Drawing upon indigenous knowledge and local resources to restore degraded land

This blog is part of the Agriculture and Ecosystems Blog’s month-long series on Restoring Landscapes.

When visiting the Agriculture and Ecosystems blog guidelines to prepare this text I was triggered by one of the first statements that can be read in the preamble:

“Many believe (…) that intensification [of agricultural production] will cause unacceptable harm to the environment, perhaps even undercutting the vital ecosystem functions that support life.”

I’m definitely one of the ‘many’ that believes that intensification following a business as usual pathway – despite the green washing effect that terms such as sustainable intensification or eco-efficiency may have – will cause unacceptable harm to the environment.

Degraded lands in northern Tanzania. Photo: Simone de Hek

A new green revolution based on the same principles that led agricultural intensification over the past 50 years is not only potentially harmful to the environment but also socially and thermodynamically untenable. There is simply not enough fossil energy to sustain it, and because fossil fuel inputs are only economically viable when agriculture is subsidised by other sectors of society, this model of intensification is likely to accentuate the socio-economic cleavage between world regions even further.

At the global scale, the average yield of most major crops has increased steadily over the second half of the past century. Yet, growth in both production and productivity has been unequal across the world and today’s crop and livestock yield gaps tend to be the widest in the poorer regions of the world, and even wider for the less resource endowed farmers at any given location.

In the least favored regions of the world, food production per capita remains at the same level as in the 1960s. There are three major reasons, from a purely agronomic perspective, for such disparities:

1. Inadequate models of agricultural development coupled with increasing (settled) population densities in rural areas led to severe degradation of the natural resource base;
2. Poor farmers in the poorer regions of the world do not have access, cannot afford or are unwilling to adopt ‘modern’ agricultural technologies;
3. Such technologies were not developed to fit the reality of smallholder systems (in the tropics) and hence they are ineffective at increasing crop and livestock productivity;

The first point is particularly true in countries that rely heavily on agriculture as a main economic activity. The environmental impacts of agricultural intensification both in the North and in the South have been profusely documented. The two most emblematic regions of the world to showcase the success of the green revolution, the Punjab in India and the Yaqui valley in Mexico, are also the most conspicuous examples of environmental degradation associated with agricultural intensification. We do not want to take that road again.

Redesigning AgroEcosystems at the landscape level

We need an ecological intensification of world agriculture in order to produce more but differently, to produce more food where food is urgently needed, and to make use of the natural functionalities that ecosystems offer to reduce the need for and increase the efficiency of external inputs.

Increasing crop and livestock productivity in the poorest regions of the world can be cost effective and can most efficiently contribute to food security and poverty alleviation. But this requires a paradigm shift in the way we think agricultural technologies and intensification. We need to be aware that:

1. Making agricultural inputs more accessible to smallholders may be a necessary – in some cases – but not a sufficient condition to increase productivity;
2. Agricultural inputs do not work on degraded soils; soil rehabilitation is a prerequisite for any form of agricultural intensification;
3. Replacing the natural vegetation of tropical landscapes with annual crops and frequent tillage disrupts their basic ecological infrastructure and leads to degradation and/or inefficient capture and use of energy, water and nutrients;
4. Smallholder farmers do not reason in terms of crops or cropping systems, they make decisions that concern their whole livelihood system;
5. Regulatory ecological services that can contribute to pest and disease management do not operate at the scale of a single field, they operate across and are influenced by the wider agricultural landscape;

We cannot continue trying to improve efficiencies of inherently inefficient systems by fiddling around with quick fixes such as improved fertiliser recommendations or genetically modified crops.

Increasing agricultural productivity and contributing to food security in the poorest regions of the world requires new research.  We need to engage in a thorough re-design of agroecosystems, perhaps drawing inspiration from the structure and functioning of the natural ecosystems that evolved in each region, taking stock of the wealth of local agricultural knowledge and of local institutions governing natural resource management.  And key to the success of such redesign is reasoning at scales broader than the agricultural field plot.

Thomas Loronjo, the Tanzanian farmer shown in the video, Farmers Innovate for an Ecologically Intensive Agriculture, inherited a degraded piece of land from his father. Soil and water conservation measures, trees on farm, crop-livestock integration and conservation agriculture were deployed all in combination to create an oasis of productive farmland in an extremely degraded landscape.

But none of this would be effective without paying due attention to the geographical, climatic, institutional and socio-political contexts in which smallholders operate. The challenge is complex and requires multi-disciplinary action.

Approaches that take a whole-system perspective at the landscape level already show promising results around the world. An example of how farmers can contribute to restoring degraded landscapes while achieving food security can be seen in the box on the right.

Soil Management in the Sahel

In the Sahel, soil management based on indigenous practices and resources from the natural vegetation proved effective for the gradual rehabilitation of degraded soils. Local shrubs of the genera Piliostigma and Guiera are used as crop shelters or ‘fertility islands’ and as a source of biomass for mulching (these shrubs, which are unpalatable to livestock, are the only green biomass present in the landscape throughout the dry season).  They bring inputs of organic matter to the soil, increasing water infiltration and reducing soil temperature.

At the same time, planting basins are dug to create an irregular surface and concentrate water infiltration in one fourth of the surface area of a field. Through the combination of these measures plus appropriate crop varieties and use of small, localised amounts of mineral P fertiliser, it is possible to harvest a crop from a degraded soil in the first year of rehabilitation.

In a Pan-African project, ABACO, funded by the European Union and led by the Africa Conservation Agriculture network, of which I am a board member, we are studying and at the same time promoting these systems among farmers in six countries across Africa through innovation platforms.

Ecological intensification and landscape restoration based on indigenous knowledge and local resources requires new inputs of knowledge from science. Are we up to the challenge?

Further reading

Tailoring conservation agriculture technologies to West Africa semi-arid zones: Building on traditional local practices for soil restoration
By Lahmar, Bationo, Lamso, Guero, Tittonell in Field Crops Research (2012)

Gaming for smallholder participation in the design of more sustainable agricultural landscapes
By Speelman, Garcia-Barrios, Groot, and Tittonell in Agr.Syst (2013)

Agroecology-based aggradation-conservation agriculture (ABACO): Targeting innovations to combat soil degradation and food insecurity in semi-arid Africa.
By Tittonell, Scopel, Andrieu, Posthumus, Mapfumo, et al. in Field Crops Research (2012)

When yield gaps are poverty traps: The paradigm of ecological intensification in African smallholder agriculture
By Tittonell and Giller in Field Crops Research (2013)