Cover crops of foxtail millet ‘German Strain R’ [Setaria italica (L.) Beauv.] and cowpea ‘Iron & Clay’ [Vigna unguiculata (L.) Walp.] were grown as monocrops (MIL, COW) and mixtures and compared with a bare ground control (BG) for weed suppression and nitrogen (N) contribution when followed by organically managed no-till bulb onion (Allium cepa L.) production. Experiments in 2006–2007 and 2007–2008 were each conducted on first-year transitional land. Mixtures consisted of cowpea with high, middle, and low seeding rates of millet (MIX-70, MIX-50, MIX-30). During onion production, each cover crop treatment had three N rate subplots (0, 105, and 210 kg N/ha) of surface-applied soybean meal [Glycine max (L.) Merrill]. Cover crop treatments COW and BG had the greatest total marketable onion yield both years. Where supplemental baled millet was applied in 2006–2007, onion mortality was over 50% in MIL and MIX and was attributed to the thickness of the millet mulch. Nitrogen rates of 105 and 210 kg N/ha increased soil mineral N (NO3 – and NH4 +) on BG plots 2 weeks after surface application of soybean meal each year, but stopped having an effect on soil mineral N by February or March. Split applications of soybean meal could be an important improvement in N management to better meet increased demand for N uptake during bulb initiation and growth in the spring.
Emily R. Vollmer, Nancy Creamer, Chris Reberg-Horton and Greg Hoyt
Gregory Peck, Ian M. Merwin, Emily Vollmer and Kristine Averill
Apple growers in New York lack the tools to produce high quality fruit for the organic or IFP marketplace. We are systematically evaluating OFP and IFP systems for pest control efficacy, fruit and soil quality, environmental impacts, and economic sustainability, in an orchard of disease-resistant `Liberty' on M.9 rootstock. The OFP system follows USDA-NOP standards and the IFP system follows newly developed NY IFP standards. In the first year of this study (2004), both systems were equally productive, but variable costs for OFP were twice that of IFP, due to 11 kaolin applications, while returns were comparable. In 2005, OFP yields were 25% greater than IFP yields, but 30% of OFP fruit was unmarketable largely due to insect damage. This loss, plus small fruit size, resulted in OFP returns of $5432 per hectare, about half the IFP returns. With only four kaolin applications in 2005, OFP costs were $2437 per hectare, marginally greater than the $2083 per hectare costs for IFP apples. Harvest maturity indices were similar and peak fruit quality was attained in both systems in early Oct. In 2004, consumer panelists could not detect differences between fruit from the two systems, but in 2005 panelists rated OFP apples as sweeter, more tart, better flavored, and more acceptable overall. Antioxidant activity, total phenolics concentrations, and mineral content of apples were similar between systems in both years. Values for all essential plant nutrients, organic matter content, pH, and CEC were also equivalent in each system both years. Cultivation was likely responsible for lowering the bulk density, soil strength, and aggregate stability of the OFP top soil in 2005. While OFP remains very challenging, IFP can be implemented successfully in New York orchards.