Study On Soil Ecological Effect With Different Mulching Measures In Tea Garden

The field experiments were conducted to study the effects of different mulching measures on soil temperature, soil moisture, soil nutrient, dynamic variation of soil microbial biomass, yield and quality of tea garden at Changsha county in Hunan province from 2004 to 2005. We found that the change rule of soil microbial biomass C,N,P and the difference of different mulching measures in subtropical hilly region, analyzed the dependency relation of main factors among them. The results were showed as follows:Mulching measures had double effects on adjustment to soil temperature. The effects not only increasing of soil temperature when the air temperature was low but also decreasing of soil temperature when the air temperature was high, particularly, in the top soil layer. The effect could alleviate the damage to roots in the period of low temperature. Compared to ck, the changes of soil temperature with mulching were smaller in a year, and the effects were decreased with deepen of soil layer.Mulching increased soil moisture in tea garden. Effects of water storage and water conservation which caused by mulching were very apparent. The effect of mulching on soil moisture differed in different depth of soil, generally is better in lower soil layer. Especially in July, August when there was lack of rainfall in subtropical hilly region, the effect of water storage and water conservation was apparent. As compared to ck, the water storage of the treatment which covered straw or grass was apparently increased. The straw mulching increased 20.84 percent, whereas the grass mulching increased 11.58 percent.Mulching measures increased the content of soil organic matter, total N, total P, and total K in tea garden. The increase of soil organic matter was apparent, compared to ck there was a 32.41 percent increase with straw mulching, and a 24.46 percent increase with grass mulching.The monthly dynamics of Soil microbial biomass carbon (SMBC) showed that the straw mulching had the highest in June and the lowest in December, the grass mulching had the highest in June and the lowest in March, and the ck had the highest in July and the lowest in December. The variance of SMBC was very significant between different treatments in soil surface (0～20cm). But it was not obvious...