Winter cover crops on processing tomato yield, quality, pest pressure, nitrogen availability, and profit margins

Abstract

Much of cover crop research to date focuses on key indicators of impact without considering the implications over multiple years, in the absence of a systems-based approach. To evaluate the effect of three years of autumn cover crops on subsequent processing tomato (Solanum lycopersicum L.) production in 2010 and 2011, a field split-split-plot factorial design trial with effects of cover crop type, urea ammonium nitrate fertilizer rate (0 or 140 kg N ha -1 preplant broadcast incorporated) and tomato cultivar (early vs. late) was conducted. The main plot factor, cover crop, included a no cover crop control, oat (Avena sativa L.), winter cereal rye (hereafter referred to as rye) (Secale cereale L.), oilseed radish (OSR) (Raphanus sativus L. var. oleiferus Metzg Stokes), and mix of OSR and rye (OSR + rye) treatments. Cover crop biomass of 0.5 to 2.8 and 1.7 to 3.1 Mg ha -1 was attained in early Oct. and the following early May, respectively. In general, OSR increased soil mineral N during cover crop growth and into the succeeding summer tomato growing season, while the remaining cover crops did not differ from the no cover crop control. The lack of a cover crop by N rate interaction in soil and plant N analyses at harvest suggests that growers may not need to modify N fertilizer rates to tomatoes based on cover crop type. Processing tomato fruit quality at harvest (rots, insect or disease damage, Agtron colour, pH, or natural tomato soluble solids (NTSS)) was not affected by cover crop type. In both years, marketable yield in the no cover crop treatment was lower or not statistically different than all planted cover crops. Partial profit margins over both years were 1320 $ ha -1 higher with OSR and $960 higher with oat compared to the no cover crop control. Thus, results from a systems-based approach suggest that the cover crops tested had no observed negative impact on processing tomato production and have the potential to increase marketable yield and profit margins.

Alternative Management Practices Improve Soil Health Indices in Intensive Vegetable Cropping Systems: A Review

“…Similarly in Brazil, vegetable yields were equivalent to or higher with cover crops vs. without (Altieri et al, 2011); in eastern Canada, growing cover crops in a tomato rotation resulted in greater crop profit margins (Belfry et al, 2017) and 7-22% greater crop yields (Chahal and Van Eerd, 2018) compared to conventional management without cover cropping. The yield benefits were likely due to soil nutrient credits provided from the mineralization of cover crop biomass prior to or during tomato production (Belfry et al, 2017). Further, the tomato yield benefits with vs. without cover crops in the crop rotation after 6-years were linked to 8.4-9.3% greater surface soil organic carbon concentrations (Chahal and Van Eerd, 2018).…”

“…Common cover crops included grasses (e.g., winter rye), legumes (e.g., hairy vetch, Austrian winter pea), brassicas (e.g., fodder radish), or mixtures of two or three of these types (Bending et al, 2004;Altieri et al, 2011;Belfry et al, 2017). Frequently, cover crops were planted following summer vegetable harvest with cover crop termination in the subsequent spring prior to planting.…”

“…Instances of reduced vegetable crop yields were largely associated with a very short period between cover crop termination and subsequent main crop planting (i.e., vegetable main crops were planted immediately upon cover crop termination), and where there was a marked shift in typical crop planting dates (i.e., a delay of 2-5 weeks after recommended planting dates) (Leavitt et al, 2011). In contrast, the studies which did not show yield penalties (Wyland et al, 1996;Altieri et al, 2011;Belfry et al, 2017) were within the window of typical planting dates but also incorporated a strategic 2 to 6-week period between cover crop termination and main crop planting, which likely improved synchrony between mineralization and crop nutrient demand without delaying recommended crop planting dates. Hence, carefully planning agronomic management of cover crop termination and the timing of subsequent vegetable crop planting may be a determining factor in the successful use of cover crops.…”

Cover crop and crop residue removal effects on temporal dynamics of soil carbon and nitrogen in a temperate, humid climate

“…Soil was tilled on May 19, 2015 and May 20, 2016 to incorporate CC residues and fertilizers and to prepare for tomato transplanting. At tomato transplanting, a starter N fertilizer (15 kg N ha -1 ) was applied with water [6,33]. No irrigation was applied to tomato crop.…”

“…Several benefits to agroecosystems have been observed with adoption of CC in crop rotations [6][7][8][9]. Improvements in soil physical [10][11][12], biological [2], and chemical [13,14] soil quality indicators are observed with CCs, which are highly dependent on the quantity and quality of CC biomass input to the soil [15].…”