Corn productivity and profitability in raised stale seedbed systems with and without cover crops

Abstract

Cover crops are promoted for reducing the negative environmental effects of high‐input row‐crop production; however, cover crop adoption in the mid‐southern United States is low, partly because of a perceived increase in risk. The objective of this research was to determine if cover crops cost‐effectively improved the productivity and water use of corn (Zea mays L.) in raised stale seedbed systems. The effects of four cover crops, namely 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.), in a raised stale seedbed environment on corn grain yield, net returns, and water use efficiency (WUE) were investigated at Stoneville, MS, on a Commerce very fine sandy loam soil (fine‐silty, mixed, superactive, nonacid, thermic Fluvaquentic Endoaquept). A cover crop preceding corn maintained or decreased yield, net returns, and WUE. Cover crops had no effect on corn grain yield in any year, except for 2017, in which Austrian winter pea and cereal rye decreased yield by 37 and 45%, respectively. Tillage radish never affected net returns; however, the inclusion of Austrian winter pea, crimson clover, or cereal rye reduced net returns by up to 57% in two of four years. Cover crops either maintained or decreased WUE by up to 44%. In the 4 yr of this research, the inclusion of a cover crop in a raised stale seedbed system only maintained or decreased corn grain yield, net returns, and WUE.

Effects of conservation practices on rainfed maize yield, furrow water infiltration, and soil moisture for surface sealing loam soils in the Yazoo‐Mississippi Delta

“…The previous winter pea treatment in Spencer et al. (2021) did not improve maize yield during any year from 2017 to 2020, so the subsequent PAM treatment in the present study is unlikely to have inherited any hidden advantages. For 2022 in the present study, the first PAM application occurred shortly before intense rainfall, and maize yield was not significantly different between PAM and CT. Perhaps the timing and method of PAM application can alter its impact on crop yield.…”

“…Wesley (1998) discussed the challenges in an NT system, which requires more attention to increased weed pressure due to the absence of tillage. Spencer et al (2021) found that cover crops grown in a subhumid climate did not boost maize yield in any of the 4 years of the study. This may be attributed to nitrogen (N) availability issues, seed-bed conditions, and fast cover crop decomposition due to early termination.…”

“…The field had been precision land formed to a 0.2% slope along the crop row direction. The present rainfed experiment was superimposed on the irrigated experiment of Spencer et al (2021), with a randomized complete block design that included eight blocks and six treatments. Each of the treatments is described in Table 1.…”

“…However, there are limited data about the potential increase in infiltration or soil water content due to these conservation practices. Examples of practices previously examined in the Mississippi Delta region include polyacrylamide (PAM; McNeal et al, 2017), cereal rye (Secale cereale L.) cover cropping (CR; Bryant et al, 2020;Spencer et al, 2021), furrow diking (FD; Bryant et al, 2019), subsoiling (SS; Pringle et al, 2017;Rix et al, 2022;Tupper, 1977), and no-till (NT) conservation (Spencer et al, 2021).…”

“…In the Mid‐South United States, conventional tillage (CT), consisting of more than one tillage operation per growing season, is still practiced widely for row crop production (Spencer et al., 2021; Wesley, 1998). The loamy soils in the Mississippi Delta region contain a high percentage of silt whose aggregates are easily disturbed by tillage.…”