Fertiliser for green farmers

Hawke's Bay fertiliser and lime company Hatuma Dicalcic Phosphate has attracted the interest of a large group of South Island farmers trying improve their environmental practices and protect their waterways.

Environment Canterbury has declared the Upper Waitaki region a red zone because the nutrient levels in the Ahuriri River are too high.

At a farm field day organised by Hatuma Dicalcic Phosphate, Environment Canterbury told farmers in the Ahuriri Valley the community wanted to see clean water in local rivers and streams, and farmers needed to better manage their nutrient application.

Environment Canterbury principal land management adviser Ian Lyttle commended hosting farmers Merv McCabe and Richard Gloag for leading the way with their farm practices, which included using Hatuma's non-water soluble fertiliser. "Merv and Richard are looking after their soil pH, managing their nutrient application and effluent to minimise nutrient loss," he said.

One of the biggest concerns for the community is the leaching of nitrate and the effect this has on waterways. Phosphate is less soluble than other fertiliser and is mostly lost where soil particles and effluent enter waterways.

McCabe and Gloag converted their 470ha property beside the river on protected Department of Conservation land three years ago. McCabe said: "We are aware of our environment so we do everything possible to protect the river.

"We use Hatuma Dicalcic Phosphate, which is just one way we reduce run-off. It's non-water soluble so it sits on the land and is absorbed by the grass."

It takes almost 300,000 litres of water to dissolve 100kg - it takes just 4160 litres to dissolve 100kg of superphosphate.

McCabe says fertiliser that dissolves quickly is "scary as you don't know where it goes".

"You don't want to lose what you are putting on for the sake of the environment and grass growth."

The Hatuma product had a double benefit because it stayed in the paddocks and therefore helped protect waterways, McCabe said. Hatuma marketing and sales manager Aaron Topp said the company was working with many Ahuriri Valley farmers to improve pasture quality and lower river nutrient levels. Farms in the Upper Waitaki region have light soils with excellent drainage so they are more susceptible to leaching, and Topp said the non-water soluble fertiliser was the best option for farmers who were conscious of protecting their waterways and wanted to maintain good production.

The McCabe and Gloag dairy farm produces 1690 milk solids per ha, well above the national average.