Use of capital fertiliser and lime to improve pasture production in Northland.

摘要

Previous research in Northland (New Zealand) identified the requirements for phosphate and lime in pasture development. Large capital inputs were necessary (1.8-2.0 t superphosphate and 2.5-5 t lime/ha in the first 12-18 months). More recently (1990-1993) three trials have been conducted on typical unimproved or improved hill country pasture to investigate lime (rates and frequencies) and phosphate (rates and forms) requirements. Results show that inputs of both fertilizer and lime are still very necessary in Northland. Marked responses occurred in the trials, with an average 40% increase to P and 16% increase to lime. The need for a soluble fertilizer like superphosphate was highlighted. In practice the aim must be to get as much of the potentially high producing land as possible into the soil test ranges for maximizing pasture production. Improvement programmes need to be tailored to the individual farm. In dairying, improvement programmes can be completed relatively quickly (1-2 years) given the current economic situation, but in hill country the programme must of necessity be longer term (4-5 years). Emphasis must first be on developing the land with the highest potential. In time, areas with lower productive potential can also be consideredfor improvement, although alternative sustainable land use options should also be considered.