Doses of phosphorus on initial development and forage production of cultivars of Panicum maximum

Francisco Eduardo Torres,Elisa Pereira De Oliveira,Larissa Pereira Ribeiro,Marcus Vinicius Morais De Oliveira,Caio Cezar Guedes Corrêa,Paulo Eduardo Teodoro,Carlos Antonio Da Silva Junior

doi:10.14393/bj-v32n6a2016-30196

Abstract

Phosphorus shortage in the Savanna is one of the main limiting factors for forage production and directly responsible for the degradation of pastures in this Brazilian region. Thus, the aim of this study was to evaluate the effect of increasing doses of P on the initial development and forage production of four cultivars of P. maximum . The experiment was conducted during the months of December 2010 to May 2011 at Universidade Estadual de Mato Grosso do Sul, Unit of Aquidauana-MS. It was used the completely randomized design in a factorial scheme 4x5, with four replications. The experimental unit consists of polyethylene pots with 5 L capacity arranged in countertop in greenhouse. The first factor consisted of four P. maximum cultivars (Massai, Mombaca, Aries and Atlas), while the second factor consists of five doses of phosphorus (0, 5, 10, 30 and 45 mg dm -3 ). It was evaluated the following morphometric traits: plant height, length and width of the leaf blade, number of tillers, dry mass of shoot and of roots at 60 DAS. The approximate dose of 25 mg dm -3 of phosphorus provided better initial development and forage production in all cultivars evaluated of Panicum maximum . Mombaca cultivar has better initial development and forage production about to the others.

Highlights

In Brazil, areas with pastures, native or cultivated, occupy around 180 million hectares, and of this total, it is estimated that 40 million hectares are in different stages of degradation (OLIVEIRA et al, 2014)
The first factor consisted of four P. maximum cultivars (Massai, Mombaça, Áries and Atlas), while the second factor consists of five doses of phosphorus (0, 5, 10, 30 and 45 mg dm-3), having as source the single superphosphate (18% P2O5, 16% CA and 8% S)
There was a significant interaction (p>0.05) among C x D for the traits plant height (PH), WLB and number of tillers (NT), which indicates that the different doses of P assessed differently influence the growth of each cultivar

Summary

Introduction

In Brazil, areas with pastures, native or cultivated, occupy around 180 million hectares, and of this total, it is estimated that 40 million hectares are in different stages of degradation (OLIVEIRA et al, 2014). The region of the Brazilian Savanna contains soils conducive to the establishment of pastures containing favorable physical characteristics, suitable topography and few climate limitations, in most cases, has limitations in relation to fertility, standing out among them the low pH and levels of nutrients, especially phosphorus (P) (BENÍCIO et al, 2011). Guedes et al (2009), claim that a major problem in establishing and maintaining pastures, on these soils, lies in extremely low levels of P available and P total. These authors add, beyond this natural poverty in P of our soils, the high adsorption capacity of this element, because of its acidity and high levels of iron and aluminum oxides. Arises the need to identify which species and / or cultivars are more responsive to phosphorus fertilization and which have better agronomic performance in low availability conditions of P

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Conclusion