No-tillage and conventional tillage effects on durum wheat yield, grain quality and soil moisture content in southern Italy P. De Vita a,c, * , E. Di Paolo b , G. Fecondo b , N. Di Fonzo c , M. Pisante d a ENEA, Italian National Agency for New Technology, Energy & Environmental, Trisaia Research Center, S.S. 106 Jonica, Km 419.5-75026 Rotondella, MT, Italy b CO.T.IR., Consorzio per le Tecniche Irrigue, 66054 Vasto, CH, Italy c Experimental Institute for Cereal Research, Section of Foggia, 71100 Foggia, Italy d Department of Food Sciences, Crop and Soil Sciences Section, University of Teramo, Via Spagna, 1, 64023 Mosciano S. Angelo, TE, Italy Received 28 May 2004; received in revised form 10 January 2006; accepted 27 January 2006 Abstract No-tillage (NT) is becoming increasingly attractive to farmers because it clearly reduces production costs relative to conventional tillage (CT). However, many producers in southern Italy are reluctant to adopt this practice because NT can have contrasting consequences on grain yield depending on weather conditions. The effect of NT and CT on continuous durum wheat (Triticum durum Desf.) under rainfed Mediterranean conditions was studied, over a 3-year period (2000–2002) at two locations (Foggia and Vasto) in southern Italy. Yield, grain quality [thousand kernel weight (TKW), test weight (TW) and protein content (PC)] and soil water content were assessed. Higher yield was obtained with NT than CT in the first 2 years at Foggia. In contrast, mean yield and quality parameters at Vasto were similar for the two treatments, except in the third year in which CT produced more than NT (4.6 Mg ha 1 versus 2.9 Mg ha 1 ). At Foggia, TW and TKW were higher in NT than CT in all years. Highest PC was obtained under CT (19.6% and 15.5% for CT versus 14.7% and 11.4% for NT, respectively, in the growing season 2000–2001 and 2001–2002) indicating that grain was shriveled with low starch accumulation. At Foggia, where this study was part of a long-term experiment started in 1995, a strong correlation was observed between yield and rainfall during the wheat growing season. The coefficient of determination (R 2 ) values for CT and NT were 0.69 * and 0.31 ns, respectively, and the regression straight line crossed around 300 mm of rainfall. These results indicate that NT was superior below this rainfall value, whereas more rainfall enhanced yield in CT. We conclude that NT performed better at Foggia with limited rainfall during the durum wheat growing season. The superior effect of NT in comparison to CT, was due to lower water evaporation from soil combined with enhanced soil water availability. # 2006 Elsevier B.V. All rights reserved. Keywords: No-tillage; Conventional tillage; Durum wheat; Yield; Grain quality; Soil water content 1. Introduction Durum wheat (Triticum durum Desf.) is the main cereal crop in Italy, with >1.6 Mha producing about 4 Tg per year. Production is concentrated in southern and central Italy (the two Italian macro areas under the European cereal subsidy regime) and it has high variability in terms of yield and grain quality. The factors most strongly influencing crop yield, particu- larly grain yield, are soil moisture and N, the former of which depends on rainfall and its distribution during the growing season (Cooper et al., 1987). Typically in www.elsevier.com/locate/still Soil & Tillage Research 92 (2007) 69–78 * Corresponding author. Tel.: +39 0835 974541; fax: +39 0835 974749. E-mail address: pasquale.devita@trisaia.enea.it (P. De Vita). 0167-1987/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.still.2006.01.012