旱地土壤的合理施肥——Ⅷ.土壤不同层次速效磷与作物对磷肥反应的关系

Rational application of Fertilizers on Drylands Ⅶ. The relationship between available P at different layer and crop response to P fertilizers

在永寿旱塬地区不同肥力的25个田块上,安排了小麦对磷肥反应的试验;同时采集供试田块的耕层(0～25cm)及0～100cm不同层次土壤,分析了其有效磷含量,研究小麦对磷肥反应和不同层次供磷量的关系。研究表明,整个看来,土壤速效磷在0～45cm范围内逐渐下降,而在45～100cm范围内大致趋于稳定。速效磷含量与小麦产量、吸磷量呈正相关,与吸磷量的关系更为密切。随着层次加深,相关系数提高,到达一定深度,所有相关系数均达到1％的显著水平。

Twenty-five field experiments were arranged on drylands in Yongshou County, and soilswere sampled from both plowing layer (0-25cm) and different depths of 0-100cm to study therelationship between wheat response to P fertiliser and available P at different,depth in soil. Theresults obtained show that the available P was high at toplayer, but low at deep layer. Itdecreased from surface to 45 cm, and then was stable from 45 to 100cm. The available P waspositively correlated with both wheat yields and P uptake by plants, the correlation being higherwith P uptake. the deeper the layer, the higher the correlation coefficient. The coefficient couldbe significant at 1% level when the layer reached certain depth.