Strip Tillage and Compost Influence Carrot Quality, Yield, and Net Returns

Abstract

<jats:p>Management practices that build soil organic matter—including reduced tillage, cover cropping, and compost applications—may be useful for protecting vulnerable crops from extreme weather events, reducing energy costs, and suppressing pests in carrot (<jats:italic>Daucus carota</jats:italic> subsp. sativa) production systems. The primary objective of this research was to assess the effects of strip tillage, compost, and carrot cultivar on carrot quality, yield, and profitability. An important secondary objective was to evaluate the impact of tillage and compost on establishment of important weeds in carrot systems—including two species that have developed resistance to linuron: Powell amaranth (<jats:italic>Amaranthus powellii</jats:italic>) and common purslane (<jats:italic>Portulaca oleracea</jats:italic>). Field experiments were conducted in 2009 and 2010 comparing conventional tillage (CT) to strip tillage (ST) under two rates of mature compost addition (0 or 3 dry t·ha<jats:sup>−1</jats:sup>) for three processing carrot varieties (‘Canada’, ‘Finley’, and ‘Recoleta’). In the ST system, a pre-established barley cover crop was left to grow as a windbreak between crop rows until carrots were established. Partial budget analysis was used to estimate net returns associated with all treatments. Compared with CT, the ST system resulted in 1) either equivalent or greater (2010, Finley cultivar) total carrot yields and net returns; and 2) either equivalent or lower summer annual weed densities. Addition of compost resulted in equivalent (2010) or higher (2009) carrot yields and gross returns but did not affect net returns as a result of the increased costs associated with compost application. Compost reduced the density of common purslane in 2009 but resulted in a threefold increase in the density of Powell amaranth in 2010. Our results demonstrate that both ST and compost applications are potentially valuable tools for improving the profitability of carrot production systems. Future research examining the mechanistic basis for compost and tillage effects on carrots and weeds as well as the long-term effects of these practices on profitability of rotational crops would be helpful for optimizing their use in vegetable production systems.</jats:p>

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

“…For example, Barralis and Chadoeuf (1980) observed 12% total emergence of germinable weed seeds following tillage compared with 8% from undisturbed soil. Likewise, reduced emergence of weeds under ST, compared with CT, systems has been observed in pickling cucumber (Wang and Ngouajio 2008), carrot (Brainard and Noyes 2012), corn (Hendrix et al 2004), and cabbage (Haramoto and Brainard 2011).…”

“…When NT vegetable systems have been combined with cover crop residues to combat weeds, reduced yields or delayed harvest have been observed in crops including winter squash, zucchini (Cucurbita pepo L.) (Leavitt et al 2011), garden tomato (Solanum lycopersicum L.), and pepper (Capsicum annuum L.) (Leavitt et al 2011;Mochizuki et al 2007). NT cover cropintensive production systems are even more challenging in small-seeded crops like carrots, where a fine seed-bed is needed to successfully establish the crop (Brainard and Noyes 2012).…”

“…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). ST systems allow retention of cover crop or crop residues between crop rows, which can improve soil moisture retention (Haramoto and Brainard 2012;Hendrix et al 2004), provide windbreaks for vulnerable crops like carrot (Brainard and Noyes 2012) and sugarbeet (Beta vulgaris L.) (Overstreet 2009;Tarkalson et al 2012), reduce incidence of certain diseases (Wang and Ngouajio 2008), and in some cases, increase beneficial insects (Bryant et al 2012) and earthworms (Luna and Staben 2002;Overstreet et al 2010).…”

Cover Crop Mulch and Weed Management Influence Arthropod Communities in Strip-Tilled Cabbage

“…In strip-tillage systems, living or dead cover crop mulches can be retained between crop rows, whereas in-row areas are tilled to limit mulch interference with the crop and improve crop establishment (Luna et al 2012). Strip-tillage in combination with cover cropping can reduce agrichemical runoff or ground water contamination, improve soil quality, protect crops and soils from extreme wind and rain events, and reduce labor and fuel inputs, ultimately improving proÞtabil-ity although protecting the environment (Luna and Staben 2002, Potter et al 2008, Mulvaney et al 2011, Brainard and Noyes 2012, Luna et al 2012.…”