What to Do When Rice Seedlings Suffer Fertilizer Burn? Master the Correct Remedial Methods

Blindly increasing the amount of chemical fertilizer applied will cause various physiological disorders in rice seedlings, making growth and development abnormal after transplanting. Applying excessive amounts of undecomposed organic fertilizer will also cause poor growth of rice. This kind of physiological disorder caused by excessive fertilizer application is "fertilizer burn."

1. Causes of fertilizer burn There are many causes of fertilizer burn in rice seedlings, which can be summarized into three: First, improper fertilization methods. For example, applying ammonia water or ammonium bicarbonate under high temperature at noon, the volatilized ammonia gas causes fumigation damage to rice plants; second, excessive fertilizer application. For example, turning in too much green manure easily causes acid damage. Applying too much nitrogen fertilizer will also produce fertilizer burn; third, poor quality chemical fertilizer causes fertilizer burn. For example, urea contains a substance called biuret, which is toxic to crops, especially affecting seed germination.

The adverse effects of fertilizer are manifold. First, it directly harms crops, causing leaves and roots to be burned, and even the whole plant to die; second, it causes agricultural environmental pollution, and the harm is even greater.

2. Remedial measures When fertilizer burn occurs in rice, immediately irrigate with "running horse water" to flush the field, so as to reduce the fertilizer concentration; for fields where the dead seedling rate reaches more than 30%, promptly plow and replant, deeply plow the surface soil layer containing much fertilizer to the bottom layer, level it with a rake and replant rice seedlings, or switch to other crops. When the amount of nitrogen fertilizer applied is large, the rice plants become spindly and the population is too large. When the number of tillers reaches the planned number, drain the water in time and bake the field. Bake until the seedlings turn yellow and the leaves stand upright, then irrigate with deep water at the booting stage, change the ventilation and light conditions in the field, control ineffective tillering, and prevent excessive vegetative growth and late maturation; at the jointing, booting, and grain-filling stages of rice, spray the leaves with a 0.2% potassium dihydrogen phosphate solution respectively to regulate the carbon-nitrogen ratio, enhance photosynthesis, and inhibit vegetative growth. If the amount of nitrogen fertilizer applied is improper and rice diseases occur, spray pesticides in time for prevention and control.