|Wick, Abbey - North Dakota State University|
|Berti, Marisol - North Dakota State University|
|Lawley, Yvonne - University Of Manitoba|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 5/2/2016
Publication Date: 4/1/2017
Citation: Wick, A., Berti, M., Lawley, Y., Liebig, M.A. 2017. Integration of annual and perennial cover crops for improving soil health. IN: M. Al-Kaisi and B. Lowery, editors. Soil Health and Intensification of Agroecosystems. San Diego, CA:Academic Press. p. 127-150.
Interpretive Summary: Use of annual and perennial cover crops in rotation are a primary tool in agricultural systems, especially for improving soil health. Environmental benefits include erosion control and nutrient capture to protect water resources. On a field scale, cover crops can be used to build physical, chemical and biological soil properties. Annual grasses, brassicas and legumes improve soil infiltration and reduce compaction through both fibrous and large tap root development. Nutrient capture, nutrient cycling efficiency and associations with microbial communities are also benefits of including cover crops in rotation. Perennial grass and legume phases contribute to soil health by mitigating salinity and increasing nitrogen reserves for subsequent cash crops. While there is abundant evidence supporting soil health improvement from cover crops, this topic continues to be explored by agricultural researchers worldwide.
Technical Abstract: Annual and perennial cover crops in rotation provide environmental services and benefit soil health. Environmentally, cover crops can fill gaps in the rotation where the field may otherwise be fallow, thereby reducing soil erosion. Additionally, using cover crops as a nutrient capture tool can reduce nutrient losses and loading in water resources. From a soil health perspective, extending the growing season with live plant cover has the potential to improve soil physical, chemical and biological properties. Grasses and brassicas improve water infiltration into soils by facilitating aggregation and creating biopores for water transfer from the surface into the soil profile. Both grasses and brassicas can penetrate compacted layers to improve rooting depth of subsequent cash crops. Annual and perennial legumes make nutrient cycling more efficient through additions of nitrogen rich organic material to the soil, potentially reducing inorganic fertilizer inputs required to support cash crops. Biologically, cover crop associations with mycorrhizal fungi provide benefits for nutrient uptake of both the cover crop and also the following cash crop through soil priming. Root and organic matter additions from cover crops supporting microbial communities benefit soil health; however, this is an area requiring continued research. The scientific and agricultural communities continue to recognize the importance of including cover crops within cash crop rotations. Based on this review of recent literature, motivations to include cover crops for purposes of improving soil health appear to be justified.