title: Assessing the production and economic benefits from preventing cows grazing on wet soils in New Zealand.
abstract: BACKGROUND
  Intensive grazing by cattle on wet pasture can have a negative effect on soil physical quality and future pasture production. On a North Otago dairy farm in New Zealand, experimental plots were monitored for four years to assess whether preventing cow grazing of wet pastures during the milking season would improve soil structure and pasture production compared with unrestricted access to pastures. The DairyNZ Whole Farm Model was used to scale up results to a farm system level and ascertain the cost benefit of deferred grazing management.
  
  
  RESULTS
  Soils under deferred grazing management had significantly higher total porosity, yet no significant improvement in macroporosity (values ranging between 0.112 and 0.146 m(3)  m(-3) ). Annual pasture production did not differ between the control and deferred grazing treatments, averaging 17.0 ± 3.8 and 17.9 ± 4.1 t DM ha(-1) year(-1) respectively (P > 0.05). Furthermore, whole farm modelling indicated that farm operating profit was reduced by NZ$1683 ha(-1) year(-1) (four-year average) under deferred grazing management.
  
  
  CONCLUSIONS
  Deferring dairy cow grazing from wet Pallic soils in North Otago was effective in improving soil structure (measured as total soil porosity), yet did not lead to a significant increase in pasture production. Whole farm modelling indicated no economic benefit of removing cows from wet soils during the milking season. © 2016 Society of Chemical Industry.
authors.affiliation: AgResearch, Lincoln Research Centre, Private Bag, 4749, Christchurch, New Zealand.
authors.forename: Seth
authors.initials: S
authors.lastname: Laurenson
authors.affiliation: AgResearch, Ruakura Research Centre, Private Bag, 3123, Hamilton, New Zealand.
authors.forename: David J
authors.initials: DJ
authors.lastname: Houlbrooke
authors.affiliation: DairyNZ, Private Bag, 3221, Hamilton 3240, New Zealand.
authors.forename: Pierre C
authors.initials: PC
authors.lastname: Beukes
mesh_terms: D000821:Animal Feed / Q000191:economics; D000818:Animals; D002417:Cattle; D003247:Conservation of Natural Resources / Q000191:economics; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D003612:Dairying / Q000191:economics / Q000379:methods*; D005260:Female; D060434:Herbivory; D007774:Lactation; D008892:Milk / Q000191:economics / Q000378:metabolism*; D018803:Models, Economic; D009520:New Zealand; D016062:Porosity; D012621:Seasons; D012820:Silage / Q000191:economics; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000032:analysis*
chemical_list: D012987:Soil; D014867:Water
keywords: dairy; pasture utilisation; profitability; soil porosity; treading damage