Strip Tillage and Oat Cover Crops Increase Soil Moisture and Influence N Mineralization Patterns in Cabbage

Abstract

<jats:p>Strip tillage (ST) is a form of conservation tillage in which disturbance is limited to the crop rows while the rest of the soil remains undisturbed. Compared with conventional, full-width tillage (CT), ST may reduce tillage costs, protect soil from erosion, and benefit cool-season crops including cabbage (<jats:italic>Brassica oleracea</jats:italic> L. var. ‘capitata’) by improving water retention, reducing soil temperatures, and improving the synchrony of inorganic nitrogen (IN) supply with crop demand. Field experiments were conducted in 2010 and 2011 in central Michigan to assess the effects of tillage (CT vs. ST) and a preceding cover crop (none vs. oats, <jats:italic>Avena sativa</jats:italic> L. var. ‘Ida’) on soil temperature, moisture, N dynamics, and yields in transplanted cabbage. Oats were sown in April and terminated 2 to 3 weeks before cabbage transplanting in early July. In-row (IR) soil moisture, temperature, and IN content were assessed from transplanting until cabbage harvest in October. In 2010, IR soil moisture was higher season-long in ST compared with CT and in oat compared with non-oat treatments, but these effects were not detected in 2011. Tillage and oat residue had little or no effect on IR soil temperature. Shortly after tillage in both years, soil IN availability was greater in CT treatments without oats compared with both ST treatments and CT with oats. However, these differences dissipated after 3 to 4 weeks, and hypothesized improvements in N release patterns under ST were not observed. No differences in cabbage marketable yield were detected in either year, although the proportion of plants that produced a marketable head was lower in cover-cropped plots in 2010. These findings suggest that soil conservation and input savings potentially associated with ST production systems may be attained without a yield penalty. More research is needed to understand and optimize cover crop management in ST systems to realize potential benefits in N use efficiency, moisture retention, and soil temperature moderation.</jats:p>

Weed Ecology and Nonchemical Management under Strip-Tillage: Implications for Northern U.S. Vegetable Cropping Systems

“…ST has been shown to reduce fuel and labor costs, protect soils, and maintain crop yields in vegetable crops including sweet corn (Luna and Staben 2002;Luna et al 2012;Brainard et al 2012b), winter squash, snap beans (Bottenberg et al 1999;Brainard et al 2012a), carrots (Brainard and Noyes 2012), cabbage (Brassica oleracea var. capitata L.) (Haramoto and Brainard 2012;Hoyt et al 1996;Mochizuki et al 2007;Mochizuki et al 2008), garden cucumber (Cucumis sativus L.) (Lonsbary et al 2004;Wang and Ngouajio 2008), and broccoli (Brassica oleracea L. var. botrytis L.) (Luna et al 2012).…”

Impact of Tillage and Irrigation Management on Bell Pepper (Capsicum annuum L.) Grown in Organic and Conventional Production Systems

“…However, in the plastic mulch system, soil VWC, although numerically greater in the well-watered treatments, was not always significantly different when well-watered and water-restricted regimes were compared. Haramoto and Brainard (2012) reported a consistent increase in soil moisture levels in strip-tillage plots compared with conventional tillage; however, this was in bare-ground grown plants. It is typically accepted that plastic mulch can reduce evaporation, compared with bare-ground production (Lamont, 2005), which may change the dynamic of soil VWC in response to well-watered and water-restricted treatments compared with bare-ground systems.…”

“…Strip tillage, when used in vegetable crops, often relies on fall-planted cover crops in lieu of crop residues to provide soil coverage and prevent erosion during winter (Carrera et al, 2007). These cover crops, when killed the following spring, provide organic matter, which may lead to enhanced soil moisture content in the intercropped areas, potentially affecting yield (Haramoto and Brainard, 2012;Wagner-Riddle et al, 1997;Wilhoit et al, 1990). Haramoto and Brainard (2012) reported a consistent increase in soil moisture levels in striptillage-grown cabbage (Brassica oleracea L.) compared with conventional tillage, some of which was attributed to increased available water in the strip-tillage-grown plants.…”

“…These cover crops, when killed the following spring, provide organic matter, which may lead to enhanced soil moisture content in the intercropped areas, potentially affecting yield (Haramoto and Brainard, 2012;Wagner-Riddle et al, 1997;Wilhoit et al, 1990). Haramoto and Brainard (2012) reported a consistent increase in soil moisture levels in striptillage-grown cabbage (Brassica oleracea L.) compared with conventional tillage, some of which was attributed to increased available water in the strip-tillage-grown plants. In addition to enhancing soil moisture status, between-row mulches may provide weed suppression (Kong et al, 2009) and act as a source of organic matter and fertility, particularly in organic systems (Hoyt, 1992).…”

“…Previous research suggests that the success of strip tillage depends on the type of crop grown, production system, soil type, and soil moisture status. In addition, it has been shown that conservation tillage may enhance growth under water-restricted conditions due to the ability of crop residues to hold water in the soil (Haramoto and Brainard, 2012). An increase in organic matter that often accompanies strip tillage may also assist water in upward movement into the root zone through capillary action.…”