Harm of straw returning to field and preventive measures

Straw returning to the field is a measure of increasing yield for soil fertility in the world. Straw returning to field can increase soil organic matter, improve soil structure, make soil loose, increase porosity, reduce capacity, promote microbial activity and crop root development. Straw returning to the field has a significant effect on increasing fertilizer and yield, generally increasing yield by 5% ~ 10%. Before wheat is sown, corn stalks are returned to the field, which has been gradually accepted by farmers in recent years. Compared with the traditional tillage method, the process of cutting stalk, turning stalk and removing root is eliminated. It can also significantly increase soil fertility and improve soil structure. Obviously improve agricultural production efficiency, reduce labor intensity, save labor costs; Reduce environmental pollution and improve the environment around farmland.



However, if the treatment method is not proper, it will also lead to the increase of soil bacteria, crop diseases and poor seedlings, seedlings and other adverse phenomena. Therefore, taking scientific and reasonable measures to return straw to the field can achieve good results.

The supporting technology of straw returning to the field is not in place, which will cause three fatal injuries to the next crop of wheat.

1, yellow seedling weak:

After corn straw is returned to the field, the nutrients in the straw can not be directly absorbed by the crop, and must be decomposed by microorganisms. The carbon nitrogen ratio suitable for soil microbial activity is 25∶1 to 30∶1, and the carbon nitrogen ratio of corn straw is 80∶1 to 100∶1. If the nitrogen in the soil is insufficient, it will lead to nitrogen competition between microorganisms and wheat, and wheat seedling yellow and weak phenomenon due to nitrogen deficiency.

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2, missing seedlings and ridging:

A large number of corn stalks return to the field, the soil becomes loose and the gap increases, the soil loss is faster, the seed and the soil are difficult to contact closely, the straw is not crushed fine, concentrated place, in the process of straw decomposition, the seed germination is affected, the field emergence is often not neat, and the phenomenon of lack of seedlings is easy to appear.

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3. Harm of diseases and insects:

There are often a lot of bacteria and eggs on the corn straw, which cannot be killed in the direct crushing process of the straw, and remain in the soil after returning to the field. Farm diseases and pests, especially underground pests, have a trend of increasing year by year, endangering the normal growth of wheat.

So, how can we avoid the harm of these stalks returning to the field?

In the process of corn straw returning to the field, master the following supporting measures, control the key indicators, these injuries can be avoided.

1. Ensure the quality of straw crushing and master the quantity of returning to the field:

Adjust the machinery well, and it is appropriate to control the length of corn straw crushing at 3-5cm, so as to avoid excessive straw and soil compaction, affecting crop emergence and growth.

Straw returning to the field is not the more the better, the amount of its return to the field should be determined according to the water source and farming conditions, in principle should ensure that the straw returned to the field is fully decomposed, can not affect the quality of the next crop farming.

The amount of corn stalk returned to the field: the general standard is 400-500kg per mu, too much will harm the next crop of wheat root growth.

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2. To achieve deep ploughing and suppression after wheat sowing:

Mechanical harvest of corn, straw is evenly scattered in the field after crushing, at this time the straw should be ploughed into the soil as soon as possible, the depth is generally required 20-30cm, it is better to harvest while breaking and buried, to achieve the crushed straw and soil fully mixed, the ground is not obviously crushed straw accumulation, in order to facilitate the decomposition of straw decomposition and ensure the germination of wheat seeds.

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After the straw is returned to the field, the sowing amount of wheat should be appropriately increased by 0.5-2 kg on the normal basis, and it must be suppressed after sowing, especially the rotating tillage wheat field. It is best to suppress the seeds with planting, so that the seeds are in close contact with the soil to ensure sufficient basic seedlings.

3, increase the application of nitrogen fertilizer, beware of carbon nitrogen ratio imbalance:

The carbon nitrogen ratio of corn straw was 80∶1 to 100∶1, and the carbon nitrogen ratio suitable for microbial activity was 25∶1 to 30∶1. The wheat base fertilizer of straw returning to the field should be increased with nitrogen fertilizer, and the wheat compound fertilizer with slightly higher nitrogen content should be used as the base fertilizer. On the basis of normal fertilization of wheat, 5-7.5 kg of urea can also be added to meet the nutrient needs of wheat and microorganisms, and speed up the decomposition and decay of straw.

4, improve soil moisture, ensure enough moisture back to the field:

Soil moisture status is an important factor to determine the decomposition rate of straw, because the decomposition of straw depends on the microorganisms in the soil, and the survival and propagation of microorganisms must have suitable soil moisture. If the soil is too dry, it will seriously affect the propagation of soil microorganisms and slow down the speed of straw decomposition, so it is necessary to water in time, and sow the soil moisture first. In the production, it is generally used to crush while harvesting, especially the corn stalk, because the moisture content of the corn stalk is higher during harvesting, and timely turning and burying is conducive to decomposition.

It is better to sow appropriately late, but also to create enough soil moisture, so as to sow enough soil moisture, and ensure that a full seedling is sown. When the moisture content is insufficient after sowing, it can also be poured in time on the suitable plots according to the soil quality. Winter water should be early, the amount of water should be small, in order to consolidate the soil. After watering, ploughing and hoeing should be done in time to break the knot.

5, clean up diseased straw, do soil and seed treatment:

(1) Clean up diseased straw:

The straw with disease can not be directly returned to the field, otherwise the disease is easy to occur if the corn is planted in the next summer. Such straw should be destroyed or decomposed at high temperature before being applied to the field.

(2) Soil treatment:

Before rotating tilling or deep tilling, 3-5kg3% of phoxius granules or 3% methyl-ocine granules and 2-5kg of pentachloronitrobenzene wettable powder were applied per mu. Or use 48% phoxiphos emulsifiable oil 500 ml diluted with 1-2kg water and 20-25kg fine sand or fine soil mix, and then mix with 2-5kG 70% methyltolbuzin wettable powder, evenly spread the ground deep turning or rotary tillage into the soil, to prevent and kill the disease and insect bacteria sources and eggs in the soil, to achieve the purpose of prevention and control of pests and diseases.

(3) Good seed treatment:

It is best to buy the coated seeds, or the seeds are mixed with chemicals. After sowing, let dry to sow. The seeds that have been sown cannot be left for a long time. In areas where underground pests occur seriously, soil treatment with chemicals should be adopted.

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Straw returning to the field is a good measure, but also to make good use of it, according to scientific and reasonable procedures, so that straw returning to the field really play its role.