The secret to enhancing crop yield
Farmers should sample their soils for pH and fertility analyses to save costs and sustain soil quality.
Farmers are notoriously eager to fertilise their soil well and when plants do nto grow to full capacity, often blame lack of water or high heat. However, it could be as simple as the pH of the soil. According to Emilie Abraham from AgriBank if there are any imbalances in the soil’s pH this should be corrected.
The pH of the soil is a measure of its alkalinity or acidity. It is an excellent chemical indicator of soil conditions, its quality and its ability to avail nutrients to crops. Soil pH imbalances can hinder the crops roots ability to absorb nutrients from the soil. It is important to test your soil pH especially when planting fields for the first time.
Also, it should be noted that different crops prefer different pH levels.
Abraham says the use of appropriate liming is recommended as this enhances fertiliser use efficiency in crops.
“Agricultural lime is a relatively cheap soil conditioner with many benefits to the farmer that far outweigh the costs of procuring and applying it.”
According to Abraham the continuous and consistent use of lime will enhance the profitability of any cropping pattern. “This is the top secret to enhancing yield per unit area. Therefore, farmers are advised to sample their soils and apply lime when necessary at least three to six months before crop establishment. This is important as it takes a significant amount of time for lime to dissolve and react with the soil to cause the desired adjustments in pH level.”
Abraham says harvested crops remove bases such as calcium and magnesium from the soil. “This is a normal and natural process. Different crops remove different amounts of calcium and magnesium from the soil which may lower the pH level.”
Heavy rainfall also affects soil pH through the leaching of basic nutrients such as calcium and magnesium beyond the root zone. Drainage water replaces them with acidic elements such as hydrogen, manganese and aluminium thereby acidifying the soil.
Application of nitrogen contributes to soil acidity by nitrification of ammonium to nitrate, a process which releases hydrogen ions.
Abraham explains that too low pH (below 5.5) increases the level of aluminium and manganese in the soil and may reach a point of toxicity to the plant. Excess aluminium ions in the soil solution interfere with root growth and function, as well as restrict plant uptake of certain nutrients.
Low pH also affects the availability of micronutrients in the soil and affects general crop development and ultimately crop yield.
Abraham says improving soil pH helps the soil physical structure by reducing soil capping and this promotes better crop emergence, and eventually results in better crop yield.
“Farmers should note that, application of lime can still be done even during crop establishment and the lime can act as a ‘buffer’ which acts as a conduit for nutrient uptake from the soil to crops via the roots. Frequency of subsequent liming should be determined by soil test results,” says Abraham.
*This article is part of a series of tips for farmers by the Agribank
STAFF REPORTER
The pH of the soil is a measure of its alkalinity or acidity. It is an excellent chemical indicator of soil conditions, its quality and its ability to avail nutrients to crops. Soil pH imbalances can hinder the crops roots ability to absorb nutrients from the soil. It is important to test your soil pH especially when planting fields for the first time.
Also, it should be noted that different crops prefer different pH levels.
Abraham says the use of appropriate liming is recommended as this enhances fertiliser use efficiency in crops.
“Agricultural lime is a relatively cheap soil conditioner with many benefits to the farmer that far outweigh the costs of procuring and applying it.”
According to Abraham the continuous and consistent use of lime will enhance the profitability of any cropping pattern. “This is the top secret to enhancing yield per unit area. Therefore, farmers are advised to sample their soils and apply lime when necessary at least three to six months before crop establishment. This is important as it takes a significant amount of time for lime to dissolve and react with the soil to cause the desired adjustments in pH level.”
Abraham says harvested crops remove bases such as calcium and magnesium from the soil. “This is a normal and natural process. Different crops remove different amounts of calcium and magnesium from the soil which may lower the pH level.”
Heavy rainfall also affects soil pH through the leaching of basic nutrients such as calcium and magnesium beyond the root zone. Drainage water replaces them with acidic elements such as hydrogen, manganese and aluminium thereby acidifying the soil.
Application of nitrogen contributes to soil acidity by nitrification of ammonium to nitrate, a process which releases hydrogen ions.
Abraham explains that too low pH (below 5.5) increases the level of aluminium and manganese in the soil and may reach a point of toxicity to the plant. Excess aluminium ions in the soil solution interfere with root growth and function, as well as restrict plant uptake of certain nutrients.
Low pH also affects the availability of micronutrients in the soil and affects general crop development and ultimately crop yield.
Abraham says improving soil pH helps the soil physical structure by reducing soil capping and this promotes better crop emergence, and eventually results in better crop yield.
“Farmers should note that, application of lime can still be done even during crop establishment and the lime can act as a ‘buffer’ which acts as a conduit for nutrient uptake from the soil to crops via the roots. Frequency of subsequent liming should be determined by soil test results,” says Abraham.
*This article is part of a series of tips for farmers by the Agribank
STAFF REPORTER
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