The Fertility And Biochemical Response For HangBaiJu Chrysanthemum (C.Morifolium) Field Soil Received With Housefly Maggot-bioconverted Swine Manure Compost

Soil ecological environment plays a key role for sustainable agricultural development, so it's necessary to protect the soil environment and improve soil quality. In this research, we aimed to find out the ecological response and biochemical mechanisms of HangBaiJu chrysanthemum (C. morifolium) (8 years) soil received by a vermicompost which was bioconverted from swine manure by housefly maggot (Musca domestica). This research was made up of two parts, including lab-scale pot experiment and field-scale experiment. The main results were as follows:In both pot experiment and field experiment, the pools of carbon (C) and nutrients (N,P) had significant increases in soils received with vermicompost. Moreover the increase of C\N\P pools had positive correlations with the rates of vermicompost application rates. In pot experiment, soil total organic carbon (TOC) was increased by 9.5%-14.3%(p<0.05) among the vermicompost application treatment, compared to the control tests (CK). By contrast there was no significant effect on TOC concentrations in soil received with inorganic fertilizer. TN and TP were aslo increased with vermicompost. It is more prominent that the available nutrients (AN>AP>AK) in soil had a much more rapidly increase for the treatments of vermicompost application. Moreover, the results in field experiment were similar to these data in pot experiment. The findings verifited that maggot-bioconverted vermicompost had a key role in increasing soil C\N\P pools, and vermicompost application mixed with inorganic fertilizer is more beneficial for chrysanthemum to absorb nutrients.Soil microbial biomasses (MBC\MBN\MBP) are the important components of C\N\P pools and play a key role in C\N\P cycle in soil.In pot experiment, MBC in the soil received with maggot-bioconverted vermicompost was increased by 43.6%-72.4%(p<0.01) compared with inorganic fertilizer Treatements. However, MBN and MBP were changed diffferently in the soil received with vermicompost. Soil microbial biomass (MBC\MBN\MBP) had negative correlations with the rates of vermicompost application in field experiment. These findings indicated that excessive application of maggot-bioconverted vermicompost may be harmful for the activities of soil microorganisms.Some extracellular enzymes involved in organic C, N and P turnover were studied in the research. Dehydrogenase,β-glucosidase and cellulose were involved in C cycle in soil. In pot experiment, the activity of dehydrogenase was improved 10.8%-52.1%(p<0.01) in soil under vermicompost application. By contrast, in field experiment, the activity of dehydrogenase was decreased. The activity of P-glucosidase was improved in the treatment with inorganic fertilizer only in pot experiment in March. In field experiment, the activity ofβ-glucosidase was twice higher in the treatment with twice rate of vermicompost. The cellulase can be detected in the field experiment only, and the activity of cellulase was inhibited by excessive vermicompost applicatioin. Urease, NAGase and LAP were involved in N cycle in soil. In pot experiment, the activity of urease in the soil received with vermicompost was 100% higher than CK in March. In field experiment, the activity of urease was improved by high rate of vermicompost application. The activity of NAGase was different with urease. Acid and alkaline phosphatase play a key role in P cycle. In pot experiment, the activity of acid phosphatase and alkaline phosphatase were increased by 75.0% and 23.8%(p<0.01) among the treatments with vermicompost application only. In field experiment, the activity of acid phosphatase had no significant difference among the different treatments, but the activity of alkaline phosphatase was increased 76.9%(p<0.05) under the double rate of vermicompost application.The rates of soil C, N and P mineralization were also investigated. In pot experiment, the rate of soil respiration in the treatment with vermicompost only is 100%(p<0.01) higher than the control group. The application of vermicompost increased the rates of soil nitrification by 31.7%-55.1%(p<0.05), and ammonification by 64.6%-114.1%(p<0.05). The rates of P mineralization were increased by vermicompost which was similar to N mineralization. In field experiment, soil C, N and P mineralization rates showed similar characteristics as in pot experiment.Finally, co-inertia analyses were carried out to test the relationship between soil chemical properties and biochemical properties. The result shows that the parameters of soil fertility (TN, TP, TK, AN, AP, AK) had positive effect on soil biochemical properties (MBC, MBN, MBP, C mineralization, N mineralization, P mineralization, and enzymes involved in N cycling activity). It can conclude that application with vermicompost mixed inorganic fertilizer is good for plants growth and increasing the fertility of soil.