有机物料与~(32)P标记过磷酸钙混合施用对磷有效性的影响

本试验利用~(32)P示踪法研究赤红壤上两种有机物料与过磷酸钙混合施用对磷有效性的影响。盆栽试验表明,纸厂废料蔗渣或猪粪与磷肥混合施用比磷肥单独施用更有利于提高格拉姆柱花草的含磷量和总吸磷量。单位施磷量引起的土壤有效磷和植株吸磷量的增加量也是有机物料单施或与磷肥混施高于磷肥单施。在前39d,~(32)P标记过磷酸钙的利用率在单独施用时为2.14％,比混合施用高一倍左右;在80d时,混合施用的磷利用率较快提高,蔗渣与磷肥混施处理超过单独施用,达22.88％。

EFFECT OF MIXED APPLICATION OF ORGANIC MANURE AND ~(32) P-LABELLED SUPERPHOSPHATE ON PHOSPHORUS AVAILABILITY

The pot experiments were conducted to study the availability of phosphorus from~(32)P-labelled superphosphate, hog manure, bagasse and their mixtures to stylosanthes guianensis CV. graham on latored soil. The results showed that the application of the fertilizers substantially increased the phosphorus uptake by plants and the forage grass yield. The mixed application of organic manure and superphosphate increased more soil Olsen-P and phosphorus uptake by plants than the single application of superphosphate. The phosphorus from organic manure was more available than that from inorganic one. For the first 39-day, the phosphorus utilized coefficient for the single application of superphosphate was 2.14%, which was 2 times as much as that for the mixtures. For the 80-day period, the mixing of organic manure and superphosphate increased the phosphorus efficiency, and the mixture of bagasse and superphosphate obtained a highest utilized coefficient of 22.88%.