东北黑土农田玉米适宜NPK用量试验研究

采用NPK三因素多水平的不完全设计，通过连续多年的小区定位试验，在12个不同NPK用量的配方中筛选出适合东北地区大豆一玉米轮作条件下的玉米适宜肥料用量。由于每小区包含有连续多年的肥料效应，理论上可提供更多的养分信息，生产实践上更为实用。初步研究结果表明：玉米适宜施氮量为162．1kg／hm^2。施磷不同用量之间，增产效果无明显差别。由于磷素的土壤积累，磷肥增产作用已经明显低于20世纪80年代，玉米对施磷的需求量降低，但氮素对磷素有显著的协助作用，施氮能显著促进玉米对磷素的吸收。建议当前玉米生产施磷量20kg／hm2—60．9kg／hm^2。图5，表2，参13。

The Study of Apt NPK Dosage in Maize Rotation District

This study adopts the imperfection trial design with NPK three factors and more levels.The examinations selected apt NPK dosages through a longtime continuous field test which was based on twelve levels in soybean-maize rotation district.It was more practicable that more nourishment information can be offered on theory because a longtime continuous fertilizer was effective in each examination district. The pilot study result showed that the appropriate amount of nitrogen application for maize was 162. 1kg/hm2.It was not distinct different among the dif-ferent phosphoric treatment groups. Because of the accumulation of soil phosphorus, the increased production by phosphate fertilizer was signifi-cantly lower than that of the 1980s. Phosphoric fertilizer requirement in Maize was decreased. Nitrogen had assistance role in promoting the phos-phoric absorption. The recommended amount of the phosphoric fertilizer application was 20 kg/hm2-60.9kg/hm2.