Importance of Soil Analysis

Tanja Folnovic

Agronomy Expert

Soil analysis is a set of various chemical processes that determine the amount of available plant nutrients in the soil, but also the chemical, physical and biological soil properties important for plant nutrition, or "soil health". Chemical soil analysis determines the content of basic plant nutrients; nitrogen (N), phosphorus (P2O5), potassium (K 2 O), pH, humus content, total CaCO3, available lime, organic matter, total sulphur (S), trace elements, and other physical characteristics (capacity, permeability, density, pH - value). Soil analysis imply :

  • Taking soil samples
  • Laboratory analysis of samples
  • The interpretation of the results by the issuance of fertilizer recommendation.

Which are the aims of soil analysis? The aims of soil analysis are:

  • To determine the level of availability of nutrients or the need for its introduction
  • To predict the increase in yields and profitability of fertilization (poor soils do not always provide yield increase due to fertilization because of possible limiting factors)
  • To provide the basis for calculating the required fertilizing of each crop
  • To evaluate the status (supply) of each nutrient element and simultaneously determine the compensation plan (nutrient management).

According to the content of nutrients in the soil obtained by chemical analysis and the requirements of the culture for a certain yield, it is easier to determine the amount of required fertilizer to achieve high and quality yields. In determining the amount of nutrients should be noted that at the best condition in the soil plants can adopt up to 80% of nitrogen, 40% of phosphorus, 60% of potassium and 40% of magnesium. High quality soil analysis is basis of planning of fertilizing, and thus the quality of the entire production cycle, which results in a high quality and yield and better farm management. When to make a soil analysis? Taking soil samples for analysis is done after harvesting of crops and before any fertilizing, at optimum soil moisture. The soil must not be depressed, along the edge of the plot or where mineral fertilizers are unevenly scattered, because the sample will not be representative and the resulting data will not be a reflection of the real situation. In the case of permanent crops (orchards and vineyards) analysis is carried out every 4-5 years. How to properly perform sampling? Samples are taken by probe, but can also by shovel. If the sample is taken by shovel, the procedure is as follows:

  • Dig a pit
  • Vertically cut the soil along the pit wall
  • The shovel must be pulled out so that the soil does not slips off it
  • Forming of sample - longitudinally along the middle of shovel soil width cca 5 cm is allowed, and left and right of the sample soil is cropped and removed.

A sample is taken to a depth of normal tillage ie, to rooting of plants, for field crops 0-30 cm, for permanent crops (orchards and vineyards) 0-30 cm and 30-60 cm. On analysis is given an average sample that is obtained by mixing all individual samples from 20-25 places evenly distributed over the entire surface from which samples are taken. If the soil is strongly sloped or area from which samples are taken is greater than 5 hectares or soil is not the same type, than more individual samples are taken. The samples are mixed and up to 1 kg of the taken soil. Thus separated sample is placed in a plastic bag on which write the following information:

  • Indication of the owner with an address
  • Designation of the plot
  • Depth of sampling
  • Indication of preculture with yield and previous fertilization
  • The name of the crop, which is planned to plant or sow and for which samples are taken
  • Date of sampling.

There're several ways of taking samples: network (a), Z-scheme (b), diagonally (c), in permanent crops (d)

taking samples

The results of chemical soil analysis for a culture you grow you can enter in farm management system Agrivi. At any time, you have insight into the soil condition that can help you to determine the right amount of fertilizer for the next culture. Analysing soil means an increase of yield. Sign up for Agrivi now.