Improvement Of Amendment To Acidic Soil And The Application In Rice-rapeseed Rotation System

With the development of agriculture and social economy, the area and extent of acid soil in China increase largely. The acid soil has become the important obstacle to sustainable development of agriculture in country. In order to solve this problem, this study set up the field and pot experiments, to study the effect of amendments improve the different acidity of acid soils, and explore the possibility for mitigation of arsenic and cadmium contamination in rice-rapeseed rotation system.The main results are as follows:1. The field experiment results showed that in the rice-rape rotation, compared with the controls, the application of soil amendment had significantly increased the yield of rice and rape, and also increased the thousand grain weight of rice and rape in acidic soil. Compared with amendment I, II, III, the amendment IV could get moer yield. Application of amendment in rice season, it is also has a certain amount of yield in rape season showed that proper dosage of amendment has great after-effect; But compared with application of amendment both in rice and rape season, continuous application of amendment has a higher yield of crops. From the perspective of correcting soil acidity, compared with the controls, the application of amendments have increased the soil pH value to varying degrees, especially the amendment IV. The application of amendment both in rice and rape can increase soil pH value larger than the single season. From the yield and improve the pH value, the amendment IV is more suitable for improving acidic soil than other three kinds of amendment, and it is better that the effect of applying amendment both in rice and rape.2. The field experiment results showed that the application of amendment could improve the soil pH and also stable soil organic matter content in acidic soil, and significantly increased the content of soil effective N,P, K, it showed that amendment has the ability of promoting the transformation of soil N, P, K to effective state, and improved the utilization of fertilizer and soil nutrient to achieve the purpose of province fertilizer.The application of amendment could complement the lack of calcium and magnesium nutrients in acidic soil, improved the content of soil exchangeable calcium and magnesium, and promoted the plant to absorb of calcium and magnesium elements. The application of amendment both in rice and rape was improved the content of soil exchangeable calcium and magnesium faster than the single season.3. The pot experiment showed that, compared with the control, the application of amendment IV and straw were reduced effective arsenic, cadmium in soil in varying degrees after rice planting, and the application of amendment IV was further reduced effective arsenic and cadmium in soil after oilseed rape planting. In the crop rotation, compared with the control, the application of amendment IV and straw were reduced the arsenic content in the rice husk and stem; while little effect on arsenic content in various organs of rape.The application of amendment IV was reduced the content of cadmium in the rice stem and husk; while significantly reduced the content of cadmium in various organs of rape. Through the crop rotation results showed that the application of amendment IV could well reduce the effective arsenic, cadmium content in the soil, and reduce plant uptake and accumulation of arsenic and cadmium.4. The pot experiment showed that, compared with the control, the application of soil amendment IV and straw have significantly increased the yield of rice and rape, and the amendment IV effect was better. The application of straw and amendment IV can promote the growth of rice and rapeseed and increase its aboveground dry weight. In the crop rotation, compared with the control, the application of amendment IV can significantly increase the soil pH value and the content of exchangeable calcium, magnesium in soil, and achieve the purpose of improving acidic soil. The crop rotation experiment results show that the calcium and magnesium content of plant was decreased that growth on the heavy metal pollution soil, it was showed that the heavy metal pollution hindered the plant to uptake of calcium, magnesium, and affect the growth of plants. That was increased exchangeable calcium, magnesium in soil and the content of calcium and magnesium in plants after applying amendment IV, indicated that amendment IV could alleviate soil heavy metal pollution, promoted the crop absorption of calcium and magnesium.