S13 - Session O1 - Biomass production of five cover crops in relation with some soil-quality indicators and colonization by arbuscular mycorrhiza fungi

Authors: Sundoss Kabalan *, Borbála Biro, Katalin Juhos, Eszter Toth

Growing Cover Crops (CC) is considered an excellent way to enhance health of soils, usually done in the off-season. Production of leaving biomass on the field in order to provide lots of benefits for the agroecosystem, including reduction of erosion, controlling potential pathogens in addition to managing nutrients in soil. Cover crops are used to improve efficiency of added fertilizers whether they are organic or mineral by increasing biological activity of soils. Our examinations were carried out in pot experiments in a greenhouse designed with five CC species, selected on the basis of single-, double- or non-symbiont plants: Phacelia tanacetifolia (P.t.), Brassica carinata (B.c.), Vicia faba (V.f.), Avena strigosa (A.s.), Vicia benghalensis (V.b.). A mixture of the five species was also used, placed in sandy soil (Arenosol) in plastic pots in 4 repetitions. We measured soil biological activity, which may be the first step toward healthy soils. We evaluated soil electrical conductivity (EC) and NH4-N and NO3-N which are considered an indicator of soil fertility. The mixture of all CC tended to have the highest EC activity. The frequency (F%) of arbuscular mycorrhizal fungi (AMF) infection was good in all CC except mustard (B.c.), which is known to be a non-symbiotic plant. Double symbiont vetch responded the most positive way to inoculation with AM fungi. AMF are known to enhance phosphorus uptake and growth performance of host plant. CC with better symbiotic performance proved to be important in maintaining soil quality and aggregation (secondary structure) stability. Vetch (V.b.) was found to have the highest capacity to maintain glomalin concentration, followed by the cover crop mixture. Mineral N-status of soil was improved by used CC, as we saw for oat (A.s.), and mustard (B.c.). Oat showed a significantly higher amount of ammonium fixation than other crops. Benefits of mycorrhizal symbiosis could be realized more particularly in the secondary structure of the used soil in this study.