EFECTO DE LA ADICIÓN DE COMPOST SOBRE PROPÁGULOS MICORRÍCICOS ARBUSCULARES EN UN SUELO VOLCÁNICO DEL CENTRO SUR DE CHILE

legume, cereal, organic agriculture, arbuscular mycorrhiza. ABSTRACT Organic amendments affect the chemical and biological characteristics of soils rganic amendments affect the chemical and biological characteristics of soils contributing to the sustainability of agroecosystems. The aim of this study was to evaluate in glasshouse conditions the effect of compost addition in an Ultisol on fungal propagules such as those colonized in the roots, mycelium and spores, together with soil chemical and nutritional characterization of three crops (wheat, beans and grass) after harvesting. Compost was based on cattle and vegetables waste and it was supplied into the soil at 0, 8, 20 and 30 Mg ha -1 on dry bases. Roots from all crops presented high arbuscular mycorrhizal fungi (AMF) colonization with the highest amount, while the hyphal length was significantly different only in beans crop. There were not significant differences for the spore numbers. The highest production of dry matter in beans and grass was reached with the highest compost supplied but in wheat this was true for the middle amount of compost. Similar results were obtained for the content of phosphorus (P) in the shoot. Compost application incremented the availability of P in the Ultisol for the three crops. It was concluded that compost application to the three crops studied was beneficial because the high viability of mycorrhizal propagules together with the great amount of phytomass and soil nutrients availability.