Soil conservation tillage effects on yield and water use efficiency on irrigated crops in Central Italy

Despite possible agronomic and environmental benefits, the diffusion of soil conservation tillage systems in Italy is currently rather low. The aim of this study was to compare the performance of different soil tillage techniques, in an effort to identify suitable soil management options for irrigated crops in Central Italy. An experiment was carried out on maize and soybean from April to October in two consecutive years (1993 and 1994) in Maccarese (a coastal location near Rome). The systems compared were: conventional mouldboard ploughing (CT), minimum tillage, ridge tillage and no-tillage (NT). In 1993, actual crop evapotranspiration was measured throughout the growing season on NT and CT soybean, using a micrometeorological technique. No significant differences due to soil tillage were found for grain yield and yield irrigation water use efficiency (IWUEy), except for soybean in 1994, in which yields and IWUEy were 59 % higher on conservation tillage treatments compared with CT. In 1994 soybean yield water use efficiency was 10.1 and 9.5 kg ha(-1) mm(-1) for NT and CT respectively. The results suggest that the adoption of soil conservation tillage is feasible, for the specific cropping system, with equivalent or better performances as conventional tillage.