蚯蚓活动对红壤磷素有效性的影响及其活化机理研究

通过盆钵生物试验研究了秉氏环毛蚓(Pheretima pingi.)在红壤基质中对稻草、花生秸、油菜秸3种有机物料分解速率的影响，研究了蚯蚓活动对红壤全磷含量和有效磷含量、对土壤碳水化合物含量、土壤磷酸酶活性的影响。并着重探讨了人工接种蚯蚓提高红壤有效磷的效果及其活化机理。研究结果揭示：①蚯蚓活动促进了有机物料的分解，加速了磷素的生物归还作用；②方差分析示明，在培养期间所有处理的土壤有效磷含量均得到显著或极显著提高；其中有机物料接种蚯蚓的3种处理分别与其不接种蚯蚓的处理的土壤有效磷含量之间差异均达显著水平；③蚯蚓活动有改善红壤酸度状况的趋势，同试验前比较(原土的土壤pH(H2O)=4．34)，在培养试验后期，3种物料接种蚯蚓的土壤pH(H2O)值分别提高了0．17单位(稻草接种蚯蚓处理)、0．35单位(油菜秸接种蚯蚓处理)和0．44单位(花生秸接种蚯蚓处理)；方差分析显示，花生秸组两处理间和油菜秸组两处理间的土壤pH值的差异达到显著水平。在150d的培养期内，3种有机物料接种蚯蚓的处理与其不接种蚯蚓的处理比较时，土壤pH值的差异亦达到显著水平；④蚯蚓活动增加了土壤碳水化合物含量。方差分析结果显示：3种有机物料接种蚯蚓的处理与不接种蚯蚓处理的土壤碳水化合物含量之间的差异均达到显著水平；⑤蚯蚓活动增强了土壤微生物活性和土壤磷酸酶活性。蚯蚓的吞食、排粪等生理过程改变了土壤微生物种群类型及其数量；蚯蚓活动提高了土壤磷酸酶活性，增加了土壤中有机磷含量，从而提高了土壤有效磷含量。蚯蚓活动及其特殊的生理过程所产生的综合作用使土壤有效磷含量和磷素有效性明显提高。

Influence of earthworm activities on phosphorus availability of red soil and activated mechanism induced by earthworm

The influence of inoculating earthworm (Pheretima Pingi. ) on phosphorus availability in red soil was studied by conducting pot experiments. Various aspects including decomposition of organic materials (rice straw, peanut residue and rape residue), soil total phosphorus and available phosphorus, soil carbohydrate content and soil phosphatase activity were taken into account. In this paper, the effect and mechanism of increasing phosphorus availability in red soil due to the inoculation of earthwormwere mainly explored. The main results were summarized as follows: (1) Earthworm activities accelerated the decomposition of organic materials and the biological returning of phosphorus in the soil ecosystems, which made phosphorus in the organic materials a direct part of soil available phosphate. Significance on the decomposition of organic materials is in the descending order of peanut residue>rice straw>rape residue. (2) Variance analysis showed that the available phosphate for all the treatments increased significantly during a 150 day incubation. Differences of the soil available phosphate contents between the treatments with organic materials plus earthworms and the treatments with organic materials but earthworm free were significant. (3) There was a tendency of improving red soil acidity by earthworm. As compared to the soil pH value (pH(H 2O)=4 34) at the beginning of incubation, the pH values increased 0 17 for the treatment with rice straw plus earthworm, 0 35 for the treatment with rape residue plus earthworm and 0 44 for the treatment with peanut residue plus earthworm, respectively. (4) Earthworm activities increased the content of soil carbohydrate. Statistical analysis indicated that the carbohydrate contents in the soil with organic material and earthworm increased significantly. (5) Inoculation of earthworm enhanced soil microbial activities and soil phosphatase activity. The physiological processes of earthworm's swallowing and excreting changed the population types and the quantities of soil microbe. Improvement of the soil phosphatase activity by inoculating earthworm increased the soil organic phosphorus and thus the soil available phosphorus content was raised. The integrative aspects of earthworm activities and its special physiological process enhanced the content of available phosphorus and the phosphate availability of red soil.