Cover Crop Impacts on Water Dynamics and Yields in Dryland Wheat Systems on the Colorado Plateau
Open Access
- 28 May 2021
- Vol. 11 (6), 1102
- https://doi.org/10.3390/agronomy11061102
Abstract
On the semiarid Colorado Plateau, dryland farmers are challenged by degraded soils and unreliable precipitation. While cover crops have been shown to support soil fertility, control erosion, and enhance soil water capture, they also use limited soil water and, thus, may impact cash crop productivity in dryland systems. Most literature on cover crops comes from relatively humid climates, where yield penalties due to cover crops may be less pronounced. Two field trials were conducted in Southwestern Colorado to assess the short-term viability of cover crops in dryland systems in this region. The effect of cover crops on subsequent winter wheat (Triticum aestivum L.) yield ranged from a decrease of 78% to an increase of 13%, depending on the amount of cover crop biomass produced in the previous year. Cover crop biomass was inversely correlated with soil nitrate levels and soil water storage at wheat planting, which decreased by 0.39 mg kg−1 and 10 mm, respectively, per 1000 kg ha−1 of cover crop biomass produced. Less available soil water and immobilized N therefore appeared to contribute to wheat yield reductions. These impacts are particularly important for semiarid environments, where decomposition of residue is water-limited and soil water recharge depends on unpredictable precipitation patterns.Keywords
Funding Information
- Western SARE (SW15-008)
This publication has 34 references indexed in Scilit:
- Soil Response to Long‐Term Cropping Systems on an Argiustoll in the Central Great PlainsSoil Science Society of America Journal, 2010
- Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North AmericaScience, 2007
- Choice of Summer Fallow Replacement Crops Impacts Subsequent Winter WheatAgronomy Journal, 2007
- Cropping Sequence Effect of Pea and Pea Management on Spring Wheat in the Northern Great PlainsAgronomy Journal, 2006
- Legume Green Fallow Effect on Soil Water Content at Wheat Planting and Wheat YieldAgronomy Journal, 2005
- Cropping System Influence on Planting Water Content and Yield of Winter WheatAgronomy Journal, 2002
- Diversity and Productivity in a Long-Term Grassland ExperimentScience, 2001
- Green Fallow for the Central Great PlainsAgronomy Journal, 1997
- The Effect of Nitrogen Catch Crops on the Nitrogen Nutrition of a Succeeding Crop: I. Effects through Mineralization and Pre-emptive CompetitionActa Agriculturae Scandinavica, Section B — Soil & Plant Science, 1993
- Summer Fallow for Dryland Winter Wheat in the Semiarid Great Plains 1Agronomy Journal, 1970