Humus contains about 10% nitrogen (N). As the humus content builds up in the soil, so does the N reserve stored in it. However, this N is locked into the humus and released only when the humus breaks down.
When a farmer cultivates virgin soil, the humus content built up over many years starts to break down due to aeration, stimulating the bacteria to feed on the organic material. The process releases N for uptake by plants.
This explains why the farmers who initially cultivated vast areas of South Africa for the production of maize and wheat had to add much less N to soil for high yield.
To maintain the organic content, and so retain the benefits of humus, you can try to provide the soil with raw organic matter in the form of crop residue and/ or manure and compost.
Depending on the crops grown, the climate and the soil type, the humus content should stabilise at a sustainable level.
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the {{IssueName}} edition of {{MagazineName}}.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
Syngenta Seedcare celebrates a decade of innovation
Syngenta's ambition is to enable their customers' investments to grow in healthy soil from treated seeds to young plants through innovation and collaboration, writes Magda du Toit.
Agri workers shine at Western Cape awards
Lindie-Alet van Staden, a garden and olive orchard manager at L’Ormarins Wine Estate in Franschhoek, was crowned as the Western Cape Prestige Agri-Worker of 2024 at a gala event recently held near Paarl.
Small and large farmers recognised at grain awards
The annual Grain SA/Syngenta awards ceremony bears testimony to the quality of farmers in the grain industry.
Growing partnerships: Fedgroup's flexible and innovative approach
Janine Ryan spoke to Warren Winchester, general manager of impact investing at Fedgroup, about why the company became involved in agriculture, and what it offers farmers and their immediate communities.
Why fish farms fail, and how to avoid becoming a statistic
The popularity of launching fish farms is not matched by their success. Leslie Ter Morshuizen, owner of Aquaculture Solutions, explores the factors that cause most of these businesses to go under.
Where history and modernity meet in a luxurious setting
Brian Berkman kept his eyes peeled for ghosts in the oldest continuously run hotel in South Africa, but all he found was a fabulous two-night stay.
THE HITCHING POST
I'm a stylish elderly lady with a radiant glow and a good sense of humour that keeps me young at heart.
Cutworms: check the weeds on your fields!
Zunel van Eeden explains why understanding the ecological interplay between cutworms and weeds is crucial for effective pest management. Producers should disrupt the life cycle of cutworms to minimise crop damage.
Does high-density grazing mimic grazing patterns of game?
In their paper on high-density grazing in Southern Africa, professors Angelinus Franke and Elmarie Kotzé from the Department of Soil, Crop and Climate Sciences at the University of the Free State say high-density grazing systems may not accurately reflect natural ecosystems. Roelof Bezuidenhout reports.
Global grain outlook: 2024/25 marketing season
In its latest summer crops report, the Crop Estimates Committee says South African farmers intend to plant 4,47 million hectares of summer grains and oilseeds in the 2024/25 season, up 1% from the previous season. As South Africa exports maize and soya bean, Annelie Coleman reports on the latest trends in the international grain and oilseed markets, amid fluctuations in weather conditions and ongoing armed conflicts.
