A trust set up to reduce nitrogen levels in Lake Taupo says it won't be buying any more farms.
The Lake Protection Trust was formed with Government and council funding to reduce nutrient run-off and seepage polluting the lake by 20%.
Over the past year and a half it has bought and resold more than a dozen farms in the catchment, converting them to low-nitrogen land uses.
But recently the sale of four properties, totalling 160 hectares, fell over, costing the trust millions of dollars.
Chief executive Graeme Fleming says the trust sold the four farms with strict land-use conditions (such as nitrogen restrictions) that the purchasers were unable to meet.
He says it is too expensive to buy and sell land, as the rural real estate market is too volatile.
Mr Fleming says the trust is nearly halfway to reaching its target of cutting nitrogen levels by 153,000kg per year by 2018.
Federated Farmers is upset that the Lake Protection Trust won't be buying any more farms.
Ruapehu president Lyn Neeson says some farmers were banking on the trust to provide them with a way out if they could not afford to farm under the area's new nitrogen discharge capping system.