Economic and Agronomic Assessment of Deep Tillage in Soybean Production on Mississippi River Valley Soils

Abstract

soil. Planting of the crop over this low density slot is critical. These soils occur in the USA, primarily in the Using deep tillage to alleviate the adverse effects of deleterious soil Coastal Plains, and in other regions to a minor extent physical properties has been tried many times. Consistent economic returns have been reported for in-the-row subsoiling of loamy sand (Buol, 1973). and coarser soils and for deep loamy soils where the subsoil slit bisectsIn the Mississippi River alluvium region, for example, the water flow channel during rainfall events where there is runoff. yield responses to deep tillage were found for cotton Recent reports of yield responses on clayey soils and silt loams led to (Gossypium hirsutum L.) on deep silt loam or sandy a reassessment of subsoiling of these soils in Arkansas. A randomized loam soils (Spurgeon et al., 1978; Tupper and Spurgeon, complete block design was conducted at four locations with tillage 1981). This response differed from that of nonplastic treatments of conventional shallow, deep chisel, subsoil dry, subsoil soils in that no response was obtained from in-the-row wet, subsoil at 45؇ to planting direction, and paratill. Plots were harsubsoiling. The best results were obtained from deep vested for grain. Economic analysis was performed using the Missistillage in the fall, which left low-density slits that geometsippi State Budget Generator (MSBG). The machinery complement was commensurate with that found on farms in the region. Net returns rically intersected the low points between old seedling above total specified costs (NRAT) rather than above direct costs rows. The low points concentrate runoff water during were calculated to reflect the decision framework of a producer. A high intensity rainfall events. Thus, it appears that deep profitable yield response was obtained from subsoiling in dry soil on tillage here was promoting infiltration and subsequent deep alluvial clayey and silt loam soils but not on the thin loessial soil water storage in these deep silt or sandy loam soils. silt loams. Net returns to subsoiling wet were not significantly higher More recent studies (Keisling et al., 1998) using a paratill than those to conventional shallow tillage. Tillage with a chisel plow on a bedded system tended to provide consistently as deep as it could be operated (approximately 15 cm) was not a higher cotton yields than conventional tillage practices. substitute for subsoiling because yield responses from deeper tillage were not comparable. The 45؇ subsoiling in dry soil tended to be No consistent soybean [Glycine max (L.) Merr.] or superior to all other tillage treatments.

Tillage Depth Effects on Soil Physical Properties, Sugarbeet Yield, and Sugarbeet Quality

“…Many deep-tillage studies have been conducted, and only a few of them have been reported because of lack or inconsistency of yield responses to deep tillage (Popp et al 2001). Early studies presented conflicting results in terms of deep-tillage influences on crop yield.…”

Effect of Three Tillage Depths on Sugarbeet Response and Soil Penetrability Resistance

“…Many deep tillage studies have been conducted but only a few of them have been reported due to lack or inconsistency of yield responses to deep tillage (Popp et al, 2001; Jabro et al, 2010). Previous studies have shown conflicting results in terms of deep tillage effects on crop yield.…”

Deep and Shallow Fall Tillage for Irrigated Soybean Grown with Different Weed Management Systems in the Midsouthern USA

“…In nonirrigated studies where all tillage was performed in the late winter or early spring on Sharkey clay soil where the profile was wet beneath the dry surface, Heatherly (1981) measured soybean yields that were similar following either DT or following shallow, disk‐harrow tillage. Popp et al (2001) found that DT of wet clay soil in late winter or early spring in Arkansas resulted in net returns from nonirrigated soybean that were similar to those resulting from conventional ST. Thus, DT of wet clay soils in late winter or early spring was not effective in increasing net return.…”

“…T he ESPS (planting soybean in late March through late April compared with planting in early May and later) produces maximum yields in both nonirrigated and irrigated environments in the midsouthern USA (Heatherly, 1999a; Heatherly and Spurlock, 1999). Deep tillage (subsoiling) has enhanced dryland yields of both ESPS and later soybean plantings on some clay soils in the midsouthern USA (Wesley and Smith, 1991; Wesley et al, 1994, 2001; Heatherly and Spurlock, 2001; Popp et al, 2001; Heatherly et al, 2002) and on coastal plain soils in the southeastern USA (Frederick et al, 1998).…”

“…Studies on Sharkey clay in Arkansas (Popp et al, 2001) and Mississippi (Wesley et al, 2001) showed average yield increases of 580 and 365 kg ha −1 , respectively, and average increases in net return of $96 and $71 ha −1 , respectively, from fall DT preceding nonirrigated soybean production. In the Arkansas study, yields following fall DT were significantly greater than those from conventional tillage even though drought was not severe.…”