1. Performance of bushy forage legumes in dynamic smallholder pasture systems in the Eastern Amazon
Stefan Hohnwald1, Eliana M. Acioli de Abreu2, Jonas B. da Veiga3, Clemens B.A. Wollny1
1Institute of Animal Breeding and Genetics, Georg-August University of Göttingen
Kellnerweg 6, Göttingen, Germany,
2Universidade Federal Rural da Amazônia (UFRA), Animal Production, Belém-Pará, Brazil
³Embrapa Amazônia Oriental, Trav. Dr. Enéas Pinheiro s/n-Marco, CEP , Belém-Pará, Brazil
Introduction: In northeastern Pará, smallholders often use cattle just as a financial instrument on their diversified farms: they buy cattle if cash flows in from crop harvest, and sell them if cash is needed for investment (Figure 1). Thus, animal production systems become dynamic and inappropriate stocking rates are one reason for early pasture degradation.
Furthermore, most woody forage legume species show development problems if directly grazed on small-scale grass-legume pastures because appropriate management and the legumes’ need for sufficient recuperation time is often neglected. However, experience shows hat even overgrazed bushes rapidly recuperate if enough recuperation time is allowed afterwards.
Thus, we hypothesize that in the flexible smallholder pasture system, with both overgrazing and long-term recuperation time, the performance of woody forage legumes is higher than on a continuously used pasture and a well-managed grass-legume pasture.
Methods:
Treatment 1: Smallholder Pasture
7 days grazing at 6 AU; 35 days restoration time
Yearly manual pasture clearing
Treatment 2: Largeholder Pasture
7 days grazing at 3 AU; 14 days restoration time
Mechanical pasture clearing twice a year
Treatment 3: Well-Managed Pasture- Control (Researcher)
7 days grazing at 4 AU; 21 days restoration time
Manual pasture cleaning twice a year (Figure 2)
Figure 1. Scheme of cash income and investment on a smallholdings during the year, implementing low and high stocking rates on pastures
On-farm experiment at Igarapé-Açu (47º W/1º S)
0.5 ha Brachiaria brizantha pastures
Alternating lines of Cratylia argentea and
Flemingia macrophylla (Figure 2)
Plantation at 1.5 x 5 m distances (n=1800/ plot)
Legume fertilization at 40 kg P2O5/ha
Three replications at three different sites
Crossbred steers (185 kg liveweight)
Grazing starting in 02/2007
Legume establishment and development: bush
heights, relative growth performance, diameters,
biomass, consumption ratio, nodule production
Documentation of forage biomass and weed invasion
First Results:
Establishment of both tested legume species was unproblematic
Establishment of F. macrophylla was much faster than that of C. argentea
Discussion:
The study will show if bushy forage legumes are better adapted for smallholdings or for large farms
Knowledge of socio-economic studies about the realistic cash flow on smallholdings has yet to be integrated
Weed invasion of the three treatments and its effects on forage biomass production must be investigated
Figure 2. Scheme (above) and photo (below) of the experimental site with a line of six months old Flemingia macrophylla bushes.
This study is financed by the German Research Association- Deutsche Forschungsgemeinschaft (DFG)