磷肥施入方式对土壤速效磷含量及玉米生长的影响

2016年和2017年分别进行了玉米盆栽和大田试验.盆栽试验中,磷肥施入方式设置磷肥基施和磷肥分3次随水施入2种,滴灌带埋深设置0,15,30 cm 3个水平.大田试验中增加了地表滴灌不施磷肥处理作为对照.结果表明磷肥以随水施入方式分次施入土壤时,能提高土壤剖面中速效磷含量,土壤剖面中速效磷呈随距滴头距离增加而减小的趋势.磷肥随水施入措施可以有效促进作物生长及产量形成,对玉米产量的影响在α=0.1水平上达到显著.滴灌带埋深为15 cm时,作物生长及产量优于地表滴灌处理.当滴灌带埋深为30 cm时,在一定程度上降低了施入磷肥对作物生长的促进作用.建议采用地下滴灌磷肥随水施入方式,但也应该避免使用过深的滴灌带埋深.

Effects of phosphorus fertigation on distribution of Olsen-P in soil and yield of maize

Pot and field experiments of maize(Zea mays L.)under drip irrigation were conducted to evaluate the effects of phosphorus fertigation and lateral depths on the distribution of Olsen-P in soil and growth and yield of maize in 2016 and 2017, respectively. Three lateral depths at 0, 15, and 30 cm beneath the soil surface and two phosphate fertilizer application methods(single basal application and split fertigations)were tested in both years. Another treatment with no phosphate fertilizer applied was considered in the field experiments as control. The phosphorus fertigation could improve the efficiency of phosphate fertilizer while the strong phosphorus adsorption was also observed. The phospho-rus fertigation significantly improved the growth and yield of maize and the phosphate fertilizer application methods imposed significant effects on the yield of maize at a significance level of α=0.1 for both the pot and field experiments. The treatments with lateral depth at 15 cm generally obtained higher yields than the treatments with lateral depths at 0 cm. However, poor phosphorus availability might be found for the crops while the drip laterals were buried at 30 cm and thus limit the growth of crops. The phosphorus fertigation and subsurface drip irrigation are recommended to improve the use efficiency of phosphate fertilizer while a large lateral depth should be used with cautious.