How to accurately judge the symptoms of crop fertilizer deficiency?

Nitrogen deficiency fertilizers. At first, the leaves are light green or yellowish, and after a short period of time, the stems are the same color, often the old leaves lose color first, and gradually expand to all leaf clusters. Lack of phosphorus and potassium fertilizers.

If there is a lack of phosphorus and potassium fertilizers, the growth of vegetables and fruits is stunted, and the leaves gradually appear to be greened, the stems are long and slender, containing wood, the leaves are smaller, the leaves are darker, and the reverse side is reddish-purple, and the conclusions are later and the fruits ripen later. Potassium deficiency. At first, the plant has light green leaves at the bottom, then the leaves are champagne gold and tan, the edges of the leaves turn dark brown, pigmentation occurs along the petioles, and the organs rot and die.

The stems of vegetables and fruits are long, thin, stiff, and woody.

Vegetables and fruits grow stunted, building stout stems containing solid wood. The top of the plant and the young position showed significant symptoms. If it is a tomato, it is easy to get navel rot, which is mainly manifested by the gradual occurrence of annular brown rot at the top of the fruit (navel), and when it is obvious, all the fruit is rotten, and sometimes with the appearance of gray-black moldy substance.

If it is a cucumber, the upper leaves are wrinkled and do not stretch, and the growth of the plant leader is stunted and withered, which is easy to be confused with the scab disease of cucumber, and the key difference is that the scab lesions are easy to break.

The supply and demand of nitrogen fertilizer are related to the growth and development of food crops, therefore, the lack of nitrogen fertilizer in rural areas will mainly be manifested as short and weak food crops, thin and short shoots and small leaves, and the color of leaves is gray-green and changes towards withering. For example, bract rice with nitrogen deficiency will be short and easy to senes, cotton wool will be short of nitrogen yellow leaves, buds and low production, Chinese cabbage will lack nitrogen and have no trees and have a poor growth trend, soybean nitrogen deficiency roots will not flourish and stop growing, sweet potato will have less nitrogen deficiency leaves and slow growth, wheat nitrogen deficiency leaves will be small and yellow, rapeseed nitrogen deficiency will be easy to senescence and short, peanut kernel nitrogen deficiency leaves are yellow and not abundant, and melon nitrogen deficiency leaf stems will not develop senescence. In addition, it should be noted that too much nitrogen fertilizer topdressing also harms the growth of food crops.

Whether it is a lack of fertilizer or defertilization is first distinguished from the appearance. Take the most familiar kiwifruit as an example. First of all, look at whether the new shoots of kiwifruit are squeezed and melted physically and mentally, and whether they are wrinkled and yellowed.

Then check whether the leaves of kiwifruit are hypertrophied, or have lobular disease, or prevent yellow leaf disease. If the leaves are hypertrophied and black, and the extrusion and melting are long and strong, it is proposed that there is no shortage of fertilizer temporarily, and fertilizer can be postponed. Observe the plant type, the body of the tree, and the stem of the tree.

Generally what is the method I use, the tree is strong, and the tree is smooth and clean, and the general fertilizer effect is very strong. Especially in the afternoon, if you find that the fallen leaves are of course loose, you should pay more attention to the observation, not necessarily lack of fertilizer, maybe it is fertilizer damage.

In the process of crop planting, if there is a lack of fertilizer, the plant will grow more slowly. At this time, reasonable fertilization is needed to supplement soil fertility and grow better.

It can be judged according to the condition of the leaves, and it can be judged according to the growth of the plant, and it is necessary to use fertilizer reasonably.

Lack of fertilizer is generally not very healthy, and you may experience a lot of illness.

There are many types of deficiencies, so let's briefly introduce the symptoms of nitrogen, phosphorus and potassium deficiency.

1. Nitrogen deficiency and yellowing: Rice nitrogen-deficient plants are short, with few tillers, small leaves, yellow-green, and early maturity. Generally, the old leaves start from the tip of the old leaves and turn down evenly, and gradually extend from the basal leaves to the heart leaves, and finally the whole leaf color fades and becomes yellow-green, and the lower old leaves are yellow.

The hair roots are slow, the fine roots and root hairs are poorly developed, and the yellow roots are more. It often occurs in yellow mud slab fields or paddy fields with shallow and thin cultivated layer and insufficient base fertilizer. If you find that there is a lack of nitrogen, you can apply a fast-acting high-nitrogen Liheng water-soluble fertilizer, which can quickly supplement nitrogen nutrients, which also contains an appropriate amount of phosphorus and potassium and medium and trace elements, so as to achieve balanced fertilization and prevent a variety of deficiency symptoms.

2. Phosphorus deficiency and redness: the seedlings are red and do not return to green after transplanting, rarely tillered, or zombie seedlings appear after returning to green; The leaves are thin and erect, sometimes slightly curled along the midrib; The leaf color is dark green and dull, the leaf tip is purple when severe, and the rice seedlings are dark green with gray-purple in the distance; The rice plants are not scattered between them, and the rice clusters are clustered, dwarf and weak; The root system is short and thin, with few new roots; If there are complications of hydrogen sulfide poisoning, the root system is gray and white, with more black roots and fewer white roots.

3. Potassium deficiency and red wilt: Potassium deficiency in rice begins to show symptoms 2-3 weeks after transplanting. Potassium deficiency plants are short, dark green, although they can root and turn green, but the leaves are yellow and brown spots, and the tips and edges of old leaves have small reddish-brown spots, and finally the leaves gradually turn russet brown from the tip downward.

In the future, every time a new leaf grows, the lesion of an old leaf will be added, and in severe cases, only a few new leaves will remain green in the whole plant, which looks like a fire from afar. The taproot and branching roots of the diseased plant are short and weak, and the whole root system is yellowish-brown to dark brown, with few new roots. Potassium deficiency red blight mainly occurs in cold-soaked fields, muddy fields and rusty paddy fields.

When potassium deficiency is found, 1-2 rapid sprays of potassium dihydrogen phosphate solution can be used to quickly replenish the required phosphorus and potassium.

If you want to confirm what kind of deficiency symptoms it is, it is recommended to consult the local agricultural department or agricultural technology station, and it is best to ask an experienced agronomist to confirm the diagnosis.

Excessive nitrogen: rice plants are long, the leaf color is dark green, the leaves are hypertrophied, the stalks are soft, easy to lodging and infected with pests and diseases, greedy for green and late ripening, and there are many grains.

Too much phosphorus: often induce zinc deficiency in rice, so the symptoms of excessive phosphorus are similar to zinc deficiency, less tillers, "stiff seedlings" do not appear, the leaves lack green, gradually turn yellowish-white along the midrib of the leaf to the edge, the old leaves appear brown spots, the whole leaf is brown in the later stage of growth, the root system grows slowly, and the whole plant dies in severe cases.

When potassium is insufficient, the plant stalks are weak, easy to lodging, and have poor cold and drought resistance. The leaves turn yellow and gradually die. Because potassium can move to young leaves, potassium deficiency begins in older leaves and later develops to the base of the plant, and there are also leaf margins that are scorched and the leaves curl or shrunk.

Nitrogen is the main component of proteins, nucleic acids, and phospholipids, while proteins, nucleic acids, and phospholipids are protoplasms, with short and thin stems, few branches or tillers, and premature aging.

Potassium can enhance the resistance of crops to disease, cold, drought, lodging and salt.

When crops are deficient in potassium due to insufficient potassium fertilizer application, it usually shows that the tips and edges of old leaves turn yellow, then turn brown and gradually wilt, and brown spots often appear on the leaves, and even form patches, but the middle of the leaf near the leaf vein still retains its original color. In severe potassium deficiency, the same symptoms occur on young leaves.

<> there are many types of crops, most crops will have short plants, smaller leaves, yellow-green leaves, and reduced fruit setting rate when nitrogen is deficient. When phosphorus is deficient, there will be poor development of leaves and roots, dark green or purple-red leaf color, and red roots. When potassium is deficient, the plant grows slowly, and the leaves shrink and dry up.

1. Nitrogen deficiency fertilizer for vegetables: At first, the leaves appear pale green or yellow, and soon the stalks repeat the same changes. The leaf color changes from the old leaves to the whole leaf.

2. Lack of phosphorus fertilizer in vegetables: Initially manifested as slow growth, then the leaves showed green spots, the stems became thinner, rich in wood, the leaves were smaller, the leaf color was darker, the back was reddish-purple, and the fruit ripening was delayed.

3. Potassium deficiency in vegetables: initially manifested as gray-green leaves at the base of the plant, then the leaves are bronze or yellow-brown, the leaf margins become brown, spots appear along the leaf veins, the tissue decays or dies, and the stems are slender, hardened and woody.

4. Calcium deficiency in vegetables: It is manifested as slow growth, forming thick wood-rich stems, and the top and delicate parts of the plant are obvious. Tomatoes are deficient in calcium, and they are prone to umbilical rot, which is manifested by the beginning of round brown rot on the top of the fruit (umbilicus), and in severe cases, the whole fruit rots, sometimes accompanied by black mold.

Cucumber calcium deficiency, manifested as the upper leaves shrunken, not stretched, plant faucet, slow growth, dry, easy to be confused with cucumber scab, the main difference is that scab spots are easy to break.

5. Lack of micro-fertilizer in vegetables: If there is a loss of green and erect between the leaf veins, the top is affected first and grows slowly, indicating zinc deficiency. Boron deficiency is indicated if the apical growth point dies, the root system is poorly developed, and the flowering vegetables only do not bear fruit or bloom abnormally.

If the new leaves have begun to lose their green color and gradually fade to white, it indicates iron deficiency.

Vegetables lack fertilizer. The long speed will be reduced to a slow speed. The leaves are yellowish. The plants are dwarfed.

The leaves are yellowish and do not grow for a long time.

See Table 2.

Table 2 Symptoms of crop nutrient deficiency.

The location of the symptoms is not easy to appear spots in the old tissue, the new tissue is not easy to appear spots, the top bud is easy to die and the top bud is not dead Nitrogen deficiency: yellowing of old leaves, premature senescence, light green and phosphorus deficiency in new leaves: dark green stems and leaves, less tillers, easy to drop fruits and lack of potassium:

The leaf tips and edges are yellow, there are many diseases, the panicle is uneven, the fruit is small, the premature senescence is deficient, and the zinc deficiency: the leaves are small clusters, the spots are often on both sides of the main vein, the plant is short, the early maturity is deficient, and the magnesium deficiency is short: the panicle is less and the spike is small, and the fruit is discolored and calcium is deficient

The leaf tip is hook-like adhesion, cabbage heart rot disease boron deficiency: stems, petioles become thicker and easy to crack, flowers are not fruitful, late maturing sulfur deficiency: new leaves yellowing, uniform loss of green, late flowering and lack of manganese:

Loss of green between the veins, with fine brown spots and lack of copper: young leaves wilt, white spots, slow growth, small fruits, few ears and lack of iron: green loss between the veins to the whole leaf light yellow, fruit drop, "withered" lack of molybdenum:

The veins of the leaves are green, deformed, and spotted all over the leaves, and the root nodules are underdeveloped.

1. Combined application of nitrogen, phosphorus and potassium fertilizers. According to the fertilizer supply performance of different soils, the law of fertilizer demand of crops and the utilization rate of chemical fertilizers, the reasonable ratio of nitrogen, phosphorus and potassium fertilizers, do not apply a single fertilizer. The nitrogen and phosphorus required by crops are the most closely related to each other and have a mutually reinforcing effect.

2. Organic fertilizer and chemical fertilizer are applied together. Organic fertilizer has complete nutrients and long-lasting fertilizer effect; Chemical fertilizers have a single nutrient but high content and quick effect. The combination of the two can learn from each other's strengths and improve fertilizer efficiency.

According to the test, the combined application of poultry enclosure fertilizer with ammonium bicarbonate, superphosphate and potassium sulfate increased the yield by more than 10% compared with the same amount of chemical fertilizer alone. 3. Coordination of large elements and trace elements. Crop growth not only needs nitrogen, phosphorus, potassium macroelements, but also needs some calcium, magnesium, copper, iron, manganese, zinc and other trace elements, such as wheat also needs some zinc fertilizer, peanuts on some molybdenum, etc., to improve yield and quality of a great role.

3. Scientific fertilization method 1. Deep application of soil covering. For example, deep application of nitrogen fertilizer can effectively prevent nutrient loss and improve the utilization efficiency of nitrogen fertilizer. According to the test, the utilization rate of ammonium bicarbonate underground deep application is 50%, while the utilization rate of surface layer application is only about 28%. The utilization rate of urea underground deep application is between 35% and 50%, while the utilization rate of surface application is much lower.

2. Centralized application. If the phosphorus fertilizer has poor mobility in the soil, it is easy to be fixed by iron, aluminum and calcium in the soil and lose its fertilizer effect, so it should be applied in holes and strips, and concentrated on the soil layer where the roots grow, so that the phosphorus is fixed around the seeds and roots, which is conducive to absorption according to the system and improves the fertilizer utilization rate. 3. Look at the sky, the ground, and the crop fertilization.

"Look at the sky" is to see whether climatic factors such as temperature, humidity, rainfall, and light have any impact on fertilizer efficiency. When the temperature is high, urea should be topdressed, and when the temperature is low, ammonium bicarbonate should be topdressed. "Looking at the ground" is to fertilize the soil.

For example, clay soil has strong fertility retention, and the amount of nitrogen can be used at one time; The fertilizer retention capacity of sandy loam soil is poor, and top dressing should be carried out in line with the principle of "eating less and eating more". "Look at crops" is to find out the nutrient deficiency factors in the soil that affect the yield and the peak demand for fertilizers of various crops according to the nutrient demand of different crops, and combine the characteristics of fertilizers to achieve formula fertilization. By taking the above measures, the effect of fertilization will be greatly improved.

What happens if plants are deficient in these minerals? Deficiency n: old leaf disease:

It is often found throughout the plant, the basal leaves are dry and scorched and dead, the plant is light green, the basal leaves are yellow, brown when dry, the stem is short and thin: the young shoots and roots of the plant grow slowly, the leaves are small, the branches (tillers) are few, the plant is particularly short, the leaf color is dark green, the flowering and maturity periods are delayed, and the resistance is weakened. Lack of k:

The stalks of the plant are weak and easy to lodging, the drought resistance and cold resistance are poor, the leaves turn yellow and gradually die, and some leaf margins are scorched, and the whole leaf is cup-shaped and lacks s: young leaf disease, the top bud is still alive but lacks green or wilted, no necrotic spots, young leaves do not wilt, there is a loss of green, no necrotic spots, and the leaf veins lose green. Lack of ca:

Diseases of young leaves, death of terminal buds, deformation and necrosis of young leaves, light green at the base of young leaves, death from the base of leaves. Lack of mg: old leaf disease, symptoms are limited to local, the base leaves are not dry and scorched, but there is a lack of green and necrotic spots and a lack of fe:

Young leaves lose green, growth is stunted, and in severe cases, the plant dies. Lack of Mn: Lack of MN in plants affects its utilization of nitrate, which is a component of chloroplasts, and Mn-deficient chloroplasts will destroy and disintegrate.

Lack of Zn: The stem internodes are short, the leaves are small and deformed, and the leaves lack green. Missing cu:

The young leaves turn white between the leaves, the whole leaf is narrow and curly, the apex growth is poor, and the plant is dwarf and clustered. Lack of MO: The plant is short, the leaves lose green and turn white, and finally wither and lack Cl:

The leaves of the plant are small, the leaf tips are dry, yellow, and eventually necrotic, the root growth is slow, and the root tips are thick. Ni deficiency: The physiological role of NI is poorly understood, and it is known to be related to the metabolism of DNA and RNA.