Maurício Roberto Cherubina b, Lucas Pecci Canisaresa b, Lucas Nogueira Souzaa b, Carlos Roberto Pinheiro Juniora b, Moacir Tuzzin de Moraesa b, Felipe Bertolc, Larissa Bortoloc, Rafael Braghieri Menilloa, Carlos Eduardo Pellegrino Cerria b
- aLuiz de Queiroz College of Agriculture – University of São Paulo, Piracicaba, SP, Brazil
- bCenter for Carbon Research in Tropical Agriculture, University of São Paulo, Piracicaba, SP, Brazil
- cFundação Mato Grosso, Rondonópolis, Mato Grosso, Brazil
Highlights
- Crop diversification enhanced soil health and multifunctionality of topsoil (0–10 cm).
- Soybean yield was higher and more stable in diversified systems than monocropping.
- Healthy soils showed higher and more stable yields.
- Water use efficiency was higher in diversified than winter fallow system (3.1–3.5 vs. 1.8 kg ha−1 mm−1 of soybean grain).
- Soil health index serves as a comprehensive metric for assessing the climate change adaptation strategies in tropical agroecosystems.
Abstract
Crop diversification strategies can improve soil health while maintaining high yields. Healthy soils perform multiple functions that can also increase resilience to climate change. However, these benefits have yet to be demonstrated in the Brazilian savannah (Cerrado biome), one of the world’s largest agricultural production regions and also one of the most vulnerable to climate change. Thus, this study evaluates the long-term (16 years) effects of crop diversification systems, including crop successions and rotations, and soybean monocropping (control), on soil health, grain yield, and yield stability in the Brazilian savannah. The experiment involved seven cropping systems with soybean as the main cash crop, integrating pearl millet, ruzigrass, sunn hemp, and/or maize into the different successions and rotations. Soil health data includes 23 indicators (8 chemicals, 10 physicals and 5 biologicals). Crop yield and weather data from the last 6 years (two rotation cycles) were analyzed. Soybean yields were higher under crop diversification compared to monocropping (soybean-fallow) (3948 – 4321 kg ha−1 vs. 2282 kg ha−1), with reduced yield variability (5–9 % vs 19 %). Results showed that crop successions and rotations enhanced soil health indicators (mainly biological and physical) compared to soybean-fallow monocropping, resulting in higher soil health index and soil’s multifunctionality. We observed a higher amplitude of grain yield in drier and warmer years and observed a positive linear relationship between soil health index and water use efficiency. Treatments with higher soil health index result in higher water use efficiency (3.1–3.5 vs. 1.8 kg ha−1 mm−1 of soybean grain) than monocropping, with successions and rotations enhancing systems’ resilience compared to monocropping. In conclusion, long-term crop diversification, particularly including cover crops with high biomass accumulation, was an effective strategy to enhance soil health, productivity, and resilience in tropical agroecosystems in the Brazilian savannah. In addition, we suggest that the soil health index be used as a comprehensive indicator for assessing the effectiveness of climate change adaptation strategies in agroecosystems.
Keywords
Climate-resilient agriculture; Soybean; Cover crop; Soil multifunctionality
