保水剂对橡胶树专用肥氮钾淋出特性的影响

目的]探寻减少橡胶树专用肥淋溶损失的途径,提高橡胶树专用肥利用率。方法]采用在橡胶树专用肥中添加保水剂的方法,模拟橡胶树每年第3次施肥期(9月份)的降雨量,开展间歇性土柱淋溶试验。研究了CMC(羧甲基纤维素钠),PAM(聚丙烯酰胺)和PAA(聚丙烯酸钠)这3种保水剂对橡胶树专用肥氮素、钾素释放特征及淋溶损失的影响,筛选保水剂及合理施用比例。结果]3种保水剂对橡胶树专用肥中氮素、钾素的淋失均有抑制作用,其中保水剂PAM用量为6%时对橡胶树专用肥中的氮素、钾素淋失抑制效果最佳。该处理对氮素、钾素首次淋失抑制率分别为44.73%,57.16%,淋溶结束时氮素、钾素累积淋出量分别较未添加保水剂的对照处理减少了20.20%,14.87%。结论]在橡胶树专用肥中添加保水剂可有效降低橡胶树专用肥中氮素、钾素的淋溶损失。

Effects of Water-retaining Agent on Leaching Loss of Nitrogen and Potassium from Special Fertilizer for Rubber Tree

Objective] The objective of this study is to explore the ways for reducing the leaching loss of speciel fertilizer for rubber tree in order to provide reference for increasing the efficiency of speciel fertilizer for rubber tree utilization. Methods] An intermittent soil column leaching experiment was conducted by adding water-retaining agent to speciel fertilizer for rubber tree, and the rainfall in the third fertilizer application-period(September) in each year was simulated. Three water-retaining agents including carboxyl methyl cellulose(CMC), polyacrylamide(PAM) and sodium polyacrylate(PAA) were selected. The effects of water-retaining agents on releasing characteristics and leaching losses of nitrogen and potassium from speciel fertilizers for rubber trees were explored to choose the proper application ratio of water-retaining agent and speciel fertilizer for rubber tree. Results] All the 3 water-retaining agents showed inhibiting effects on leaching losses of nitrogen and potassium from speciel fertilizer for rubber tree. PAM had the best inhibiting effect at a dosage of 6%, and the relative for nitrogen and potassium losses in the first leaching was 44.73% and 57.16%, respectively. Compared to the control treatment, accumulated leaching losses of nitrogen and potassium was decreased by 20.20% and 14.87%, respectively. Conclusion] Leaching losses of nitrogen and potassium from speciel fertilizer for rubber tree can be reduced by adding water-retaining agent to specific rubber fertilizer.