Fertilizer is an indispensable nutrient for our crops. Chemical fertilizers can supplement the nutrients needed for crops in time. Different fertilizers can play different roles on crops. Then, how to judge the lack of fertilizer in crops?

1. Nitrogen deficiency

The main symptoms are: the new branches are thin and short, the leaves are small and erect, the leaf color is gray green, the petiole, vein and cortex turn red; the flowers are small and the fruit is early and easy to fall off; the fine roots are more, the large roots are less, the new roots are yellow, and the ability to resist diseases and insect pests and drought is weakened. Soybean as the column, in the growth period of lack of nitrogen fertilizer, starting from the lower leaves, the leaf color becomes light, light green, and then gradually become yellow and dry, sometimes the leaf appears bronze markings. In severe cases, the plant stops growing and the leaves gradually fall off.

2. Phosphorus deficiency

In the early stage of crop growth, the effect of phosphorus fertilizer is not obvious, but in the middle and late stages, phosphorus deficiency will affect the effective accumulation of nitrogen and protein synthesis. Different crops lack phosphorus, its performance symptoms are not the same.

Such:
1. The manifestations of phosphorus deficiency in wheat are: slow seedling growth, poor root development, reduced tillers, purple at the base of the stem, dark green leaves, slightly purplish red, few small grains in the spike, and a significant reduction in thousand-grain weight.
2. The performance of phosphorus deficiency in corn is: slow growth at seedling stage, obvious symptoms at 5 leaf stage, purple leaves, short and small corn cobs, curved shape, premature baldness, and most grains are not full.
3. The performance of soybean phosphorus deficiency is: the leaf color becomes dark, thick green or black green, the leaf shape is small, sharp, narrow, and upright, the plant is thin and small, and the growth is slow. Severe, the stem may appear red, after flowering soybean if the lack of phosphorus, the leaves appear brown spots.
4. The performance of phosphorus deficiency in fruit trees is: poor fruit quality, slow growth, scarce leaves, yellow-brown leaf color, prone to early abscission.

3. Potassium deficiency

1. The tip of the lower leaf of general crops turns yellow, and gradually withers and yellows along the edge of the leaf. Both sides of the leaf vein and the leaf midvein are still green. In severe cases, most of the leaves are yellow and the edges of the leaves are burned.
2, cereal crops show that the tillering ability is weakened, the stem is soft, easy to lodging.
3, dicotyledonous plant leaves curl, gradually shrink, sometimes incomplete leaves, but the middle of the leaf remains green.
4. The quality of root crops is reduced and the quality is poor.
5 The fruit ripening period is inconsistent, the pulp wood increases, and the taste is sour and bitter but not delicious.