The cost of organic conversion and lower crop yields than regular cotton ( at least in the early years after a switch ) have quelled farmers ' interest 有机转换的代价和有机作物比一般棉花收成低（至少在转变后的前几年）降低了农民的兴趣。
An attempt is made in this paper to review briefly the experiences of obtaining high crop yields and to identify what constrains maximizing crop yields in pakistan 本文努力简述巴基斯坦获得作物高产的经验和确认最高作物产量的限制因子。
Unfortunately the areas for expansion are rather limited but there exist a good potential to increase crop yields through the correct use of fertilizer and other inputs 遗憾的是扩大土地面积极为有限，但通过正确使用肥料和其它投入可提高作物产量。
Data on national and provincial crop yields and areas sown to the selected crops were obtained from the china agricultural yearbook , 1990 which reports 1989 data 几种作物的全国和各省产量及播种面积源于1990年中国农业年鉴，该书报导了1989年的数据。
In general , crop yields in latin american countries are low but scientific research has demonstrated that high sustainable yields are possible in tropical and subtropical areas 拉美国家产量通常很低，但科学研究已证明高产稳产在热带和亚热带地区已有可能。
The proof of professor lin ' s conviction is presented in table 1 , which shows the contribution of inorganic fertilizers to a variety of crop yields in 63 long - term studies 表1给出了林教授有说服力的材料，说明了在63个长期试验中各种无机肥料对多种作物产量的贡献。
However , balanced fertilization ' s influence over crop yield , value and net profits provides an opportunity to china ' s market economy that is too large to ignore 尽管如此，平衡施肥对作物产量、生产价值和纯利润的影响为中国的市场经济提供了一个不容忽视的巨大机会。
Examination of past research results indicates that crop yields , even in research trials hardly ever reach their yield potential , as calculated from soil moisture availability 考察以往的研究结果，即使在试验的条件下，也很难达到根据土壤水分有效性所计算出来的产量潜力。
Not only should fertilizer recommendations be made more site - specific but also the efficiency of applied nutrients be enhanced with a view to increasing crop yields in cropping systems 不仅施肥推荐应更针对具体地点，而且提高养分利用率也应以提高种植制度中作物产量为目的。
