Taking soil samples after the harvest is the most popular and best time. A specialist explains
from A to Z, how to do research and what to look out for in order to be knowledgeable and, most importantly, more
money in your pocket.
A basic soil analysis is best done every two years. The idea is to check the pH and phosphorus, potassium and nitrogen levels, says agronomist Maciej Kobus – a representative of HeavyFinance.
In addition, once every three to four years it is worth examining the organic carbon content of the soil – in short, the humus level. This gives the farmer information on whether the way he cultivates, maintains the fertility of the soil, raises it, or perhaps deteriorates it. The last option means that the farmer is doing something incorrectly and the soil is becoming depleted. If this is the case, regardless of fertilization, yields will in the long run deteriorate and something needs to be changed, the specialist points out.
Maciej Kobus draws attention to another soil test, not very popular, which should be performed in winter crops every year in late February and early March. It is about checking mineral nitrogen content. – If one applies organic fertilizers, sows catch crops – using, for example legumes, i.e. those that accumulate nitrogen, or has peas or soybeans in the sowing structure, then it is worth doing such a study. Only in this way you can know exactly how much nitrogen is in the soil, how much plant has at its disposal, the agronomist says.
The result of such a study can bring great savings, as accurate information on the availability of this yield – determining component, allows optimal planning of the fertilizer dose. – It may turn out that there are 60 or even 80 kg of nitrogen in the fourth component. However, it is also often the case that there is only 10 kg of this nitrogen.
So the spreads are really significant, points out Maciej Kobus. So why is such a low popularity of this type of testing? First of all, it’s all about deadlines. To take samples, you have to wait until the frost lets up, and, as you know, farmers take off with the first dose of fertilizer as soon as that happens. So it’s also a matter of test results should therefore be available practically overnight, the representative of the company points out HeavyFinance. However, he stresses that, according to him, it is even worth delaying the start a bit with the first dose of nitrogen, and have an accurate test result for its content in the soil.
These are the simplest savings. In fact, no one knows whether they have 10 or 40 kg of N in the soil in the pure component. It is dependent on a great many factors, and only testing makes it possible to accurately determine this state, says Kobus, indicating the possibility of reducing expenses on fertilizers by tens and, in the case of larger farms, even hundreds of thousands of zlotys even hundreds of thousands of zlotys for larger farms.
Sample methodology
It is assumed that for 4-5 hectares of soil there should be one pooled test from 20 to 50 samples taken from this acreage. Of course, it is possible to do more accurate tests from smaller fields, but this involves with higher costs. Each sample is an expense of a dozen to several dozen zlotys, explains the specialist. Another important point he points out is the depth from which samples are taken. Basic tests for pH, NPK and carbon are usually taken from the arable layer, which is a depth of 15-20 cm. The situation is slightly different for mineral nitrogen testing. In the case of this test, it is good to do from a 0-30 cm profile, since nitrogen is easily leached into deeper soil layers.
At least once in a while, a sample should be taken from the 0-30 and 30-60 cm profiles, notes the agronomist. The examination of the deeper soil layer gives us information on how much nitrogen is there and whether there there is a possibility of using it, or whether it will be lost irretrievably.
In the case of rapeseed, which has a tap root, the plants will calmly take up this fertilizer, while plants with other, shallower root systems, may not be able to acquire it, and then this nitrogen will be lost. It will move into groundwater and will flow into the Baltic Sea, and there, due to its accumulation, blue-green algae will bloom. This is how it, this is how it works, the specialist explains.
Importantly, in order to obtain reliable results, soil samples should be taken a minimum of one month after the application of the last fertilizer. Hence the popularity of testing for pH and NPK content during the harvest. The second issue is technology. After all, sampling nowadays uses pickups, quads or special rovers, so summer is the best time, because we don’t cause any damage to the crops that have already come off the fields, says Maciej Kobus.
Polish soils are acidified and barren
How important regular soil testing is is indicated by data on the acidity and humus content of soils used for agricultural purposes in our country. As much as 64% of agricultural land (9.4 million hectares) requires liming due to due to severe soil acidification, with 6.7 million hectares having a pH below 5.1, signaling the the onset of devastation. Humus content, on the other hand, is just over 1%, and as Maciej Kobus points out, it would be useful to have an average level of around 4%. The popular term these days is regenerative agriculture.
In fact, this is how our grandparents operated. Unfortunately, the economics of production caused farmers to grow mostly a lot of rapeseed and wheat, willingly or unwillingly.
In addition, not all of them owned animals, which made us exploit the soil a lot. Anyone with agricultural education realizes this. However, economics was and is inexorable. The bank will not wait, notes Kobus. Fortunately, however, there are already programs that promote increasing the sequestration of carbon dioxide and thus increasing humus levels. This is in the interest of the farmer. The farmer, who until now could not afford proper crop rotation, but as the mighty of this world saw what this was leading to what this leads to, the policy changed a bit, the specialist adds.
They test the soil for free. The farmer will still make money from it
Today, by doing something to take care of the soil, we can diversify income, says Maciej Kobus, citing the example of ecoschemes. There is also hope for carbon farming programs aimed at generating certificates for soil absorption of CO 2. In addition, the HeavyFinance representative points out that farmers can already earn an extra income of around PLN 200 per hectare per year starting next year.
As part of the program, the company will test their soil for organic carbon content, also offering advice on cultivation methods, intercropping, or fertilization methods. So that the farmer maximize sequestration and improve the economics of production, and thus the health of his farm, concludes Maciej Kobus. By mid-September, HeavyFinance is expected to survey more than 150,000 hectares of farmland in our country.
