kg/hm^2） accumulated more DM and partitioned more DM into panicles than leaves and culms at heading and physiological maturity stages. The hybrid rice （Pukhraj） produced and partitioned more DM into panicles than F-Malakand and Bamati-385 at heading and physiological maturity stages. Higher DM accumulation and greater amounts of partitioning into panicles at heading and physiological maturity stages was noticed with increase in P and Zn levels, and the increase was significantly higher in the coarse rice genotypes than fine. We concluded that the growing hybrid rice with application of 120 kg/hm^2 P ＋ 15 kg/hm^2 Zn not only increases total DM accumulation and partitioned greater amounts into the reproductive plant parts （panicles） but also results in higher harvest index.
基金supported by the National Key Research and Development Program of China (2016YFA0601601)National Natural Science Foundation of China (Grants Nos. U1502233,41405001)+1 种基金the Jiangsu Collaborative Innovation Center for Climate ChangePh.D. Programs Foundation of Ministry of Education of China (20135301120010)
文摘Using Moderate Resolution Imaging Spectroradiometer(MODIS) data from the dry season during 2010–2012 over the whole Yunnan Province, an improved temperature vegetation dryness index(iTVDI), in which a parabolic dry-edge equation replaces the traditional linear dry-edge equation, was developed, to reveal the regional drought regime in the dry season. After calculating the correlation coefficient, root-mean-square error, and standard deviation between the iTVDI and observed topsoil moisture at 10 and 20 cm for seven sites, the effectiveness of the new index in depicting topsoil moisture conditions was verified. The drought area indicated by iTVDI mapping was then compared with the drought-affected area reported by the local government. The results indicated that the iTVDI can monitor drought more accurately than the traditional TVDI during the dry season in Yunnan Province. Using iTVDI facilitates drought warning and irrigation scheduling, and the expectation is that this new index can be broadly applied in other areas.
