Technical requirements for transplanting rice seedlings

The key points of rice transplanting techniques are summarized as suitable water depth, field surface hardness, the first three belts, the best planting depth, strong seedlings of appropriate age, reasonable close planting, scientific irrigation, early application of tiller fertilizer, timely pest control, timely early rush, strict planting and orderly transplanting.

1. Suitable depth of water

It is required that the water layer of the field should be adjusted to about 1 cm (in the state of water) one day before transplanting, which is beneficial to the operation of the transplanter, too little water on the surface of the field, difficult to walk, easy to stick mud in the seedling claws, clamp the seedlings, and the seedling trough is easy to be filled with sundries. the supply of seedlings is uneven and even folded, resulting in a serious shortage of seedlings. The water in the field is too deep, the standing of seedlings is not correct, the depth of transplanting is uneven, and there are many floating seedlings, so it is easy to push and press seedlings in the process of transplanter, which can not guarantee the quality of transplanting seedlings.

2. Field hardness

When transplanting rice seedlings, the method of testing the surface hardness of the field is that the index finger enters the field (about 2 cm) in a deep trench, and the surrounding ooze slowly closes, which is the best state of transplanting rice seedlings. If the precipitation is not good, the field is too soft, the seedlings can not be planted firmly, the posture of standing seedlings is chaotic, and the seedlings are pushed and pressed by the transplanter, the seedlings are easy to sink after planting, affecting the growth of slow seedlings and tillers. The hardness of the field surface is too high, the resistance to transplanting is large, it is easy to hurt the seedlings, the depth of transplanting becomes shallow, and the traces can not be closed in time, resulting in floating seedlings and lack of seedlings.

3. The best insertion depth

Whether the depth of mechanical transplanting is suitable or not has a great influence on the turning green, tillering and preservation of seedlings. Generally, it is easy to disperse seedlings when the depth of transplanting seedlings is 0.5 cm, and more seedlings are inverted and drifted, and the depth of transplanting seedlings is more than 3 cm, which will inhibit the turning green and tillering of seedlings, especially the tillering of low nodes is obviously inhibited, the late tillers of high nodes are increased, the tillers are delayed, the quality of tillers is poor, and the weak seedlings will become rigid seedlings when they are planted deeply. When the depth of transplanting seedlings is about 2 cm, there is no phenomenon of inverting and drifting seedlings, and the plants have more roots, robust growth and strong tillering ability. therefore, the depth of mechanical transplanting of rice seedlings is about 2 cm, and the depth of artificial transplanting is 1-1.5 cm. The bowl is flat with the mud surface, and it is suitable to throw seedlings into the soil 2x3 (mud condition).

4. Insert the first three belts

According to the arrangement of transplanting rice seedlings, it is planned to carry out the work of three belts on the day before transplanting, and transplant seedlings at the same time. Do not finish the work of the first three belts at one time, so as to avoid the phenomenon of burning seedlings caused by excessive concentration of fertilizer, at the same time, it can also prolong the time for the control of leafminers and improve the preventive effect on leafminers. The first three bands before insertion are with phosphorus: 125g / m2 diammonium phosphate; second, with medicine: 70% Ambroxol 6g / 100m; third, with biological fertilizer, such as beneficial micro-yield-increasing bacteria, world green biological fertilizer, etc., use in accordance with the instructions.

5. Strong seedlings of suitable age

The quality of seedlings during transplanting period has a great influence on seedling turning green and tillering. Generally speaking, dry-raised middle seedlings (3.1-3.5 leaves) and dry-raised large seedlings (4.1-4.5 leaves) are robust seedlings with white and vigorous roots, strong flat cattail, tall and green leaves, proper seedling age, neat and uniform seedling age, high dry weight and strong stress resistance. such seedlings return green quickly, tiller early and grow vigorously. On the other hand, for the overgrown seedlings with poor seedling quality, the leaves are pulled on the surface of the water after transplanting, which is extremely vulnerable to the harm of leaf miners, and the leaves rot quickly, even if the leaves remain intact, the leaves stand very slowly after withdrawing water, slow seedlings are slow, and return to green late. In case of adverse environmental conditions, the rate of dead leaves and seedlings is high.

6. Reasonable close planting

The density of transplanting seedlings (the basic number of seedlings per square meter) should be determined according to the comprehensive factors such as soil fertility, seedling quality, climatic conditions, cultivation level and so on. The basic number of seedlings per unit area is better than the planned number of ears per square meter (more than 600 ears per square meter). In general, the land numbers with fertile soil, high fertilization level, strong fertilizer supply capacity, good seedling quality and good climatic conditions can be sparsely planted, and the basic number of seedlings per square meter should not be too much, and it is generally appropriate to have 125 seedlings per square meter, while the soil is barren. The land number with poor fertilizer supply capacity and poor climatic conditions can appropriately increase the density, and it is more appropriate to control the basic seedling number at 140 plants per square meter.

7. Scientific irrigation

Immediately after planting, the water depth is about 4cm, and the height of the seedling is 2. 3. The heart leaf of the seedling is not submerged, which promotes the seedling to turn green early, tiller early, and grow quickly. When the surface water reaches water at room temperature, the days required for seedlings to turn green are 9: 10 days, 6: 7 days when the depth of water is 2 cm, and 4 days when the depth of water is 4 cm. Under certain conditions, when the water depth of seedling protection increases by 2 cm, the plant height increases by 1 cm, and the number of roots increases by about 2. Immediately after the rice turns green, remove the shallow water layer and maintain about 3 cm shallow water layer, in order to increase the water temperature and mud temperature and speed up the tillering of rice. The optimum temperature for rice tillering is 3032 ℃, and the optimum water temperature is 3234 ℃. When the air temperature is lower than 20 ℃, the water temperature is lower than 22 ℃, the tillering is slow, the air temperature is lower than 15 ℃, the water temperature is lower than 16 ℃, or the air temperature is more than 40 ℃, and the water temperature is more than 42 ℃, the tillering stops. Keeping the shallow water layer can increase the mud temperature, reduce the temperature difference between day and night, improve the effectiveness of soil nutrition, promote tillering, and reduce the mud temperature without water or deep water, and inhibit the occurrence of tillering. It is necessary to leave a good outlet with a height of 5 cm in advance, so as to prevent the seedlings from being submerged by water depth or long-term deep water flooding when the precipitation is too much, so as to reduce the root activity.

8. Early application of tiller fertilizer

Tiller fertilizer was applied immediately after 3-5 days after transplanting, and the amount of fertilizer applied was 30% of the total nitrogen fertilizer. Among them, 80% of the total tiller fertilizer was applied in the whole field 4-5 days after planting, and the other 20% (urea 1 kg / mu) was applied in the field after 7-9 days. Which yellow which weak application, promote the fertilizer response in the 6-7 leaf stage (effective tiller full leaf position), promote early tillering, fast tillering, more tillering, reduce ineffective tillering. In order to prolong the fertilizer period, sulfuric acid and urea can be mixed and 3 kg of ammonium sulfate can be used instead of 1 kg of urea. The critical amount of the three elements in rice seedlings at tillering stage is 2.5% nitrogen, 0.25% phosphorus oxide and 0.5% potassium oxide. the tillers are exuberant when the leaf nitrogen content is 3.5% and smooth when the potassium content is 1.5%. Biological silicon fertilizer was all used in tillering fertilizer, and 5kg / mu was applied together with the first tillering fertilizer.

9. Timely pest control

Before the occurrence of rice leafminer, from the end of May to the first ten days of June, the insect situation was investigated in time after transplanting, and when the damage was found, the insect was sprayed and controlled in time. The method of investigation is to select the seedlings 8-10 days after planting close to the water surface and lay out (pull) the leaves on the water surface, gently stroke the leaves with hands, and find that there are small particles in the middle of the leaves, that is, the larvae of leaf miners, which should be sprayed immediately.