In Chinyika village, Gutu district, smallholder farmers appear to have found a novel strategy to restore soils, damaged from decades of chemical use and mechanical ploughing: they are driving cattle onto their crop fields and enclosing them there for a period of time, at least seven days.
The idea is that the cattle use their hooves to loosen hard capped soils, while dropping their dung and urine, which in turn improves soil fertility including water retention, according to Dr Paul Muchineripi, a conservation expert who is working with the community on the issue.
The project requires that individual cattle owners bring their livestock together into one community herd.
“They (Chinyika villagers) have brought their cattle together and they are using moving kraals,” Dr Muchineripi elaborated.
“They put the cattle in a certain area over night for seven days before moving it to the next area. They have been doing this in their gardens before planting vegetables and they do this in every garden,” he added.
As climates change, the preservation and prudent management of soils becomes of great importance, particularly in the context of sustainable food production.
Like elsewhere in Zimbabwe, farmers in Chinyika have been utilising the soil in an extractive and exploitative manner for decades, which has led to an overall reduction in farm output. The soil can no longer give its strength.
Soil, living soil is made up of mineral matter (the dead part) and organic matter in various stages of decay and trillions of micro-organisms of all sorts, according to John Wilson, a Harare-based agro-ecology expert.
Now, when soils lie bare and exposed to the sun for long periods of time (we have a long dry season in Zimbabwe) the organic matter oxidises and drops very quickly.
Research done in the 1980s by the Institute of Agriculture Engineering in Hatcliffe, just outside Harare, showed that virgin clay soils that were ploughed every year dropped from about five percent organic matter to less than one percent in five years.
Virgin sandy soils declined from around three percent to less than one percent in around three years, it stated. Conservation farming is trying to address this issue, explained Wilson, “but we really need to develop some draft power tools (such as a chisel plough) for conservation farming if it is really going to take off.”
What this means is that soils are getting depleted through a gradual process of mechanical and chemical-based farming. In Chinyika, a dry and semi-arid region, the evidence was all too obvious.
“The soil has been used for decades without any restoration efforts as well as being damaged by the use of chemical fertilisers. Overtime this has led to reduction in soil productivity,” Dr Muchineripi said. He was talking to farmer lobby group Pelum Zimbabwe.
Dr Muchineripi noted that declining yields have always had the farmers in bewilderment. However, after receiving training on holistic management, a programme that uses livestock to enrich soil fertility, the community is now aware of how to keep the soil healthy.
“When yields diminished they were wondering why but now they know what happens to the soil and what they need to do so that it remains productive. They needed to replenish what the soil has lost over many years,” he said.
As far as chemical usage is concerned, here is what John Wilson had to say, in a previous interview with The Herald Business:
“Fertilisers are a short-term measure and not sustainable. They damage the micro-organisms and acidify the soil. Fertilisers have become like a drug to the soil.
Many soils are ‘addicted’ to them and will not produce if one doesn’t use fertiliser.”
He continued: These soils are largely dead. Farmers in this position cannot stop using them overnight. They need to gradually reduce their use as they also use strategies to bring the biology back into the soil. It’s not simple, but absolutely necessary.