广东坡地不同施钾处理春玉米吸钾特征及产量反应研究

Characteristics of K uptake by spring corn and its yield response to different K fertilizer treatments on slope land of Guangdong

针对广东旱坡地土壤钾素水平低、供钾潜力差这一问题,进行旱坡地春玉米钾吸收特征以及高产施肥技术研究。研究表明,玉米植株不同部位对钾的吸收量,以茎秆最大,占植株吸钾总量的55%以上,籽粒次之,占吸钾总量的18 51%～24 81%;苗期吸钾量比较少,不超过吸钾总量的1%,孕穗期吸钾量不超过吸钾总量的35%,吸钾量最多则在生长的中后期。当施钾肥量水平较底时,增施钾肥,可以显著提高玉米吸收N、P2O5的量;当施钾肥量水平中等时,增施钾肥,亦可以提高玉米吸收N、P2O5的量,但增幅趋缓;当施钾肥量水平较高时,增施钾肥,则会显著减少玉米吸收N、P2O5的量。利用钾素肥料效应方程式和试验结果,对春玉米产量与钾肥施用量进行了统计分析,确定了最高施钾肥量,并总结了玉米高产施钾肥技术。表3,参4。

In view of the problem that soil potassium level on the dry slope land of Guangdong is low, and its potential capacity of providing potassium is bad, the paper deals with the characteristics of K uptake by spring corn and the technique of applying fertilizer on dry slope land.It is found that the absorb amount to potassium of stem is the largest, reaching over 55% of that the total absorb amount to potassium of plant; the absorb amount to potassium of seed is the second place, reaching 18.51%-24.81% of that the total absorb amount to potassium.The absorb amount to potassium in the seedling stage is comparatively little, not reaching 1% of that the total absorb amount to potassium; the absorb amount to potassium in the booting stage not reaching 35% of that the total absorb amount to potassium.When the amount of applying potash fertilizer is low, applying potash fertilizer may remarkably lift the absorb amount to N and P_2O_5 of the spring corn; when the amount of applying potash fertilizer is middle, applying potash fertilizer may lift the absorb amount to N and P_2O_5 of the spring corn too; when the amount of applying potash fertilizer is high, applying potash fertilizer may remarkably decrease the absorb amount to N and P_2O_5 of the spring corn.The statistical analysis has been underway against the amount of applying potash fertilizer and the yield of the spring corn, and fixed the largest amount of applying potash fertilizer, moreover summed up the technique of applying potash fertilizer for high yield of the spring corn.