AgResearch is developing a new generation of ryegrass and clovers with better root structures which soak up more of the nutrients from fertiliser and animal effluent.
Scientist Jim Crush says the move is being driven by increasing concern that waterways are being degraded by effluent that drains off paddocks and into streams and rivers.
But he says there are other advantages to longer and more absorbent root structures.
Mr Crush says improved root systems will have improved drought tolerance.
He says hopefully it will allow a reduction in the phosphate fertiliser requirement of pasture systems which will substantially reduce the environmental footprint of agriculture.
Fertiliser is a major cost in farm budgets, so any reduction in the phosphate fertiliser requirement has a direct beneficial effect on farm budgets.
Mr Crush says field trials of the new ryegrass and clover breeds are set down for autumn next year.