CONSERVATION SYSTEMS RESEARCH FOR IMPROVING ENVIRONMENTAL QUALITY AND PRODUCER PROFITABILITY
Location: National Soil Dynamics Laboratory
Title: Evaluating Soil Compaction for an Annual Winter Grazing/Vegetable Production Rotation in North-Central
Submitted to: Southern Conservation Agricultural Systems Conference
Publication Type: Abstract Only
Publication Acceptance Date: July 20, 2009
Publication Date: July 20, 2009
Citation: Raper, R.L., Balkcom, K.S., Reeves, W.D., Schwab, E.B. 2009. Evaluating Soil Compaction for an Annual Winter Grazing/Vegetable Production Rotation in North-Central [abstract]. In: Reiter, M.S., editor. A Multidisciplinary Approach to Conservation. Proceedings of the 31st Southern Conservation Agricultural Systems Conference, July 20-23, 2009, Melfa, VA. p. 47-48.
Degraded soils of Alabama have demonstrated the ability to respond well to conservation tillage in a large variety of crops. Winter annual grazing/sod-based rotations with summer vegetable production can offer reduced economic risks for producers but may change tillage requirements for vegetable production. More information is needed to know if current conservation tillage methods are compatible with winter annual grazing vegetable rotation systems. A 3-year field study was conducted on a Wynnville fine sandy loam, in north-central Alabama to evaluate soil compaction in vegetable production systems after winter annual grazing. In the fall, all plots were planted to ryegrass [Lolium multiflorum (L.)] and grazed from early December to mid-April at a stocking rate of 2.7 cattle per acre. After grazing, a rotation of sweet corn [Zea mays, (L.)], southern field pea [Vigna unguiculata (L.)], and watermelon [Citrullus lanatus (L.)] was established. All three crops were grown simultaneously in a factorial arrangement of three surface tillage treatments (chisel/disk/level, disk/level & no surface tillage) and three deep tillage treatments (no deep tillage, in-row subsoiling & paratilling) in a randomized complete block design with four replications. Soil strength measurements were taken using a tractor-mounted multiple-probe soil cone penetrometer to evaluate the level of soil compaction in all of the plots.
In-row cone index values near the soil surface peaked greater than the critical 300 psi root limiting value for the strict no-till plots (no surface/no deep tillage) in all three crops. In-row subsoiling and paratilling without surface tillage were equally effective in reducing cone index values to the tillage depth (16 in). Surface tillage (chisel/disk/level and disk/level) without deep tillage reduced the in-row cone index values at the peak (2 to 4 in) but had little effect on cone index values below this depth. Yields for all three crops responded differently to tillage treatments. Maximum corn yield was achieved with the combination of both deep tillage and surface tillage. Southern field pea yields increased with surface tillage (chisel/disk/level and disk/level) two of the three years although deep tillage had no effect. Watermelon yields were not affected by surface tillage but in two of the three years in-row subsoiling had greater yields compared to no deep tillage. Soil compaction problems from winter annual grazing can be reduced by either surface tillage and/or deep tillage.