Everyone knows that humic acid is beneficial to soil and crops, but many people don’t understand humic acid at all, nor do they understand its functions and effects. At the same time, there are many types of humic acid or humic acid fertilizers on the market, and most people don’t know which type is best. They not only don’t know how to choose the most suitable humic acid, but they also don’t know how to use it correctly.
Below, I will introduce some aspects to pay attention to when using humic acid:
① Humic acid fertilizers come in granular, powdered, and liquid forms, such as humic acid compound fertilizer, humic acid foliar fertilizer, and humic acid water-soluble fertilizer. However, in addition to humic acid or fulvic acid, most humic acid fertilizers also contain added nitrogen, phosphorus, potassium, and other micronutrients necessary for crop growth and development. From this perspective, humic acid fertilizers should be considered a mixed organic and inorganic fertilizer.
② The humic acid used in humic acid fertilizers primarily originates from three sources: lignite, weathered coal, and peat (also called turf). However, in terms of humic acid extraction rates, turf has the highest extraction rate, weathered coal the lowest, and lignite a moderate rate.
Functions and Effects of Humic Acid
The effects of humic acid or humic acid fertilizers are mainly determined by its inherent properties. As a natural organic active substance, its functional value in soil and crops is primarily achieved through its strong complexing, adsorption, colloidal, redox, ion exchange, and high biological activity.
Generally speaking, the agricultural value of humic acid mainly lies in improving soil fertility, promoting fertilizer efficiency, stimulating crop growth, enhancing crop resistance, increasing crop yield, and improving crop quality.
12 Tips for Using Humic Acid
1. In winter, when soil temperature is low, applying fertilizer to greenhouse crops can easily lower the soil temperature. However, adding an appropriate amount of humic acid fertilizer during fertilizer application can mitigate the adverse effects of low temperatures on the root system.
2. In summer, during periods of high temperature and drought or the rainy season, applying an appropriate amount of humic acid fertilizer can reduce the negative impact of drought or waterlogging on crops.
3. When using microbial fertilizers or inoculants, using them in conjunction with humic acid fertilizers can enhance the capabilities of beneficial microorganisms, thereby increasing their activity, reproduction, number, and effectiveness.
4. When crops exhibit poor root development, weak growth, premature aging, or nutrient deficiencies, using humic acid can stimulate capillary root growth, improve water and fertilizer absorption capacity, restore and enhance crop growth, mitigate the effects of premature aging, and quickly replenish missing nutrients.
5. When crops need to increase size and improve color and gloss, humic acid can promote the formation of a waxy paper layer and cuticle layer on the fruit surface, thereby promoting cell expansion (increasing size), improving fruit surface smoothness, and enhancing fruit color.
6. During the crop’s growth period, humic acid is most effective and offers the highest return on investment during the four stages of crop growth and development: after transplanting, before flowering, during fruit enlargement, and during color change.
7. Because humic acid can enhance the effectiveness of fertilizers, when using humic acid with chemical fertilizers, the amount of chemical fertilizer can be reduced by about 10%, thus saving on fertilizer input.
8. Humic acid fertilizers containing the word “ammonium” are not suitable for fertigation or foliar spraying; they should be applied by covering the soil. Potassium humate and potassium fulvate, on the other hand, offer the best cost-effectiveness when applied through fertigation, drip irrigation, or foliar spraying. 9. Potassium-loving crops or fruit-bearing vegetables and vegetables respond best to potassium humate or potassium fulvate. Humic acid-based compound fertilizers are highly effective on field crops, fruit trees, and vegetables.
10. When using humic acid, combining fertigation with foliar spraying will yield more significant results. However, it’s important to note that applying a large amount at once is less effective than applying small amounts multiple times.
11. On acidified or saline-alkali soils, humic acid can improve soil structure, reduce salt damage, promote root growth and development, and prevent nutrient deficiencies and premature aging. However, sodium humate is not suitable for use on saline-alkali soils.
12. When crops suffer from root weakness and poor growth due to drought, waterlogging, low-temperature freezing damage, or pesticide damage, humic acid can effectively alleviate or mitigate these symptoms and enhance the crop’s resistance to adverse environmental conditions.
