Date Posted: November 23rd, 2009
Women farmers from the Guruve district of northern Zimbabwe benefitted from learning the zero tillage approach because it allows them to prepare land with their own hands, rather than waiting to plough with cattle. The zero tillage approach has other benefits as well. In fact, it is one aspect of conservation agriculture – a set of practices designed to counteract the environmentally-harmful effects of some traditional agricultural practices. In particular, it aims to prevent soil erosion and nutrient depletion.
This story from a past issue of FRW illustrates that conservation agriculture also appeals to farmers as a way to reduce dependence on chemical fertilizers and make fields more resilient to climatic changes:
“Southern Africa: Conservation methods help farmers cope with climate change, high fertilizer costs” (FRW #35, September 2008)
There are three basic principles to conservation agriculture:
-Minimal soil disturbance. This usually means reducing or ceasing mechanical tillage, as mechanical tillage can compact soil over time. Two tillage alternatives promoted within conservation agriculture are basin tillage (in which farmers dig small basins or pits that capture water and plant nutrients) and “ripping” (using a device that breaks up compacted soil, allowing water and roots to penetrate deeply). This reduces soil loss and erosion.
-Permanent soil cover. Plant residues are left on the field. This preserves moisture and serves as a mulch that enriches the soil when the residues break down.
-Crop rotation. In conjunction with intercropping, this technique reduces soil depletion and deters pests.
The Food and Agriculture Organization of the United Nations, along with many international and local NGOs, actively promotes conservation agriculture. It’s important to note that farmers converting to conservation agriculture must invest significant time and/or labour in the first few years. A lot of work is required to break up soil that has been hard packed by traditional tilling, and benefits such as improved soil fertility and pest resistance take time to develop.
As broadcasters, you can help farmers learn about conservation agriculture and decide whether conservation techniques would work well on their farms. First hand accounts by farmers who have tried conservation agriculture can provide valuable insight. You may wish to profile a local farmer who practices conservation agriculture. An NGO that promotes conservation agriculture or a local farmers’ group may be able to point you in the direction of such a farmer. Some questions to ask the farmer include:
-What made you decide to try conservation agriculture (for example, was the farmer having trouble coping with erratic rainfall or experiencing soil erosion)?
-What kind of work was involved in the first year or two?
-Did you see an increase in crop yields? If so, how long did it take to see this increase?
-What advice do you have for others who are considering conservation agriculture?
More detailed information on conservation agriculture practices is available on the following sites:
-African Conservation Tillage Network: http://www.act.org.zw/-FAO page on conservation agriculture: http://www.fao.org/ag/ca/
The following Farm Radio International scripts also deal with the topic:
-“The promise of conservation agriculture” (Package 76, Script 1, October 2005)
-“Is tillage really necessary? The benefits of conservation agriculture” (Package 76, Script 2, October 2005)