Winter Rye as a Cover Crop Following Soybean under Conservation Tillage

Abstract

rye cover crop following soybean to increase the amount of winter and spring surface residue cover prior to plant-Use of a winter rye (Secale cereale L.) cover crop following soybean ing and during the seedbed and establishment phase of [Glycine max (L.) Merr.] has been shown to reduce the soil erosion potential in a corn (Zea mays L.)-soybean rotation system, but little the corn year. They demonstrated that regardless of is known about the effect of rye on residual soil NO 3 -N (RSN). An tillage management or rate of N application, planting a irrigated field study was conducted for 4 yr on a Sharpsburg silty clay winter rye cover crop following soybean increased the loam (fine, smectitic, mesic Typic Argiudoll) to compare crop rotation total surface residue cover by 30% over soybean alone. and winter rye cover crop following soybean effects on RSN underThe combined surface cover obtained from soybean and several tillage practices and N fertilization rates. Treatments each year rye residues was equivalent in cover and persistence to were (i) tillage: no-till or disk; (ii) rotation: corn following soybean/rye that provided by corn residue. Increased residue cover (Cbr) or soybean/rye following corn (BRc), corn following soybean reduced the risk of soil erosion until development of a (Cb) or soybean following corn (Bc), and corn following corn (Cc); protective corn canopy, without adversely affecting corn and (iii) N rate: 0, 100, and 300 kg N ha Ϫ1 (applied to corn). Rye in grain yield. the Cbr/BRc rotation was planted in the fall following soybean harvest and chemically killed in the spring of the following year prior to corn Research indicates that in addition to affecting surplanting. Each spring, before tillage and N application, RSN was face residue cover, a winter rye cover crop can also determined to a depth of 1.5 m, at 30-cm intervals. The net springinfluence the dynamics of N cycling (Ditsch and Alley, to-spring change in RSN between subsequent spring seasons was 1991). Planting a winter rye cover crop following corn computed for each plot, and annual aboveground N uptake for rye,in a no-till system reduced spring NO 3 -N accumulation corn, and soybean were determined. Rye, rotation, N rate, and tillage in soil due to N uptake by rye (Ditsch et al., 1993; significantly influenced RSN in the top 1.5 m of soil. The presence Shipley et al., 1992). Early-spring rye is usually killed of rye (BRc) reduced total spring RSN between 18 and 33% prior and its residues returned to the soil before planting corn.to corn planting in 2 of the 3 yr, compared with the no-rye system When these residues decompose, significant changes in (Bc), as rye immobilized from 42 to 48 kg N ha Ϫ1 in aboveground soil NO 3 -N can occur due to mineralization of N from dry matter. Recycling of N in high-yielding rye cover crop residues led to an increase in RSN accumulation after corn in the succeeding rye residue. This may cause a build-up of NO 3 -N in soil spring. Up to 277 kg RSN ha Ϫ1 accumulated at high rates of N following 643

Soil-profile distribution of inorganic N during 6 years of integrated crop-livestock management

“…These results confirm several reports of lower soil nitrate-N content at various locations in the soil profile under NT compared with CT (Angle et al, 1993;Dou et al, 1995;Kessavalou and Walters, 1999).…”

“…This compares with 78 AE 67 kg N ha À1 within the 0-120-cm profile of a Typic Hapludult in Pennsylvania (Dou et al, 1995), 143 AE 51 kg N ha À1 Table 2 Soil nitrate (NO 3 )-N as affected by tillage (CT, conventional tillage and NT, no tillage), cover crop management (ungrazed and grazed), and soil-profile zone (0-40 cm is the upper rooting zone, 40-90 cm is the lower rooting zone, and 90-150 cm is below the typical rooting zone) at the end of 1, 2, 3, 4, and 6 years of evaluation. within the 0-150-cm profile of a Typic Argiudoll in Nebraska (Kessavalou and Walters, 1999), and 457 AE 176 kg N ha À1 within the 0-210-cm profile of Udic Argiustoll/Udertic Paleustoll in Oklahoma (Raun and Johnson, 1995). Rate of change in soil nitrate-N content varied significantly by cropping system and tillage regime, and to a much lesser extent cover crop management (Table 3).…”

“…Soil-profile nitrate-N content under no tillage (NT) was 67 AE 14% of that under conventional tillage (CT) during the second year of a corn (Zea mays L.) production study with a diversity of cover crops and fertilizer rates in Pennsylvania (Dou et al, 1995). During yearly measurements of a 3-year study in Nebraska, nitrate-N content was nearly equal (5 AE 26 kg N ha À1 lower) under NT as under CT in the surface 0-90-cm depth, but was lower (23 AE 21 kg N ha À1 ) under NT than under CT in the 90-150-cm depth (Kessavalou and Walters, 1999). In Iowa, soil-profile nitrate-N content tended to be lower under NT than under CT, but leachate concentration of inorganic N at 120-cm depth was unaffected by tillage system (AlKaisi and Licht, 2004).…”

Cropping system and nitrogen dynamics under a cereal winter cover crop preceding corn

“…Decreases in total soil mineral N contents in the WCC plots indicated uptake of soil NO 3 -N into WCC bio- mass. Kessavalou and Walters (1999) observed that measured cereal rye N uptake was nearly equivalent to observed reductions in spring residual soil NO 3 -N. Similar soil NO 3 -N reductions with delay in kill date of cereal rye WCC were observed in both fertilized (early N split) and unfertilized (late N split) rye. However, the application of N-fertilizer during cereal rye growth (early N split) improved soil NO 3 -N content at planting across all kill date treatments.…”

Corn Nitrogen Fertilization Requirement and Corn-Soybean Productivity with a Rye Cover Crop

“…However, research has found differing annual crop yield responses with RCC. Corn grain and silage yield decreases have been reported with use of RCC (Raimbault et al, 1990;Kessavalou and Walters, 1997;Thelen and Leep, 2002;Singer and Kohler, 2005;McDonald et al, 2008;Kramberger et al, 2009;Salmerón et al, 2011;Krueger et al, 2012;Reese et al, 2014). A 15% corn yield increase was observed in 2 out of 3 yr in a study conducted on sandy soils in Wisconsin with no N application to the RCC and with low RCC biomass production .…”