Economic assessment of plantain (Plantago lanceolata) uptake in the New Zealand dairy sector

Pasture-based dairy production is associated with nitrogen-leaching losses to water. The New Zealand (NZ) Government has recently focused on regulating these losses through a broad-ranging policy package. Nitrogen (N) limits under this proposed legislation are stringent, dictating that around 40% of dairy farms must reduce their leaching, on average, by 42%. This study employed comprehensive economic models to account for the farm-, sector-, and national-level impacts of different levels of adoption of narrow-leaved plantain (Plantago lanceolata). This alternative forage species holds substantial promise for reducing the risk of N leaching from dairy farms. Model output indicated that total NZ dairy profit was higher each year by 1, 1.6, 2.5, and 4.3% under the policy package if 10, 20, 30, and 45% of pasture intake by dairy cows consisted of plantain, respectively. Further, national economic output increased by $277 m, $396 m, $526 m, and $979 m, under the policy package if 10, 20, 30, and 45% of pasture intake consisted of plantain, respectively. These represent increases in national economic output of 0.08, 0.11, 0.15, and 0.28%. Modelled outcomes emphasise the potential value of plantain, given the scarcity of low-cost mitigation options compatible with NZ dairy systems. Further, they indicate the significant return accruing to investment in further plantain research to aid successful implementation on farm.