Tiếng Việt
中文 (中国)
Not only is lime widely used in construction, but it also plays a very important role in agriculture. Besides, there are many types of lime with different molecular structures and functions. Therefore, farmers should clearly understand the nature of lime to apply it correctly in the appropriate field.
Limestone powder (CaCO3) is commonly used in agriculture
Three common types of lime in agriculture
Firstly: Limestone (CaCO3) has the effect of raising soil pH and supplying Calcium to the soil.
Secondly: Slaked lime (Ca(OH)2) and quicklime (CaO) have very strong disinfectant effects and react with high heat when added to water.
Thirdly: Dolomite (CaMg(CO3)2) simultaneously supplies Ca and Mg, raises pH, kills pathogens, and generates less heat when added to water.
Dolomite (CaMg(CO3)2) simultaneously supplies Ca and Mg
Note:
- Overuse of slaked lime and powdered lime can cause hardening of cultivated soil and adversely affect the soil microbial system.
- Dolomite is expensive, and excessive use can also cause soil hardening and reduce the diversity of the soil microbial system.
The main roles of lime in agriculture
Improving soil’s physical and biological properties
Calcium positively affects soil structure and physical properties by flocculating the clay-humus complex. For clay soils that are plastic and sticky when wet, then dry hard and crack when sunny, applying lime will flocculate small clay particles into larger aggregates, making the soil more aerated and stabilizing its temperature and moisture regime. For sandy soils with a loose structure, applying lime will help make the soil more cohesive and retain humus, preventing rapid decomposition.
Appropriate liming helps raise soil pH towards neutral, which is favorable for the development of the soil microbial system, thus improving soil biological properties.
Supporting nutrient supply for plants
The Ca2+ supplied by lime aids in nutrient exchange on the surface of soil colloids and in the soil solution, making it easier for plants to utilize nutrients.
It enhances the decomposition of difficult-to-digest organic matter containing N, P, K into easily digestible forms.
Powdered lime spread around the base to prevent fungi and supply Calcium to soil and plants
Powdered lime spread around the base to prevent fungi and supply Calcium to soil and plants
Improving soil pH favorably
Applying lime will help raise soil pH towards neutral, which is favorable for better nutrient absorption by plants. However, this also depends on the crop group’s sensitivity (very sensitive, sensitive, or less sensitive) to high pH and liming. Therefore, when applying lime, it is necessary to consider the type of crop for appropriate supplementation.
Applying lime will help raise soil pH towards neutral, facilitating better nutrient absorption for plants
Applying lime will help raise soil pH towards neutral, facilitating better nutrient absorption for plants
Protecting and reclaiming cultivated land from degradation
Lime reduces soil acidity and effectively prevents the degradation process of clay minerals in the soil, preserving soil fertility.
It replenishes the lime lost from the soil due to leaching, excessive application of chemical fertilizers, and uptake by plants for their growth.
Replenishing lime lost from the soil due to leaching
Replenishing lime lost from the soil due to leaching
Effective pest and disease control for crops
After harvest, plants are often weakened. Using lime to eliminate moss and harmful fungi adhering to the stem, branches, and leaves is a very effective disinfection measure. A typical example is lime combined with copper sulfate to create Bordeaux mixture for controlling fungal diseases and moss, which is widely applied.
Notes for using lime effectively
1st: Choose the appropriate type of lime
- Quicklime is suitable for heavy soils, acidic saline soils, and soils requiring rapid improvement.
- Limestone is used for acidic soils with light mechanical composition.
- Dolomite is often used for infertile soils and soils heavily leached of Mg.
- Gypsum (CaSO4) should not be used for saline soils that are not acidic.
Note: Farmers should choose the appropriate lime for their soil type, desired speed of improvement, and cost.
2nd: Lime application method
- To increase efficiency when applying lime, farmers can mix it with water or apply lime directly in fine powder form when there is no wind.
- Do not apply lime mixed with manure, ammonium nitrogen fertilizers, or superphosphate. Treat with lime at least 1 month before applying other types of fertilizer to ensure safety and maximize lime’s effectiveness.
- The amount of lime applied should be reasonable because the pH is raised gradually to around 6 – 6.5, which is suitable for many types of crops. Applying too much can lead to mineral nutrient disorders in plants, rapid decomposition of organic matter, reduced buffering capacity, and release of toxic gases in the soil. The most effective way is to combine liming with plenty of organic fertilizer for rapid pH improvement.
Combine with organic fertilizer application to increase soil porosity and stabilize soil pH
This article also provides some useful information about lime and how to use it effectively for farmers to refer to. Besides using lime to improve soil, farmers should combine it with applying plenty of organic fertilizers such as composted manure, humic acid, WEHG fertilizer, soybean meal, Trichoderma fungi, etc., to increase soil fertility and provide a source of easily digestible nutrients for plants to absorb. Wishing farmers good health and a successful harvest.