The Effect Of Planting And Breeding Wastes On Soil Organi Carbon And Soil Enzyme Activity Under Rice-wheat Rotation System

At present,a lot of this study is not recycling, on the basis of organic fertilizer and straw burning condition frequently, through field experiment in the Chengdu plain field, research of the Chengdu plain rice and wheat crop rotation system under different ratio of planting and raising waste counters-field influence on soil organic carbon and enzyme activity, and the mechanism of different soil layer soil organic carbon, find out the best ratio of planting and raising returning waste, for the region, more efficient agricultural waste recycling,The treatment of fertilization were set as no-fertilizer(CK), normal chemical fertilizer (NKP), manure with 5000kg/hm2 and chemical fertilizer (NKM1), manure with 10000kg/hm2 (NKM2), manure with 20000kg/hm2 (M3), manure with 20000kg/hm2 (M4), chemical fe20rtilizer and straw (NPKS), manure with 10000kg/hm2 and straw (M3S), manure with 30000kg/hm2 and straw. Soil sample were collected in different growing period of wheat and rice at 0-20cm soil layer. The aim of this study was to analyze the effect of different fertilization treatment on soil total organic carbon, soil water soluble organic carbon, soil dissolved organic carbon, readily oxidizable carbon and soil enzyme activity, and the dynamic changes of soil labile organic carbon along the growing period. The mainly results as follows(1) The experiment of wheat and rice indicated that the treatment of manure and straw amendments could significantly increase the concentrations of TOC and soil labile organic carbon.In 0-20 cm soil layer. TOC, WSOC, DOC and ROC content are increased with increment of manure.Organic carbon and its components under treatment of straw return are greater than the corresponding no straw returning treatment, high quality of manure and straw with the most obvious effect on soil organic carbon and its components, rice and wheat season TOC, WSOC and DOC and ROC content reach maximum under M4S processing, were 19.32 and 20.11 g/kg,94.00 and 97.96mg/kg,55.70 and 74.75 mg/kg,2.81 and 2.40 g/kg(2) Manure and straw counters-field has significant effects on soil enzyme activity in rice and wheat season. Besides NKM1,other treatments significantly improve the soil urease activity at soil surface when compared to CK treatment. On the other hand, no significant effect on soil urease activity was found on change of quality changes of manure and straw returning. The soil urease activity to achieve the maximum of M4S, by 76.69% and 62.5% higher than that of CK treatment; Surface soil neutral phosphatase and sucrace activity after manure returning amount reached to 10000 kg/hm2 maximum, then decreased with increasing dosage of pig. Straw returned to deal with soil neutral phosphatase and sucrace activity is significantly higher than the corresponding handle without straw, soil neutral phosphatase and sucrace activity peak under NKM2S processing, were 3.22 and 3.15 mg g- 1h-1. In 20-40 cm soil layer, soil enzyme activity is far less than the surface, and no significant differences between different treatment(3) The concentrations of soil organic carbon and their components in different growth period change significantly (P<0.01). The concentrations of TOC, WSOC and DOC and ROC in different treatment at 0-20 soil layer in rice season with the passage of growth period showed increased after then, reach maximum at the jointing stage, and then reduce the trend; In 20-40 cm soil layer, the changes of TOC and ROC in different growth period were different from those at surface soil layer, soil organic carbon and oxidative organic carbon content with the increase of growth period goes on slow, and the change is less than the surface. The wheat season surface TOC content increases with crop growth and development; Soil WSOC and DOC content peaked at jointing stage, then decreased; Easy oxidation of soil organic carbon in points reach maximum leaf period, after falling and stable. Wheat season 20-40 cm soil layer soil organic carbon along with the growth period does not change significantly advance, WSOC and DOC and the changing trends and surface soil ROC are similar, but the change is far less than the surface soil.