Water quality of surface runoff and lint yield in cotton under furrow irrigation in Northeast Arkansas

Authors: Adviento-Borbe, Arlene; BARNES, BRITTANY - Arkansas State University; ISEYEMI, OLUWAYINKA - Orise Fellow; MANN, A.D.H. - University Of Arkansas; Reba, Michele; ROBERTSON, J. - University Of Arkansas; Massey, Joseph; TEAGUE, TINA G. - University Of Arkansas

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2017
Publication Date: 2/1/2018
Publication URL: https://handle.nal.usda.gov/10113/5815904
Citation: Adviento-Borbe, A.A., Barnes, B., Iseyemi, O., Mann, A., Reba, M.L., Robertson, J., Massey, J., Teague, T. 2018. Water quality of surface runoff and lint yield in cotton under furrow irrigation in Northeast Arkansas. Science of the Total Environment. 613-614:81-87. https://doi.org/10.1016/j.scitotenv.2017.09.020.
DOI: https://doi.org/10.1016/j.scitotenv.2017.09.020

Interpretive Summary: Furrow irrigation is a common and effective water management practice that maximizes water savings while maintaining yields in cotton production in the Midsouth US. However, when excessive water is applied, large nutrient losses through transport of irrigation water can occur. Many current studies on irrigation management strategies focus on water use efficiency and water runoff reduction but less information exists on the influence of irrigation practices on water quality and nutrient losses. This paper highlights the impact of furrow tillage and fertilizer application on total volume of water runoff and water quality characteristics that may negatively impact the environment. Conservation furrow tillage practice reduced nutrient concentrations, total volume of runoff water and maintained water quality characteristics below risk levels. Lint yields increased through improved furrow tillage irrigation and adequate N rate application. This information will enable cotton producers, extension workers and irrigation engineers to develop efficient irrigation management strategies and crop practices that minimize impairments to water systems in Arkansas while maintaining high yield.

Technical Abstract: Use of furrow irrigation in row crop production is a common practice through much of the Midsouth US and yet, nutrients can be transported off-site through surface runoff. A field study with cotton (Gossypium hirsutum, L.) was conducted to understand the impact of furrow tillage practices and nitrogen (N) fertilizer placement on characteristics of runoff water quality during the growing season. The experiment was designed as a randomized complete block design with conventional (CT) and conservation furrow tillage (FT) in combination with either urea (URN) broadcast or 32% urea ammonium nitrate (UAN) injected, each applied at 101 kg N ha- 1. Concentrations of ammonium (NH4-N), nitrate (NO3-N), nitrite (NO2-N), and dissolved phosphorus (P) in irrigation runoff water and lint yields were measured in all treatments. The intensity and chemical form of nutrient losses were primarily controlled by water runoff volume and agronomic practice. Across tillage and fertilizer N treatments, median N concentrations in the runoff were < 0.3 mg N L- 1, with NO3-N being relatively the highest among N forms. Concentrations of runoff dissolved P were < 0.05 mg P L- 1 and were affected by volume of runoff water. Water pH, specific electrical conductivity, alkalinity and hardness were within levels that common to local irrigation water and less likely to impair pollution in waterways. Lint yields averaged 1111 kg ha- 1 and were higher (P-value = 0.03) in FT compared to CT treatments. Runoff volumes across irrigation events were greater (P-value = 0.02) in CT than FT treatments, which increased NO3-N mass loads in CT treatments (394 g NO3-N ha- 1 season- 1). Nitrate-N concentrations in CT treatments were still low and pose little threat to N contaminations in waterways. The findings support the adoption of conservation practices for furrow tillage and N fertilizer placement that can reduce nutrient runoff losses in furrow irrigation systems.