Crop and Soil Response to Organic Management Under Mediterranean Conditions

Abstract

Organic agriculture can contribute to maintain the long-term sustainability of the agroecosystems, preserve and improve soil quality and guarantee good quality food products. The objective of this study was to investigate the effects of different organic fertilizers and a biostimulant on crop performance and soil properties. The research was performed in an experimental farm in Southern Italy and covered a 2-year rotation of lentil and durum wheat for a period of 4 years. An organic commercial fertilizer and a compost, obtained from municipal wastes, with and without a commercial biostimulant, were compared in a randomized complete block design. The results showed that compost, as the only nutrient source, did not significantly decrease lentil and wheat grain yields, even though, in 2011 and 2012, wheat grain quality was better with the organic commercial fertilizer. Probably, the mineralization rate of compost, depending also on environmental conditions, and, consequently, the nutrient availability was not enough to meet the needs of wheat crop. Biostimulant significantly increased the straw yield of lentil by 20% and the weight of 1000 seeds of wheat by 4%. At the end of the experiment, the compost, applied at low doses, significantly increased soil TOC content (+ 3.4%) compared to the organic commercial fertilizers. Conversely, the biostimulant seemed to have no effect on the soil properties. Overall, under the local Mediterranean conditions, the compost may be used as an alternative nutrient source, with positive effects for lentil and wheat productivity, economic sustainability and soil fertility.