Comparison of organic and conventional managements on yields, nutrients and weeds in a corn–cabbage rotation

Abstract

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.

ESTUDO ETNOBOTÂNICO DE Libidibia ferrea (Mart. ex Tul.) L.P. Queiroz EM UMA COMUNIDADE RURAL NO MUNICÍPIO DE BOM JESUS – PIAUÍ

“…In contrast, Carvalho et al (2013), Menezes Júnior et al (2014), and Santos et al (2015) observed that the conventional system was superior to the organic system regarding the increase in carrot, onion, and green corn production, respectively. However, Bajgai et al (2013) reported that maize and cabbage yields were similar in both production systems.…”

Residue incorporation mitigates tillage‐induced loss of soil carbon in laboratory microcosms

“…The residue was ground to <4 mm and incorporated at 15 t/ha based on biomass production levels in a related field trial (Bajgai et al ., , ). The C/N ratio of the ground residue was 34:1 (42.1 and 1.25%, respectively).…”

“…Furthermore, it may have a relatively high economic value and is a compatible rotation crop in a vegetable enterprise. A laboratory study was conducted to separate the effects of residue incorporation and tillage on CO 2 ‐C emissions and soil C in an associated field trial that had a corn–cabbage ( Brassica oleracea L.) rotation (Bajgai et al ., , ). In that trial, tillage was used for weed control in the organic soil management system (SMS), whereas herbicide was used for weed control in the conventional SMS, and both SMSs received corn residue or not.…”

Molecules Best Paper Award 2015

“…The grain yield of maize was increased by 45% in the plots applied with barley mulch compared with the ones with no mulch (non-treated control) (Dhima et al, 2006). Similarly, the maize residues incorporated in an organically grown maize-broccoli rotation were found to reduce weed biomass in the following crop (broccoli) by 22e47% (Bajgai et al, 2013). The incorporated mulch also helped to improve the soil nutrient status.…”