不同施肥制度下茬口对作物产量增益、土壤养分状况及施肥贡献率的影响

根据1991—2002年共12年的田间试验,研究了不同施肥制度下,茬口对作物产量增益、土壤养分状况及对施肥贡献率的影响。结果表明:与重茬相比,豆茬较有利于作物的高产和稳产;施用氮肥使其产量增益减小,并且施用氮肥愈多,产量增益愈小;增施有机肥情况下,产量增益的减小更为明显。在土壤养分方面,豆茬不仅能提高土壤的供氮能力,还能改善土壤的供磷、供钾量,有助于土壤养分状况的改善;施肥制度进步能够提高作物产量;施肥贡献率随着施肥制度的进步逐渐增大,但其增幅趋缓;随着施肥制度的进步,施肥贡献率在豆茬和重茬上所表现的差异逐渐缩小,最后趋同。

Effects of stubble on crop yield-increase efficiency, soil nutrient status, and contribution rate of fertilization under different fertilization systems

Based on the 12 years field experiments in 1991-2002,this paper studied the effects of stubble on crop yield-increase efficiency,soil nutrient status,and contribution rate of fertilization under different fertilization systems.The results showed that compared with continuous maize stubble,soybean stubble contributed more to the high and stable crop yield,but applying fertilizer N made this yield-increase efficiency lower.The more the fertilizer N applied,the lower the yield-increase efficiency was.The decrease of yield-increase efficiency was more obvious under the application of organic manure based on fertilizer N.As for soil nutrient status,soybean stubble could not only enhance the capacity of N-supply,but also improve the capacities of P-and K-supply.The improvement of fertilization system could increase crop yield,and enhance the contribution rate of fertilization though the extent of the enhancement declined gradually.With the development of fertilization system,the difference of the contribution rate of fertilization between soybean stubble and continuous maize stubble reduced gradually,and tended to be equal at last.