The Problem: Agriculture in Brazil, a contributor to over 29% of their overall GDP, experiences soil erosion in almost 70% of their usable land.

Soil erosion is one of the ten major soil threats identified in the 2015 Status of the World’s Soil Resources report. Soil erosion occurs naturally under all climatic conditions and on all continents, but it is significantly increased and accelerated by unsustainable human activities (up to 1,000 times) through intensive agriculture, deforestation, overgrazing, and improper land use changes. In agriculture, soil erosion can lead to up to 50 percent loss in crop yields.

Root Causes

• Agricultural Practices
  • The cropping system practiced over most Brazilian soils is the sugarcane cropping system where the highs and content lead to increased erosion.
  • Expansion into areas of native vegetation (Brazilian Savannah (Cerrado) and Brazilian rainforest (Amazon)) can lead to increased soil erosion and nutrient loss, as well as decreased agricultural productivity
  • Tilling the soil for seedbed preparation, weed suppression, and soil aeration can disrupt soil structure, increasing surface runoff and soil erosion. Additionally with frequent tillage can also reduce crop residue, which helps protect the soil from the impact of raindrops and wind
  • Lack of knowledge about soil’s potential decreases yield and wears out terrain. In order to take advantage of the country’s resources, mapping of the quality of soil through spatial soil information practices (DMS technologies) the developing economy can achieve its greatest productive potential.
• Overgrazing
  • Overgrazing by livestock reduces ground cover, enabling erosion and compaction of the land by wind and rain.
  • It reduces soil fertility and soil chemical properties as Soil Organic Matter content was 30-50% lower (p=0.012), and exchangeable calcium 40-60% lower when compared to non-grazing areas. Nitrate nitrogen content was also lower in overgrazed valleys.
  • Overgrazing was also found to affect physical soil water properties, increasing topsoil temperature and decreasing moisture content. It also increases the density of the topsoil, due to the pressure of animals’ weight, reducing the ability of plants’ roots to penetrate the soil.
• Deforestation
  • The Amazon Rainforest has lost 800 million trees in the last 6 years from deforestation. This has caused a profound impact on the soil.
  • Trees and roots provide a shelter for soil. The soil specifically improves the ability and capacity of soil to absorb water. However, when these trees are removed, the land is left vulnerable to the different natural elements. The soil is at risk of wind erosion, water erosion, etc.

Why This is a Problem

• Brazil takes up 37% of their land in agriculture purposes for feeding its population (national use) and propel their economy at the same time (imports).
• Agribusiness contributed approximately 27% to the Brazilian GDP in 2020, with soybean and sugarcane being the main commodities produced.
• Brazilian Economy
  • Soil degradation contributes to, most notably, land devaluation due to losses of key nutrients and organic matter, which ultimately cost the Brazilian economy an addition $5.5 billion USD
  • Roughly 20 million metric tons of topsoil are effected by soil erosion, and therefore decreased crop yield, which decreases potential yield of production greatly
  • Some Brazilian states are already paying in excess of $200 million annually to address soil loss.
• The Brazilian Population
  • Brazil is the largest country in terms of arable land and a top-5 producer of 34 agricultural commodities, including essential goods like coffee, sugarcane, and citrus. Therefore, if Brazil's soil erosion problem is ultimately decreasing their agricultural yield by 2-3 fold, that means this is a huge contributor to agricultural/food shortage, as Brazil is the fourth largest agricultural producing country in the world.
  • Soil erosion, and/or the causes that contribute to it, tend to effect local water sources. Therefore, coastal communities of Brazil are highly effected by this issue, with damage of property and resources ultimately leading to displacement
  • Social-economic impact: Healthy soils are a pre-requisite to achieve the United Nations’ Sustainable Development Goals (SDGs) and form the basis of FAO’s Four Betters: better production, better nutrition, a better environment, and a better life, leaving no one behind.
  • Soils have an inherent capacity to meet crop demands in terms of availability of nutrients and water, influencing the photosynthetic process of the plant and consequently the production of biomass, which can be defined as their productive potential (SoilPP)

Why This Has Not Been Solved Yet

In the last 50 years, Brazil turned from an importer of food to a global food supplier, due to its favorable climate and advanced agricultural practices. However, in Brazil, demand for bioenergy crops, agricultural exports, and climate change are fueling erosion across the country. Agribusiness contributes 22% of the GDP and ⅓ of all employment, but the country’s diverse crop and livestock operations have been destructive to soil.

Next Steps

Government policy and private efforts should be put towards ensuring the sustainable use of soil, mainly in agriculturally dense areas in Brazil, where severely eroded areas are increasing, leading to a decrease in agricultural productivity and the depletion of soil nutrients by 25.9 times more.

Understanding and optimizing agricultural systems to complete the United Nations SDGs: sustainable agriculture and food production. This not only involves new practices but also the expansion of knowledge in Brazilian communities living in this sector.

• Need: techniques that focus on the systematic measurement of continental extensions on a fine scale, with analysis of subsurface soils, as indicated by Bishopp and Lynch18. Although SoilPP can be estimated through the evaluation of its chemical, physical and biological properties25,
• Barriers: lack of knowledge about the soil’s potential to produce biomass and whether it can be used as an indicator to identify if crop yield can be increased.