The humic acid and the nitro humic acid substance can help the soil to form a granular structure. Increase the water permeability of the soil. Protect the water, the air permeability. Increase the plowing property. Adjust the acidity of the soil, Increase macro lelementes and trace nutrient elements. And it is beneficial to the preservation of the quick-acting food in the soil. As the land of our country is vast, there are a wide variety of soil. Some of the poor basic soil are in urgent need of improvement. So the humic acid is used as the soil conditioner. And it can be used in the fields of increasing production of crops, forestry, planting and improving the mountains and rivers.
Humic acid researchers in China used three kinds of weathered coal humic acid modifiers to improve calcareous soils in North China and Northwest China. The results showed that nitrohumic acid had the best effect on phosphatase activity and available phosphorus content. The researchers proved that humic acid fertilizer has five functions: soil modification, yield increase, warming, stimulation and aftereffect. Russian and Indian literature reported that humic acid or nitrohumic acid is a good nitrification inhibitor. Adding this kind of substance to urea can obviously improve fertilizer efficiency and prolong the retention time of urea nitrogen in soil. The researchers also pointed out that the interaction between humic acid organic matter and urea plays an important role in improving soil fertility and improving the agrochemical properties of organic-inorganic fertilizers.