“… there will be a reduction in precipitation with a direct impact on the productivity of corn, rice and beans”
Eduardo Delgado Assad, researcher at Embrapa Informática Agropecuária (Brazilian Agricultural Research Company – Agricultural Computing), explains the effects of climate change on South American agriculture.
Eduardo Delgado Assad, researcher at Embrapa Informática Agropecuária
Eduardo Delgado Assad is an agricultural engineer from the Federal University of Viçosa, with a doctorate from the University of Montpellier, France. Specialized in remote sensing at the CNES (Centre National d’Études Spatiales) in Toulouse, he has been a researcher at Embrapa since 1987. Assad was head of Research and Development at Embrapa Cerrados and at Embrapa Informática Agropecuária, national technical coordinator of the Ministry’s Agricultural Zoning of Climatic Risks of Agriculture, and Secretary of Climate Change and Environmental Quality at the Ministry of the Environment.
Agriculture is one of the sectors most affected by extreme natural phenomena. With climate change, risks to food and nutrition security are multiplied by the increased frequency and intensity of extreme events, as well as climate-related catastrophes. Increased average temperature implies changes in precipitation and wind. Over the past 20 years, studies carried out in Brazil have shown the impact, based on analyzes of the vulnerability of grain production in the face of extreme events and climate change.
Brazil is a large producer of grains, meat and fruits, and the agricultural sector contributes 21.4% of GDP and 19.5% of the workforce. In the last harvest of 2020, 232 million tons of grains were produced. Some important effects of production losses were observed, mainly for off-season corn and soybeans. These losses were due to climatic variations such as intense drought and heat waves.
More than 90% of Brazilian agriculture is “rain fed”, depending on the rainy season, both in terms of quantity and distribution. Interaction between rainfall, temperature and water in the soil is crucial for production in Brazil. To estimate possible losses, climate models are used to verify current productivity and estimate future ones, mainly in terms of water deficit.
Projections of the effects of climate change on agriculture in Brazil for 2050 indicate significant losses. Regions most vulnerable to climate change would be the Amazon and the Northeast: In the Amazon, increase in temperature can reach 8°C by 2100, and models indicate the possibility of changes in the Amazon forest to a savanna-like vegetation. Agriculture would suffer significant losses in all states, with the exception of the coldest ones in the South and Southeast, which would register mild temperatures.
For future productivity estimates, official data from Brazil from the Brazilian Institute of Geography and Statistics are used, which provides a historical series of data on planted area, production and productivity in each municipality in Brazil. In this way, the loss of productivity is estimated as a function of future climate parameters, using the IPCC climate models, in the specific case the Hadgem2-ES model, adapted for Brazil and provided by INPE (National Institute for Space Research) known as ETA- Hadgem.
Future projections are made for soybean, corn, rice, bean crops. Considering Brazilian heterogeneity in terms of climate, soil, relief, vegetation, estimates were made for the Amazon, Cerrado, Semiarid, Atlantic Forest and Pampa Biomes. Most agricultural production is in the Cerrado Biome and the southern region of the Atlantic Forest.
The table below shows the possible losses in each Brazilian biome for each crop in periods ranging from 2010 to 2050. Most critical periods are the decades of 2020 – 2030 and 2030 – 2040. The greatest losses would be in the Cerrado and Atlantic Forest , which may be greater than 30% in relation to the period from 2010 to 2020. This situation occurs if nothing is done to mitigate the impacts of climate change.
Adoption of low carbon emission practices, which is already an official agricultural financing policy, may reduce this impact. Some unpublished results show that those who adopted these practices in the event of extreme water deficit events lost 10% in productivity. Farmers who did not adopt lost 25% in productivity.
Estimate of yield losses for soybean, corn, rice and bean crops in 5 Brazilian Biomes, between 2011 and 2050.
| Productivity kg / ha | ||||||||
| Biome | Crops | 2011/2020 | 2021/2030 | Difference (%) | 2031/2040 | Difference (%) | 2041/2050 | Difference (%) |
| Amazon | Soy | 3,078 | 2,815 | -9 | 2,968 | -4 | 3,100 | 1 |
| Corn | 2,543 | 2,465 | -3 | 2,495 | -2 | 2,559 | 1 | |
| Rice | 1,917 | 1,849 | -4 | 1,893 | -1 | 1,929 | 1 | |
| Blackbeans/ pinto beans | 678 | 671 | -1 | 674 | -1 | 681 | 0 | |
| Cerrado | Soy | 3,244 | 2,202 | -32 | 2,923 | -10 | 3,556 | 10 |
| Corn | 4,331 | 2,630 | -39 | 4,152 | -4 | 4,619 | 7 | |
| Rice | 2,105 | 1,525 | -28 | 1,748 | -17 | 2,090 | -1 | |
| Blackbeans/ pinto beans | 1,179 | 733 | -38 | 942 | -20 | 1,175 | 0 | |
| Atlantic Forest | Soy | 3,349 | 2,377 | -29 | 3,066 | -8 | 3,560 | 6 |
| Corn | 4,818 | 3,051 | -37 | 4,597 | -5 | 5,013 | 4 | |
| Rice | 3,542 | 2,926 | -17 | 3,169 | -11 | 3,581 | 1 | |
| Blackbeans/ pinto beans | 1,171 | 972 | -17 | 1,051 | -10 | 1,205 | 3 | |
| Pampa | Soy | 2,458 | 2,122 | -14 | 2,397 | -2 | 2,523 | 3 |
| Corn | 3,812 | 2,538 | -33 | 3,670 | -4 | 3,941 | 3 | |
| Rice | 7,337 | 7,331 | 0 | 7,337 | 0 | 7,337 | 0 | |
| Blackbeans/ pinto beans | 1,030 | 1,030 | 0 | 1,030 | 0 | 1,030 | 0 | |
| Caatinga | Soy | – | – | 0 | – | 0 | – | 0 |
| Corn | 660 | 699 | -6 | 686 | -4 | 473 | -28 | |
| Rice | 1,604 | 1,648 | -3 | 1,265 | -21 | 1,813 | 13 | |
| Blackbeans/ pinto beans | 321 | 338 | -5 | 272 | -15 | 369 | 15 | |
In Central America, mainly in countries like Costa Rica, Honduras, Guatemala and El Salvador, results indicate the impacts of climate change on agriculture. There will be a reduction in precipitation with a direct impact on the productivity of corn, rice and beans.
In all cases, there is a tendency to reduce productivity, even if losses are mitigated by the increase in technology. The possibilities for reducing impacts will necessarily involve the adoption of integrated systems, which in essence, act directly in the management and conservation of soil and water.
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