Editorial – From desertification to vibrant communities

By
23 December 2012

Sustainable agriculture in dry and degraded areas is about the resilience of farmers and ecosystems. Increasing the soil’s organic matter content is the most essential thing that dryland farmers can do to increase the stability of their farm.

Organic matter contains nutrients and offers a space for the temporary storage of applied fertilizers, it absorbs and releases water, supports soil life and soil biodiversity, increases water infiltration and protects against erosion.

Over the years, soils have lost a considerable part of their organic matter content. Agricultural policies heavily promoted the application of chemical fertilizers while neglecting the importance of organic matter, as elaborated in the theme overview of this issue of Farming Matters.

As a result, many farmers have chosen to apply nitrogen fertilizers in search of high yields and, at the same time, they have reduced the application of organic matter. This is a fundamental mistake: after a number of years, their yields decline as the organic content of the soil drops. Water soluble nitrogen is washed out every time it rains, and micronutrient deficiencies and drought damage become apparent. This is happening on a very large scale in dryland areas.

Farmers experience more drought today than they did thirty years ago, largely because the organic matter content in their soils has gone down, sometimes dramatically. The absence of organic matter in the soil multiplies the effects of climate change.

There are some basic metrics of dryland farming that everyone involved in dryland development should know. Each year of cultivation without the application of organic matter and with the removal of crop residues and stubbles reduces the organic matter content by about 5 to 10 tons per hectare. If a farm family increases the soil organic matter content by 1%, they create additional storage for 160,000 litres of water per hectare.

Let us think through the consequences of this. Dryland soils badly need more organic matter, so dryland farmers need to develop smart methods to increase the biomass on their farms. At the same time, policy makers need to understand these simple facts and get their priorities right.

Edith van Walsum
director ILEIA