Beneficial effects of biological soil crusts from the Monte desert on soils and grasses

ARANIBAR JULIETA; CORVALÁN VIDELA MARÍA ELENA; GRECO SILVINA

Exposici�n; Tarea Vida; 2018

Trabajo enviado para publicación en Plant and SoilAimsand background Biological soil crusts (BSC) are widespread in the Monte desert, with unknown effects on plants. BSCs, by fixing atmospheric N and retaining soil moisture, may enhance grass emergence, growth, and nutritional value. Our aim was to evaluate the effect of different functional types of BSC on soil moisture, nutrients, and grass properties.Methods We sowed Leptochloa crinita seeds in pots with different BSC types (cyanobacteria, squamulose phycolichens, squamulose cyanolichens, gelatinous cyanolichens, mosses) under two irrigation treatments: well watered and drought. We determined soil moisture, soil nitrate and phosphate at two depths; BSC total N, organic matter, ammonium, soil respiration, and δ15N; grass emergence, biomass, C/N, and δ15N. Results Different BSC types increased nitrate and moisture, and decreased phosphate contents at different soil depths. BSCs had higher respiration rates, total N and ammonium concentrations, δ15N values similar to atmospheric N2, and increased grass emergence, nitrogen content, and biomass.Conclusions BSC had positive effects on grass emergence, biomass and quality. The differential effects of BSC types on each variable, under drought and well watered irrigation, show the importance of biodiversity on ecosystems. Different organisms may complement to improve soils under fluctuating environmental conditions, and enhance grass growth.