36th International Carrot Conference Abstract

STRIP-TILLAGE, COMPOST, AND PLANTING DENSITY EFFECTS ON CARROT QUALITY AND YIELD

Daniel Brainard, Corey Noyes and Rick Oomen

Biotic and abiotic stresses during carrot stand establishment can greatly reduce carrot quality and yield. Practices that increase soil organic matter including reduced-tillage, cover cropping, and compost addition may improve crop resilience to these stresses. In Michigan, processing carrot growers on sandy soils use pre-established barley or wheat cover crops combined with strip-tillage to provide wind-protection for vulnerable carrot seedlings while building soil health. The primary objective of this research was to assess the effects of strip tillage, compost on carrot quality, yield, and profitability. 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-¹) 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. 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.

Last updated Thursday, 25-Jul-2013 11:50:51 CDT