Dr. Dan Taylor

The debate about policy frameworks for increasing soil fertility is timely given the current food crisis. Now seems an appropriate time for revisiting some of the issues.

First of all I think we need to revisit the concept of soil fertility. When resource poor farmers speak about soil fertility they mean something different to us. They refer to a ‘context’ in which the crop grows rather than a ‘content’ which the soil contains. For example in isiZulu the word umnotho has a dual meeting – it can mean either ‘wealth’ or ‘fertility’. When farmers refer to a fertile soil they say the ‘soil is with fertility or wealth’. Thus fertility provides the context for a successful harvest and the wealth that ensues.

So we might just have something to learn from resource poor farmers. Rather than asking how much N, P or K a soil might need, we might ask how do we ensure the correct context for the crop to grow? Asking the question in this way ensures that we move beyond a polemical argument around the use or non-use of fertilisers to ask how do we make the soil fertile or wealthy.

We have in Malawi started a number of on-farm maize trials and demonstrations to compare the use of fertiliser and compost manures on ‘traditional’ OPV and hybrid maize varieties. Though the results, thus far, are variable and still inconclusive, it appears that compost manures – dependent obviously on their quality – provide a viable alternative to inorganic fertilisers. However one of the main benefits of compost use are attributable to good soil moisture holding capacity but, over the past few seasons, rainfall has been excellent and so we await drier season before drawing final conclusions. Farmers have claimed that, in drier seasons,  their best maize harvest occurred where they had applied compost, but we would like to verify this for ourselves.

Given that water, rather than nutrients, is the limiting factor in African agriculture, an infertile soil may still produce a reasonable harvest. As one farmer once said to me ‘our fertiliser is the rain’. Viewed from this perspective, and in the light of the aforegoing, we can question whether soil health and wealth can be secured by the ever increasing use of  fertilisers. If nothing else, it leads us to the conclusion that farmers, and those who advise farmers, should be more cautious custodians of the land and soil.

To get back to Malawi, the growing reliance of farmers on state subsidies for otherwise unaffordable farming inputs – read fertiliser – does little to convince us that this is  the way forward for Malawian – or African  – agriculture given current predictions of climate change. Likewise the dependence on a single crop, maize, for food security, to the detriment of a range of other well-adapted crops appears to us foolhardy in the extreme given unpredictable weather patterns. Our work on soil fertility accompanies a crop diversification strategy which is designed both to promote the conservation of agricultural biodiversity and offer farmers real and lasting alternatives.

Dr. Dan Taylor, Director
Find Your Feet