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Reversing agricultural land degradation worldwide

Irrigated fields under CA
Irrigated fields under conservation agriculture in Sonora, Mexico. Photo Credit: CIMMYT

Agricultural land degradation and its end result of desertification have been receiving considerable attention by the international community in recent decades. However, the general lack of understanding and awareness about the root causes of land degradation persists, thus the slow progress in reversing the alarming trends of land degradation and land abandonment. Worldwide, empirical and scientific evidence clearly shows that soil degradation in agricultural land use and decreasing productivity are closely related to the prevalence of mechanical soil tillage, the agricultural method of using mouldboard ploughs, disc harrows, tines, rotivators, hoes and other mechanical tools to prepare the field for crop production. The reasons behind these practices are to:

  • prepare a seedbed for crop establishment;
  • control weeds, insect pests and pathogens;
  • aerate the soil and distribute plant nutrients; and
  • facilitate other farm cultural practices.

Generally associated with the term conventional tillage agriculture, these practices contribute over the long term to:

  • destruction of soil structure, loss of soil organic matter, soil biodiversity and soil health;
  • exposed soils and landscapes, surface sealing, decreased water infiltration, increased runoff and soil erosion;
  • disruption of many important soil-mediated ecosystem functions; and
  • loss in productivity, resilience and eventual abandonment of land.

In developing countries, the combination of all these elements is a major driver of food and nutrition insecurity and a host of other related challenges, such as poverty reduction, effective adaptation to climate change, and sustainable and equitable development in general. In industrialized countries, the poor condition of soils and sub-optimal yields due to conventional tillage agriculture are further exacerbated by:

  • over reliance on the application of mineral fertilisers, as the main source of plant nutrients; and  
  • reduction or doing away with crop diversity and rotations, including legumes.

This situation is now leading to further problems of increased threats from insect pests, weeds and diseases which pull farmers into a vicious cycle of having to apply ever more pesticides and herbicides, and in turn damaging further biodiversity and polluting the environment.

It is commonly reported that since World War II, we have lost some 400 million hectares of agricultural land from degradation, and this loss continues at the alarming rate of some 7 million hectares per year.  Our agro-ecosystems globally are facing a serious challenge when it comes to reversing the loss and rehabilitating abandoned lands. Sustainable solutions do exist and have been known for quite some time, at least since the mid-thirties when the American Midwest suffered massive dust storms and soil degradation due to intensive ploughing of the prairies.

“It can be said with considerable truth that the use of the plough has actually destroyed the productiveness of our soils,” stated Edward Faulkner - provocatively – in his 1943 book, the Ploughman’s Folly.

More recently in 2007, David Montgomery showed - in his well-researched book on Dirt: The Erosion of Civilizations - that in general the rate of soil degradation and soil erosion is considerably greater than the rate of soil formation with any form of tillage (including non-inversion tillage), thereby rendering agro-ecosystems unsustainable. Similar to Faulkner, Montgomery concluded that tillage has caused the destruction of the agricultural resource base and of its productive capacity nearly everywhere, and continues to do so.

Soil compaction and loss in water infiltration ability caused by regular soil tillage leads
to impeded drainage and flooding after a thunderstorm in the ploughed  field (right)
with sugar beet, and no flooding in the no-till Conservation Agriculture field (left).
Photo Credit: Wolfgang Sturny

Tillage-based agriculture globally has converted our agricultural land and soils into – for lack of a better term – ‘dirt’ and, even worse, it has led to excessive use of agrochemicals, seeds, water and energy, whilst increasing production costs, decreasing input factor productivity, and reducing overall resilience. These aspects have led to degraded ecosystems and loss of ecosystem (and societal) services, including quality and quantity of water, loss of biodiversity, and unique landscapes. The good news is that in response to these land degradation issues, a new agricultural paradigm known as no-till conservation agriculture is emerging. An agroecological based approach to managing the natural capital base for sustainable productivity and resilience, conservation agriculture has been spreading in all continents, specially over the past three decades.

This approach pays special attention to:

  • soil as a living biological and multi-functional system, whose health and functions must be understood and managed correctly;
  • biodiversity in the soil (microorganisms and mesofauna) and above the ground; and
  • landscape ecosystem functions and services at the farm, landscape, community and territorial level.

This new paradigm is based on three linked principles:

  • no or minimum mechanical soil disturbance (no-till seeding and weeding);
  • maintenance of soil mulch cover with crop residues, stubbles and cover crops; and
  • diversified cropping involving annuals and perennials, including legumes.

These principles - when put into practice along with other best management practices of crop, nutrient, pest, water, energy and farm power management - have shown in all continents to be able to address the weaknesses of conventional tillage agriculture.

Global scientific evidence on the superior performance of no-till conservation agriculture is ample. Several pilot scaling initiatives in the Middle East and North Africa region have been led by the International Center for Agricultural Research in Dryland Areas (ICARDA) in collaboration with farmers, and public and private sectors. These have demonstrated the ability of conservation agriculture to intensify production sustainably and improve agricultural livelihoods, whilst reversing land degradation and adapting to climate change.

No-till conservation agriculture systems are now spreading globally in all continents at the combined annual rate of 10 million hectares, and in 2013 they covered some 160 million hectares of annual rainfed and irrigated cropland, corresponding to about 11% of global annual cropland. Some 50% of land under conservation agriculture is in the developing countries, particularly in Latin America and Asia. More recently, the practice has begun to take hold and spread in Africa and the Near East, as farmers and their communities learn how to overcome constraints. Conservation agriculture is also being applied to perennial crops in orchard systems involving olives, vines and fruit trees; in plantation systems with oil palm, cocoa, tea, coffee, rubber and coconut; and in agroforestry systems.

No-till conservation agriculture is one of the best climate-smart solutions to combat land degradation and desertification. It is also the best practical approach to pursue the goals of sustainable agriculture to maximize productivity with resilience and harness a wide range of ecosystem services to improve rural livelihoods, and food and nutrition security almost everywhere.

What we have learned in recent years is that farmers are willing to take greater control of their futures by experimenting with and adopting radically new and innovative practices such as conservation agriculture in order to build sustainable agricultural livelihoods in the face of climate change and other critical challenges related to food and nutrition security. However, mass transformation to no-till conservation agriculture requires the engagement of the whole society, including the farmers themselves and the public, private and civil society actors.

Mobilizing policy and institutional support from governments, the scientific research and education community and a host of different service providers can be painstakingly slow, but when farmers themselves are leading the transformation, the probability of success is much higher. Increased policy and institutional support and better cooperation nationally and internationally will help ensure that no-till conservation agriculture becomes the norm for agriculture development in the future.

About the author

Amir Kassam is the moderator of the Global Conservation Agriculture Community of Practice (Global CA-CoP) communication platform hosted by the Food and Agriculture Organization (FAO) of the United Nations, Rome.