Climate, Rotation, and Tillage Impacts on Soybean Yield Gains in a 50-Year Experiment.

Area of Science:

• Agronomy and Crop Science
• Climate Change Adaptation
• Sustainable Agriculture

Background:

• Understanding the impact of management practices and climate on soybean productivity is crucial for future food security.
• Long-term data is essential for evaluating the sustainability of agricultural systems under changing environmental conditions.

Purpose of the Study:

• To investigate the interactive effects of tillage intensity, crop rotation (soybean monocropping vs. soybean-maize rotation), and climate patterns on soybean yield and phenology over 50 years.
• To identify resilient management strategies for soybean production in a warming climate.

Main Methods:

• Analysis of a 50-year field-scale dataset (1975-2024) in Indiana, USA, comparing eight production systems.
• Evaluation of soybean yield and plant height in response to spring and summer weather patterns across four tillage intensities (Moldboard Plow, Chisel, Ridge/Strip-Till, No-Till) and two rotation systems.
• Statistical analysis of yield trends, temperature and precipitation effects, and rotation/tillage impacts.

Main Results:

• Soybean yield positively correlated with increased spring temperatures (796 kg/ha/°C), particularly in monocropping systems.
• No-till systems demonstrated improved yield resilience compared to tilled systems.
• Soybean-maize rotation yielded 7.7% higher than monocropping, with significant variation based on tillage and year.
• Consistent yield gains observed over time (25.6–29.5 kg/ha/year) across various rotation and tillage regimes.

Conclusions:

• Soybean production can achieve consistent yield gains despite climate change through strategic crop rotation and tillage practices.
• No-till and crop rotation with maize are key strategies for enhancing soybean yield resilience.
• The 50-year dataset provides a valuable baseline for calibrating crop models to design sustainable future cropping systems.