When calcium is lacking, the growth of plants is hindered and internodes become shorter, so plants that grow normally are generally shorter and softer. The apical buds, lateral buds and apical meristems of calcium-deficient plants first appear element deficiency, which is easy to rot and die, and the young leaves are curled and deformed, and the leaf edges begin to turn yellow and die gradually. Calcium deficiency leads to undeveloped terminal buds and root tips, which leads to "broken neck" symptoms, and young leaves turn green and deformed and appear hooked. In severe cases, the growth point is necrotic, and the tip and growth point are pectin-like. Roots often turn black and rot when calcium is lacking. Generally, the calcium supply of fruits and storage organs is very poor. Many kinds of vegetables rot due to calcium deficiency, and fruits and vegetables often judge calcium deficiency by storage tissue deformation. The young leaves of cereal crops are curly and dry, and the tips and edges of functional leaves are yellow. Plants rot before they get old. Less fruit, more seeds. The new leaves of leguminous crops do not stretch, and the old leaves appear gray-white spots. The veins are brown and the petiole is soft and drooping.