采用施肥比计算大白菜施肥量的初步研究

在不施有机肥情况下,采用施肥比(施入养分量/吸收养分量)和测土施肥参数相结合的方法,研究大白菜的施肥量。池栽和大田小区试验结果表明,青岛地区大白菜亩产5000～9000公斤,三要素施肥比分别为氮1.51,磷0.81,钾0.82,三者与大白菜产量呈显著负相关。利用该施肥比求得的大白菜氮、磷、钾施肥比例为1:0.24:0.60～0.64。大白菜从土壤中吸收的氮、磷、钾分别占总吸收量的73.7％、98.6％和67.3％;化肥利用率为钾43.0％>氮19.8％>磷2.3％,与三要素化肥增产效果一致。

PRELIMINARY STUDIES ON CALCULATING RATIO OF NPK TO CHINESE CABBAGE

Under the conditions of non-applicating organic fertilizers, the fertilizer rates for Chinese cabbage (Brassica pekinensis) were studied by adopting fertilizer ratio (nutrient amount given/amount absorbed by crop) in combination with fertilization parameters determined on soil. The trial results of culture in greenhouse cement pools and on field plots revealed that in the area round Qingdao for Chinese cabbage to produce 5000—9000kg per mu, or 75000—135000kg ha~(-1), the NPK ratio must be kept at 1.51: 0.81: 0.82. The NPK ratio was in significantly negative correlation to the crop yield and the best ratio calculated being 1: 0.24: 0.60—0.64. The NPK absorbed from soil was 73.7, 98.6 and 67.3％ of the total amounts got by the crop.