| Red soil was highly weathered and leached, and contained low pH and nutritive element content, which became less good for growing crops. Resource utilization of rice straw has been an important issue in present agriculture development of our country. Straw returning is frequently used, with low efficiency caused by the difficulty of degradation and the shortage of technology. The microbial transformation of rice straw includes the decomposition of rice straw, cultivation edible mushroom and so on. Cultivation mushroom is welcomed for the utilization of waste residue. The application of spent mushroom compost (SMC) has also been reported.In this thesis, experiments were carried out on the whole rice straws reused for cultivation of edible mushroom. Five treatments were carried out to compare the output and economical benefits, which were oyster mushroom and phoenix-tail mushroom planted in the raw material by ridge cultivation, oyster mushroom and needle mushroom planted in the clinker by bag cultivation, and oyster mushroom planted in the raw material by bag cultivation. Mushroom residues under bag cultivation of oyster mushroom in the clinker were determined by chemical analyses after the oyster mushroom harvested. The yields (1.60kg/kg substrate) and economic benefits (4.62yuan/kg substrate) of the oyster mushroom were highest in constituting ratio of100%straw litter. The results showed that contents of total nitrogen and phosphorus were decreased, but total potassium was increased during decomposition of rice straws.We also study the decomposition of rice straw adding decomposition agent. Treatments were prepared by mixing rice straw2kg, with the decomposition agent8g, and urea at the mass of60g,37g,37g and27g, and cow manure at1100g,400g,1100g, and1100g, respectively. Treatment of rice straw2kg, with the decomposition agent8g, and urea25g were used as the control. The rice straw of the treatment of urea37g and cow manure1100g was well degraded judged by the temperature of pile, and the appearance, germination index and nutrients of the decomposing products.Finally, the potential utilization of SMC and cow manure compost (CMC) was studied by the effect on the quality of soil, and the yield of peanut. Three types of red soil were used in pot experiment, Quaternary red clay, latosol, and latosolic red soil. Fertilizers were prepared by mixing SMC at the rates of0%,40%,40%,20%and20%of total nitrogen, with CMC at40%,0%,20%,0%, and20%, and urea at60%,60%,40%,80%, and60%, respectively. Conventional urea (100%urea N) and fertilizer with20%CMC N+80%urea N were used as the control. Soil organic matter and soil nutrients, the numbers of bacteria, fungi and actinomyces, the content of soil microbial biomass carbon, the morphology of peanut plant and the yield of peanut was analyzed. Fertilizer with40%SMC N and40%SMC N+20%CMC N showed a increase in above indicators compared to the control in Quaternary red clay, and fertilizer with40%SMC N+20%CMC N was better.Field plot experiment was carried out in Quaternary red clay with seven treatments the same with pot experiment and one treatment of fertilizer with GURUN. Soil organic matter and soil nutrients, the content of soil microbial biomass carbon, the morphology of peanut plant and the yield of peanut was analyzed. Fertilizer with40%SMC N and40%SMC N+20%CMC N showed a increase in above indicators compared to the control, and fertilizer with40%SMC N+20%CMC N was better.Above all, microbial transformation is an effective methods to degrade rice straw and improve nutritional condition. These results indicate that SMC and CMC can be considered as alternative organic fertilizers for growing peanut in upland red soil. |
