Arbuscular mycorrhizal fungi in the soil using cover crops with and without nitrogen addition

Abstract

This study aimed to evaluate the occurrence of mycorrhizal fungi and glomalin content in soil under different cover crops with and without the application of nitrogen in the cover. The following cover plants were used: Crotalaria juncea (Crotalaria juncea L.), wild beans from Ceará (Canavalia brasiliensis Mart. ex Benth.), Guandú ‘BRS mandarin’ [Cajanus cajan (L.) Millsp.], millet ‘BR05’ [Pennisetum glaucum (L.) R.Br.] and sorghum ‘BR 304’ [Sorghum bicolor (L.) Moench]. The absolute control of the experiment was the treatment without the use of cover crops, that is, the vegetation of spontaneous occurrence in the area. The experimental design was randomized blocks in subplots with three replications. Spore density, mycorrhizal colonization rate, easily extractable glomalin, and species present in the rhizosphere of the cover crops were determined. No differences were found in the diversity of mycorrhizal fungi associated with the different cover crops studied or in the values of spore density, root colonization, or glomalin content. Nitrogen application did not influence the mycorrhizal activity in the investigated cover crops. The most frequent species associated with cover crops were Scutellospora pellucida and Scutellospora persica in C. juncea; Gigaspora sp. on Sorghum; Glomus macrocarpum in Guandu; G. macrocarpum and Glomus clavisporum in millet; and Glomus microaggregatum and Glomus tortuosum in Spontaneous Vegetation.

Conservation Tillage in Medicinal Plant Cultivation in China: What, Why, and How

“…Soil inversion tillage destroys fungal hyphae and negatively influences AMF production of glomalin protein [97]. Even after three years of the NT system, aggregate and glomalin t values were considerably lower as compared to values from continuous pasture for 15 years.…”

“…The methods of conservation tillage are becoming increasingly diverse as standardized approaches have to be tailored to fit local conditions. In the NT system of many places, soil vegetation cover brings plentiful benefits, e.g., erosion protection, intake of organic material into the soil, nutrient cycling, and maintenance of an ideal microclimate for microbial development [97]. In Brazil, Crotalaria juncea, wild beans, Cajanus cajan, millet 'BR05', and sorghum 'BR 304' were used as cover crops cultivated after the corn crop.…”