Post Details

The agriculture sector has a major contribution to the country's economy. Horticulture, for instance, generates more than $1 billion annually. The demand for food is high not only locally but also internationally. However, food production is determined by the soil health. The primary indicator of soil health is soil pH. The yields from the farm and what you can grow can be predicted by the soil pH. It is therefore important to manage the soil pH for your crop.

Factors Affecting PH

Most crops perform well when the pH levels are neutral, ranging between 6 to 7.5. Low pH can inhibit the nitrogen cycle. Some inherent factors affecting soil pH include soil texture, mineral content, and climate. Minerals in the parent material determine the pH of newly formed soils. When the rainfall amounts are high, the soil pH decreasing as a result of acidification caused by leaching. In dry environments, the soil pH is either alkaline or neutral since weathering and leaching are low. However, soils with high organic matter content have a high buffering capacity and hence more resistant to changes in pH. Mostly, sandy soils contain little organic matter content leading to high rates of infiltration and water percolation and low buffering capacity. This makes them susceptible to acidification.

Nitrogen levels in the soil also affect the soil pH. Some sources of nitrogen such as manure, fertilizers, and legumes either form or contain ammonium. As the ammonium is being converted into nitrates, during the nitrification process, it releases H ions. The nitrate provided or formed combines with basic cations such as potassium, calcium and magnesium leaching the soil. These bases are replaced or removed by the H ions and in the process the soil becomes acidic. The application of sulfur fertilizers increases soil acidity making the pH levels to become lower.

Know Your Levels

Farmers need to know the pH levels of their soils to know which management techniques to employ. Regular soil testing is therefore important to help you know the crops that you can grow. Soil testing also helps you know the best time to apply fertilizers, the quantity to use, and the nutrients required by the soil. To have an accurate soil pH of the farm, multiple soil tests are recommended.

Management Techniques

Different crops thrive well at varying soil pH. For instance, legumes require neutral pH ranging from 6.5 to 7.0. Grains perform well at a pH that is slightly acidic to neutral – 6.0 to 7.0.

Some of the measures that can be applied to raise the soil pH or reduce acidification include:

• Liming to increase the pH of acidic soils. Lime not only corrects the soil acidity but also provides the soil with important nutrients such as Magnesium and Calcium, and prevents elements like Aluminium and Manganese from harmful to plants.
• Proper fertilization: fertilizers should be applied as per the plant's needs. This is because elements such as nitrogen and sulfur can raise soil acidity. Proper irrigation management should be used to minimize the leaching of nitrates.
• To minimize the acidifying effects of nitrogen fertilizers, farmers should diversify crop rotation.
• Applying irrigation water and manure and other organic material that have a high content of calcium or magnesium bicarbonates.

Using cover crops, diverse rotation with high-residue crops, and applying solid manure improves soil buffering capacity, increases organic matter content, and minimizes changes in soil pH. Due to the global-positioning, solid infrastructure, and favorable climate, the agriculture industry is growing at a fast rate. However, the farmers will not be able to meet the demand for food if the soil pH is not maintained. Soil testing should be put into emphasis to ensure that food production does not reduce.