滴施磷酸二氢钾后土壤中磷的移动和分布

在室内采用土柱模拟滴灌施P肥,研究了P在土壤中的移动和分布。试验结果表明:①滴施含P量200mg/L的KH2PO4后P在砂壤土、轻壤土、重壤土中分别纵向移动了22、16、14cm。横向和纵向移动的距离基本相同。②随着滴施P浓度的增加,P的移动距离增大,P的主要累积层加深。赤红壤中滴施P浓度200、400、800、1000mg/L时,P分别移动了12、16、20、22cm,而且有效P和全P含量增加显著的土层深度分别为0～8、0～12、0～18、0～20cm。在相同质地情况下,滴施高浓度P肥溶液可以明显增加P的移动距离。

Movement and distribution of phosphorus in soil under drip fertigation of KH2PO4 solution

In order to evaluate the movement and distribution of phosphorus fertilizers in soils under drip fertigation, a soil column experiment was conducted to simulate drip fertigation. The results indicated that: (1) KH2PO4 moved vertically 22 cm in sandy loam soil, 16 cm in light loam soil and 14 cm in clay loam soil, respectively; P moved similar distance both in vertical and horizontal direction. (2) In lateritic soil, the higher P concentration was, the longer distance P moved in vertical direction. In terms of available P, vertical P movement in treatments of 200, 400, 800 and 1 000 mg/L were 12, 14, 20 and 22 cm, respectively; Both of total P and available P were significantly concentrated in the layer of 0 - 8, 0 - 12, 0 - 18 and 0 - 20 cm in the treatments of 200, 400, 800 and 1 000 mg/L, respectively. It is concluded that drip fertigation with high P concentration solution could increase the distance of P movement