Soil type affects forage shrub feed quantity more than feed quality

Andrew P. Smith, Audrey Ropp
CSIRO Agriculture, Waite Campus

Key Messages
• Modelling shows that leaf biomass can amount to 1.5–3 t ha–1 for common saltbush and 4–6 t ha–1 for Eyres saltbush at the start of autumn each year
• Edible biomass production on the swale soils was about half of the biomass on the dunes
• Considering the data reported previously, the sampling produced some surprising results – with plant material being more nutritious for livestock,
• Old Man Saltbush (Eyres Green and DeKoch) and Malle Saltbush contained similar metabolisable energy of 9-10 Mj/kg
• No shrub type has dry organic matter digestibility greater than 60%
• There were no significant variations in feed energy value plant nutritional characteristics due to plant size or soil type (landscape location) over the site
• Forage shrubs offer scope for strategic use as a source of protein to complement metabolisable energy provided by other feedstuffs,
• The next step is to test how the inter row can be best managed to ensure optimal livestock production from forage shrub plantations.