The lack of access to markets is one of the problems holding small scale farmers back. during millennia of weathering. They are inherently low in plant nutrients (Bationo et al 2006). Compounding this natural deficit, nutrients leach and are taken away from the soil and fields with every pass of the hoe and plough, with wind and water erosion, and with every harvest. “Traditionally, African farmers have used fallows to maintain soil fertility by allowing fields to go back to bush for a number of years between cultivation cycles. The bush was cut and burnt, leaving ashes for nutrients, few weed seeds, and a friable soil that is good for two or three years of cultivation. As Africa’s population increased over the 20th century, the cycles got progressively shorter and soils became increasingly degraded. Fallowing is predicted to disappear entirely from 20 African countries in the next
several years and is practised on less than 25 percent of land in another 29 countries (Angé, 1993). Traditional practices have not been replaced by new methods of soil management and cropping systems due to lack of essential inputs, knowledge and incentives. “Farmers’ removal of the major plant nutrients and essential micronutrients for plant growth has not been offset by additions of nutrients; hence Africa’s small-scale farmers are literally “mining” the soil.” (AGRA, Africa’s Soil Health Crisis) In 2012 Fredrick Kunda from the Department of Land Reclamation in Zambia, presented a paper at the Global Soil Partnership Workshop also pointing out harmful practices such as slash and burn agriculture (Chitemene system) which is not properly managed.
One of the solutions small scale farmers can use to protect the soil and improve their yield is to make use of zaï holes or planting pits concentrating organic material and/or fertilizers around the plants
He says: “The current status of the soils in Zambia shows a need for soil fertility improvement. Soil moisture stress in the soils and drought are also causing low crop yields. “In addition, poor agricultural practices also influence the productivity and quality of the soils. These include mono cropping systems, of maize in particular, continuous use of inorganic fertilizers without liming, and burning of crop residues. During land preparation, current ploughing practices lead to capping/hardpan formations with the initial rains. This causes runoff and interferes with emergence of the crops. The practice of soil ridging, if not well managed along the contour, can contribute to rill and gully erosion.” The use of mineral fertilizers in Zambia has increased rapidly, partly due to the Farmer Input Support Programme through which about 20% of smallholder farmers can access fertilizers. The use of ammonium nitrate is now causing an increase in soil acidity. What can we do? Numerous projects are being carried out, but the lack of integrated information and the fact that soil rejuvenation is not prioritised as an area for investment seem to be stumbling blocks. One of the ongoing successful projects is the AGRA Soil Health Programme which is supported by the Bill & Melinda Gates Foundation and the Rockefeller Foundation. Since 2009 AGRA has trained almost two million farmers in 13 countries in Integrated Soil Fertility Management (ISFM) and has reached out to another 3,5 million farmers through radio and other communication channels to promote ISFM practices, such as fertiliser micro dosing. In the end, getting back to basics is what is being called for. In his presentation, Mr Kunda summarised the four key elements to apply in practising conservation agriculture in Zambia: 1. Cereal - legume rotations: the legumes (soybeans, groundnuts and common beans) improve N-input through nitrogen fixation and nutrient recycling: 2. Targeted application of farm inputs placed closer to the crop, in restricted fixed locations, for example planting pits; 3. Leaving crop residues on fields after harvest (not burning them), hence improving water infiltration and preventing soil erosion; 4. Use of minimum tillage systems during the dry season enabling earlier planting for farmers. These elements and other basic principles regarding soil preservation will be discussed in a series of articles in ProAgri Zambia.
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