SYMBIOTIC EFFICIENCY OF RHIZOBIA STRAINS WITH COWPEA IN SOUTHERN MARANHÃO

Thiago Palhares Farias,Ana Regia Alves De Araújo,Fatima Maria De Souza Moreira,Bruno Lima Soares

doi:10.1590/1983-21252016v29n311rc

Thiago Palhares Farias, Ana Regia Alves De Araújo + Show 2 more

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https://doi.org/10.1590/1983-21252016v29n311rc

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Abstract

ABSTRACT The objective of this study was to evaluate the symbiotic efficiency of three novel nitrogen-fixing bacterial strains with cowpea cv. BRS Guariba as forage. Two experiments were carried out in the field in Balsas and São Raimundo das Mangabeiras, MA, in a randomized block design with seven treatments and four replications: three novel strains efficient in symbiotic nitrogen fixation with cowpea (UFLA 3 -153, UFLA 3-154 and UFLA 3-164), two strains already approved as inoculants by MAPA (UFLA 3-84/SEMIA 6461 and INPA 3-11B/SEMIA 6462), and two controls without inoculation, with and without mineral N. Symbiotic efficiency of strains was determined by the number of nodules, nodules dry matter, shoot dry matter, relative efficiency, crude protein content and shoot N content. Strains UFLA 3-154 and UFLA 3-164 were the most efficient in Balsas, whereas UFLA 3-153 and UFLA 3-164 were the most efficient in São Raimundo das Mangabeiras. Strains UFLA 3-153, UFLA 3-154 and UFLA 3-164 were more efficient in symbiotic nitrogen fixation with cowpea than the strains already approved as inoculants UFLA 3-84 and INPA 3-11B in the climatic and edaphic conditions of southern Maranhão. UFLA 3-164 is the most efficient strain in this region.

Highlights

Cowpea [Vigna unguiculata (L.) Walp.] is a Dicotyledonea plant, which belongs to the Fabaceae family, and is an important protein source in food and feed (PADULOSI; NG, 1997)
Two experiments were carried out in the cerrado region of southern Maranhão, in soil classified as Dystrophic Red-Yellow Latosol (Oxisol), under no-tillage, at Fazenda Cajueiro, in Balsas (MA), and in soil classified as Dystrophic Yellow Latosol under conventional no-tillage, at the Federal Institute of Education, Science and Technology of Maranhão (IFMA), Campus São Raimundo das Mangabeiras (MA), between January and March, 2013
In the experiment carried out in Balsas, all the three new strains evaluated in this study (UFLA 3153, University of Lavras (UFLA) 3-154 and UFLA 3-164) were able to nodulate cowpea, and UFLA 3-154 and UFLA 3-164 presented the highest values for number of nodules, and were superior to those of the strains approved as inoculant in cowpea (UFLA 3-84 and INPA 3-11B)

Summary

Introduction

Cowpea [Vigna unguiculata (L.) Walp.] is a Dicotyledonea plant, which belongs to the Fabaceae family, and is an important protein source in food and feed (PADULOSI; NG, 1997). With 30 to 50 g kg-1 of nitrogen in the dry matter, legumes species, such as cowpea, are used in rotation with other crops to protect the soil, reduce erosion, or as green manure to improve soil fertility and forage production rich in protein (TIMKO et al, 2007; KAMBASHI et al, 2014a). Cowpea plant is used as animal feed, supplementing the protein content in silage, which are mostly made up of grasses, improving the intake and digestion of low quality forages (OSAFO et al, 2013). Due to its dual purpose, after harvesting the grain for human consumption, cowpea plant is available for animal feed, becoming a low-cost forage as food supplement (KAMBASHI et al, 2014b)

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