It may not be completely organic, but a philosophy based on ‘harmony with nature’ has worked wonders for soil health, productivity and the surrounding environment for South Africa’s largest tomato grower, ZZ2. The company’s ‘Natuurboerdery’ (natural farming) practices range from composting, plant extract application and using predatory insects all the way through to more standard measures such as the choice of rootstocks, growing regions, planting times and varieties.
“Physically mining your soils and your environment in order to produce crops is not sustainable,” says the company’s chief agronomist Bertus Venter. “We want to do disturb the environment as little as possible. We also look at what nature and environment give back to you that you can actually utilise in your farming practices.”
To elaborate, he described the inherent balance in nature which is disturbed every time a crop is planted. “So if you only have tomatoes there, nature is saying ‘we like more diversity’ and then there are certain soil-borne diseases and a few worms that will eat some of the tomatoes. But if you have good farming practices, you start to let nature be slightly more forgiving. For example, soil health is one of our specific focuses with natural farming. Healthy soil will house a healthy plant, which will produce healthy produce.”
The foundation for ZZ2’s soil practices is compost, and the grower has a lot of it – 50 000m3 per year in fact. To service its production operations across South Africa and Namibia – also including avocados, pome fruit, stone fruit, mangoes and onions – the group generates its own compost over 28ha of land on three sites, serviced by 15ha of storage space for the raw materials needed for the process.
“Compost, as we see here, is one of our key role players in terms of soil health. Our composting process is very scientific and it’s a fairly intensive programme,” Venter says. “The four main ingredients we use on this compost are sawdust, woodchips, chicken and cattle manure, and then any other organic material that is available at that stage according to the season. For example, in the citrus season we use a lot of citrus pulp from the juice factories.
“We use a lot of the organic waste from the net houses, where we do leaf pruning to bring that organic material into the composting. Most of our waste fruit from our packhouses are stored in tomato sawdust, and once saturated it’s brought back to the compost and incorporated – the nutrients being utilised in the composting process. Even if compost had no nutritional value, we would still use it, but it’s an expensive product to use. We use it to enhance soil biology and health to improve the soil’s physical characteristics, as well as to improve the water holding capacity and water use efficiency of the plant. Natural processes are never exactly the same, but if you calculate the chemical nutrition available in the compost and compare it to that which you can purchase in a bag, we’re not very far behind regarding what it costs you to buy fertiliser versus what you get nutrient-wise.”
According to ZZ2 general manager Burtie van Zyl, composting has proven its weight in gold in recent years in the Western Cape apple sector. “It was very hot and dry in the Cape over the last two years, and our yields and quality were much better compared to all the neighbours who simply continued with the regular programmes,” van Zyl says. – Farming Portal