Leucaena feeding systems in Argentina. I. Five decades of research and limitations for adoption

Alejandro Radrizzani,Alejandro Perticari,Nahuel A Pachas,Cristina Goldfarb,Dante Pueyo,Santiago Lacorte,Luis Gándara

doi:10.17138/tgft(7)381-388

Abstract

Keynote paper presented at the International Leucaena Conference, 1‒3 November 2018, Brisbane, Queensland, Australia.This review describes the history of research in Leucaena leucocephala (leucaena) feeding systems carried out by the National Institute of Agricultural Technology (INTA) over the last 5 decades and discusses the main limitations resulting in poor adoption in Argentina. Leucaena was introduced in the subtropical region of the north of the country in the late 1960s and early 1970s. Since then, INTA has conducted research to evaluate forage and animal productivity, leucaena accessions, rhizobial strains, contribution to soil carbon and total nitrogen and density effects on competition and other ecosystem interactions in silvopastoral systems. In spite of the convincing research results showing the excellent potential of leucaena to increase forage quality and animal production in suitable areas, there has been poor adoption of this forage tree legume on a broad scale.

Highlights

In the subtropical region of the north of Argentina, livestock feed mainly on pastures and grasslands dominated by grasses, which are deficient in protein for most of the year.Leucaena leucocephala has excellent potential to increase forage quality and animal production in suitable areas for its growth (Goldfarb et al 2005; Radrizzani and Nasca 2014)
This review describes the history of research in Leucaena leucocephala feeding systems carried out by the National Institute of Agricultural Technology (INTA) over the last 5 decades and discusses the main limitations resulting in poor adoption in Argentina
Experiments involving forage and animal productivity have shown that leucaena has excellent potential to increase animal production in areas suitable for leucaena in the subtropical region of northern Argentina

Summary

Introduction

In the subtropical region of the north of Argentina, livestock feed mainly on pastures and grasslands dominated by grasses, which are deficient in protein for most of the year. During 3 consecutive winters (May‒September 1981, 1982 and 1983) on a cattle farm located in ‘Empedrado’, Corrientes province (27o54'41.25" S, 58o44'47.81" W; 71 masl; MAR 1,350 mm), Gándara et al (1986) compared LWGs of heifers and cows grazing native grasslands with access to protein banks of leucaena cv. On the Experimental Farm located in the southeast of Formosa province (MAR 1,150 mm) in the years 1980, 1981, 1983, 1987, 1988 and 1989, Roig (1992) studied LWGs of weaner and yearling steers grazing Pangola grass pastures or Pangola grass with 10% of area as a leucaena protein bank. In another study to evaluate the effectiveness of naturalized rhizobia, Eöry et al (2010) collected soil samples from 28 sites in northeast Argentina (Corrientes, Chaco and Formosa provinces), where leucaena had been growing for up to 50 years since establishment They found little or no presence of nodulating rhizobia in these soils, though some of the naturalized rhizobia were more effective than the control strain CB81 (Eöry et al 2010). The low radiation available under high density (2 m inter-row spacing) limits grass growth but moderate density (4 m inter-row spacing, 40,444 plants/ha) allows an efficient combination with grasses that produces an adequate fiber:protein balance in available forage

Limitations to adoption

Findings

Conclusion