Sampling and chemical analysis of the soil

Why is it necessary to sample and analyse the soil?

Not all land is equally provided with nutrients. Depending on the parent material on which the soil was formed, they have different content of certain nutrients that the plants use in their cultivation.

Their content is highly affected by the way the soil is exploited, and primarily by its fertilisation. Every plant species has its own specific characteristics in terms of the need for certain nutrients.

The plants intake a large number of various nutrients. Biogenic elements (nitrogen, phosphorus, and potassium) are a part of the plant species and build their tissues.

Every year a certain quantity of biogenic elements is removed from the production fields. The quantity that is removed depends on the yield and the plant species. Removed elements should be returned in adequate quantities to the soil by fertilisation, in order that the required level of their contents in the soil is maintained.

Removal of nutrients with 1t of yield and corresponding vegetative mass

Low contents of nutrients in the soil will not allow the plants to fully express their genetic potential, which will inevitably result in a low yield. High contents of nutrients are also undesirable since they can have harmful impact on the cultivated plants, intake of other nutrients.

In order to determine the contents of nutrients in the soil, monitor the pace with which they change and maintain the optimum level of provision with the most important nutrients, it is necessary to make sampling and analysis of the soil.

The chemical analysis of the soil is the basis for rational application of mineral fertilisers. Fertilisation based on the soil analysing, in addition to the provision of optimum quantities of corresponding nutrients for cultivation of plants can make significant money savings.

How is the sampling made?

An average sample consists of the adequate number of individual samples. Depth from which samples are taken for the control of fertility with arable and vegetable crops is at 0-30 cm, while with fruits it is at 0-30 cm and 30-60 cm (two layers).

Sampling of soil is made with the state of the art automatic equipment for sampling. The advantages of this type of soil sampling related to the manual sampling are numerous. The equipment is completely automated; all instructions are given by pushing a corresponding button in the vehicle cabin. Every individual sample is taken from the same (assigned) depth; human work is reduced to the minimum which significantly reduces the possibility for any failure in the work. The operating performance of the sampling equipment is much greater. During its working day, equipment can take samples from an area of 300-500 ha, depending on the size of the plots and their mutual distance.

During the soil sampling, Victoria Logistic’s Agroteam uses GPS technology as well. By recording, plot mapping with a GPS device, we obtain precise coordinates of the plot and its surface. If a plot is large, it is divided into several smaller parts which are sampled individually. If analysis of the soil results in different contents of nutrients in individual samples, there is a possibility for each sample to be fertilised by a corresponding formulation and quantity of the fertiliser. During sampling, the coordinates of each point of drill, i.e. the place where the sample is taken from, are recorded.

Owing to that, in four years, when the sampling for analysis of fertility is repeated, we will have a possibility to take the sample from the same place. It enables monitoring of the dynamics of the change of readily available nutrients in the soil.

Sampling may be also made manually, i.e. with a shovel or different types of probes. In such a case, individual samples are collected in a suitable container. The collected earth should be crushed, well stirred and any excess of soil should be removed. An average sample should weigh maximum 1 kg. The bag with the sample should contain a card with the information about the owner of the sampled plot, the cadastre number of the plot, the surface area of the plot, number of samples if there are more than one in one plot, data on the period before sowing and the plan of sowing for the following year on the sampled plot. Such a sample is adequately marked and ready for analysis.

The best time for sampling is after harvesting of crops while the soil is settled, i.e. while it is in the physically undisturbed state. After the end of the production season, it is the right time to make analysis and determine the contents of nutrients in it. The obtained data is of great importance for the subsequent period.

Sampling of the cultivated land (especially ploughed land) disables moving of the vehicle along the plot, an average sample that is not taken from the same depth is obtained, distribution of individual samples is not regular, and therefore the sample taken in such a way cannot represent adequately the whole surface of the plot. Thus, chemical analyses of the soil that are not fully reliable are obtained. It is of special importance that the plots, for which sampling is planned, have not been fertilised in the previous four months.

The expert service of Agroteam starts the season of soil sampling at the end of June, after the harvest of small grains, oilseed rape, early vegetables and other crops. Harvest waste is mainly well chopped and does not represent a problem during sampling. After the harvest of root crops, it often happens that high stems remain on the plot (especially in case of the sunflower), and they should be treated with a Tarup forager or chopped in another way. Sampling in orchards and vineyards is made after harvest. For perennial crops, it is important that the distance between the furrows is at least three meters so that the vehicle with the sampling equipment can move among them. Since these crops are mainly based on upper grounds, excessive slopes of the plots may present a problem. The season of soil sampling finishes when the rainfalls, mud or bad weather conditions disable further work. Given the importance of this measure as well as the time interval in which it can be implemented, all producers should take a little time and make soil sampling.

The expert service of Agroteam provides services of soil sampling and analysis, giving recommendations for fertilising, advice for correct selection and application of the plant protection agents and improvement of the agricultural production. Agroteam grounds its mission exactly on the improvement of the production and achievement of as better production results as possible by its business partners. We are known for the sampling of soil not only in our country, but in the region as well.