Runoff, erosion, and nutrient transport arising from furrow irrigation in a corn conservation production system

Abstract

Contemporary row‐crop practices in the mid‐southern United States contribute to declining water tables and impairment of downstream waters, threatening the sustainability of irrigated agriculture and vital ecosystem services. This research was conducted to determine whether agro‐hydrology can be altered by cover crop or traffic pattern. The effects of cover crop {Austrian winter pea [Pisum sativum var. arvense (L.) Poiret], crimson clover [Trifolium incarnatum L.], cereal rye [Secale cereal L.], and tillage radish [Raphanus sativus L.]} and traffic pattern (traffic, nontraffic) on runoff, erosion, and nutrient transport from a furrow irrigation event were investigated at Stoneville, MS on a Commerce very fine sandy loam (a fine‐silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquept). Relative to winter fallow, the inclusion of a cover crop reduced erosion by at least 16% but had no effect on runoff or the transport of total P, total Kjeldahl nitrogen (TKN), soluble reactive phosphate (SRP), NH4–N, or NO3–N. Eliminating traffic in furrows reduced runoff, erosion, and SRP transport up to 13%. Traffic pattern had no effect on the transport of total P, TKN, NH4–N, or NO3–N. Regardless of treatment, total N loss never exceeded 0.2% of N applied as inorganic fertilizer. This research demonstrates that cover crop and equipment traffic pattern can be manipulated in reduced tillage systems to improve the sustainability of irrigated agriculture and ecosystem services in the mid‐southern United States.

Improving soil water storage with no‐till cover cropping in the Mississippi River Alluvial Basin

“…Many studies (e.g., Blanco‐Canqui et al., 2011; Daigh et al., 2014; Locke et al., 2015) showed that CCs can reduce runoff and sediment and nutrient loads from croplands. Other studies demonstrated that CCs reduce erosion, but not always loss of nutrients (Spencer et al., 2022). In the Mississippi Delta, Spencer et al.…”

“…In the Mississippi Delta, Spencer et al. (2022) reported no winter CC effect on runoff inception and volume during an irrigation event in maize, when compared to winter fallow for 3 years, suggesting that the rapid degradation of CC residue in humid subtropical climate may limit impacts on soil hydrology. Improved soil water storage with NT suggests that it may contribute to the long‐term sustainability of agriculture in this region, and conservation practices should be considered an integral part of cropping systems to offset irrigation demand during summer.…”

“…The WUE for winter pea was greater than for other CCs in the southern High Plains, owing to greater biomass production (DeLaune & Mubvumba, 2020). Spencer et al (2022) measured low runoff volume in irrigated maize planted after Austrian winter pea in the Mississippi Delta. Information is lacking as to whether Austrian winter pea CC reduces water availability for following cash crops in a humid environment.…”

“…Many studies (e.g., Blanco-Canqui et al, 2011;Daigh et al, 2014;Locke et al, 2015) showed that CCs can reduce runoff and sediment and nutrient loads from croplands. Other studies demonstrated that CCs reduce erosion, but not always loss of nutrients (Spencer et al, 2022). In the Mississippi Delta, Spencer et al (2022) reported no winter CC effect on runoff inception and volume during an irrigation event in maize, when compared to winter fallow for 3 years, suggesting that the rapid degradation of CC residue in humid subtropical climate may limit impacts on soil hydrology.…”

“…Spencer et al. (2022) measured low runoff volume in irrigated maize planted after Austrian winter pea in the Mississippi Delta. Information is lacking as to whether Austrian winter pea CC reduces water availability for following cash crops in a humid environment.…”