Abstract

GONZALEZ, Pedro J et al. Effect of inoculating the arbuscular mycorrhizal fungi (AMF) strain Glomus hoi-like on the response of Brachiaria hybrid cv. Mulato II (CIAT 36087) to organic and nitrogen fertilization. cultrop [online]. 2011, vol.32, n.4, pp. 05-12. ISSN 0258-5936.

The objective of this work was to evaluate the effect of inoculating the arbuscular mycorrhizal fungi (AMF) strain Glomus hoi-like on the response of Brachiaria hybrid cv. Mulato II (CIAT 36087) to organic and nitrogen fertilization. The experiment was carried out in the Pastures and Forages Station of the Genetic Breeding Enterprise “Niña Bonita”, located in Artemisa province, on a Lixiviated Red Ferralitic soil. Rates of 15 and 30 t of cattle dung ha-1, 30 t of cattle dung ha-1 combined with 150 kg N ha-1 year-1, 15 and 30 t of cattle dung ha-1 combined with 0, 75 and 100kg N ha-1 year-1 plus the inoculation of AMF strain Glomus hoi-like, and the corresponding controls without cattle dung or N, to establish eleven treatments, were assessed. These were distributed in a random block design with four replications. Cattle dung was uniformly spread on the plots and incorporated into the soil with the last plowing labor; the N fertilizer (urea) was applied in split dosages, distributed at sowing and after the each cut of the forage. G. hoi-like was applied trough a mycorrhizal formulation containing 25 spores g-1. The mycorrhizal formulation was applied at sowing by seed recovering method. Cattle dung improved the soil chemical properties when increasing its pH, organic matter and available P and K contents, and its effects was observed during the first two years after its application; the highest effects were observed with the application of 30 t ha-1. The inoculation of G. hoi-like combined with the application of 75 or 100 kg N ha-1 year-1 produced the highest mycorrhizal colonization percentages, visual density and spore density, so as dry matter (DM) nutrient contents and DM yields similar to those obtained with 30 t of cattle dung ha-1 plus 150 kg N ha-1 year-1 without inoculation. The effects of G. hoi-like inoculation on the mycorrhizal structures and on the reduction of both fertilizer dosages was observed during the first two years of the experiment. It was shown the possibility for reducing the dosages of cattle manure and N fertilizer for applying to Brachiaria híbrido cv. Mulato II cultivated in a Red Ferralitic soil without affecting the yields and the nutritive value of the forage, at least during the first two years of the pasture establishment, through the inoculation of AMF strain G. hoi-like.

Keywords : arbuscular mycorrhizal fungi; organic fertilization; N fertilization; Brachiaria.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )