Beef manure and urea applied to corn show variable effects on nitrous oxide, methane, carbon dioxide, and ammonia

Authors: NIRAULA, SURESH - North Dakota State University; RAHMAN, SHAFIQUR - North Dakota State University; CHATTERJEE, AMITAVA - North Dakota State University; CORTUS, ERIN - University Of Minnesota; MEHATA, MUKESH - South Dakota State University; Spiehs, Mindy

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2018
Publication Date: 7/16/2019
Citation: Niraula, S., Rahman, S., Chatterjee, A., Cortus, E.L., Mehata, M., Spiehs, M.J. 2019. Beef manure and urea applied to corn show variable effects on nitrous oxide, methane, carbon dioxide, and ammonia. Agronomy Journal. 111(3):1448-1467. https://doi.org/10.2134/agronj2018.08.0547.
DOI: https://doi.org/10.2134/agronj2018.08.0547

Interpretive Summary: When manure is used as fertilizer on crop land, it has been shown to improve soil health and increase crop yields compared to commercial fertilizer. However, the nutrients in manure can be quite variable. Little is known about the potential emissions of ammonia and greenhouse gases such as carbon dioxide, methane, and nitrous oxide when manure is used as a nitrogen fertilizer. A two-year study was conducted to measure gas emissions from crop land that received beef manure to compare it to crop land that received commercial fertilizer or no fertilizer. Two types of beef manure were used: solid beef manure and solid beef manure that contained wheat straw as bedding material. Crop yield was the same for plots that received both types of beef manure as well as the commercial fertilizer. Cumulative nitrous oxide emission over the growing season was highest when commercial fertilizer was used, but the use of commercial fertilizer reduced cumulative carbon dioxide emission by 42% compared to both types of manure. Cumulative methane emission was highest from plots that received the beef manure with bedding. When comparing manure versus commercial fertilizer, manure reduced cumulative ammonia emission by ~11%. No fertilizer was able to reduce all gaseous emissions, which highlights the challenges producers face when selecting a fertilizer to use on their crop field.

Technical Abstract: Land application of beef cattle (Bos taurus) manure can improve soil health and increase corn (Zea mays L.) yield compared with commercial fertilizers. However, ammonia (NH3), nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) emissions may lead to nutrient losses and environmental concerns. The objective of this research was to quantify NH3, N2O, CO2, and CH4 emissions from commercial and manure fertilizers applied to corn. In addition, residual soil N, corn yield, plant tissue N, and grain N were determined. The 2-yr field study was conducted in Fargo-Ryan silty clay soil. Treatments consisted of urea only (UO), solid beef manure (SM), solid beef manure with straw bedding (BM), and no fertilizer (NF). All treatments were applied to meet the corn N demand and yield goal of 10,760 kg ha–1 (160 bu ac–1). Greenhouse gases were quantified using static flux chambers, and NH3 was quantified using acid traps, for a total of 13 measurement dates in each growing season. Manure applied to soil reduced cumulative N2O by 23% in SM and 31% in BM compared with the UO soil. Cumulative CO2 emission (cCO2) was 42% lower in UO than in SM or BM. Cumulative CH4 emission (cCH4) ranged from –0.04 (NF) to 0.21 (BM) kg CH4–C ha–1, with the highest emission from BM. Cumulative NH3 emission (cNH3) was 11% lower in manure than UO. Cumulative residual soil N was 11% greater in Year 2. Fertilizer source did not affect the yield and grain N uptake (P > 0.05). The results highlight the challenges that come with variability in manure, soil, and weather as well as the potential for meeting crop N demand while reducing greenhouse gas emissions when using manure as an N source.