Timing Effects of Deep Tillage on Penetration Resistance and Wheat and Soybean Yield

Abstract

In many southeastern Coastal Plain soils, subsoil pans have strengths that restrict root growth. To reduce strengths, soils are deep tilled annually, and perhaps biannually for double cropping. We evaluated the effect of deep tillage in fall, in spring, or at both times on strength of a Goldsboro loamy sand (fine loamy, siliceous, thermic Aquic Kandiudult) and on the yield of wheat (Triticum aestivum L.) and drilled soybean [Glycine max (L.) Merr.] in a double‐cropped system. Treatments consisted of all combinations of surface tillage (disked and not disked) and deep tillage (no deep tillage, paratillage before wheat planting, before soybean planting, and before both) in four replicates. Soil strengths, measured as cone indices, showed that disked, non‐deep‐tilled treatments resulted in a pan at the 20‐ to 30‐cm depth, generally associated with an E horizon. In more recently and more frequently deep‐tilled treatments, mean profile cone indices were 0.31 to 0.36 MPa lower than treatments not deep tilled or deep tilled for the previous growing season. If soil was deep tilled only once a year, it was 0.26 MPa softer when tilled only in spring than when tilled only in fall. Deep tillage at the beginning of either season reduced soil cone indices and improved wheat and soybean yields over other treatments. Deep tillage at the beginning of both seasons maintained the softest soil. For every megapascal decrease in mean profile cone index, wheat yields increased 1.5 to 1.7 Mg ha−1 and soybean yields increased 1.1 to 1.8 Mg ha−1

Alternative Management Practices for Water Conservation in Dryland Farming: A Case Study in Bijar, Iran

“…Deep plowing with subsoiler has similar characteristics to that of the chisel plow, but the only difference is the plowing depth. Studies have shown that deep tillage system can improve soil physical properties including decreased bulk density, infiltration rate and hydraulic conductivity, increased soil moisture in soil profile and yield under dryland production (Busscher et al, 2000;Busscher et al, 2002;Busscher et al, 2006;Laddha and Totawat, 1997;Motavalli et al, 2003b;Nitant and Singh, 1995) . Conservation tillage is the recommended method which helps to retain the crop residues in the soil surface at the same time conserves the soil and water (Sow et al, 1997).…”

Geoestatística e atributos do solo em áreas cultivadas com cana-de-açúcar

“…Dentre os atributos físicos utilizados para avaliar a compactação do solo, a resistência do solo à penetração e a densidade do solo têm sido atualmente priorizadas para avaliar sistemas de uso e manejo, por serem atributos diretamente relacionados ao crescimento das plantas e de fácil e rápida determinação (BUSSCHER et al, 2000). Além, a resistência do solo à penetração apresenta maiores correlações com o crescimento radicular (STOLF, 1991), destacando-se como a melhor estimativa do impedimento mecânico ao crescimento radicular e como um indicador mais sensível à compactação do solo (SERAFIM et al, 2008).…”

Soil resistance to penetration and least limiting water range for soybean yield in a haplustox from Brazil

“…Water infiltration, porosity, bulk density (D b ), and soil resistance to penetration (PR) are some of the physical attributes that are used to characterize soil compaction. Nowadays, PR is considered the most indicative attribute of soil compaction in management systems (Busscher et al, 2000;Beutler et al, 2001). This is because it is directly related to plant growth (Letey, 1985) and shows a strong relationship with plant root growth (Hoad et al, 2001).…”