Zinc function and factors that impede absorption
Zinc is one of the essential trace elements for crops and is involved in the metabolism of growth hormones, promoting the synthesis of tryptophan from indoleacetic acid and serine, and further synthesizing growth hormones. Crops deficient in zinc, the synthesis of indoleacetic acid is blocked, growth is stagnant and leaves become smaller.
Zinc promotes protein metabolism and is an element that maintains the structural integrity of ribonucleoproteins.
Zinc is a component of the enzyme glutamate dehydrogenase and is essential for the synthesis of glutamate.
Zinc plays an important role in the development of reproductive organs and fertilization.
Zinc in soil can be differentiated into zinc in the water-soluble form, zinc in the substitutional form, zinc in the insoluble form and zinc in the organic form. The solubility of zinc-containing mineral decomposition products is large, and it exists in the soil in the state of divalent cation or monovalent complex ion, etc., and is absorbed and utilized by plants.
1. Soil pH
Plants are susceptible to zinc deficiency at soil pH 6.5. Hydrogen ion concentration decreases pH will rise, effective zinc decreases. Chinese Academy of Agricultural Sciences, a large number of testing and analysis results show that the soil effective zinc and hydrogen ion concentration is positively correlated. pH rise a unit, the solubility of zinc decreased by about 100 times.
The more acidic the soil is below pH 5.5, the less effective zinc there is. Be aware that a strong acidic environment will also reduce the effective zinc content.
2. Soil carbonate
Soil effective zinc content and carbonate is negatively correlated. The higher the carbonate content, the lower the effective soil zinc content. Experimental comparison of the amount of sodium bicarbonate, the more the amount of zinc absorbed by rice is less.
3, soil organic matter
Soil organic matter content and diethylenetriamine pentaacetic acid extracted effective zinc is positively correlated, but the soil organic matter is too high (such as peat soil), the effective zinc in the soil with the increase in organic matter will appear downward trend.
4、Temperature
Soil temperature is high, the effective zinc content is also high. Zinc deficient crops in the early spring low temperature symptoms of zinc deficiency, in the temperature after the natural relief or disappear.
5. Improper fertilizer application
Too much phosphorus fertilizer will lead to crop zinc deficiency, too much nitrogen fertilizer will also lead to soil effective zinc reduction. Soil amended with lime is also prone to zinc deficiency.
6、Soil slope direction (Xiushan County provides data, this data is a wide range of average value)
Soil cultivation surface is flat, effective zinc content is lower, mountainous plots cultivation surface orientation and effective zinc content is also related. The order was: flat < east < south < north < west, with the highest effective Zn content on the west-facing tillage surface.
The ratio of soil zinc content to effective zinc is about 8:2. Those who have done soil tests will decide whether to supplement zinc fertilizer according to the data. Generally, in the case of strawberries, for example, one kilogram of zinc sulfate heptahydrate fertilizer can last for about 2 years, and does not need to be supplemented every year.
