Some farmers asked, "What are the symptoms of plant potassium deficiency when planting corn?" How to effectively prevent it? ”
In my hometown, because the temperature is higher than in the surrounding areas, the spring corn seedlings were transplanted slightly earlier, and the seedlings grew almost 10-12 leaves.
Wandering around the fields, I found that the corn planted by Uncle Li was somewhat abnormal. His corn seedlings only spread 8-9 leaves, and their growth rate is obviously slower. At the same time, yellow stripes can be seen on the lower leaves, and the leaves are pale green.
In excluding factors such as disease, I realized that this symptom is most likely caused by potassium deficiency.
In general, after the symptoms of potassium deficiency in maize plants, they show slow growth, which is more obviously characterized by yellowing of the lower leaf margins but still pale green in the middle. If potassium fertilizer is not replenished in time, the leaves of the seedlings will gradually become wrinkled, the trunk is fragile and easy to bend, the disease resistance is weakened, and even affect the ear of the ear, the corn fruit is small, and the weight of the thousand grains decreases, resulting in a decrease in corn yield.
So, how to effectively control potassium deficiency in corn?
First of all, potassium fertilizer is applied to the base fertilizer during land preparation. In general, maize yield is directly proportional to potassium uptake, that is, the higher the potassium absorption of the plant, the more likely it is to increase the yield. However, it does not mean that the more potassium fertilizer is applied, the better, and everything is balanced, so within the reasonable range of needs, more potassium fertilizer can be applied appropriately.
For example, for plots with general soil fertility, when applying base fertilizer, you can apply 2000-3000 kg of decayed farmhouse fertilizer per mu and 150-200 kg of grass and wood ash, and then spread 10-15 kg of potassium sulfate in shallow ditches on both sides of the planting line, which will help prevent potassium deficiency in maize plants.
Secondly, according to the growth characteristics of reasonable topdressing. Many crops, including corn plants, have different levels of potassium demand absorption at different stages of growth.
Through years of planting experience, combined with the test, it was found that during the entire growth period of maize plants, the jointing stage of the plant seedlings to the big horn mouth stage was the period with the highest potassium absorption. Therefore, potassium fertilizer should be applied intensively during the period from jointing to the mouth of the big horn, and can be applied in small quantities and multiple times, and the application of potassium sulfate or potassium chloride per mu is about 5-8 kg each time.
However, it should be noted that the nitrogen demand is higher during the tillering stage of maize plants, and when applying nitrogen fertilizer, do not forget to add potassium fertilizer appropriately to avoid imbalance in the ratio of nitrogen and potassium, causing plant lack of potassium. Because, long-term observations have found that potassium deficiency in maize plants is largely caused by a large amount of topdressing nitrogen fertilizer, after all, excessive nitrogen fertilizer will affect the absorption of potassium by plants.
Of course, if the maize plant has already developed symptoms of potassium deficiency, it is recommended to spray foliar 0.2%-0.3% potassium dihydrogen phosphate solution 2-3 times at intervals of 5-7 days each time, which will help promote rapid return to normal growth of the plant, because foliar spraying is faster than root potassium fertilizer.
The above is only a personal experience, I hope to help farmer friends.