Rice straw returning technique for polyculture of crawfishes in lotus root field

Abstract

The invention discloses a rice straw returning technique for polyculture of crawfishes in a lotus root field. The rice straw returning technique comprises the following steps: collecting complete ricestraws in a rice harvesting season namely autumn, stacking the rice straws on ridges of the lotus root field; spreading the rice straws into the lotus root field when crawfishes enter caves for dormancy in winter, and keeping a shallow water level in the lotus root field in winter; trapping big crawfishes but not small crawfishes from March in early spring to a prosperous sprouting period of lotus leaves in the lotus root field in the last ten-day of April, and selling all the crawfishes trapped by virtue of earth cages; and applying a proper amount of nitrogen fertilizers in a leaf-erectingsprouting period of lotus roots so as to balance a C / N ratio, and additionally applying a proper amount of lotus root expansion fertilizers in batches from August to September. According to the rice straw returning technique, the crawfishes can cling to and stay in spaces formed by the rice straws in water, nutrients released through decomposition can be absorbed and utilized by the lotus roots and can be also utilized by small-sized planktons in water so as to promote production of the small-sized planktons, the planktons and straws fragments can be taken as baits of the crawfishes, and excrement of the crawfishes is a high-quality organic fertilizer. By replacing a chemical fertilizer with the organic fertilizer, the comprehensive utilization rate of the straws is increased, and breedingis combined with high-efficiency economic agriculture. The technique is suitable for the middle and lower reaches of Yangtze river.

Description

technical field [0001] The invention relates to a technique for returning rice straw to the field for intercropping crayfish in a lotus root field, and belongs to the technical field of combining agricultural planting and breeding. Background technique [0002] Rice straw is rich in nutrients. In 2015, the amount of straw resources of major crops in China was 718.7853 million tons, and the total nutrient resources of nitrogen (N), phosphorus (P2O5), and potassium (K2O) reached 625.6, 197.9, and 11.595 million tons, respectively. Rice, wheat and corn are the three major grain crops with the largest amount of straw nutrient resources, accounting for 33.1%, 14.5% and 34.2% of the total nutrient resources respectively (Song Dali, 2018). Although there are many ways to comprehensively utilize straw, the management of straw burning has not fundamentally improved. It shows that part of the crop straw is not fully utilized and is discarded. In the vegetable planting area, the unre...

AI Technical Summary

Problems solved by technology

[0005] Rice is harvested in autumn, and the rice straw is rich in nutrients. If the discarded rice straw near the lotus root base is spread in the lotus field, but the crayfish have not yet entered the hole for dormancy, if the rice straw is directly spread in the lotus field, it will be damaged due to small A large amount of molecular nutrients seep out, causing the concentration of the water layer to rise suddenly and turn yellow, which may choke the crayfish to death