小麦-玉米轮作土壤中磷肥化学行为及积累态磷生物有效性的研究

本文用改进的石灰性土壤无机磷分级方法系统地研究了河北省主要类型土壤的磷素形态，小麦 玉米轮作中水溶性磷肥施入土壤后的动态转化。研究结果表明，潮褐土、褐土、潮土的磷素形态为:无机磷占土壤全磷的73.2%～96.4%，Ca-P占无机磷的79.1%～90.8%，Ca10－P占Ca-P的51.7%～97.4%。小麦 玉米轮作中水溶性磷肥施入土壤后的化学行为:第一年，小麦和玉米共吸收利用了施入磷的２４.６％～２７.４％，作物主要消耗了土壤积累态Ca2－P，其次为Ca8－P；第二、三年，作物分别吸收利用了施入磷的１９.０％～２０.４％、１２.４％～１７.３％，主要消耗了土壤积累态Ca8－P，其次为Ca2－P、Ａｌ-Ｐ，再次为Ｆｅ-Ｐ。土壤积累磷以Ca8－P为主，其次为Ca2－P，再次为Ａｌ-Ｐ、Ｆｅ-Ｐ。土壤各形态无机磷的转化主要发生在Ca2－P与Ca8－P之间。化学磷肥与有机肥配施提高了土壤积累态磷的有效性。施用磷肥的效应在连续３年小麦-玉米轮作中均表现明显的增产效应。

THE TRANSFORMATION OF APPLIED PHOSPHORUS AND AVAILABILITY OF RESIDUAL P IN WHEAT-MAIZE ROTATION

The study on the transformation of applied phosphorus and availability of residual phosphorus in wheat maize rotation was conducted on calcareous soils for three years The results showed that inorganic P accounted for 73 2%～96 4% of total soil P, Ca P was 79 1%～90 8% of inorganic P, Ca 10 P, Ca 8 P, Ca 2 P was 51 7～97 4%, 1 7%～44 8%, 0 9%～3 6% of Ca P, respectively and 24 6%～27 4%, 19 0%～20 4%, 12 4%～17 3% applied P was taken up by wheat and maize at each rotation, respectively The main fractions of residual phosphorus was Ca 2 P, Ca 8 P Most of absorbed P by crops was Ca 2 P, Ca 8 P, Al P, Fe P, that was important P resource at successive cultivating P fertilizer used together with manure increased the availability of residual P compared with P fertilizer applied alone Adding P fertilizer during three years successively cultivating increased the yield of wheat and maize