Increasing Organic Matter and Biology in Pastoral Systems | Diverse Pastures

Over the next month we are going to write a series of posts about how to increase organic matter and biology in pastoral systems. This is a very important topic and one that can have huge implications on a farming system. The posts are going to focus on the following topics:

  • Diverse Pastures
  • Topping
  • Sabbatical Fallows
  • Compost
  • Targeted Biological Inputs

1. Diverse Pastures

We need diversity of species in our pastoral systems. This is very important because it this brings diverse root profiles to our underground ecosystem. 

Diverse roots bring diverse microbe populations and also bring increased efficiency in capturing volatile nutrients.

Recent studies of Grass species show

  • Cocksfoot, Phalaris and Browntop have double the root mass compared to Ryegrass (Popay and Crush 2010)
  • Overseas studies indicate, Tall Fescue and Prairie grass also significantly exceed the root mass of Ryegrass at depths of 100mm or more (Craine, et al 2002)
  • Popay and Crush (2010) also found a strong negative correlation between root mass and N leaching
  • Diverse species provide diverse root exudates, = more species of microbes (FAO 2004)

Diverse pastures containing up to five plant species were compared with perennial ryegrass-clover pastures in NZ

  • Dry matter production from diverse pastures was  comparable with that from standard pastures
  • Diverse pastures were less affected by water stress
  • Milk solids production from cows grazing diverse and standard pastures was similar.
  • The nitrogen concentration of urine and N excreted by cows was lower when grazing diverse pastures.
  • Diverse pastures may be a useful tool for reducing nitrate-N leaching while maintaining or increasing milk solids production

Ref.  Dairy NZ technical paper 14, Grant Edwards, Professor of Dairy Production, Agricultural Sciences Department, Lincoln University,