ENVIRONMENT
5. CONCLUSIONS
The results of this study show that cover crop species and their residue management can strongly affect the weeds and the yield response in the following pepper crop. Oat was the most weed suppressive cover crop compared to canola and hairy vetch both throughout the cover crop growing period and in the following pepper crop regardless the different cover crop residue managements, probably due to its severe chemical and physical effects. The conversion of cover crop aboveground biomass in mulch strips in NT conditions was clearly the most effective weed management strategy compared to MT and CT especially when hairy vetch and oat were adopted. Even if the inclusion of an inter-row hoeing in the early growing stage of the pepper determined a strong weed reduction in all residue management treatments, it only proved to be a suitable weed control practice in NT, while in MT and CT conditions it may still be necessary to use additional means for controlling the weeds, such as herbicides or other tillage operations. Regardless cover crop management, hairy vetch determined a marketable pepper yield of about 40 t ha-1 of FM in weed-free conditions and in any case almost twice than canola and oat in presence of weeds. The use of canola and oat, as green manure or mulches, should be evaluated in fertilization programs to determine the amount of fertilizer required for obtaining a reasonable pepper yield. Therefore, the use of hairy vetch residues placed in mulch strips in NT system combined with an inter-row hoeing enable us to obtain a
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satisfactory weed control and pepper yield. The inclusion of legume cover crops in vegetable crop sequences in no-tillage systems could be a part of an ample strategy for reducing the amount of chemical inputs used both for controlling weeds and for N-fertilizing vegetable crops in the Mediterranean environment.
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