Response of rainfed bread and durum wheat to source,level and timing of nitrogen fertilizer on two Ethiopian Vertisols: II. N uptake,recovery and efficiency

In trials conducted at 2 highland Vertisol sites in Ethiopia in 1990 and 1991, 2 locally popular wheat cultivars, 1 spring bread wheat (Triticum aestivum L.) and 1 durum wheat (T. durum Desf.), were supplied with nitrogen (N) fertilizer at 0, 60 and 120 kg N ha^–1 in the form of large granular urea (LGU), standard urea prills or ammonium sulfate. N was applied all at sowing, all at mid-tillering or split-applied between these two stages (1/3:2/3). While durum wheat exhibited the highest N concentration in grain and straw, bread wheat, because of its higher productivity, resulted in a greater grain and total N uptake. In general, split application of N and use of LGU as N source enhanced grain and total N uptake, apparent N recovery and agronomic efficiency of N, particularly under severe water-logging stress. Where significant, the interactions among the experimental factors substantiated the superior responsiveness of the bread wheat cultivar to fertilizer N, and the beneficial effects of split N application and LGU as an N source. Split application of N tended to nullify the positive effects of LGU, presumably by approximating the delayed release of N achieved with LGU. Considering the potential benefits to Ethiopian peasant farmers and consumers, split application of N should be advocated, particularly on water-logged Vertisols; LGU could be an advantageous N source assuming a cost comparable to the conventional N source urea.     

磷复肥喷浆造粒“三内”技术研究与开发(一)

介绍磷复肥喷浆造粒“三内”技术 ,该技术集喷浆造粒、分级、返料、破碎为一体在转筒内完成全过程 ,实现机头喷浆机尾出产品 ,粉体在筒内闭式循环造粒新技术     

流动注射分析法对复合肥中五氧化二磷的分析

在复合肥的生产过程中，用流动注射分析测定磷矿，磷石膏，磷酸中的五氧化二磷，该方法制样简单，分析速度快，结果准确。     

我国化肥催化剂工业现状

全国48家化肥催化剂制造厂总能力为57Kt/a,产量近30kt/a,设备利用率不到50%。平均万吨氨耗催化剂10.36t,高于国外5.60t水平。现生产31个品种203个型号的催化剂中有103种经部级鉴定,但经常使用的约50种。目前化肥催化剂工业水平与国外相比还存在四方面差距。     

2000年化肥工业发展的几个问题

本文分析预测了我国２０００年的化肥需求量和世界化肥市场价格及其对我国化肥发展的影响。     

Increasing urea-N efficiency for transplanted lowland rice by pneumatic injection: Yield and economics at the farm level

To increase the fertilizer-N efficiency in lowland rice (Oryza sativa L.) cultivation, new management practices are needed. Main cause of the present low efficiency is the low N recovery by plants, as a considerable part of the N applied is lost; deep placement techniques improve the recovery. A pneumatic injector, with which urea prills can be point-placed at a depth of 5–10 cm in paddy soils, was tested in 38 on-farm trials in 1989/90, mostly during the wet season. The experiments, located in Africa and Asia, focussed on differences in grain yield between conventional methods of broadcasting urea and injection by the pneumatic injector, at recommended N-rates. The study shows that the pneumatic injector is effective as a tool to improve the N fertilizer efficiency. The average yield increases per region, resulting from the use of the injector, ranged from about 250 to 1300 kg grain ha^–1. The value of the yield increase would allow most farmers to recover the costs of the injector within one season, even if labour was hired to carry out the injections. The average labour requirement of the injector was 40 hours ha^–1. In Indonesia, injection of prilled urea gave yields similar to those obtained with urea briquettes.     

化肥企业质检机构的管理

针对我国化肥生产企业质检机构的现状 ,结合国家相关政策的要求 ,就如何搞好化肥企业质检机构的管理提出了诸多指导性意见     

Nitrogen fertilizer use in rainfed agriculture

Agronomic efficiency (AE) is defined as the increase in economic yield of a crop per unit fertilizer applied. Components of AE are physiological efficiency and apparent recovery fraction. The latter can be further separated into uptake efficiency and availability index. Ways to increase the nitrogen fertilizer use efficiency in rainfed agriculture through fertilizer management are discussed.     

高浓度烤烟专用肥肥效试验

介绍高浓度烤烟专用肥肥效试验。结果表明：楚雄磷肥厂生产的高浓度烤烟肥，可以代替进口的同类化肥。     

复合胺改性尼龙6的动态流变性能研究

在己内酰胺水解聚合时加入一定量的复合受阻胺，合成出含有复合胺的改性尼龙6树脂，研究了复合胺对尼龙6熔体的动态流变性能的影响。实验表明：随着剪切频率的增加，尼龙6熔体的复数粘度减小、储能模量和损耗模量均增大；但由于复合胺的加入，在尼龙6大分子链上引入了空间位阻基团，复合胺改性尼龙6熔体的复数粘度、储能模量及损耗模量均比未改性样增大；改性前后尼龙6的损耗因子均随剪切频率的增加呈现先增加后减小的变化趋势，在频率为18 rad／s的位置出现极大值——内耗峰，但改性尼龙6的峰值更大；改性前后尼龙熔体的lgG′～lgG″曲线均在对角线右下方，随复合胺的加入，曲线向右下方位移增大，熔体的粘性响应更明显。