Synergies and trade-offs between ecosystem services and economics in dryland cover crop systems

Replacing bare fallow periods with cover crops in dryland agroecosystems
can help reverse soil degradation and control erosion but may also result
in cash crop yield penalties due to water limitations. Two field trials
were conducted on the Colorado Plateau to quantify the impact of cover
cropping on crop production, multiple ecosystem services, and economic
trade-offs in this semi-arid region. No-till and different cover crop
planting windows (fall and spring) were explored as strategies to optimize
ecosystem service provision and productivity trade-offs. After three full
cover crop cycles (6 years), fall-planted cover crops improved soil
structure and erosion control, but associated wheat yield penalties (48%
decrease on average) and additional costs caused a 176 USD ha-1 cycle-1
average decrease in net returns. However, including the hypothetical sale
of forage (based on 50% cover crop biomass removal) more than offset these
costs in fall-planted treatments; with both forage and wheat revenue,
cover cropping increased net returns as compared to the fallow control by
92 USD ha-1 cycle-1. Spring-planted cover crops presented a lower
productivity trade-off (24% average wheat yield penalty) but did not
provide clear ecosystem service benefits and did not produce enough
biomass to offset costs of cover cropping. Our findings indicate that
fall-planted cover crops have the potential to reverse soil degradation
and control erosion in dryland systems globally, but productivity
trade-offs and decreased economic returns must be compensated for by
alternative revenue sources, conservation payments, or other incentives to
ensure their feasibility.