Reversing and Mitigating Agricultural Land Degradation Worldwide:

Can Conservation Agriculture Contribute to Implementation of

Land Degradation Neutrality?

By Amir Kassam, Chair, ICAAP-Africa, ACT

The world has lost some 400 M ha of agricultural land from degradation since World War II. In 2016, the United Nations Convention to Combat Desertification (UNCCD) introduced the concept of land degradation neutrality (LDN) intended to halt the ongoing loss of healthy land through land degradation, combined with measures to reverse past degradation. A major reason for the slow progress in reversing the land degradation trends is the general lack of understanding and awareness about the root causes of land degradation and abandonment. The article presents scientific and empirical evidence clearly showing that the root causes of soil degradation in agricultural land use and decreasing productivity are closely related to the soil life disrupting agricultural paradigm based on mechanical soil tillage. The article put forward the notion that agricultural land use based on Conservation Agriculture (CA) systems appears to be one of the best solutions for any size farmer to contribute to the objectives of LDN to combat degradation and desertification, pursue sustainable agriculture intensification, and harness a wide range of ecosystem services from agricultural landscapes.

Introduction

The United Nations Convention to Combat Desertification (UNCCD) was established as a result of the Rio Earth Summit in 1992. In 2016, it introduced the concept of land degradation neutrality (LDN) defined as “a state whereby the amount and quality of land resources necessary to support ecosystem functions and services and enhance food security remain stable or increase within specified temporal and spatial scales and ecosystems”. Within the UNCCD, this definition is intended to apply to affected areas as defined in the text of the Convention. The LDN conceptual framework has been developed to guide countries in operationalising this definition.

According to the description of LDN at the UNCCD website, LDN is a new initiative intended to halt the ongoing loss of healthy land through land degradation. Unlike past approaches, LDN creates a target for land degradation management, promoting a dual-pronged approach of measures to avoid or reduce degradation of land, combined with measures to reverse past degradation. The concept of LDN was introduced into the global dialogue to stimulate a more effective policy response to land degradation. LDN was adopted as target for Sustainable Development Goal 15 dealing with life on land, and building capacity to achieve LDN is a primary goal of the UNCCD.

The overall objective is that losses are balanced by gains, in order to achieve a position of no net loss of healthy and productive land.

The objectives of LDN are to:

1. Maintain or improve ecosystem services;

2. Maintain or improve productivity, in order to enhance food security;

3. Increase resilience of the land and populations dependent on the land;

4. Seek synergies with other environmental objectives;

5. Reinforce responsible governance of land tenure.

The LDN conceptual framework is applicable to all types of land degradation so that it can be implemented by countries according to their individual circumstances. Setting national targets for LDN is voluntary. Countries are invited to do so in accordance with their specific national circumstances and development priorities. See endnote[i] for advice from UNCCD on LDN implementation.

As the overall objective of the LDN approach is to promote measures to avoid or reduce land degradation, combined with measures to reverse past degradation, this article elaborates on the role of Conservation Agriculture (CA) as a measure that can contribute to either avoiding or reducing land degradation or to reversing past degradation on agricultural lands..

Extent and seriousness of global agricultural land degradation

The seriousness of agricultural land degradation, and its end result of desertification, has been receiving considerable attention by the international community for decades. A major reason for the slow progress in reversing the land degradation trends is the general lack of understanding and awareness about the root causes of land degradation and abandonment. Worldwide empirical and scientific evidence clearly shows that the root causes of soil degradation in agricultural land use and decreasing productivity – as seen in terms of loss of soil health and eventual abandonment of land – are closely related to the soil life disrupting agricultural paradigm based on mechanical soil tillage, the agricultural methods of using mouldboard ploughs, disc harrows, tine, rotavators, hoes and other mechanical tools to prepare the fields for crop establishment and weed control. This mechanical disturbance leads to loss in soil organic matter, soil structure and soil health, and debilitates many important soil and landscape mediated ecosystem processes and functions.

For the most part agricultural soils worldwide have been mechanically de-structured, agricultural landscapes are kept exposed and unprotected, and soil life is starved of organic matter, thus reduced in biological activity, and is deprived of habitat. The loss of soil biodiversity, damaged soil structure and its self-recuperating capacity or resilience, increased compaction of topsoil and sub-soil, poor infiltration and increased water runoff and wind and water erosion, and greater infestation by insect pests, pathogens and weeds indicates the current poor state of the health of most agricultural soils.

In the developing regions, a combination of all these elements is a major cause of low agricultural productivity and inadequate food and nutrition security, poor adaptation of agriculture to climate change and a general lack of pro-poor development opportunities for smallholder farmers.

In industrialized countries, the poor condition of soils and sub-optimal yield ceilings due to excessive soil disturbance through mechanical tillage is being exacerbated by: (a) the over reliance on the application of mineral fertilisers, as the main source of plant nutrients, and (b) reducing or doing away with crop diversity and rotations, including legumes. The situation is now leading to further problems of increased threats from insect pests, diseases and weeds against which farmers are forced to apply ever more pesticides and herbicides, and which further damages biodiversity and pollutes the environment.

It is reported that we have lost some 400 M ha of agricultural land from degradation since WWII. This abandonment is due to the severe degradation and erosion arising from tillage-based agriculture systems in both industrialized and less industrialized countries. A recent study puts the annual global cost of land degradation due to land use and cover change at 300 billion USD, of which Sub-Saharan Africa accounted for some 26%, Latin America and the Caribbean some 23%, and North America some 12% . Other reports indicate much higher costs, and in cases where priceless ecosystem services are lost, it is argued that it is not possible to put a cost value. This shows that our agro-ecosystems globally are facing a serious challenge of reversing the trends and of rehabilitating abandoned lands into productive and regenerative agriculture. However, solutions for sustainable soil management in farming have been known for a long time, at least since the mid-thirties when the mid-west of USA suffered massive dust storms and soil degradation due to a combination of intensive inversion ploughing of the prairies and multi-year drought.

The main purpose of tillage throughout ages has been two fold, namely: to mechanically break and loosen the soil and bury weeds in order to prepare a clean-looking seed bed for sowing and crop establishment. Subsequently, during the season, tillage operation is often used to control weeds. It is commonly held belief by conventional non-organic and organic tillage farmers that the main benefit from tillage is to control or even eradicate weeds. However, in reality, tillage has been shown to increase weed infestation.

Thus, for instance, in 1943, Edward Faulkner wrote a book ‘Ploughman’s Folly’ in which he provocatively stated that it can be said with considerable truth that the use of the plough has actually destroyed the productiveness of our soils. More recently (2007), David Montgomery in his well-researched book ‘Dirt: The Erosion of Civilizations’ shows that in general, with any form of tillage, including non-inversion tillage, the rate of soil degradation (and loss of soil health) and soil erosion is generally by orders of magnitude greater than the rate of soil formation, 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 in the world, and continues to do so.

Tillage-based production systems everywhere have converted our agricultural soils and landscapes into – for a lack of a better term – ‘dirt’ and even worse in terms of excessive use of agrochemicals, seeds, water and energy, whilst increasing production costs, decreasing factor productivity, and reducing overall resilience. These have led to degraded agro-ecosystems and dysfunctional societal ecosystem services, including poor water quality and quantity, disrupted water, nutrient and carbon cycles, suboptimal water, nutrient and carbon provisioning and regulatory water services, and loss of soil and landscape biodiversity.

Conservation Agriculture as a contributor to achieving LDN

The good news is that in response to these land degradation issues, a different agriculture paradigm known as Conservation Agriculture (CA), and agroecological approach to managing the agricultural natural resource base, and the crop and landscape potentials, has been spreading in all continents, especially over the last three decades. The new approach pays special attention, for greater productivity and resilience, to: (a) soil as a living biological and multi-functional system, whose health and functions must be understood and managed correctly; (b) biodiversity in the soil (microorganism and mesofauna) and above the ground; and (c) landscape ecosystem functions and services at the farm, landscape, community and territorial level.

Consequently, tillage-based agriculture paradigm in all continents is undergoing a transformation to a new agricultural paradigm that can: (i) mobilize greater crop and land potentials sustainably to meet future food, agriculture and environmental demands; (ii) maintain highest levels of productivity, efficiency and resilience (‘more from less’); and (iii) control agricultural land degradation, and rehabilitate or regenerate degraded and abandoned agricultural land for agricultural production and for farm-level and societal level ecosystem services.

The alternate paradigm is that of Conservation Agriculture (CA) comprising of land-based agricultural production systems that are defined by the application of three linked principles:

(i) no or minimum mechanical soil disturbance (through no-till seeding/crop establishment and no-till weed management);

(ii) maintenance of soil mulch cover (with crop residues, stubbles and cover crops);

(iii) diversified cropping (involving annuals and perennials, including legumes, in sequences/rotations and/or associations).

These principles when put into practices (as indicated in the parenthesis) with locally formulated adapted practices, along with other best management practices of integrated crop, nutrient, pest, water, energy, labour and farm power management, have shown in all continents to be able to address the fundamental weaknesses of the conventional tillage agriculture.

CA is not a panacea as it does not solve ALL problems, but complemented with other good integrated good practices it allows for intensification of production in terms of crop yields rather than increase in production inputs. CA principles serve as a biologically dynamic foundation for ecological sustainability to all land-based production systems, including rainfed and irrigated systems, annual and perennial systems, orchards and plantation systems, agroforestry systems, crop-livestock systems, rice-based systems and organic systems.

Consequently, many conventional tillage farmers at all levels of agricultural development and of all farm sizes from small-scale to large-scale and farm power from manual systems to mechanized systems have responded to the opportunity of transforming their tillage-based farming to CA systems. Thus, a vast array of different types of CA production systems is now in existence globally, forming part of innovation system that is creating new knowledge and experience in terms of the new ecological paradigm of agriculture that is replacing the conventional intrusive ‘Green Revolution’ agriculture. Transforming to a CA system and managing it innovatively is not like adopting a new seed variety, or a new type of mineral fertilizer or new equipment. CA is a whole new system of managing agricultural production and land resources with a totally different mind-set and commitment to land and environmental stewardship, innovation and learning, which involves a longer-term vision of land management. This is particularly so because transforming from tillage-based production system to a CA system cannot be achieved overnight, given the degraded state of agricultural lands resulting from tillage agriculture at all levels of output.

What is becoming clear is that CA has the potential to move away from intensive agrochemical and fossil fuel use and from intensive mechanical and chemical disturbance of the agro-ecosystems to levels that are much lower, or even avoid their use altogether such as is the case with certified as well as uncertified organic farming. In such systems, weeds and other pests are managed biologically with the CA core practices including the incorporation of cover crops in manual and mechanized CA systems to not only smother weeds but also to enhance soil health and nutrient fertility. In mechanized CA systems on small and large farms, the practice of ‘planting green’ allows no-till crop establishment of subsequent crops that follow cover crops without the use of herbicides such as glyphosate. Instead, cover crop is killed off with a crimper or a knife roller followed by no-till seeding directly into the ‘trampled’ green biomass. What is worth noting is that in most agroecologies, including dryland environments, wherever CA has been practiced in for more than about 10 years, the benefits include improved biomass and yield outputs and interseason stability, as soil organic matter and soil health improved with time but also reduced the use of the purchased inputs of seeds, nutrients, pesticides, fuel, water and time, in addition to a reduction in soil erosion and land degradation. Such benefits have often led to an increase in the livestock carrying capacity and stocking rates. In marginal dryland and semi-arid environments, where there is a higher risk of land degradation and desertification resulting from tillage agriculture, CA farmers are able to cultivate sustainably and profitably.

It would seem that what is important and needed more and more is to increase the generation of the above adapted empirical and scientific knowledge and its wider dissemination and accessibility so that farming in the future becomes more regenerative rather than degrading, less dependent on agrochemicals, more efficient and reliable in the face of climate change, and a source of affordable food and agricultural products. Researchers need to focus more on how constraints to adoption of CA systems can be removed to accelerate their adoption, including finding solutions to overcome competition for crop residue, and what the tillage equipment industry can offer to smallholder farmer in terms of no-till equipment.

Global scientific evidence on the superior performance of no-till CA is ample. Several pilot scaling initiatives with farmers in different parts of Africa have been led by some governments, ACT, some CGIAR Centres, NGOs, and public and private sectors. These have demonstrated the ability of CA to intensify production sustainably and improve agricultural livelihoods, whilst reversing land degradation and adapting to climate change. Many countries including Brazil, Argentina, Paraguay, Uruguay, US, Canada, Spain, Italy, Zimbabwe, Tanzania, Kazakhstan, China and Australia have been able to restore, with help from CA systems, large areas of degraded or abandoned agricultural lands back into production. Restoring or regenerating functionally degraded agricultural lands into more productive lands with improved ecosystem services appears to be a general feature of much of agricultural lands where CA has been established for several years. In Alberta, Canada, CA has helped to establish a carbon offset trading scheme, and in the Parana Basin in Brazil, CA has helped to minimize soil erosion and establish a participatory watershed service programme called ‘cultivating good water’. In the Andalusia region in Spain, CA has permitted the control of soil erosion and land degradation in olive systems. In Brazil, vast areas of degraded cerrados have been transformed into highly productive agricultural lands with the help of CA systems.

Since 2008/09, CA systems have been spreading globally in all continents at the combined annual rate of 10 M ha. In 2008/09, CA covered some 107 M ha of annual rainfed and irrigated cropland, corresponding to 7.4 % of global annual cropland, and in 2013/14 it covered some 160 M ha of annual cropland, corresponding to about 11% of global annual cropland. In 2015/16, CA covered more than 180 M ha of annual cropland, corresponding to 12.5% of global annual cropland. Some 50% of CA land is in the low income countries, particularly in Latin America and Asia, and during the last decade it has begun to spread in west and central Asia and in Africa as farmers and their communities learn how to overcome constraints to adoption of CA. CA principles are also being applied to perennial crops in orchard systems involving olives, vines and fruit trees, in plantation systems such as oil palm, cocoa, coffee, rubber and coconut, and in agroforestry system where CA systems with trees are being referred to as being part of ‘evergreen agriculture’. This ongoing transformation is an illustration that farmers are willing to take greater control of their future by experimenting with radically new and innovative no-till CA principles and related practices in building sustainable and regenerative farming systems.

Many development organizations, national and international, in every continent are now involved in promoting the adoption and uptake of CA. National and international research institutes, ministries of agriculture, NGOs, private sector and national and regional CA associations have played an important role in generating scientific and technical evidence on the superior performance of CA systems in all continents. They have all shown through pilot scaling and long-term dissemination initiatives that the new agricultural paradigm of CA is an effective base for farming systems development that is capable of mitigating and reducing land degradation while at the same time offering the possibility of sustainable production intensification. In addition, CA is increasingly being seen to be climate-smart, as it has a strong ability to mitigate and adapt to climate change, thus strengthening food security.

Agricultural land use based on CA systems appears to be one of the best solutions for any size farmer to combat degradation and desertification, pursue the sustainable agriculture intensification goal and harness a wide range of ecosystem services from agricultural landscapes. CA systems have been identified as the best climate-smart agricultural systems. What is now needed is increased policy and institutional support to CA farmer organizations and increased cooperation nationally and internationally to accelerate the transformation of the conventional tillage agriculture to CA.

Concluding remarks

LDN does not necessarily propose any specific agricultural land use system. It provides an enabling platform that can facilitate the development of policy and institutional capacity to promote the adoption and spread of sustainable production systems such as CA.

What we have learned in recent years is that farmers everywhere are willing to take greater control of their futures by experimenting with, and adopting radically new and innovative practices such as those related to CA in order to build sustainable agricultural livelihoods in the face of climate change and other critical challenges related to food and nutrition security. However, widespread transformation of tillage agriculture systems to CA systems 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 CA becomes the norm for agriculture development in the future.

Ultimately, no amount of ecological sustainability in the production system such as CA can withstand the unlimited demand for food and non-food commodities placed upon the global land resource base. The world already produces enough food to feed more than double its current population but a significant proportion of it is fed to livestock, and some 30% is reported to be wasted. Thus, in general, mainstream approaches to agricultural assessments regarding national and international food security appear to be simplistic and limited in scope. As a result, they are unable to identify and address the root causes of the damage caused to land resources, the environment and human health by the current agricultural paradigm. Such assessments are also decoupled from the human and ethical consequences of the demands and pressures placed upon agricultural production and farmers by the food and agriculture system as a whole, including consumer demand, diets, industry, government and the economy. However, a discussion on how such aspects relate to promoting or hindering land degradation is outside the scope of this article.