西南山地林下经济模式对土壤养分和土壤微生物数量的影响

为进一步加强农林牧业资源共享,推动生态农业的发展,在重庆市荣昌县6种不同的林下经济模式下,分别对土壤养分和微生物数量的变化及其相互关系进行了研究。结果表明,不同的林下经济模式对土壤养分的影响各有差异,有机质和全钾在麻竹林下养禽模式中增加最多,全磷在桉树林下养禽模式中增加最多,全氮、碱解氮、速效钾含量则在马尾松林下养畜模式中增加最多。从微生物总量来看,土壤中表现为桉树林下禽模式最多,其次为桉树林下种菌模式,最少的是麻竹林下种菌模式;腐殖层中最多的是麻竹林下养禽模式,最少的是桉树林下种菌模式。微生物数量与有机质、有效磷和碱解氮呈正相关关系。由于土壤养分和微生物数量的变化趋势不一致,因此在研究林下经济过程中应将二者结合起来。

Influences of Under-forest Economy Mode on Soil Nutrients and Microbe Quantity

In order to enhance the resources sharing among agriculture, forestry and animal husbandry and promote the development of ecological agriculture, researches on the change and interrelation of soil nutrients and the amount of microbes were separately conducted under six forest economy modes in Rongchang County, Chongqing City. Results show that soil nutrients were differently influenced by the under-forest economy modes. Organic matter and total potassium increased the largest in the raising poultry mode under Dendrocalamas, while total phosphorus increased the largest in the raising poultry mode under eucalyptus. Total nitrogen, available nitrogen and available potassium increased the largest in the raising poultry mode of Masson pine. In view of total microorganism biomass in soils, the poultry mode showed highest ratio in Eucalyptus, followed by the bacteria mode in Eucalyptus, and then the least one is bacteria mode in Dendrocalamas. The raising poultry mode under Dendrocalamas behaved the most, and the bacteria mode in Eucalyptus behaved the least in humus layers. The amount of microbes is directly correlated with the amounts of organic matter, available nitrogen and available phosphorus in soils. As the variation tendencies of soil nutrients and microbe quantity are different, the two should be combined in the study of under-forest economy processes.