陵县试区土壤速效磷、钾养分的演变浅析

Temporal variability of soil phosphorus and potassium nutrients in Lingxian experimental region

本文研究了山东省陵县土壤养分定位监测试区土壤速效磷、钾养分随时间的变异。结果表明,1992～2002年10年间,耕层土壤速效磷含量呈上升趋势,增加0 33mg L-1 a-1;而土壤速效钾含量呈下降趋势,降低1 52mg L-1 a-1。土壤速效磷和速效钾养分时间变异趋势与土壤磷养分平衡处于盈余状态和钾养分平衡处于亏缺状况有关,土壤 作物系统内磷素(P)盈余平均为38 6kg hm-2 a-1,其实际平衡盈余率大大超过合理的范围,磷肥用量明显偏高,未得到合理高效利用;而钾素(K)亏缺平均为95 7kg hm-2 a-1,其实际平衡亏缺率略低于允许平衡亏缺率,若试区土壤钾素长期处于亏缺状态,会明显降低土壤供钾能力。

Temporal variability of soil phosphorus and potassium nutrients in Lingxian experimental region was studied. The results indicated that available P contents of plow layer soil samples showed a general tendency with increase of 0.33 mg.L^(-1).a^(-1) in 4 sampled times from 1992 to 1997,1999, and 2002, while soil available K contents with a decrease of 1.52 mg.L^(-1).a^(-1). Temporal variability of soil phosphorus and potassium nutrients was related to nutrient balance of phosphorus and potassium in soil-crop system. Phosphorus (P) surplus was 38.6 kg.hm^(-2).a^(-1), and phosphorus real surplus rate greatly exceeded its rational range, phosphate fertilizer was not efficiently used. Potassium (K) deficit was 95.7 kg.hm^(-2).a^(-1),and potassium real deficit rate was lower than its permissible deficit rate. If soil potassium in Lingxian experimental region was deficient for long-term, soil potassium supplying power will decrease significantly.