Cover Crop Mixtures Do Not Use Water Differently than Single‐Species Plantings

Abstract

Recent recommendations advocating the use of cover crop mixtures instead of single-species in semi-arid environments require rigorous scienti c studies. One of those stated bene ts is greatly reduced water use by cover crops grown in mixtures. e objectives of this study were to characterize soil water extraction patterns and determine water use of cover crops grown in singlespecies plantings and in a 10-species mixture and to compare cover crop water use to evaporative water loss from no-till fallow.e study was conducted at Akron, CO, and Sidney, NE, during the 2012 and 2013 growing seasons on silt loam soils. At each location there were a dryland treatment and an irrigated treatment. Soil water contents were measured by neutron scattering and time-domain re ectometry at six depths (0.0-1.8 m, Akron) or four or ve depths (to 1.2 m or 1.5 m, Sidney). ere were no consistent signi cant di erences in soil water contents or growing season crop water use with the single-species plantings compared with the 10-species mixture. Cover crop water use (216 mm) averaged 1.78 times greater than evaporative water loss (122 mm) from the no-till fallow treatment with proso millet (Panicum miliaceum L.) residue. ere appears to be no evidence from data collected in this semi-arid environment, even when irrigated to simulate higher rainfall environments, to support the conclusion that cover crops grown in multi-species mixtures use water di erently than single species-plantings of cover crops.

Cover Crop Effects on Corn Plant Sap Flow Rates and Soil Water Dynamics

“…Cover crops can reduce available soil‐water reserves for the following cash crop (Nielsen et al, 2015). In contrast, CC also can increase the soil water budget by decreasing evaporation, improving water infiltration, and increasing soil OM content (Dabney et al, 2001; Rawls et al, 2003).…”

“…Despite numerous benefits of CC, growers are reluctant to use CC because of concerns about reduced soil water for the following cash crop (Basche et al, 2016). Actively growing CC can reduce available soil water for the next cash crop (Blanco‐Canqui et al, 2015; Nielsen et al, 2015). However, CC also reduce water losses by increased water infiltration and reduced runoff (Blanco‐Canqui et al, 2012).…”

“…reduce available soil water for the next cash crop (Blanco-Canqui et al, 2015;Nielsen et al, 2015). However, CC also reduce water losses by increased water infiltration and reduced runoff (Blanco-Canqui et al, 2012).…”

Integrating Historic Agronomic and Policy Lessons with New Technologies to Drive Farmer Decisions for Farm and Climate: The Case of Inland Pacific Northwestern U.S.

“…However, water is a major limitation in the iPNW and existing research with single-and multi-species cover crops in eastern Washington and in semiarid eastern Colorado (Nielsen et al, 2015) has not found agronomic and economic benefits (Thompson and Carter, 2014;Roberts et al, 2016).…”

Increasing the Accuracy and Automation of Fractional Vegetation Cover Estimation from Digital Photographs

“…Four separate crops (seeding rates and row spacing given in parentheses) were included in the analysis: corn: Zea mays L. The oat, rapeseed, and flax data were collected from field studies conducted at the United States Department of Agriculture, Agricultural Research Service (USDA-ARS) Central Great Plains Research Station (40˝09 1 N, 103˝09 1 W, 1383 m elevation above sea level) located near Akron, CO, USA [33]. The crops were planted no-till into proso millet stubble on 4 April 2013.…”