摘要
近年来我省因施肥不平衡,作物缺钾状况日趋突出。80年代通过滇中地区多组钾肥试验结果表明,施钾在水稻、玉米、马铃薯上均有明显的增产效果,而早地玉米、马铃薯上施钾又比水田稻谷上效果明显。不同作物施钾肥效高低似与土壤速效养分中N/K比值有关。稻田N/K比高的施钾效果就好,旱作随N/K比增加,亩产反而降低。较适合的NPK比例稻田为1:0.5:0.5,旱地（玉米、马铃薯）为1: 0.5:1。经按亩施K_2O_4、8、12公斤用量的亩净增产量与土壤速效钾含量计算其回归方程,得出稻田土壤速钾临界值大体为169.25,110.86,77.2ppm,旱地大体为154.41,173.1,203.29ppm,要做到施钾充分经济有效,可在拟定钾肥用量曲线上选择低于土壤相应速钾临界值的田地施用。土壤速钾含量愈低,增产增收效益愈大,否则将得不偿失。本文还分别计算了钾肥效应曲线方程及其经济效益。
In recent years, K deficiency in crops has become serious because of fertilization imbalance. In 1980, the results of a large number of K fertilizer trials in the middle regions showed that the K fertilizer aPPlicalion has an obviouse effect on rice, maize and potato for yield increasing. Moreeo-ver, the efffct on maize and Potato in non irrigated land was more obviods than on rice in Paddy field. K fertilizer efficicency on various crops seemed to de relevant to N/K ratio in the available nutrient of soil. The higher the N/K ratio, the better the K fertilizer efficiency in Paddy field, on the contrary, the yield of upland crops dropped while the N/K ratio increased. The available NPK ratio in paddy field was 1:0.5:0.5 and that on maize and Potato in non-irrigated land was 1:0.5: 1. We obtained regression equation by culculating the net increase in yield and the content of soil available K. The crifical values of soil available K from the regression equations were 169. 25, 110.86, 77.2ppm in Ppaddy field and 154.41, 173.1 and 203.29ppm in non-irrigatde land by applied 4, 8, 12 Kg K2O respec tively. In order to apply K fertilizer economically and efficiently the soil available K of paddy field or non-irrigated land in stum be lower than the critica lvalues of soil available K. The lower the content of soil available K, the higher increase the yield and income increased after applying K fertilizer.From various curve equations of K fertilizer efficiency, the economic effect was analysed.
出处
《西南农业学报》
CSCD
1990年第2期92-95,共4页
Southwest China Journal of Agricultural Sciences
关键词
钾肥
肥效
云南中部
Paddy soil, Upland soil, Available K, Available N/K ratio, Crop yield, Middle Yunnan
