Pay attention to "three precautions" when corn straw is returned to the field

At present, it is almost the harvest season of corn, and the return of corn straw to the field has been gradually accepted by farmers, but some farmers do not have a comprehensive grasp of this technology, and there are some problems and even negative effects in the application. In some fields, the emergence rate of wheat is low, the seedling is yellow, the seedling is weak, and even the seedling is dead. According to the analysis, the main reasons are the imbalance of carbon-nitrogen ratio, the crushing of straw is too coarse and the soil is too loose, which should be prevented in production.

? Prevent carbon-nitrogen ratio imbalance. The C / N ratio of corn straw is 65 85 ∶ 1, and the C / N ratio suitable for microbial activity is 25 ∶ 1. If there is insufficient nitrogen in the soil after straw returning, microorganisms will compete with crops for nitrogen, and wheat seedlings will be yellowed, emaciated and poor growth. Solution: after straw crushing, ammonium bicarbonate 50 kg or urea 20 kg per mu can be sprinkled on the straw surface, and then ploughed.

? Prevent the straw from being crushed too thick. Some pieces of crushed straw are too long, the length is more than 10 cm, which is not conducive to ploughing and sowing. Solution: use a large straw grinder with relatively high horsepower, so that the straw is crushed finely, the rotary tillage is deeper, and the straw is evenly mixed with the soil.

? Prevent the soil from being too loose. After the straw is returned to the field, the soil is too loose and has many macropores, so wheat seeds can not be in close contact with the soil, which affects the germination and growth, does not take root firmly, and even appears the phenomenon of "hanging roots". In order to solve this problem, in addition to improving the crushing quality of straw, we should also pay attention to the following aspects: ⑴ applied sufficient nitrogen, phosphorus and potassium fertilizer. ⑵ increases soil moisture. ⑶ can improve the quality of sowing. ⑷ suppressed and watered in good time. After sowing the wheat, dry it for one day and suppress it with stone to make the soil dense.

In addition, the diseased straw can not be returned directly to the field, otherwise the disease is easy to occur if corn is planted in the following summer. This kind of straw should be destroyed or composted at high temperature before being applied to farmland.