Rice cultivation heavily relies on the supplementation of nitrogen, which can reduce ineffective tillering and improve the effective panicle rate. While nitrogen fertilizer is beneficial, applying too much of it can have adverse effects. Some farmers, in their eagerness for better yields, end up applying excessive nitrogen fertilizer, which can backfire. So, how to deal with excessive nitrogen fertilization in rice? Let's find out.
Hazards of Excessive Nitrogen Fertilization in Rice
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Nitrogen toxicity: Excessive nitrogen fertilizer leads to the accumulation of nitrate nitrogen in rice plants, causing toxicity, early death of lower leaves, premature aging of roots, and lodging of stems with ineffective tillers, resulting in significant yield reduction.
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Flat grains: Excessive nitrogen fertilizer promotes excessive vegetative growth aboveground while slowing down root growth. Many tillers form ineffective tillers due to lack of root support, resulting in flat grains.
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Lodging susceptibility: Excessive nitrogen fertilizer causes rice plants to elongate excessively, with thicker stems and larger, thinner leaves that are more prone to breaking, leading to lodging.
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Low grain setting rate: Excessive nitrogen fertilizer results in excessive vegetative growth, low grain setting rate, and direct loss of income for farmers.
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Increased susceptibility to diseases and pests: Excessive nitrogen fertilizer reduces rice plants' resistance to adversity, making them more susceptible to diseases, pests, and frost damage.
Handling Excessive Nitrogen Fertilization in Rice
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Reduce application: Control the amount of nitrogen fertilizer used and apply it in small doses over time.
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Field drying: Advance field drying to crack the soil, hinder and damage the root system of rice, slow down nitrogen absorption, and control excessive growth.
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Watering to dilute: Dilute nitrogen fertilizer by watering rice paddies directly and then supplement them appropriately with potassium dihydrogen phosphate or other potassium fertilizers to effectively mitigate the harm caused by excessive nitrogen fertilizer.
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Increase silicon fertilizer application: Farmers with the necessary conditions can use silicon fertilizer once or twice to enhance rice's resistance to lodging.
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Disease and pest control: Excessive nitrogen fertilizer leads to an increase in diseases and pests, so disease and pest control for rice must be done well. It is recommended to use propiconazole and potassium dihydrogen phosphate (as a source of phosphorus and potassium) together to prevent rice blast, bacterial leaf blight, and rice blast in sensitive varieties, and to further add triadimefon or pyrazole fungicides to prevent rice blast.
Overall, the hazards of excessive nitrogen fertilization in rice are significant. Therefore, it is essential to grasp scientific nitrogen fertilizer application methods and appropriately supplement phosphorus and potassium fertilizers. If excessive nitrogen fertilization has already occurred, timely water control, field drying, and strengthened disease and pest control measures are necessary.
