The combined influence of cover crops and manure on maize and soybean yield in a Kentucky silt loam soil

Authors: GEBREMEDHIN, MAHETEME - Kentucky State University; SARR, SAIT - University Of Louisville; COYNE, MARK - University Of Kentucky; Sistani, Karamat; Simmons, Jason

Submitted to: Sustainability
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/23/2019
Publication Date: 10/31/2019
Citation: Gebremedhin, M., Sarr, S., Coyne, M., Sistani, K.R., Simmons, J.R. 2019. The combined influence of cover crops and manure on maize and soybean yield in a Kentucky silt loam soil. Sustainability. 11(21):6058. https://doi.org/10.3390/su11216058.
DOI: https://doi.org/10.3390/su11216058

Interpretive Summary: Soil conservation practices such as cover cropping, animal manure use, no-tillage, and crop rotation can improve soil quality by enhancing soil physical, chemical, and biological properties. Cover crops and animal manure combination can be a viable alternative management practice and source of nutrients for intensive farming and improving soil health/quality. cover crops and manure applications as soil quality building practices by farmers is still relatively small. The experiment was conducted at a small-producer farm in Logan County, Kentucky, USA. This research evaluated whether manure and cover crops in combination influenced the physical, chemical, and biological properties of agricultural soils. Three fertilization treatments were employed: 1) poultry manure, 2) chemical fertilizers (urea, diammonium phosphate, and potash), and 3) a non-fertilized control. A second set of treatments consisting of winter cover crops or no cover crops was used within each fertilizer treatment. Considering the site-specific soil conditions, cover crop and manure use may need longer-term assessment to reveal their impact on the yield and soil quality benefits, especially to resource-limited producers adopting these conservation practices.

Technical Abstract: Management that degrades soil can be one of the main causes of low agricultural productivity and environmental problems in many agricultural regions. There is renewed interest in soil conservation practices to promote sustainable agriculture by improving soil quality and productivity. In this study, the short-term on-farm benefits of cover crops and manure on crop yield and biomass were examined during two consecutive growing seasons. The experiment was conducted at a small-producer farm in Logan County, Kentucky, USA. Soybean (Glycine max L.) and maize (Zea mays L.) were used as summer annual rotation crops in no-tilled soils. A cover crop mix of cereal rye (Secale cereale L.), Austrian winter pea (Pisum sativum L.), and crimson clover (Trifolium incarnatum L.) was planted after the main crop was harvested each year. Aboveground biomass of the soybean and maize were assessed, and yield was estimated from hand-harvested plants. In the first year of the study (2016), there were apparent but not significant beneficial effects of animal manure and cover crops on soybean yield, but not on biomass. The biomass and maize grain yield in the second year (2017) were detectable, significant, and increased as a result of the cover crops and manure application (P < 0.05). While beneficial effects of combining cover crops and manure may not be obvious in the first year of a rotation, they can be apparent in subsequent years. However, longer-term observation and measurement are necessary to better quantify the relationship between sustainable conservation practices and productivity.