Integrated nutrition system with AMF, green manure and mineral fertilizers in Manihot esculenta Crantz

Abstract

In recent years the positive results of mycorrhizal inoculant application in different crops and their integration with the mineral fertilization schemes have increased. In order to establish an integrated plant nutrition system for the cultivation of Manihot esculenta Crantz, including also green manure and low doses of mineral fertilizer, two field experiments were carried out on Ferralitic Red Lixiviated Soils. In the first one, five levels of mineral fertilizer were studied, in the presence or not of the inoculation with the arbuscular mycorrhizal fungus Glomus cubense/ INCAM-4, in a random block design with factorial arrangement and four replicates. In the second, Canavalia ensiformis was introduced as a green manure, preceded and intercalated, and 12 treatments were studied, consisting of mycorrhizal inoculation or not of canavalia and cassava in the presence of a fixed fertilization fund of NPK corresponding to 25 % of fertilization recommended for cassava. Treatments with four doses of fertilizers (0, 25, 50 and 100 % NPK) were also included in a randomized block design with four replicates. The inoculation decreased the fertilizer quantities by 33 % in order to obtain high yields and increased its agronomic efficiency by 67 %, with the crop showing a good mycorrhizal function. The inclusion of the previous and intercalated inoculated canavalia decreased in another 33 % plus the amounts of mineral fertilizer, with a positive response to the intercalation in the yield (P <0,05 %) and doubling the agronomic efficiency of fertilizers.