The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their t...The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.展开更多
With the development of economy, meat gradually plays an important role in Chinese people’s dietary pattern. As the most direct reflection of agricultural system, food system has always been the main output of agricu...With the development of economy, meat gradually plays an important role in Chinese people’s dietary pattern. As the most direct reflection of agricultural system, food system has always been the main output of agricultural system, and pork has occupied an important position in Chinese food system. We attempts to find the systematical disorder of current agricultural system by analyzing the meat output of the agricultural system. H-P Filter and Grey Prediction GM(1,1) Model was adopted to explore the inner rules between pork production and agricultural system in China. The results indicated that pork consumption ratio in Chinese urban residents’ dietary pattern constantly kept about 6%, the growth potential of grain yield is limited while the growth potential of pork yield is increased in China. By Grey Prediction GM(1,1) Model, we predicted the pork yield would reach 59.07 Mt in 2020, 110.25 Mt in 2060, 205.78 Mt in 2100, the demand of feed would reach 177.22 Mt in 2020, 330.75 Mt in 2060, 617.34 Mt in 2100. In China, agricultural system is traditional “pork-grain” mode, feed has been one of the biggest section that consumed grain. The present “pork-grain” agricultural system cannot meet the huge demand of grain from feed, adjusting the agricultural structure is imperative. Reforming the current agricultural system into grassland agricultural system which takes the beef and mutton as predominates would be a good choice for China in the future.展开更多
人工草地建设是缓解内蒙古地区草地生存压力的必要途径,而水分短缺是该区人工草地建设中牧草生长的主要限制因素,适量的人工补水以实现牧草的高产节水是解决这一问题的关键。以当地主要牧草冰草和紫花苜蓿为研究对象,开展单播和混播条...人工草地建设是缓解内蒙古地区草地生存压力的必要途径,而水分短缺是该区人工草地建设中牧草生长的主要限制因素,适量的人工补水以实现牧草的高产节水是解决这一问题的关键。以当地主要牧草冰草和紫花苜蓿为研究对象,开展单播和混播条件下不同灌溉量对牧草产量、光合性能和水分利用效率影响的对比试验。研究结果表明:(1)豆禾混播有利于提高冰草和紫花苜蓿的产量;(2)8月初现蕾期是冰草和紫花苜蓿收割的最佳季节,此时牧草产量最高;(3)灌溉量达到田间持水量的45%(包含降雨量在内的单位面积灌溉量在7月初达到903.8 m3/hm2,在8月初达到1812.4 m3/hm2)是牧草高产节水的最佳补水选择;(4)6—8月水分胁迫更有利于提高牧草的长期水分利用效率(long-term water use efficiency,WUEL),开花期后补水对提高牧草WUEL的作用开始显著;(5)在牧草产量最高的8月初水分胁迫更有利于提高牧草的瞬时水分利用效率(instantaneous water use efficiency,WUEI),而在7月初光照强烈、水分蒸发量大时,较多地补水更有利于提高牧草的WUEI。展开更多
基金Project supported by the Higher Education Links between China and UK (No. SHA/992/308)
文摘The objectives of the present study were to examine the spatial patterns of sward dry matter (DM) and nitrogen (N) yields in a grass silage field at first, second, and third cuts over a 3-year period; quantify their temporal stabilities with temporal stability maps; and assess the potential for site-specific management in each pasture-growing period using classified management maps. At cut 1, the spatial patterns of DM and N yields proved to be well defined and temporally stable and were likely to be due to differences in the net N mineralization rates across the field during spring. In contrast, at cut 2, the patterns of DM production were patchy and temporally unstable. It was concluded that, in principle, a simple site-specific approach to N fertilization would be possible in this field during spring at cut 1. At later harvests, the rationale for a site-specific approach to fertilizer management was less clear with logistics appearing to be more complex and less feasible.
文摘With the development of economy, meat gradually plays an important role in Chinese people’s dietary pattern. As the most direct reflection of agricultural system, food system has always been the main output of agricultural system, and pork has occupied an important position in Chinese food system. We attempts to find the systematical disorder of current agricultural system by analyzing the meat output of the agricultural system. H-P Filter and Grey Prediction GM(1,1) Model was adopted to explore the inner rules between pork production and agricultural system in China. The results indicated that pork consumption ratio in Chinese urban residents’ dietary pattern constantly kept about 6%, the growth potential of grain yield is limited while the growth potential of pork yield is increased in China. By Grey Prediction GM(1,1) Model, we predicted the pork yield would reach 59.07 Mt in 2020, 110.25 Mt in 2060, 205.78 Mt in 2100, the demand of feed would reach 177.22 Mt in 2020, 330.75 Mt in 2060, 617.34 Mt in 2100. In China, agricultural system is traditional “pork-grain” mode, feed has been one of the biggest section that consumed grain. The present “pork-grain” agricultural system cannot meet the huge demand of grain from feed, adjusting the agricultural structure is imperative. Reforming the current agricultural system into grassland agricultural system which takes the beef and mutton as predominates would be a good choice for China in the future.
文摘人工草地建设是缓解内蒙古地区草地生存压力的必要途径,而水分短缺是该区人工草地建设中牧草生长的主要限制因素,适量的人工补水以实现牧草的高产节水是解决这一问题的关键。以当地主要牧草冰草和紫花苜蓿为研究对象,开展单播和混播条件下不同灌溉量对牧草产量、光合性能和水分利用效率影响的对比试验。研究结果表明:(1)豆禾混播有利于提高冰草和紫花苜蓿的产量;(2)8月初现蕾期是冰草和紫花苜蓿收割的最佳季节,此时牧草产量最高;(3)灌溉量达到田间持水量的45%(包含降雨量在内的单位面积灌溉量在7月初达到903.8 m3/hm2,在8月初达到1812.4 m3/hm2)是牧草高产节水的最佳补水选择;(4)6—8月水分胁迫更有利于提高牧草的长期水分利用效率(long-term water use efficiency,WUEL),开花期后补水对提高牧草WUEL的作用开始显著;(5)在牧草产量最高的8月初水分胁迫更有利于提高牧草的瞬时水分利用效率(instantaneous water use efficiency,WUEI),而在7月初光照强烈、水分蒸发量大时,较多地补水更有利于提高牧草的WUEI。
