Trees for timber with arable crops in Italy

The AGFORWARD research project (January 2014 - December 2017), funded by the European Commission, is promoting agroforestry practices in Europe that will advance sustainable rural development. This report, which focuses on "Trees for timber with arable crops in Italy" contributes to the second objective, to identify, develop and field-test innovations (through participatory research) to improve the benefits and viability of agroforestry systems in Europe. In turn the report will form part of Deliverable 4.11: "Lessons learnt from innovations related to agroforestry for arable farmers". Similar reports are available for agroforestry of high nature and cultural value, agroforestry with high-value trees, and agroforestry for livestock systems. We studied alley-cropping system established by incorporation of hybrid poplars and endemic oaks along the farm drainage ditches. Such a practice could enhance both financial and environmental value of the farmland. After four years, the height of the poplar trees in the alley cropping system were similar to poplars grown in a plantation system with medium to high soil fertility. During 2016 a double crop was grown of durum wheat and soybean. The greatest light interception by the trees, at a particular point of the arable crop alley, rose from 3% in 2015 to 14% in 2016. The levels of nitrogen isotope ?15N and carbon isotope ?13C were greater in the leaves of sugar beet than the poplar. The level of oxygen isotope ?18O was also higher in the xylem of the sugar beet than the poplar, indicating that the sugar beet was extracting more surface water than the tree. Those preliminary data of C, N and O stable isotopes denotes that poplar trees might intercept N leaching from crop alley, and tree and crops do not compete for soil moisture, using water from different soil layers.