Conservation practices are increasingly entering agricultural production in various forms such as green manure with cover crops, No-till, Strip-till, etc. They are proven to be effective in increasing the organic content in the soil, improving fertility, reducing soil erosion and increasing resilience to climate change.
Why is it important to have knowledge about the soil?
Before proceeding to the application of conservation practises on the farm, it is necessary to get acquainted with the condition of the soil. Through soil analysis, we study its physical, chemical and biological properties. These are the main components of the soil and by analyzing them we can identify where in the field any of these functions is violated. Based on the results of soil analysis, we can orient our strategy towards solving the most pressing problems by applying different practices and cover crops.
Chemical analyzes give us information about the content of nutrients that the plant needs the most – macro- and micronutrients. The main minerals are nitrogen (N), phosphorus (P) and potassium (K), and together with them are the mesoelements – sulfur (S), calcium (Ca) and magnesium (Mg). Chemical analyzes give us information about the content of nutrients that the plant needs the most – macro- and micronutrients. The main minerals are nitrogen (N), phosphorus (P) and potassium (K), and together with them are the mesoelements – sulfur (S), calcium (Ca) and magnesium (Mg). Soil reaction (pH) is another important indicator that is studied by chemical analysis. It measures the acidity or alkalinity of the soil. pH largely determines the availability of minerals to plants and is a key factor in many reactions related to vegetation and final yield. Each crop has a different sensitivity to soil reaction. That is why this indicator helps us to manage the crop rotation in the right way. This includes the choice of roof crops in a certain mix. It would be unfavorable to plant crops with a scope beyond that of the soil reaction. Then, productivity will certainly be reduced.. It measures the acidity or alkalinity of the soil. pH largely determines the availability of minerals to plants and is a key factor in many reactions related to vegetation and final yield. Each crop has a different sensitivity to soil reaction. That is why this indicator helps us to manage the crop rotation in the right way. This includes the choice of roof crops in a certain mix. It would be unfavorable to plant crops with a scope beyond that of the soil reaction. Then, productivity will certainly be reduced.
Physical analyzes determine the structure of the soil and its porosity (water and air retention properties). One of the indicators is the mechanical composition. It represents the ratio of sand, clay and dust, which is often decisive for the bulk density of the soil. Together with the specific electrical conductivity and stability of the units, they give the clearest idea of the soil structure. Depending on the values of the given analyzes, we can determine the susceptibility of the soil to erosion.
The indicators of aggregate stability and bulk density are dynamic and depend on the way the field works – mostly on what tillage is done. With reduced tillage, the analyzes help to monitor the dynamics of these two indicators, especially when working with roof crops. That is, we monitor the effect of roof crops on soil structure. The lower the bulk density, the more air enters and the aeration of the soil improves.
Through the bulk density we can calculate the area of the mineral content in the soil. Laboratory tests are usually performed in units of mg / kg (ppm – parts per million) of soil. Volumetric density provides information about what weight soil is contained per unit volume. Based on this, the nitrogen content (N) per decare can be calculated.
Biological indicators that provide information about the condition of the soil are the content of organic matter – mainly carbon (C), total mineralized nitrogen (excludes nitrate and ammonium form) and respiratory activity of microorganisms – carbon dioxide (CO2), which is released during respiration. the soil. CO2 is released as a result of the decomposition of soil organic matter and plant debris from the soil fauna. Respiratory activity of microorganisms is a very important indicator of soil health because it measures the level of microbial activity, as well as the content and decomposition of organic soil matter. In short, it determines how rich the soil is in life. The greater the respiratory activity of microorganisms, the greater their presence.
The content of organic matter in the soil or the so-called humus is one of the main indicators that determine its fertility. In combination with the clay content in the mechanical composition, they determine the moisture retention capacity of the soil, as well as its cation exchange capacity or the ability of the soil to retain minerals.
Soil analyzes for optimal fertilization
Laboratory tests of soil samples and their analysis give accurate information about minerals and based on it, we have the opportunity to determine the optimal fertilizer rates. Depending on the number of samples from one field, flat fertilization can be done according to the dynamics of different minerals. Another possibility is to use an even more specialized service for sampling and preparation of individual recommendations for variable fertilization rates. In this way fertilization can be significantly optimized and fertilizer costs can be saved.
When soil sampling and analysis is performed
Soil sampling and analysis of the general condition of the soil (chemical composition, physical properties and biological activity) is done in periods when there is greatly reduced or zero activity of microorganisms in the soil to be as objective as possible. These are usually periods of drought and high temperatures (summer) or very low temperatures (late autumn to late winter). The recommended frequency of soil sampling and analysis of the general condition of the soil is after each complete cycle of crop rotation, but not less than 3 years. When soil sampling and analysis are needed to select the appropriate fertilizer formulation and rate (flat or variable), it is done at least 3 weeks before sowing.