Symptoms of Fertilizer deficiency and excessive nutrients in Rice

During the growth and development of rice, if there is a lack of certain nutrient elements, the metabolism of crops will be hindered and destroyed, resulting in unique symptoms of roots, stems, leaves, flowers and seeds. Nitrogen deficiency: short plants, few tillers, small and erect leaves, yellow-green leaves, short and thin stems, few grains per spike, and high sterility. Phosphorus deficiency: "stiff seedlings" are often formed in the early growth stage, which is characterized by slow growth, no tillering or delayed tillering, thin and weak seedlings. The leaf color is dark green or grayish green with purple, the leaf shape is narrow and long, the leaf is small, and the leaf body is slightly curled in ring shape. The old roots turn yellow, the new roots are few and slender, and when serious, they become black and rotten. The mature stage is inconsistent, the spike has few grains, the 1000-grain weight is low, and the empty shell rate is high. Potassium deficiency: Brown spots often appear on leaves. Generally after tillering, the old leaf tip first appears smoke-like brown dots, and along the leaf edge is embedded scorched. In the peak tillering stage, the brown spot develops into brown spot, the shape is irregular, and the edge boundary is clear, often divided by or block between the leaf veins. Brown spots continue to develop from old leaves to adjacent new leaves, brown spots are continuous when there is a serious lack of potassium, and the whole leaf turns red and withered, like burning. Zinc deficiency: seedling growth stagnant, no tillering, brown patches appear in the middle of the back of the old leaves, leaf veins turn white, and leaf sheaths turn white in severe cases. Excessive nitrogen: overgrown rice plants, thick green leaves, hypertrophic leaves, soft stems, easy lodging and infection of diseases and insect pests, greedy green late ripening, many blighted grains. Excessive phosphorus: it often induces zinc deficiency in rice, so the symptoms of excessive phosphorus are similar to zinc deficiency, with few tillers, no "stiff seedlings", green leaves, yellow-white along the midvein of the leaves, brown spots on the old leaves, brown in the whole leaves in the later growth stage, slow root growth and death of the whole plant in severe cases.