Long term effects of withholding phosphate application on North Island hill country: Ballantrae

Results from fertiliser cessation experiments at Ballantrae, Te Kuiti and Whatawhata, on yellow-brown earths, were used to evaluate the fertihser cessation compared to continued application on hill country breeding ewe systems. At Balhmtrae, on farmlets previously receiving 125 kg superphosphatelhalyr, continued fertiliser application generated a positive cash flow after 8 years. On farmIets previously receiving rates of 200-375 kg superphosphatelhalyr positive cash flows were generated by continued fertihser application after 4, 5 and 6 years at Te Kuiti, Whatawhata and Ballantrae respectively. Fertiliser cessation is a sound strategy to survive periods of low product price:fertiIiser cost ratio. However, it will decrease sustainable productivity and hence farm resale value. Fertihser recommendations cannot remain constant over time but must consider: animal enterprise, product and fertibser price, soil P status, and level of pasture utihsation.