Researching On The Dynamic Change Of Soil Nutrient And Characteristics Of Microorganism In Bamboo Forests

In this dissertation, we researched soil nutrient dynamic change and ecological characteristics of microorganism in bamboo forests using the incubation experiment, and field experiment. Information provided in this work may contribute to a better understanding soil carbon and nitrogen in bamboo soil environment, which will be useful reference for application fertilizer reasonable. Main original conclusions are shown as follows.1. The dynamic changes of soil carbon and nitrogen and ecological characteristics of microorganism were investigated during bamboo high-speed growth in bamboo forests. The results showed that various nitrogen forms (total nitrogen, alkaline hydrolysis nitrogen, ammonium nitrogen, nitrate nitrogen) and carbon forms (organic carbon,20℃DOC,80℃DOC) were decreased in different degree during bamboo growing. Total soil nitrogen (TN) and total organic carbon (TOC) reduced by 21% and 18%, respectively, and also TN and TOC were strongly inter-correlated (R2=0.89**), which showed that the soil carbon and nitrogen decreased significantly during bamboo high-speed growth, soil microbial biomass carbon was also decreased greatly with the range of 261mg/kg. The PLFA analysis indicated that with the soil nutrient consumption during bamboo high-speed growth, the PLFAs that represented bacteria and total PLFA decreased, while the PLFAs that represented fungi increased. Thus, the change of soil nutrient effect soil microbial community structure significantly in bamboo forests.2. The effect of different fertilizer treatments on soil nutrient migration and microbial community structure in bamboo forests were investigated. The result showed the ammonium nitrogen, nitrate nitrogen and available phosphorus in different fertilizer treatments all followed the order:FFP>SSNM>CK. Soil microbial biomass carbon and nitrogen in FFP was higher than that in SSNM, while the ratio of C/N was 34 in FFP. Soil surface losses analysis showed that particle nitrogen (PN) and water-soluble nitrogen (DN) were the main form of total nitrogen losses, while DN was the main pollution for the water. Under different fertilizer treatments, the loss of DN followed the order:FFP> SSNM> CK. The PLFA analysis showed that the PLFA content varied with different fertilizer treatments. It was also showed here that the soil microbial community structures varied in response to various fertilizer treatments. The summed abundance of the PLFAs which could estimate bacteria and fungi all followed the order:FFP>SSNM>CK, while the ratio of G+/G- followed the order:CK>FFP>SSNM. 3. Nutrients release (N, P, K, Ca and Mg) from bamboo forest were studied under different fertilizer treatments (CK, SSNM, FFP) by using UNIBEST (the universal bioavailability environment/test) ion-exchange resin method. Results showed that the release of N,P significantly increased with fertilizer increased. The resin capsules absorption of NH4+-N was 23.2umol/cm2 in FFP, which was more than SSNM. Resin capsules absorption of N and P in different fertilizer treatments followed the order:FFP>SSNM>CK. The result also showed the content of ASON increased significantly with the fertilizer increased. The dynamics of bamboo soil nutrient release was fit to equation RAQ(i,t)=atb, a and b are the constants, RAQ means resin adsorption quantity, t means incubation time.