Spent Mushroom Substrates Influence Soil Quality and Nitrogen Availability in a Semiarid Vineyard Soil.

Two spent mushroom substrates (fresh, F-SMS, and composted in aerobic conditions, C-SMS) were annually applied for 4 yr at two different rates (8 and 25 Mg ha^-1 as dry matter) to a vineyard soil (Typic Haploxerept) located near Logroño (Ebro Valley, La Rioja, Spain). Soil samples were collected at three depths (0-5, 5-15 and 15-25 cm), and analyzed for soil organic carbon (SOC), water-soluble carbon (WSC), potentially mineralizable nitrogen (PMN), Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. and exchangeable Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. , microbial biomass carbon (MBC), soil C0₂ evolution (SR), β-glucosidase activity (CLU) and soil mean weight diameter (MWD) of aggregates and water-stable aggregates (WSA). The highest rate of F-SMS and C-SMS (25 Mg ha^-1) increased SOC, total nitrogen ( Total N), and labile organic forms (WSC and PMN) at 0- to 5- and 5- to 15-cm soil depth and microbiological activity (MBC and GLU) at 5- to 15-cm soil depth. There were no differences in soil C0₂ emissions between F-SMS and C-SMS amendments. Applications of SMS did not increase the soil aggregation but increased the content of inorganic N in the soil surface (0- to 5-cm depth) layer. Factor analysis showed the positive relationship between labile organic matter fractions and N availability. Finally, application of SMS to semiarid vineyard soils facilities SMS recycling with simultaneous improvement in soil quality indicators related to labile organic matter and microbiologic activity. However, increased PMN and soil Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed. indicate a potential risks for N leaching from SMS amendments that should be further evaluated. INSET: 1. [ABSTRACT FROM AUTHOR]