Research on Change Low Output Forest of C itrus changshanhuyouin Red So il Hilly of J inqu Ba sin

The results of research on the influence to the output, quality and nutrition of the soil when taking somemeasure such as fertilizing, bagging and covering , taking the low output Citrus changshanhuyou grew 10 years inthe hilly district of red soil in Quzhou ( Zhejiang Province). The result showed that coverage imp roved the appearance and quality of the fruits of Citrus changshanhuyou. Fertilizer, p ig manure or bio-organic fertilizer could allraise the percentage of N , P , K and organic matter in soil . But the effect of taking bio-organic fertilizer and pigmanure wasmore obvious that availN , avail P and avail K in soil increased by 2 to 7 times of CK , totalN , totalP and organic matter increased by 2 to 3 times and the output increased by 60% to 97% . Taking p ig manure increased the ratio of sugar and acid, imp roved the quality of fruits. The coverage on summer decreased temperatureof soil in Citrus changshanhuyou garden and frequency of appearance of high temperature obviouslywhich made Citrus changshanhuyou in a more app rop riate environment of soil’s temperature. The average surface temperature inJuly to Sep tember decreased by about 1 ℃ and the temperature of soil 20 cm below the surface decreased by 1. 6 -119℃ . The higher the temperature raised, the more obvious the effect of the coverage making temperature lowerwas. Coverage which raised weight of single fruit by 10. 6% to 15. 0% and output of single tree by 13. 0% to 16.6%, decreased evaporation of soil’smoisture, increased water and organic matter in soil and helped fruits to grow.