Effect of spent mushroom compost on P and K fertilit in a vineyard soil of the La Rioja region (Spain)

C. Larrieta et al...Use of manures and organic wastes to improve soil quality and nutrient balancesAt present, 306.000 Mg of Spent Mushroom Substrate (SMC) are yearly produced in La Rioja region (Spain), the production of mushroom represents the second major activity in this region after vineyard farming. These SMC have been accumulated at opencast dumping sites, where lixiviation becomes in a serious contamination source for groundwaters. This organic waste, owing to its high organic matter (OM) content and appreciable amounts of essential plant nutrients as N, P, K, Ca and Mg, and could be exploited as a soil fertilizer and amendment to increase the OM content in vineyard soils which are generally low (< 1 %) in La Rioja region (Peregrina et al., 2010). However few information exits about the SMC utilization in vineyard with the agronomic conditions of the La Rioja region. For this we studied the effect of two different SMC (fresh and recomposted) with two different rates of dry matter (DM), as organic amendment (25 Mg ha-1.) and as fertilizer (8 Mg ha-1), in the P and K soil fertility.We thank the staff of the Laboratorio Regional (C.A.R), particularly to Mª Carmen Arroyo. Also we thank Susana Grijalba from the compost treatment plant of Pradejón, This work was supported by Consejería de Agricultura, Ganadería y Desarrollo Rural de La Rioja (PR- 04-07), Secretaría de Estado de Universidades e Investigación (M.E.C.), PROFIT (CIT-310200-2007-63) and Agencia de Desarrollo Económico de La Rioja (I+D 2006-I-ID-0053). Also was funding the investigation by FEDER and INIA.Peer reviewe