Andrew Hoggard

Biography

I am an Equity owner/manager of a 300ha dairy farm north of Feilding in the Manawatu Province of New Zealand. Were we milk 550 cows.

I have a Bachelor of Applied Economics degree, majoring in Agricultural Economics, from Massey University, graduating in 1996.

Was a Grand Finalist in the Young Farmer of the Year contest in 2003 placing 7th , and regional runner up in 2008 for the Sharemilker of the Year contest.

I am currently the National Chairman of Federated Farmers Dairy Industry Group.

 

Abstract

The circular economy – Nitrogen leaching in pasture based systems

The dairy industry in New Zealand has undergone phenomenal growth over the last 20 years. As the industry has grown there has been an increasing focus on the impact of dairy on the New Zealand’s waterways, ranked by the OECD as the 2nd cleanest in the world. The target of that focus was initially cows walking in waterways, then it became how effluent from cowsheds was managed and has now focused on the loss of nitrogen from soil.

Nitrogen, along with phosphorus, promote nuisance algae growth in waterways and this algae makes waterways less attractive for recreation and impacts on the life supporting capacity of the waterway.

In pasture-based farm systems, Nitrogen loss is difficult to manage because unlike Phosphorus it is highly soluble, so when soils are wet, it will leach through the soil profile and into waterways.

In response to public concerns the industry has responded with significant investment in mitigation research and varied programmes to increase adoption of best practice nutrient management methods on farm. Most of these initiatives are detailed in the Sustainable Dairying: Water Accord, a 2013 industry agreement covering all New Zealand dairy farmers.

The key driver of N loss in New Zealand’s pasture-based systems are urine patches. When a cow urinates on pasture it deposits nitrogen at a rate equivalent to 1000 Kg/N ha. By comparison, Nitrogen fertiliser is applied at rates of 20-30 kg/N/ha, and cowshed effluent is applied at a rate of around 35kgN/ha. At these rates the nitrogen is more likely to be held in the rootzone and be utilised by the pasture.

The NZ government is progressively implementing strict environmental limits to protect our high quality waterways, with every region in the country required to have water quality limits by 2025. The challenge for the dairy Industry is to develop mitigation solutions that will work on farm, while ensuring we continue to utilise pasture-based systems.

For more information see http://www.dairynz.co.nz/publications/dairy-industry/sustainable-dairying-water-accord/


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