关键词: 化肥需求比例, 作物生产, 有机肥, 土壤养分供应, 有效养分, 模拟模型

Abstract: Based on the mass balance of available nutrients and the all experimental results published later after 1980, the present study simulated nutrient uptake, and nutrient supplies from soils, applied chemical fertilizers and manures in the whole China; and then predicted the optimal ratios of N, P, K fertilizers required for crop production in the country. It is predicted that the optimal ratios of N∶P₂O₅∶K₂O would be 1:0.38:0.25 for N, P, K fertilizers in the year of 2000. It is indicated that chemical fertilizers and manures contributed 34% and 18% to the total crop N demand, 18% and 25% to the total crop P demand, 13% and 19% to the total crop K demand, respectively, while the other percentages were occupied by soil supplies. Manures which are traditionally employed as main fertilizers in China supplied a large quantities of nutrients, especially K and P, to crop production. Therefore, the application of manures had great effects on the prediction of demands and ratios of chemical fertilizers although little attention on this disturbance has been paid to the prediction of fertilizer demands until now.

Key words: requirement of chemical fertilizer, crop production, manure, soil nutrient supply, available nutrients, simulation model