Soil aggregate stability increased with a self-regenerating legume cover crop in low-nitrogen, no-till agroecosystems of Saskatchewan, Canada

Abstract: Black medic (Medicago lupulina L.) is a self-regenerating cover crop which was tested for its ability to improve soil physical properties. Soil aggregate stability was assessed in plots that included a black medic cover crop in a no-till grain rotation, which was fertilized with two levels of nitrogen (N), for 15 yr. In the wheat phase of the rotation, the medic cover crop increased mean weight diameter by 21% in the reduced N fertilizer treatment but not in the recommended N treatment. Generally, the addition of medic reduced the proportion of small aggregates and increased the proportion of large aggregates. This pattern was stronger in reduced N compared with recommended N fertilizer levels. This study provided evidence for medic to increase aggregate stability under low external N input grain production.

[1]  M. Beare,et al.  Aggregation and Organic Matter Storage in Meso-Thermal, Humid Soils , 2020, Structure and Organic Matter Storage in Agricultural Soils.

[2]  D. Tyler,et al.  Thirty-four years of no-tillage and cover crops improve soil quality and increase cotton yield in Alfisols, Southeastern USA , 2019, Geoderma.

[3]  M. Ryan,et al.  No-till and cropping system diversification improve soil health and crop yield , 2018, Geoderma.

[4]  J. L. Gabriel,et al.  Cover crops to mitigate soil degradation and enhance soil functionality in irrigated land , 2018, Geoderma.

[5]  W. May,et al.  Soil bacterial community responses to black medic cover crop and fertilizer N under no-till , 2017 .

[6]  M. Entz,et al.  Characteristics of Black Medic Seed Dormancy Loss in Western Canada , 2017 .

[7]  W. May,et al.  Effect of black medic (Medicago lupulina) and nitrogen fertilizer on crop yield and soil nitrogen , 2015 .

[8]  S. TurmelM.,et al.  The influence of a long-term black medic (Medicago lupulina cv. George) cover crop on arbuscular mycorrhizal fungal colonization and nutrient uptake in flax (Linum usitatissimum) under zero-tillage management , 2011 .

[9]  H. Blanco‐Canqui,et al.  Addition of Cover Crops Enhances No‐Till Potential for Improving Soil Physical Properties , 2011 .

[10]  J. Germida,et al.  No-till soil management increases microbial biomass and alters community profiles in soil aggregates , 2010 .

[11]  J. Six,et al.  SOIL BIOLOGY & BIOCHEMISTRY Fertilizer and Residue Quality Effects on Organic Matter Stabilization in Soil Aggregates , 2009 .

[12]  D. Angers,et al.  Aggregate Stability to Water , 2007 .

[13]  T. Vyn,et al.  Nitrogen fertilization and cover crop effects on soil structural stability and corn performance , 1998 .

[14]  C. Campbell,et al.  Soil aggregation as influenced by cultural practices in Saskatchewan: I. Black Chernozemic soils , 1993 .

[15]  J. Oades.  The role of biology in the formation, stabilization and degradation of soil structure , 1993 .

[16]  J. Blesh,et al.  Crop rotations for increased soil carbon: perenniality as a guiding principle. , 2018, Ecological applications : a publication of the Ecological Society of America.