Effects Of Straw Mulching On Soil Organic Carbon And Available Nutrient Contents In P.salicina Plantation

Prunus salicina plantation in Guizhou karst region was studied as the research foreststand. Forest surface soil was dealt with different types of mulch materials and differentamount. Based on field investigation and laboratory test, seasonal change of soil organiccarbon components and soil available nutrients were determined. The results were describedas follows:(1)Whether corn straw mulching, rice straw mulching or no coverage, in the0to30cmsoil, the performance of the seasonal change of soluble carbon and microbial biomass was:spring>summer>autumn> winter.(2) The hydrolysis nitrogen contents in the0-10cm surface soil of processing area andcontrasted zone were described a similar rule: in the autumn presented peak, in the spring andsummer presented center, in winter presented the lowest. The available phosphorus contents of0-30cm soil were described a rule: higher value in the autumn and winter, but a lower value inthe spring and summer. The available potassium contents of0-30cm soil were described a rule:the contents in summer and autumn were significantly higher than those in spring and winter (P<0.05),but in summer and autumn, the difference was not significant, the same as availablepotassium contents in spring and winter.(3)In each season, the more volume rice straw and corn straw mulched, the stronger theeffect of DOC, MBC interception was, the accumulation of DOC, MBC in the surface layerwas very outstanding. In the surface soil (0to10cm), with the same type of material mulching,the more volume rice straw and corn straw mulched, the higher hydrolysis nitrogen andavailable phosphorus contents were. in10-30cm soil layer, the relationship between hydrolysisnitrogen contents and the amount of coverage was not obvious.(4) Under the same amount of coverage, the DOC contents of the0-10cm surface soilwith corn straw mulching were significantly higher than those with rice straw mulching (P <0.05).But in10-30cm soil layer, the difference was not significant. The MBC contents of0-30cm soil with corn straw mulching were significantly higher than those with rice strawmulching (P <0.05).(5)Under the same amount of coverage, the hydrolysis nitrogen contents of the0-20cmsoil with corn stalk mulching were higher than those with rice straw mulching. The soilavailable phosphorus contents of the0-10cm surface soil with corn straw mulching were higherthan those with rice straw mulching. The available potassium contents of0-30cm soil were notregular in the spring, summer and autumn, but in the winter, the available potassium contentsin the area which was covered by corn straw were higher than the area which was covered by rice straw.In conclusion, straw mulching could be effective in the soil nutrient storage, And theaccumulation of surface nutrient was very outstanding. The more coverage, the more obviousin storing nutrient. And the use of corn straw mulch was superior to the effect of rice strawcovered. Therefore, using straw mulching in the karst area was available to improve soilenvironment and economic forest survival rate.