Conventional soil management systems (SMS) use synthetic inputs to maximize crop productivity, which leads to environmental degradation. Organic SMS is an alternative that is claimed to prevent or mitigate such negative environmental impacts. Vegetable production systems rely on frequent tillage to prepare beds and manage weeds, and are also characterized by little crop residue input. The use of crop residues and organic fertilizers may counteract the negative impacts of intensive vegetable production. To test this hypothesis, we evaluated the effect of sweet corn (Zea mays L. var. rugosa) residue incorporation in a corn–cabbage (Brassica oleracea L.) rotation on crop yields, nutrient uptake, weed biomass and soil nutrients for organic and conventional SMS in two contrasting soil types (a Chromosol and a Vertosol). Yields of corn and cabbage under the organic SMS were not lower than the conventional SMS, possibly due to the equivalent N, P and K nutrients applied. Macro-nutrient uptake between the organic and conventional SMS did not differ for cabbage heads. Corn residue incorporation reduced the average in-crop weed biomass in cabbage crops by 22% in 2010 and by 47% in 2011. Corn residue-induced inhibitions on weed biomass may be exploited as a supplementary tool to mechanical weed control for the organic SMS, potentially reducing the negative impacts of cultivation on soil organic carbon. Residue incorporation and the organic SMS increased the average total soil N by 7 and 4% compared with the treatments without residue and the conventional SMS, respectively, indicating the longer-term fertility gains of these treatments. Exchangeable K, but not Colwell P, in the soil was significantly increased by residue incorporation. The clayey Vertosol conserved higher levels of nutrients than the sandy Chromosol. Yields under organic SMS can match that of conventional SMS. Residue incorporation in soil improved soil nutrients and reduced weed biomass.
History
Publication title
Renewable Agriculture and Food Systems
Volume
30
Pagination
132-142
ISSN
1742-1705
Department/School
School of Geography, Planning and Spatial Sciences
Publisher
Cambridge University Press
Place of publication
United Kingdom
Rights statement
Copyright 2013 Cambridge University Press
Repository Status
Restricted
Socio-economic Objectives
Assessment and management of terrestrial ecosystems