By Jamie Martin
A recent 34-year study led by the USDA Agricultural Research Service (ARS) shows that continuous cropping systems can significantly reduce greenhouse gas (GHG) emissions while sustaining crop yields in semi-arid regions. This research, conducted in the Northern Great Plains of the United States, evaluated three dryland cropping systems to assess their impact on both crop productivity and GHG emissions.
The traditional crop-fallow system, commonly used in dryland farming, leaves fields unplanted during summer, which can lead to higher GHG emissions and reduced long-term soil health.
In contrast, continuous cropping involves planting crops annually, eliminating the fallow period. The USDA researchers, led by Upendra M. Sainju, found that no-till continuous cropping systems can reduce net GHG emissions by 66-149% compared to the conventional till crop-fallow system.
Two continuous cropping systems were studied - a no-till spring wheat-pea rotation (legume-nonlegume) and a no-till continuous spring wheat system (nonlegume).
The legume-nonlegume rotation was shown to be the most effective in balancing crop yield and reducing GHG emissions. While the continuous nonlegume system improved carbon sequestration, it led to lower yields due to increased weed pressure and soil acidity.
The results indicate that adopting continuous cropping, especially in rotation with legumes, is a promising strategy for maintaining crop productivity while addressing climate change challenges in semi-arid farming.
Photo Credit: usda
Categories: National