The role of symbiotic interrelations in the availability of nutrients for five cover crops

Abstract

Biomass production of cover crops and relation with electrical conductivity (EC), soil glomalin content and the mycorrhiza frequency (F%). Cover crops (CC) serve as essential source of nutrients in the soil and improving of the soil properties. The production of cover crops is considered as a benefit of the soil quality; by protecting of the soil from erosion, reduce the weeds and the so-called soil-borne plant pathogens and increase soil biological activity. There are different varieties of cover crops that can be grown: such as legumes, non -legumes, brassica and grass-type of plants. Each of these cover crops have their own benefits to the soil system, the presence of cover crops helps in maintaining the nitrogen cycle as well as bolster the growth of nitrogen and phosphorus producing and/or solubilizing bacteria. Our examinations were carried out in pot experiments at MATE Buda Campus, in a heated greenhouse. The pot experiment was designed with five types of cover crops species (Phacelia tanacetifolia, P.t.; Brassica carinata, B.c.; Vicia faba, V.f.; Avena strigosa, A.s.; Vicia benghalensis, V.b.) and a mixture of the five species, placed in sandy soil (arenosol) in plastic pots in 4 repetitions. We measured soil biological activity, which can be the first step to achieve healthy soils. We assessed the saline content of the soils, i.e., the quantity of salts in the soil-plant environment. This parameter is considered as an indicator of soil health and fertility. Considering of the pot experiment the mixture of all the cover crops tended to show the maximum electrical conductivity quite significantly compared to the other cover crops. The formation of cover crops might support also the growth of the symbionts, such as the mycorrhiza fungi. Different plants can have variable interactions with the AM Fungi. We have measured the Frequency of mycorrhizal infection (F%). The percentage of mycorrhiza colonization was good in all CC except the mustard, B.c. (0%), which is known as a non-symbiotic plant. Wetch is responding positively to AM fungal inoculation. It is well known that the AMF has the ability to improve the uptake of the phosphorus (P) of the hosting plants as well as the performance of its growth (Finlay 2008). The hyphae of arbuscular mycorrhizal fungi produce a protein called glomalin. The glomalin concentration along with the cover crop can be very important in maintaining the soil quality and the aggregation-stability. It was found in the pot experiment, that the vetch (V.b.) has the highest capacity to retain glomalin concentration followed by mustard (B.c.) and the mixture of cover crops. Further aim is to test the benefits of mycorrhiza symbiosis and interrelation with their “helper” bacterial community in the secondary structure of soil.