New research proposes agricultural intensification measures that would allow Brazil, the world's top soybean exporter, to raise soybean production by 36% over the next 15 years while preserving the Amazonian rainforest.
The study largely relies on the Global Yield Gap Atlas, an agronomic database that covers more than 15 crops in 75 countries.
If current trends continue, Brazil will convert around 13 million acres of environmentally sensitive rainforest and savannah to soybean agriculture by 2035, resulting in biodiversity loss and climate-threatening CO2 emissions.
Brazil can grow more soybeans without deforesting Amazon
Meredith Petrick/Unsplash
Globally, developing nations face a conundrum that puts economic progress against environmental conservation, as per ScienceDaily.
They frequently convert forests into crops and pastures as they boost their agricultural production.
However, large-scale tree clearance undermines the world's potential to avert additional climate worsening and biodiversity loss.
Brazil is a prime example. The country has the world's biggest rainforest, covering 1.2 million square miles, or an area more than 16 times the size of Nebraska.
The Amazon features vast areas of rainforest that, when converted to agriculture, emit massive amounts of CO2 into the atmosphere, worsening climate change.
Brazil, the world's top soybean exporter, has made increasing agricultural production a national priority.
Agricultural encroachment degraded large parts of the country's rainforest during the 1990s.
The Amazon basin accounted for one-third of the land converted for Brazilian soybean development between 2015 and 2019.
"We believe there is a pressing need for major crop-producing nations to evaluate their capacity to produce more on existing farmland in the present context of high grain prices and food supply disruptions," the authors said in a study published Oct. 10 in the journal Nature Sustainability.
It would be difficult to protect the last bastions of forests and biodiversity on the planet while being sensitive to the economic aspirations of developing countries without an emphasis on intensifying crop production within the existing agricultural area, coupled with strong institutions and policies that prevent deforestation in frontier agricultural areas.
Moratoria and incentives have been used to limit deforestation in Brazil since 2000.
However, rising commodity prices and political pressure to recover fast from the combined effects of the COVID-19 epidemic and Ukraine's war have put the Amazonian rainforest in jeopardy.
If present trends continue, Brazil will convert around 57 million acres to soybean cultivation over the next 15 years, with approximately one-fourth of the development taking place in environmentally sensitive regions.
The study, conducted by Patricio Grassini, Sunkist Distinguished Professor in Agronomy and associate professor in Nebraska's Department of Agronomy and Horticulture, demonstrates how Brazil may increase agricultural productivity without turning additional rainforest and savannah to crops.
With a properly managed approach to improve production on existing acres, the government could raise annual soybean output by 36% by 2035 while lowering greenhouse gas emissions by 58% from present levels.
Analyzing intensification and land use change scenarios
We investigated three scenarios with varying soybean and maize yields and areas by 2035 and evaluated the results in terms of productivity, land use change, and GWP, as per Nature.
A 15-year future time horizon is long enough to allow for the implementation of long-term policies, investments, and technologies aimed at closing the exploitable yield gap and implementing land-use policies, but it is also short enough to minimize the long-term effects of climate change on crop yields and cropping systems.
Historical trends in soybean and second-crop maize acreage and yield remain unchanged in all areas between the baseline year (2019) and the final year under the BAU scenario (2035).
Similarly, soybean acreage grows in accordance with the similar trend of land use change observed throughout 2008-2019
Researchers considered an NCE scenario in which there is no physical augmentation of cropland while full closure of the exploitable yield gap occurs in regions where the current yield gaps are small (the Pampa and the Atlantic Forest) and 50% closure of the exploitable yield gap occurs in regions where the current yield gaps are large (the Pampa and the Atlantic Forest) (the Amazon and the Cerrado).
These rates are comparable to previous yield increases in the Pampa and Atlantic Forest.
A full yield closure scenario in the Amazon and Cerrado would have been unrealistic because it would have required yield improvement rates three to four times higher than historical rates, much higher than those in the Pampa and the Atlantic Forest, and far beyond those reported for major soybean-producing countries.
In the case of second-crop maize, we projected that the exploitable yield gap will be completely closed by 2035 since historical yield improvement rates are sufficient to achieve that yield level.
They estimated that the share of second-crop maize area would grow from 47% (Amazon), 39% (Cerrado), and 31% (Atlantic Forest) to 100%, 70%, and 50%, respectively, based on the degree of water constraint in each region.
