氮钾肥配施对赤红壤上甜玉米生长影响的研究

A STUDY ON THE EFFECTS OF NITROGEN FERTILIZER CONCINED WITH POTASSIUM FERTILIZER ON THE GROWTH OF SWEET CORN ON LATERITIC RED SOIL

本文研究氮、钾肥配施对赤红壤上甜玉米生长的影响,于1986年秋作和1987年春作进行两次盆栽试验及植株和土壤的化学分析。结果表明:氮、钾肥配施可增加供试土壤有效氮和速效钾含量,可增加甜玉米穗叶(吐丝明)含N量和含K量,降低穗叶含P量、含Ca量和含mg量。不施钾肥处理的甜玉米穗叶含K量≤1.30％,吐丝前有明显的缺K症。施高量钾肥(0.33克KCl/公斤土)处理的穗叶含Mg量≤0.15％;吐丝后出现明显的缺Mg症;施K_1水平(0.17克KCl/公斤土)的钾肥较适宜。单施氮肥处理,甜玉米果穗和籽粒的产量随施氮量增加而显著降低。配施钾肥处理,甜玉米增产率随施氮量增加而增大。增施氮肥可明显增加籽粒粗蛋白质含量,降低水溶性糖含量。施钾肥与不施钾肥比可明显增加水溶性糖含量,增加粗蛋白质总量(克/盆),但降低租旦白质含量。在供试赤红壤盆栽甜玉米条件下。

Experiments with pot culture were carried out in greenhouse both in Autumn of 1986 and Spring of 1987 to study the effects of N fertilizer combined with K fertilizer on the growth of sweet corn(Zea nays Var.rugosa)on Lateritic red soil.The 3 levels of N fetilizer apptication were 0.33,0.67 and 1.0g(NH4),SO4 Per kg soil,and the amounts of K fertilizer application were o,0.17 and 0.33g KCl per kg soil,respectively.Nine treatments with 9 replicates were made for available N,readily available K and slowly available K in the soil,total N,P,K,Ca and Mg in the ear leaves of the sweet corn plants at silking stage,yield and quality of the kernels.The experimental results are as follows:The application of N fertilizer combined with K fertilizer increased the contents of available N and readily available K in the soil,increased total N and K but decreased total P,Ca and Mg in the ear leaves.In the treatment with no K fertilizer application,the K content in the ear leaves was 1.30 % or<1.30%,and symptoms of K deficiency could clearly be indentified before silking.In the treatment with 0.33g KCl per kg soil,the Mg content in the ear leaves was 0.15% or <0.15%,and obvious symptoms of Mg deficiency appeared after silking.The plants in the treatment with 0.179 KCl per kg soil did not show any symptoms of deficiency.In the treatmemt with only N fertilizer added the yields of ears and kernels were Markedly decreased with increased N fertitizer.However,when K fertilizerwas incorporated,increasing the N fertilizer raised the kernel yield.At the same tine,increase in N application also raised the crude protein content of the kernels,but decreased the level of water soluble sugar.In comparison with no K fertilizer application,applying K fertilizer clearly increased the content of water soluble sugar in the kernels;but lowered the percentage of crude protein.The pot culture also suggested that applying 0.67g(NH4)2SO4 together with 0.11g KCl per kg soil for sweet corn plants growing on Lateritic red soil achieved betler economic benifit.