FAO Regional Office for Latin America and the Caribbean

The integrated management of soil and water, which are considered major factors of production, is crucial for sustainable agricultural production. Soil and water support the production of biomass, in general, and agricultural products (foodstuffs) in particular. Soil provides raw materials, ensures carbon sequestration and storage, maintains the geological heritage and facilitates water conservation, the nutrient cycle and the safeguarding of biodiversity. It is thus essential for meeting the need for crops and the welfare of a growing population.

Soil and water conservation in Latin America and the Caribbean

Basic resources for food security and ecosystem services

Soil and water are strategic resources that contribute towards food security and the generation of ecosystem services. The General Assembly of the United Nations declared 2015 the International Year of Soils to highlight the importance of this resource.

Soil is the thin, fragile surface layer of the land. It is made up of mineral particles, organic matter, microorganisms, water and air. Soil forming processes are very slow and require long periods of time. For temperate grasslands, 100 years are required to form 1 to 2 cm of soil. As its (re)generation is very slow, soil should be considered as a non-renewable resource. In Latin America and the Caribbean (LAC), soils vary considerably, from highly productive to infertile.

The region of Latin America and the Caribbean is well endowed with water resources. It accounts for 15% of global land area, 10% of world population and receives 29% of the planet's precipitation. However, the space-time distribution is unequal; the region features the most arid and the most humid places in the world, so the availability of water for its different uses can vary considerably between and within countries.

Soil and water at risk

Land use

Latin America and the Caribbean have the world's largest reserves of arable land. About 47% of the soil is still covered with forest, but this figure is in rapid decline because of an expanding agricultural frontier. During the last 50 years (1961 - 2011), the region's agricultural surface area increased considerably, from 561 to 741 million hectares, with the greatest expansion in South America: from 441 to 607 million hectares.

However, the expansion of production has generally been accompanied by an intensive use of inputs, soil and water degradation, a reduction in biodiversity and deforestation, under a market-oriented focus that undermines not only the quality and availability of natural resources but also the livelihoods of individuals, especially the most vulnerable.

Water use

Soil management can significantly affect the quality and quantity of water available in a basin. The hydrological balance is disrupted by deforestation, changes in land use and plant cover, the overexploitation of aquifers and the drainage of natural water bodies. In the last three decades, water extraction has doubled in LAC at a rate much higher than the world average. In this region, the agricultural sector and especially irrigated agriculture, uses most of the water, accounting for 70% of extractions. This is followed by extraction for domestic use with 20% and industry with 10%. At this point it is worth noting that soil is an excellent repository of humidity, hence the advisability of managing soil and water in an integrated manner.

Soil and water degradation and contamination

Soil degradation (physical, chemical and biological) is apparent in reduced plant cover, lower fertility, soil and water contamination and, as a result, poorer harvests. LAC accounts for 14% of global degradation, with a high of 26% of land affected in Mesoamerica, while South America has 14%. The main causes of degradation include water erosion, the intense application of agrochemicals and deforestation. Four LAC countries have over 40% of their national territory degraded and 14 countries a level of degradation of national territory of between 20% and 40%.

The region has two fundamental problems relating to water: a reduction in water availability and a loss of water quality. Reduced availability (quantitative degradation) occurs when the water balance is disrupted and water use exceeds supply. Loss of water quality (contamination) occurs when water utility is reduced and its properties are damaged by the environment and its organisms. This occurs with inadequate wastewater treatment, excessive application of fertilizers and agrochemicals, excessive irrigation and contamination from industrial, mining or energy use.

Degradation is also associated with poverty and lack of access to land and water resources. Poor farmers have less access to land and water, and work poor quality soils that are highly vulnerable to degradation. Some 40% of the world's most degraded land is in areas with high levels of poverty.

Climate change as a risk for soil degradation in LAC

Climate change is modifying precipitation and temperature behaviour. Major changes are envisaged in agro-ecosystems as we now know them. In LAC, changes in rainfall patterns and in maximum, minimum and average temperatures will affect the yields of staple crops such as wheat, rice and beans. This will generate pressure for non-agricultural areas to be used to grow food. This and projected growth of world population and corresponding demand for food make climate change an additional risk for soil and water degradation, due to an expansion of cropland and an intensification of production. For example, towards mid-century there is expected to be a gradual replacement of tropical forests by savannah in eastern Amazonia, and of semi-arid vegetation by arid-zone vegetation, because of increased temperature and less water in the soil.

Meeting the challenge with good soil and water conservation practices

In Latin America and the Caribbean there are many experiences that integrate production and the conservation of biodiversity, in particular indigenous and traditional food and agriculture production systems, family farming, conservation of agro-biodiversity, management of shared resources and protection of natural resources.

In order to safeguard and disseminate good soil and water conservation practices, FAO forms part of WOCAT (World Overview Conservation Approaches and Technologies), which proposes alternatives to deal with this challenge. WOCAT is a global network of soil and water conservation information and specialists that has developed a methodology for the systematization of practices and approaches. It is a system in constant growth that currently includes 25 practices/technologies and 12 soil and water conservation approaches of eight countries of the region, and many more of other parts of the world. In order to locally strengthen the use of this systematization methodology, the FAO Regional Office for Latin America and the Caribbean (RLC) has proposed a systematization methodology based on the WOCAT methodology to gather information on soil and water conservation practices and technologies for adaptation to climate change, through the synthesis and review of original questionnaires and modules, promoting the use of digital tools for this work and reducing the time and resources needed for the systematization exercise.

WOCAT approach for the systematization of practices, technologies and approaches

In order to enhance food security, strengthen family farming, adapt to climate change and ensure the provision of environmental or ecosystem services, we need to reverse the processes of soil degradation, secure the supply of water needed for higher food demand in the world and adopt good land management practices, in general, for all aspects of agricultural activity. Some broad principles that need to be considered in all cases are increased plant cover and soil organic matter, improved infiltration and retention of moisture, and reduced contamination of the environment and the soil.

There are many conservation practices and approaches and agricultural production systems in the world. These vary according to environment, social and economic conditions of production, type of produce and its final destination (home consumption, sale, export), among other factors, thereby generating a wealth of intricate information on each that WOCAT gathers by means of questionnaires, open days for discussion and validation, and the presentation of findings through summary sheets. WOCAT has special data collection modules on the adaptation of technologies/approaches to climate change and elements for mapping those technologies. The WOCAT database is available on its website, with information on conservation practices, technologies and approaches from all parts of the world.

The systematization methodology adjusted for Latin America and the Caribbean was produced by the FAO Regional Office in collaboration with the Federico Santa Maria Technical University of Santiago, and thanks to the support of experts from Honduras, Costa Rica, Colombia, Ecuador, Bolivia (through GIZ), Argentina and Chile. The main report of this project summarizes the discussions held to formulate a modified systematization questionnaire and provides summary sheets of 12 conservation practices and technologies systematized by experts of the region. The annexes of the document examine the new systematization questionnaire, the Interviewer Manual (aimed at guiding the work of the practitioner applying the methodology), two pilot questionnaires on approach systematization (Argentina and Bolivia); and the complete questionnaires of the 12 technologies systematized in the project.

Utilización del agua en América Latina y el Caribe