Evaluation of Urochloa decumbens cv. Basilisk in Response to Nitrogen Fertilization and Inoculation With Diazotrophic Bacterium

Alessandra Mayumi Tokura Alovisi,Luciene Kazue Tokura,Robervaldo Soares Da Silva,Willian Isao Tokura,Jucinei De Souza Fernandes,Gilson Domingos Do Mar,Waldenio Antonio De Araújo,Luana Gonçalves Perondi,Alves Alexandre Alovisi

doi:10.5539/jas.v10n12p458

Alessandra Mayumi Tokura Alovisi, Luciene Kazue Tokura + Show 7 more

Open Access

https://doi.org/10.5539/jas.v10n12p458

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Abstract

Nitrogen fertilization provides a great response in pasture productivity and quality but, after applied to the soil, this element undergoes several transformations, what increase its losses. To minimize this problem, a promising alternative currently suggested is diazotrophic bacteria use, which can contribute to a greater use of nitrogen by plants. This study aimed to evaluate the effect of nitrogen doses with and without inoculation of seeds with Azospirillum brasilense on the structural characteristics, chemical composition, and mass production of Urochloa decumbens cv. Basilisk. The experimental design was completely randomized, arranged in a 2 &times; 5 factorial scheme, with four replications. Treatments consisted of forage seed inoculation or not with Azospirillum and five nitrogen doses (0, 50, 100, 150, and 200 kg ha-1). The variables analyzed were plant height, number of tillers, shoot dry mass (SDM), root dry mass (RDM), SDM/RDM ratio, chlorophyll index, nutrient content in forage shoot, crude protein (CP), neutral detergent fiber (NDF), and nitrogen use efficiency. The inoculation of forage seeds with A. brasilense associated with nitrogen doses up to 100 kg ha-1 contributed positively to dry mass, plant-shoot nutrient content and bromatological composition of U. decumbens cv. Basilisk. The inoculation of seeds of U. decumbens cv. Basilisk, with A. brasiliense, is a viable alternative for partial substitution of nitrogen fertilization.

Highlights

In Brazil, nearly 180 million hectares have been grown with pastures, mainly grasses of the genus Urochloa (Dias, 2011)
The objective of this study was to evaluate the effect of nitrogen doses, with and without inoculation of the seeds with Azospirillum brasilense, on the structural characteristics, chemical composition, and mass production of Urochloa decumbens cv
The variables plant height, number of tillers, shoot dry mass, and root dry mass were described by an increasing linear model (Figures 1a, 1b, 1c, and 1d)

Summary

Introduction

In Brazil, nearly 180 million hectares have been grown with pastures, mainly grasses of the genus Urochloa (Dias, 2011). The state of Mato Grosso do Sul owns an area of 16 million hectares under pasture, about 50% of which are degraded due to the low system productivity, which compromises the economic potential of livestock (Holsback, 2016). A poor input of nutrients and, a decrease in soil organic matter stand out among the fertility decline factors. Among the alternatives for recovering soil fertility in grazing areas, nitrogen fertilization is one of the most important practices, but it is more difficult to manage (Vogel, Martinkoski, & Ruzicki, 2014) given the nitrogen dynamics in the soil, being a nutrient of low residual effect (Aguiar & Silva, 2005)

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