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Testing Soil pH and Nutrient Content – Why Is It Worth It?



Soil can be compared to a well-equipped workshop. If a farmer understands the "tools" it contains, such as nutrients and pH, they can efficiently address any related issues. This knowledge brings both profits and satisfaction. Mineral resources and pH influence the condition of the soil and each other. This article explains how to test soil pH and nutrient richness, and why it is important to do so before sowing and fertilizing.



Testing soil pH and fertility before sowing – key factors influencing yield




Acidification, i.e., soil pH



Acidification, i.e., soil pH, is the pH level of the soil. It affects the development of essential fungi and bacteria and the nutrient uptake by plants. Different plant species thrive in different pH ranges based on their nutritional requirements. For instance, wheat requires a minimum pH of 5.5 for cultivation. When the pH is too high, plants cannot absorb iron adequately, causing them to turn yellow.


Acidic soil – the impact of pH on plant growth and nutrient uptake




Soil pH Assessment



The simplest, though least accurate, method to assess soil pH is to smell it. While experienced farmers can recognize the proper smell of the soil, this does not provide sufficient information about the need to regulate pH in different areas of the field. Unfortunately, indicator papers are also inaccurate. Despite their low cost and the ability to take numerous samples, their assessment is subjective, leading to different interpretations by different people.


Soil ph testing – comparing measurement methods from indicator strips to laboratory analysis




Soil pH test kits are more accurate but involve a chemically complex test. Additionally, these kits provide results across different pH ranges, necessitating either the purchase of multiple kits or prior knowledge of the pH ranges in the field.


Soil pH tester kit – measuring accuracy across different acidity levels




A superior and accessible solution for every farmer is to use a portable, digital soil pH tester. It provides significantly higher measurement accuracy (up to 0.1 pH units) than previously mentioned options. Simply insert a special electrode into the ground and wait for the result. While this device has a cost, it enables you to independently create a field map that accounts for pH differences, informing the appropriate amount of carbonaceous lime to use in each location.


Portable digital soil pH tester – fast and accurate readings for farmers




The most accurate test can be conducted in the Agricultural and Chemical Station laboratory. Importantly, pH measurements up to 0.5 enable proper adjustment of liming. Additionally, extended periods of high temperatures and water deficits impact soil pH, necessitating a simple and readily available testing method. This allows decisions on irrigation, which also lowers soil pH.


Soil pH testing in the Agricultural-Chemical Station lab – agricultural substrate analysis




Rich in minerals



It is also worth noting that liming activates nutrients in the soil. For instance, high pH levels may result from elevated potassium or sodium content. Therefore, before liming, precise measurements of the soil's elemental content should be conducted. This analysis will indicate the required nutrient levels to achieve a larger, higher-quality yield.


Soil mineral content – the effect of liming on activating nutrients




Soil Content Assessment – Sampling



Soil samples are collected using an Egner Riehm stick. It should be driven into the ground to a depth of 20-25 cm, twisted, and the collected sample poured into a bucket. Alternatively, a spade can be inserted to a similar depth to cut off the sample from the tip.


Soil sampling with the Egner-Riehm stick – assessing nutrient availability




After collecting all samples, mix them thoroughly and transfer the mixture into a bag to create a composite sample. This composite should consist of approximately twelve individual samples from an area no larger than 4 hectares. Therefore, it is advisable to prepare a field map divided into zones of up to 4 hectares or areas with uniform soil and terrain characteristics prior to sampling. Avoid collecting samples from field edges, areas affected by drainage ditches and mounds, ditches, furrows, molehills, depressions, and locations near roads and buildings.

How to correctly take soil samples for laboratory testing? Key principles




The packaging (average sample) must be signed, preferably with a marker, providing all necessary information and protected against high temperatures and sunlight. Deliver it to the Agricultural and Chemical Station within 3 days. If you intend to deliver it later, the soil sample should be dried at room temperature to prevent mold. Additionally, besides testing the reaction (pH) and the abundance of macroelements (P2O5, K2O, MgO), you may order tests for microelements, such as copper (Cu), zinc (Zn), manganese (Mn), iron (Fe), and boron (B), and request fertilizer recommendations.


Packing and labeling soil samples for testing at the Agricultural-Chemical Station







If your acreage consists of several fields in different locations, it is advisable to create separate samples from each field. The same applies to hilly areas and sloped fields. Primary samples should be taken from the bottom, middle, and top of the plot. Collection of samples can be commissioned to a company that provides such services or to a Chemical and Agricultural Station. These entities perform this task regularly, thus minimizing common errors that may contaminate the sample. Additionally, they can collect material from greater depths, which is beneficial as roots can absorb nutrients from up to 2 meters deep.



When and how often should soil be tested? Recommendations for regular soil analysis




When to conduct a soil test?



All analyses should be conducted post-harvest but prior to fertilization and sowing. Avoid sampling on extremely wet or dry days as this may yield inaccurate results. How often should tests be performed? It is recommended to conduct soil tests every four years. However, due to changing climatic conditions, annual tests are advisable, and for mineral nitrogen, biannual tests are recommended.


Soil analysis after harvest – how weather conditions affect test results




Why is it worth testing the soil?



Without detailed data in the nutrient balance, it is impossible to determine the appropriate amount of fertilizer. Soil analysis in terms of pH and mineral content involves costs, but fertilization by estimation is less economical. Feeding the soil is one of the most expensive agrotechnical procedures. Additionally, if nitrogen is added to a field where it is already present, the wheat will cease feeding the fungi that supply it with nitrogen from the soil. When they die, you will need to spend money on fertilizer that could have been naturally provided to the plant for free.


Why is soil testing worthwhile? Key insights for farmers on costs and savings




Instead of fertilizing, consider introducing nitrogen-fixing bacteria to the soil, taking into account the pH range of 6-7.5, in which these microorganisms thrive. Additionally, ensure sufficient levels of potassium, calcium, and magnesium, as these elements are crucial for the structure and quality of soil aggregates.


Nitrogen-fixing bacteria in soil – the role of pH and nutrients in their development




It is clear that all aspects of soil, including its physical and biochemical properties, influence each other, creating a self-propelling process of degradation or quality improvement. Any agrotechnical activities and fertilization not based on accurate knowledge will cause harm. The soil, crop, and ultimately the farmer's financial interests will suffer.


The impact of fertilisation and agronomic practices on soil’s physical and biochemical properties







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