The lower Ili River Basin is located in semi-arid area, and the annual rainfall is 177mm. Therefore, the irrigation is inevitable for agriculture. Large-scale irrigated agriculture had been developed since 1960＇s in ...The lower Ili River Basin is located in semi-arid area, and the annual rainfall is 177mm. Therefore, the irrigation is inevitable for agriculture. Large-scale irrigated agriculture had been developed since 1960＇s in the lower parts of the river and the total irrigated area is about 32 000 hm2. In the project area, the paddy rice-upland crop rotation has been practiced. Due to the domestic water use for hydropower and agriculture as well as water use among riparian countries, the deficit of water for agriculture in the lower part has been concerned. The authors, therefore, conducted the field survey and water balance analysis of the Akdara irrigation project in the lower Ill River Basin in order to assess the land and water uses. Moreover, the impact of the water use on water environment to the basin was analyzed. The following results were obtained as following （1） the groundwater level in the irrigated district varied from 1.5 m to 3.5 m through year. （2） 1970＇s groundwater level was drastically raised from 8 m to 3 m and the groundwater had been recharged in this period. （3） Water use efficiency of agriculture, which is the ratio of total evapotranspiration to the total water withdrawal was as low as 0.23.展开更多
To estimate the impact of crop rotation on the pathotype and genetic structure of Phythophthora sojae in fields, 372 isolates of P. sojae were obtained from long-term localisation experimental fields in Heilongjiang P...To estimate the impact of crop rotation on the pathotype and genetic structure of Phythophthora sojae in fields, 372 isolates of P. sojae were obtained from long-term localisation experimental fields in Heilongjiang Province of China. The hypocotyl inoculation method was used to characterize the virulence of P. sojae on 13 differential cultivars, and the amplified fragment length polymorphism（AFLP） technique was used to analyze difference in the genetic structure of P. sojae. The results indicated that an abundant diversity of genetic structures and pathotypes of P. sojae, a more uniform distribution of pathotypes and less dominance of pathotypes occurred in corn-soybean and wheat-soybean rotation fields than in a continuous soybean mono-cropping field. These findings suggested that P. sojae did not easily become the dominant race in rotation fields, which maintain disease resistance in soybean varieties. Therefore, the results of this study suggested that Phytophthora stem and root rot of soybeans could be effectively controlled by rotating soybeans with non-host crops of corn and wheat.展开更多
The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorith...The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.展开更多
【目的】系统阐述国内外烟草绿肥模式的研究热点和发展趋势,为推动中国烟草绿色高效生产提供理论支撑。【方法】利用Bibliometrix工具,结合中国知网和Web of Science数据库,综述全球烟草绿肥模式的发文量变化、重要研究机构与学者、研...【目的】系统阐述国内外烟草绿肥模式的研究热点和发展趋势,为推动中国烟草绿色高效生产提供理论支撑。【方法】利用Bibliometrix工具,结合中国知网和Web of Science数据库,综述全球烟草绿肥模式的发文量变化、重要研究机构与学者、研究热点变化和趋势等重要内容,系统对比分析国内外相关研究进展。【结果】截至2024年,国内外烟草绿肥相关研究论文合计684篇,全球烟草绿肥相关研究迅速增长,中国增长趋势尤为显著。中国农业科学研究院与法国国家研究中心是全球重要的烟草绿肥研究机构。国内研究通过大量田间试验验证了绿肥对烟田生态系统的正向调控,而国际学界更注重根际互作等基础理论突破。【结论】文献计量分析揭示了烟草—绿肥轮作研究的现状,即:全球烟草—绿肥轮作研究呈现显著的地域分化特征,国内外研究范式差异明显,近10年来中国已成为该领域的核心贡献国。通过基础理论与应用技术的双向融合,有望突破绿肥应用研究的地域限制,为全球烟区可持续发展提供系统解决方案。展开更多
基金Supported by Global COE Program (Global Center of Excellence for Dryland Science) Funded by MEXT"Historical Interactions between the Multi-Cultural Societies and the Natural Environment in a Semi-Arid Region in Central Eurasia" Project Funded by Research Institute for Humanity and Nature, Japan
文摘The lower Ili River Basin is located in semi-arid area, and the annual rainfall is 177mm. Therefore, the irrigation is inevitable for agriculture. Large-scale irrigated agriculture had been developed since 1960＇s in the lower parts of the river and the total irrigated area is about 32 000 hm2. In the project area, the paddy rice-upland crop rotation has been practiced. Due to the domestic water use for hydropower and agriculture as well as water use among riparian countries, the deficit of water for agriculture in the lower part has been concerned. The authors, therefore, conducted the field survey and water balance analysis of the Akdara irrigation project in the lower Ill River Basin in order to assess the land and water uses. Moreover, the impact of the water use on water environment to the basin was analyzed. The following results were obtained as following （1） the groundwater level in the irrigated district varied from 1.5 m to 3.5 m through year. （2） 1970＇s groundwater level was drastically raised from 8 m to 3 m and the groundwater had been recharged in this period. （3） Water use efficiency of agriculture, which is the ratio of total evapotranspiration to the total water withdrawal was as low as 0.23.
基金Supported by the Special Fund for Agro-scientific Research in the Public Interest(201303018)the National Natural Science Foundation of China(31370449)
文摘To estimate the impact of crop rotation on the pathotype and genetic structure of Phythophthora sojae in fields, 372 isolates of P. sojae were obtained from long-term localisation experimental fields in Heilongjiang Province of China. The hypocotyl inoculation method was used to characterize the virulence of P. sojae on 13 differential cultivars, and the amplified fragment length polymorphism（AFLP） technique was used to analyze difference in the genetic structure of P. sojae. The results indicated that an abundant diversity of genetic structures and pathotypes of P. sojae, a more uniform distribution of pathotypes and less dominance of pathotypes occurred in corn-soybean and wheat-soybean rotation fields than in a continuous soybean mono-cropping field. These findings suggested that P. sojae did not easily become the dominant race in rotation fields, which maintain disease resistance in soybean varieties. Therefore, the results of this study suggested that Phytophthora stem and root rot of soybeans could be effectively controlled by rotating soybeans with non-host crops of corn and wheat.
基金Jiangsu Water Science and Technology Project(2021081)。
文摘The rapid identification of planting patterns for major crops in a large irrigated district has vital importance for irrigation management,water fee collection,and crop yield estimation.In this study,the OTSU algorithm and Mean-Shift algorithm were employed to automatically determine threshold values for mapping two main rotated crop patterns at the pixel scale.A time series analysis was conducted to extract the spatial distribution of rice-wheat and wheat-maize rotations in the Chuanhang irrigation district from 2016 to 2020.The results demonstrate that both threshold segmentation algorithms are reliable in extracting the spatial distribution of the crops,with an overall accuracy exceeding 80%.Additionally,both Kappa coefficients surpass 0.7,indicating better performance by OTSU method.Over the period from 2016 to 2020,the area occupied by rice-wheat rotation cropping ranged from 12500 to 14400 hm 2;whereas wheat-maize rotation cropping exhibited smaller and more variable areas ranging from 19730 to 34070 hm 2.These findings highlight how remote sensing-based approaches can provide reliable support for rapidly and accurately identifying the spatial distribution of main crop rotation patterns within a large irrigation district.
文摘【目的】系统阐述国内外烟草绿肥模式的研究热点和发展趋势,为推动中国烟草绿色高效生产提供理论支撑。【方法】利用Bibliometrix工具,结合中国知网和Web of Science数据库,综述全球烟草绿肥模式的发文量变化、重要研究机构与学者、研究热点变化和趋势等重要内容,系统对比分析国内外相关研究进展。【结果】截至2024年,国内外烟草绿肥相关研究论文合计684篇,全球烟草绿肥相关研究迅速增长,中国增长趋势尤为显著。中国农业科学研究院与法国国家研究中心是全球重要的烟草绿肥研究机构。国内研究通过大量田间试验验证了绿肥对烟田生态系统的正向调控,而国际学界更注重根际互作等基础理论突破。【结论】文献计量分析揭示了烟草—绿肥轮作研究的现状,即:全球烟草—绿肥轮作研究呈现显著的地域分化特征,国内外研究范式差异明显,近10年来中国已成为该领域的核心贡献国。通过基础理论与应用技术的双向融合,有望突破绿肥应用研究的地域限制,为全球烟区可持续发展提供系统解决方案。
