Addition of Cover Crops Enhances No-Till Potential for Improving Soil Physical Properties
- Humberto Blanco-Canqui *a,
- Maysoon M. Mikhab,
- DeAnn R. Presleyc and
- Mark M. Claassend
- a Kansas State University, Dep. of Agronomy, Agricultural Research Center–Hays, 1232 240th Ave.Hays, Kansas 67601-9228
b USDA-ARS, Central Great Plains Research Station, Northern Plains Area, 40335 Rd. GG, Akron, CO 80720
c Dep. of Agronomy, Kansas State University, Manhattan, KS 66506
d Kansas State University, 202 S. Roupp, Hesston, KS 67062
Inclusion of cover crops (CCs) may be a potential strategy to boost no-till performance by improving soil physical properties. To assess this potential, we utilized a winter wheat (Triticum aestivum L.)–grain sorghum [Sorghum bicolor (L.) Moench] rotation, four N rates, and a hairy vetch (HV; Vicia villosa Roth) CC after wheat during the first rotation cycles, which was replaced in subsequent cycles with sunn hemp (SH; Crotalaria juncea L.) and late-maturing soybean [LMS; Glycine max (L.) Merr.] CCs in no-till on a silt loam. At the end of 15 yr, we studied the cumulative impacts of CCs on soil physical properties and assessed relationships between soil properties and soil organic C (SOC) concentration. Across N rates, SH reduced near-surface bulk density (ρb) by 4% and increased cumulative infiltration by three times relative to no-CC plots. Without N application, SH and LMS reduced Proctor maximum ρb, a parameter of soil compactibility, by 5%, indicating that soils under CCs may be less susceptible to compaction. Cover crops also increased mean weight diameter of aggregates (MWDA) by 80% in the 0- to 7.5-cm depth. The SOC concentration was 30% greater for SH and 20% greater for LMS than for no-CC plots in the 0- to 7.5-cm depth. The CC-induced increase in SOC concentration was negatively correlated with Proctor maximum ρb and positively with MWDA and cumulative infiltration. Overall, addition of CCs to no-till systems improved soil physical properties, and the CC-induced change in SOC concentration was correlated with soil physical properties.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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