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ARS Home » Midwest Area » Bowling Green, Kentucky » Food Animal Environmental Systems Research » Research » Publications at this Location » Publication #370011

Research Project: Developing Safe, Efficient and Environmentally Sound Management Practices for the Use of Animal Manure

Location: Food Animal Environmental Systems Research

Title: Does potentially mineralizable nitrogen predict maize yield in newly cropped soil

item GEBREMEDHIN, MAHETEME - Kentucky State University
item SARR, S - University Of Louisville
item COYNE, M - University Of Kentucky
item FREYTAG, M - University Of Kentucky
item Sistani, Karamat

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/28/2020
Publication Date: 4/11/2020
Publication URL:
Citation: Gebremedhin, M., Sarr, S., Coyne, M., Freytag, A., Sistani, K.R. 2020. Does potentially mineralizable nitrogen predict maize yield in newly cropped soil. Agrosystems, Geosciences & Environment. 3(1).

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. 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: The contribution of soil organic nitrogen (SON) to the plant available nitrogen (N) pool during the growing season is sometimes difficult to predict due to variation in soil physical, chemical, and biological chemical properties, environmental factors (temperature and precipitation), and management practices. Potentially mineralizable nitrogen (PMN) is an accepted soil quality indicator and its increase is a management strategy to meet crop N demands while reducing chemical N fertilizer requirements in subsequent seasons. In this study, conducted in Madison county, Kentucky (37.85N; 84.29W), we examined how implementing a conservation practices (combined use of cover crops and animal manure) affected PMN, and its influence on maize grain yield in a site newly converted from fallow to cropping. Six treatments were used: 1) an unamended control; 2) cover crops; 3) horse manure; 4) cover crop and manure; 5) chemical fertilizer; and 6) cover crops and chemical fertilizer. Soil samples were taken before treatment application (Spring) and at harvest (Fall) of each year and analyzed for PMN. The seasonal PMN and maize grain yield were influenced by cover crops and manure (p < 0.05). Maize yield had a positive response to cover crops but not manure. The correlation between PMN and yield was weak (R2 = 0.03) but positive, indicating that PMN can suggest beneficial effects of adopting soil conservation practices that can also benefit, but not necessarily predict, crop yield.