| Summary: | Poster In the twenty-first century, climate change, caused by the rising concentrations of CO2 and other greenhouse gases, leads agriculture to apply techniques for reducing its emissions and to contrast the changed conditions. In such a context, perennial forage cropping systems would increase the capacity to store large amounts of C in the soil and therefore agroforestry represents one of the most important tool. The agroforestry systems can be realized by planting trees on cropping lands or introducing herbaceous plant species in forests or orchards with the aim to increase the global pasture area. Trees can store CO2 like organic carbon in their woody tissues and can also reduce the risk of soil erosion as they cover the ground for almost all the year and they reduce the speed of the wind (water and wind erosion, respectively). In addition, during the warm season the canopy shadow of the trees can create a cooler microclimate for grazing and a diurnal shelter for the livestock. The aim of the present study was to evaluate the sustainability of agro-silvo-pasture systems under Mediterranean conditions in order to produce new knowledge about the productivity and the nutritive value of under canopy meadows. Poplar plantations (Populus deltoides Marsch, var. Dvina) and olive orchads (Olea europea L.) were identified as agro-silvo-pasture systems. The poplar plantations are in the Natural Park of Migliarino San Rossore Massaciuccoli (Pisa, Italy), while the olive orchards in Manciano (Grosseto, Italy). The soil of the poplar trial is a loam with subalcaline pH. The trial followed a randomized block design with two shadow treatments (shadowed and non-shadowed), eight pure plant species and three mixtures and four replicates. Plant species were: five legumes (Medicago sativa L., Trifolium repens L., Hedisarium coronarium, Onobrychis viciifolia Scop., Trifolium brachycalycinum Katzn et Morley), and three grasses (Dactylis glomerata L., Lolium perenne L., Bromus catharticus Vahl) and three mixtures (M. sativa and Dactylis glomerata; T. repens and L. perenne; B. catharticus and O. viciifolia). The poplar plantation layout is 6 x 6 m. The soil of the olive orchad trial is a clay-loam with sub-alkaline pH. The olive orchad systems followed the same experimental design as above. Plant specie were: M.sativa and a six perennial species meadow composed by three grasses (D. glomerata, Festuca arundinacea L., B. catharticus) and three perennial legumes (O. viciifolia, T. brachycalycinum, M. sativa). The layout of the olive orchads is 10 x 5 m, equivalents to 200 plants per hectare. The plots of both trials were sown on March 2014. During 2014 the forages will be harvest using the modified Corral method in order to assess the curves of growth and re-growth of the different species and mixtures. It is important to highlight that for assessing the curve of re-growth of each plant species and therefore to simulate their management in an alley-cropping system model when each species will reach the boot stage we will totally harvest the plots. Then, in the further harvest, we will mow without returning the portion already harvested. The harvest will be carried out at the same sward height and in a surface of one square meter for each replicate. The period of harvest will start at spring and will finish at the end of the growing season, at regular intervals of about 15 days. The nutritive value will be determined using several parameters such as the crude protein, the fiber quality and the in vitro digestibility by anaerobic batches.
|
|---|