Messiga, Aime J., Sharifi, Mehdi, Hammermeister, Andrew, Gallant, Kyle, Fuller, Keith, and Tango, Martin
The effects of cover crop mixtures combined with organic and industrial wastes on selected soil properties were assessed in a vineyard in Eastern Canada. The experimental treatments were randomly arranged in a nested design with three replicates. Four alleyway cover crop mixtures [control with no cover crop (CONT), oats + pea + hairy vetch (OPV), oats underseeded with red clover (ORCl), and timothy + alsike + red clover (TM)] were applied to main plots. Five fertility treatments [fertilizer without N (NDEF), full synthetic fertilizer (FERT), wood ash (WA), municipal solid food waste (MSFW), and mussel sediment (MS)] were assigned to sub-plots. Changes in selected soil quality (0–15 cm) were assessed at the beginning of the growing season (May 9, 2011 and April 28, 2012), at bloom in early-July (July 06, 2011 and 2012), and at harvest in late-October (October 31, 2011 and October 20, 2012). At bloom, soil mineral N was 23.56 kg ha −1 for OPV and 20.68 kg ha −1 for ORCl, but only 16.38 kg ha −1 for CONT and 12.53 kg ha −1 for TM. At harvest, soil mineral N was 21.95 kg ha −1 for ORCl, but only 15.43 kg ha −1 for OPV and TM and 9.10 kg ha −1 for CONT. Soil mineral N was mainly in the form of NO 3 − –N until bloom, but at harvest majority of soil mineral N was consisted of NH 4 + –N. After one year of experiment, the three organic and industrial amendments maintained greater soil pH (7.34 for MSFW and 7.35 for WA) and Mehlich-3 extractable P (399 kg P M3 ha −1 for MSFW and 333 kg P M3 ha −1 for WA) compared with FERT (pH 7.17; 306 kg P M3 ha −1 ) and NDEF (pH 7.12; 288 kg P M3 ha −1 ) treatments. After two years of experiment, the combination of cover crop × amendment improved soil organic-C by 8.8% and 10.6% and -N by 8.1% and 9.8% compared with amendment alone and cover crop × FERT treatment, respectively. Potentially mineralizable N estimated by UV-absorbance of NaHCO 3 extraction was greater under ORCl (0.79 abs) compared with the other cover crops (0.69 abs). The microbial biomass C was 205 kg ha −1 under MSFW and 212 kg ha −1 under WA, but only 168 kg ha −1 under NDEF, 125 kg ha −1 under FERT. The combination of cover crops and organic or industrial wastes provide comparable soil mineral N supply and available P with fertilized treatments while improving soil physical and biological properties and overall soil quality in this vineyard production system. [ABSTRACT FROM AUTHOR]