Innovative crop and weed management strategies for organic spinach: crop yield and weed suppression

In organic agriculture, it is important to tackle crop and weed management from a system perspective to make it effective, especially in poorly competitive crops such as vegetables. For that reason, we developed two innovative integrated crop and weed management systems for a field vegetable crop sequence in a commercial organic farm that we have been comparing to a standard farm system from 2006 to 2008. The three systems are applied to a spinach-potato-cabbage-tomato two-year crop sequence and include different levels of technical innovation: Standard Crop Management System (SCMS); Intermediate Crop Management System (ICMS); and Advanced Crop Management System (ACMS). ICMS is based on a sequence of physical weed management treatments, whereas ACMS also includes a subterranean clover (Trifolium subterraneum) living mulch. In this paper we analyse the results obtained on spinach (Spinacia oleracea) in terms of crop yield and weed suppression. Both innovative systems increased total spinach fresh weight yield compared to SCMS, despite higher weed biomass. In ACMS, total weed biomass decreased linearly with increasing biomass of the subterranean clover living mulch

Innovative crop and weed management strategies in organic spinach: machine performances and cultivation costs

Weed competition is one of the most serious problems in vegetable crops. Physical and cultural methods represent the only adoptable solutions in organic farming systems. A two-year (2006-08) on-farm research is being carried out to test innovative operative machines for physical weed control on a typical vegetable crop sequence in the Arno Valley (Pisa, Italy). In this work we present the first results, obtained on organic fresh market spinach (Spinacia oleracea). The new strategy is compared with the standard crop and weed management system, characterised by the use of biodegradable maize starch mulch, and with a system in which the use of improved physical methods is coupled with the use of a subterranean clover (Trifolium subterraneum) living mulch. Performances of the operative machines, labour time requirement and cultivation costs of the three crop and weed management systems are reported. The two innovative strategies showed interesting results, determining effective weed control and a significant reduction of costs for working and hand labour (-70%)

Leguminous cover crops: an important tool for improving resource use efficiency in organic arable cropping systems

Cover crops are one of the most effective tools for organic farmers to improve the efficiency of their agro-ecosystems, while also reducing economic costs and environmental problems. The choice and usefulness of a cover crop species strictly depend on its adaptability to specific climate and soil conditions, but also on its relationships with other species (crops and weeds) and on the quality of farm management. Nine different pure species and three species mixtures were cultivated for two years as winter cover crops in a rainfed stockless arable organic cropping system as part of the MASCOT long-term experiment. Leguminous cover crops showed the highest level of biomass production in both years. Hairy vetch (Vicia villosa), either in pure stand or in mixture with grasses, was the most productive and stable species, and had the highest N uptake (ca. 200 kg ha-1). Besides, leguminous species significantly increased the content of N (up to 100%) and P (up to 50%) in weeds and associated grass crops, probably as a result of increased nutrient availability in soil through root exudates