The Simulation System Of Organic Carbon Turnover In Paddy Soil

Soil productivity is strongly linked to soil organic matter (SOM) because SOM plays important roles in improving soil structure, soil water holding, infiltrating and capacities, and the nutrients supply to crops. Paddy soil is a Chinese characteristic soil. It is significant that effect of managing measures on soil organic matter turnover in paddy soil. The paddy soil characteristic and the growth laws of paddy were realized, on the basis of the long-term located experiment, changes in soil organic carbon and some impact genes were investigated in paddy soil by means of analysis of the 22-year soil samples, under different managing measures. Based on some information of the experiment, made use of the computer language-Delphi, a computer model was developed according to the organic carbon dynamics, and was tested by the long-term located experiment. The main results were summarized as follows:1 , A long-term experiment was carried out to study the changes of organic matter (O.M.) in paddy soil derived from red soil under 3 rice-based cropping systems, 3 applying rates of green manure and 2 ground-water levels. The results showed the content of organic matter was increased gradually when upland soil was puddle and cropped under submerged conditions. Among the different based-rice cropping systems, the rate of increase of O.M. in the treatments of rice-rice-flooded fallow in winter were the highest, those in the treatments of rice-rice-astragalus came the second, and those in the treatment of rice-rice-rape were the lowest. Among the different application rate of green manure, the rate of increase of O.M. in the treatments of high application rate of green manure were the highest, those in the treatment of normal application rate of green manure came the second, and those in the treatments of chemical fertilizer were the lowest. The effect of ground-water levels on changes of O.M. was not significant. Therefore, rice-based cropping systems and applying rates of green manure were significant to impact on the turnover of plough horizon's SOM.2, The simulation system of organic carbon turnover in paddy soil was carried out in computer and validated(1) Soil organic carbon turnover in paddy soil simulation model, 3 kinds of module were designed for the simulation of soil organic C turnover course: Organic...