Vigorously popularize the return of rice straw to the field

Vigorously popularizing the return of rice straw to the field is one of the most economical and effective ways for the recycling of nutrients from soil-crop-soil. It plays a very important role not only in improving soil and improving soil fertility, but also in improving soil potassium and silicon nutrition conditions, balancing crop nutrition, and alleviating the contradiction between the shortage of potash fertilizer resources and the rapid increase in chemical fertilizer prices in China.

1. Increase the content of soil organic matter, the content of organic matter in rice straw is high, and the content of organic matter in dry rice straw is 40%, which is beneficial to the accumulation and renewal of soil organic matter after returning to the field. According to the results of our positioning experiment for three consecutive years, 150 kg of dried rice straw was applied for every 667 square meters, and the soil was measured every year after the late rice harvest. The content of soil organic matter increased year by year, and the increase in the first year was relatively high. It was 0.11%-0.12%, and the 3-year average increase was 0.06%-0.09%. In terms of the composition of soil humus, free, loose, stable and tightly bound humus increased after rice straw was returned to the field, and the proportion of free and loosely bound humus increased greatly. the same is true of the accumulation of various forms of humus in the second and third years. This shows that returning rice straw to the field can not only increase the quantity of soil humus, but also improve the quality of humus.

two。 Improving the physical properties of soil due to the increase of soil organic matter accumulation due to the return of rice straw to the field, these organic matter formed humus through a series of decomposition and transformation processes under the action of microorganisms, which were reunited with clay minerals to form organic-inorganic composite colloids, so the soil structure was improved. The results of positioning experiment showed that 150 kg of dry rice straw was applied in every 667 m2 paddy field for 3 consecutive years, and the content of available potassium was measured at the tillering stage of late rice. The content of available potassium was 243 mg / kg higher than that of the control. The late rice plant with early rice straw returned to the field was 3 cm ~ 8 cm higher than the control, the heading date was 2 ~ 4 days earlier, the seed setting rate was 3.8% higher than that of the control, and the leaf flax leaf spot was significantly reduced without symptoms of potassium deficiency.

4. The results of the experiment on improving the content of soil available silicon showed that 150 kg of dry early rice straw was applied in every 667 square meters of rice field, and the soil available silicon content was determined by 6 samples at each growth stage of late rice. The average results showed that the available silicon content of rice plant returned by rice straw was 75.8 mg higher than that per kilogram of soil without straw, and the silicon uptake of rice plant per kilogram of rice straw was 22 grams higher than that of the control.

5. After returning straw to enhance the activity of microorganisms in soil, due to the sudden increase of fresh carbon sources in soil, the organic energy available for the life activities of soil microorganisms increased, various groups of microorganisms multiplied in large numbers, rice straw returned to field combined with application of nitrogen fertilizer, the ratio of phosphorus to nitrogen was coordinated, and the microbial proliferation was greater. The total amount of soil microorganisms measured at the tillering stage of late rice showed that the total amount of microorganisms in the soil with early rice straw returned to the field was 64.8% higher than that without straw application.

6. To enhance the activity of soil enzymes the life activity of microorganisms in soil is the basis for the formation and accumulation of enzymes in soil. After returning rice straw to the field, the soil microorganisms increased greatly, and the activities of catalase and invertase in the soil increased significantly. Due to the enhancement of enzymatic reaction, the decomposition of organic matter and the transformation of mineral nutrients in soil were accelerated, and the utilization rate of nitrogen, phosphorus and other nutrient elements in soil was improved.