Soil acidity: learn to control this factor correctly
One of the most important activities when preparing the soil for farming is the correction of soil acidity. This is an indispensable practice.
In addition, rainwater and irrigation water carries important elements, such as calcium, magnesium, and potassium, depleting and acidifying the soil. Likewise, the crop extracts these nutrients, leading to the acidity condition, including naturally neutral terrains.
Continue reading to find out what soil acidity is, and learn how to control this factor with good farming practices.
What is soil acidity?
Acidity is a biochemical condition resulting mainly from the absence of adequate amounts of calcium (Ca), magnesium (Mg) and potassium (K) elements. Therefore, hydrogen ions (H) are observed in the soil solution in an amount that characterizes a greater or lesser acidity.
The amount of hydrogen ions is evaluated by measuring its pH, the so-called hydrogen ionic potential. The lower the soil’s pH value, the higher its acidity. On the contrary, the higher the pH, the less acidic the soil, with neutrality at 7.0.
In turn, very acidic soils greatly damage the crop’s health and constitute a strong obstacle to agricultural production. Acidity releases toxic elements into the plant, such as aluminium and manganese, while reducing nutrient availability.
Thus, it is necessary to correct this condition for a pH range that is more appropriate for the culture. It is, in fact, an essential practice for most crops and an important reason to know the soil’s quality.
How to avoid harmful soil acidity?
The soil’s pH change to raise its value towards neutrality is carried out through the so-called acidity correctives. There are some alternatives to recover the soil, the most common being limestone.
The correction work is the first measure of land preparation for the crop and, in general, precedes the planting season in about 60 to 90 days. Soil analysis should be carried out to identify the real needs and size the application of the most appropriate corrective.
What are the benefits of soil acidity correction?
Most crops do not get along with very acidic soils, as they have developed in environments close to neutrality or only slightly acidic.
Thus, several difficulties encountered by plants and crop cultivation in high acidity regions are resolved with correction. In fact, the benefits of this work are not limited to cases of very high acidity, being important whenever the pH is below the best index for the crop.
Soil pH rise
The main response and main objective of soil acidity correction is the elevation of its pH. The other benefits are a consequence of driving the pH closer to the nature of the cultivated plant. However, a prior terrain analysis is indispensable to truly know the local reality. With this data, you can define the best concealer and scale the application.
Increased availability of nutrients in the soil
Some important nutrients for a plant’s good development are unavailable in the soil (they do not dissolve, and the roots cannot absorb them). This is the case, for example, of phosphorus (P), indispensable for vegetables numerous metabolic processes but practically inaccessible in acidic soil.
Better fertilizer efficiency
Most fertilizers used in agricultural production are made more efficient when applied to the soil of mild acidity. Thus, the correction also brings, as a result, better use of the fertilization that is performed in the cultivation.
Reduction of toxic effects of some soil elements
The most significant case is aluminium, which toxicity to plants is a serious problem in acidic soil. In fact, for many cultures, it is hindering sustainable production.
Improvement in soil biological activity
Soil microorganisms that interact directly and indirectly with plants benefit from the correction. Thus, the processes of decomposition of organic matter, for example, achieve greater efficiency in the release of nutrients and the natural conditioning reactions of the terrain.
How to be efficient in the application?
To achieve all the benefits of a well-made soil correction, it is necessary to adopt some measures to ensure final efficiency. It is important to care since several poorly conducted agricultural practices can lead to soil degradation. See the main aspects that should be observed.
Concealer to be applied
Several products can be used as correctives to soil acidity, but limestone is usually prefered. The type of limestone also varies, especially due to the presence of magnesium in its composition.
The result of the terrain analysis can point out the best option. In any case, it is important to pay close attention to each product’s characteristics, especially for the quality expressed by limestone’s relative power of total neutralization (PRNT).
After defining the type of concealer to be used, the dosage required for correction should be considered. In this sense, it is necessary to scale properly because excess limestone in the soil can be harmful, as well as the use of smaller quantities does not promote the desired effect.
Limestone requires time to react with the soil solution to counteract the acidity levels observed in the terrain. Thus, the application should be carried out at least 60 and 90 days before planting.
There are two basic ways to carry out soil tillage, depending on whether the planting type is conventional or direct. In this way, the operation can be of embedded or shallow distribution.
In the first case, the limestone is spread evenly over the soil before the ploughing and grading operations, which aim to ensure good incorporation of the concealer with the particles of the ground.
In the case of no-tillage, the distribution takes place superficially between the lines. To this end, limestone spreading machines perform the service in the best way.
As seen, the soil acidity should be well evaluated so that the measures adopted for its correction are the most appropriate and achieve the necessary result.
Now, learn more about soil liming and the steps for its realization to ensure the best results for your crop!