US maize farmer Kevin Kalb told Grain SA’s annual congress how he improved his yields while using less fertiliser than other farmers.
By Francois Williams, senior journalist at African Farming and Landbouweekblad
By changing the way he farmed, American maize farmer Kevin Kalb improved his profitability. The turning point came in 2016 when Southern rust (Puccinia polysora), a highly destructive and rapidly spreading fungal disease, destroyed about half of his crop.
He realised he was farming too much land and could not manage it all properly. He gave up about 500 hectares of land that he had been renting and decided instead to focus on his own land and manage it properly.
Kalb was recently the keynote speaker at the annual Grain SA Congress, held at Nampo Park in Bothaville, Free State.
Kalb, who farms maize in Dubois County, Indiana, regularly wins yield contests for dryland maize. His main message is that farmers are, in most cases, probably using far more fertiliser than necessary.
Since he started farming 32 years ago, he has never used dry fertiliser. Instead, he applies fertiliser in liquid form and focuses on micronutrients such as boron and zinc.
He believes NPK fertilisers (nitrogen, phosphorus and potassium) are overused and that they increase salt levels in the soil, to the detriment of the plant.
His focus is to make the soil biology as healthy as possible by also adding sugars and humic acid to the soil. The soil’s pH level should not be too low, because then fertiliser is wasted. A farmer would do better to spend money applying lime to raise the pH level than to waste fertiliser on soil with a pH that is too low, he says.
Soil Becomes like a ‘Drug Addict’
Kalb says he is not a fan of fertiliser. Once the soil biology starts functioning properly, farmers can be far more efficient by using much less fertiliser than they normally would.
According to him, soil can gradually become like a drug addict because of the excessive salts and heavy metals in fertiliser, and eventually it damages your soil.
In a drought-stricken country like South Africa, Kalb believes grain farmers should always keep in mind how they can change their soil to retain more moisture. He admits this cannot be done overnight, because he himself has been working for the past 15 to 20 years to farm more sustainably.
Seed genetics is a more important factor for better yields than fertiliser, Kalb believes. At a media conference after his speech, he said people forget that using the right genetically modified seed means farmers need to spray fewer harmful pesticides.
His focus is to get the maize plant as healthy and green as possible from the very beginning and to keep it that way. That is how efficiency and yield are improved.
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