Crop production and input requirements in developing countries
建立模型分析发展中国家作物生产技术，估算28种作物在雨养和灌溉土地上的增产潜力及投入需求，结果显示1980-2000年间若年增产3.5%，耕地需年增0.9%，灌溉地年增1.7%，投入年增5.8%。
This article describes a model developed to analyse crop production technology and to estimate possible increases in crop production and associated input requirements in developing countries. Production increases are defined for 28 crops, each of which is grown in one or more of six classes of rain-fed and irrigated land at specified yield levels. The estimation and analysis is carried out for each one of 90 developing countries, which together account for 98% of the population of the developing world, not counting China. The results show that for a 3.5% per annum increase in crop production over the period 1980–2000 in the 90 developing countries (the growth rate was 2.9% per annum in the period 1966–1981), arable land has to expand at a rate of 0.9% annually, while irrigated land should increase at 1.7% per year. Current input use should increase at 5.8% per year, of which agricultural inputs should grow at 4.3 and non-agricultural inputs at 7.1%.