长期施肥对红壤旱地磷的影响

以12年的红壤长期肥力监测定位试验不同处理土壤为材料,研究了连续施肥对土壤磷组分和土壤对磷吸附解吸的影响。连续施用化学磷肥和化肥加有机肥,均可提高土壤全磷、有机磷、无机磷数量。施用有机肥料,土壤中的磷以Ca-P和Al-P积累为主要表现形式,化学磷肥的施用能够提高土壤的全磷,并以Al-P增幅为最大,在所有处理中均表现为土壤O-P相对稳定。有机肥料处理土壤对外源磷的吸附强度明显少于施用化学磷肥和不施用磷肥的处理,有机肥料能够显著提高吸附磷的再利用,在NPKM处理中解吸磷占吸附磷的47.72%,M处理中占42.89%,其它处理中解吸磷占吸附磷数量一般少于8%。有机肥与化学肥料配合施用明显提高磷肥的利用率。

The Effect of Long Term Fertilizer Application on Phosphorus in Red Upland Soil

The effect of long-term fertilizer application on P composition, absorption and desorption in soil was studied using the soil taken from different treatments of a long-term experiment for monitoring soil fertility. The soil total P, organic P and inorganic P content increased after applying chemical P fertilizer or mixing applying chemical P fertilizer and organic fertilizer. The accumulation of Ca-P and Al-P was the main phenomena if applying organic fertilizer. Applying chemical P fertilizer could increase soil total P, and the increment of Al-P was the highest. O-P in soil was relative stable in all treatments. The intensity of soil absorbing fertilizer P in the treatment with applying organic fertilizer was obviously less than that in the treatments with applying chemical fertilizer P or without applying P fertilizer. Organic fertilizer could significantly increase the re-utilization of absorbed P. The amount of desorption P was 47.72% of absorption P in the NPKM treatment, 42.89% in M treatment, less 8% in other treatment. Mixing applying chemical fertilizer and organic fertilizer could obviously increase utilization efficiency of P fertilizer.