How can the reviving period of rice be shortened after transplanting?
After rice is transplanted, it generally turns from green to yellow, and then from yellow back to green; this period is called the reviving period. The reviving period is generally 7-10 days. If measures are taken to shorten the reviving period to 2-3 days, then “one shortening” can promote “three earlies.” That is, shortening the reviving period promotes early growth, early tillering, and early full heading. In this way, more panicles can be produced, the low-temperature cold damage in August can be avoided, and a high and bumper yield can be achieved. There are 5 measures to shorten the reviving period of rice seedlings.
Cultivate strong seedlings
As the farming proverb says: “Good seedlings are half the grain.” On the basis of cultivating strong seedlings, apply a “send-off fertilizer” 4-6 days before transplanting to promote the sprouting of new roots in the seedlings. In this way, seedling quality is good, and after transplanting they can grow by day and by night, shortening the reviving period. The “send-off fertilizer” must be applied at the right time. If applied too early, the new roots sprout and grow too long, the seedlings become too tender, and the plants are severely damaged when pulled, causing the reviving period to be delayed after transplanting. If applied too late, the seedlings have not yet absorbed it and it cannot play its “send-off” role. As for the amount of fertilizer, generally apply 2-5 kg of urea per mu of seedling field; if seedling quality is good and soil fertility is high, less can be applied.
Apply sufficient base fertilizer
To make rice seedlings revive quickly after transplanting, sufficient base fertilizer must be applied. The base fertilizer should be mainly farmyard manure, with an appropriate supplement of chemical fertilizer. At present, the common problems in production are: first, the amount of fertilizer applied is insufficient; second, the amount of farmyard manure applied is small, and the techniques for composting, management, and storage are extensive, so fertilizer quality is not high. To better bring the role of base fertilizer into play, the base fertilizer should adopt the fertilization method of “coarse fertilizer as the base, fine fertilizer applied on the surface”; that is, evenly broadcast farmyard manure during field preparation, plow it into the plow layer when plowing the field, and then before transplanting apply quick-acting fertilizer to the soil surface to meet the needs of reviving and the early tillering stage.
Pay attention to water-surface fertilizer
Water-surface fertilizer is also called harrow fertilizer. When rice is transplanted, air temperature and soil temperature are low, and fertilizer decomposes slowly. To facilitate early reviving of rice seedlings after transplanting, attention should be paid to applying water-surface fertilizer. Before the final field preparation and harrowing, evenly broadcast quick-acting nitrogen chemical fertilizer on the field surface, harrow promptly, and harrow the fertilizer into the surface soil layer 3-6 cm deep. The fertilization rate is generally 3-5 kg of urea per mu, or 10 kg of ammonium bicarbonate. This can ensure timely fertilizer supply to promote greening after transplanting, promote early growth and rapid development, strengthen stems, and increase panicles.
Transplant at the right seedling age
It is necessary to grasp the seedling age well and transplant at the right time. If seedlings grow in the seedling field for too long, they will enter reproductive growth early, and young panicle differentiation has already begun at transplanting. Such overage seedlings are called by the people “carried to the bridal sedan chair with a fetus.” After transplanting, they revive very slowly and do not develop. Therefore, it is necessary to strictly control transplanting rice seedlings at the right age, ensure that rice seedlings can grow and develop normally, and lay a good foundation for achieving high yield.
Timely management
In the early stage after rice seedling transplanting, the seedlings are tender and weak, and they fear both deep flooding and water cutoff with drought. At this time, shallow water and frequent irrigation should be practiced, which helps raise soil temperature and promote early reviving. 7-10 days after transplanting, apply the first fertilizer to promote early tillering.