Clover can and does meet all the nitrogen requirements of pastures growing as much as 20 tonne of DM/ha annually with minimal impact on water quality. <em>Photo: Supplied.</em>
Flat easy contoured land with rich black topsoil has always commanded a price premium over steeper country with lower carrying capacity.
Currently most farms operate on small financial margins and the extra freight cost from ports and main centres for those in remote areas is significant. The lowest priced farms are in remote regions on steep country of modest fertility with basic housing, which is fine as stepping stone properties.
In short, things are cheap for a reason and experience has taught us that paying a premium for high quality land, products, or services, nearly always provides best value in the long term. And yet the fertiliser models used by farm consultants are based on the lowest cost per kilogram of nutrient. Inherent in that is the theory that all nutrient performs the same regardless of the form in which it is provided.
Phosphorus is an example. The superphosphate manufactured here in New Zealand was developed to meet both essential phosphorus and sulphur requirements. Initially the rock used was from Nauru and Christmas Islands and cheap by today’s standards. Due to the marked increase in pasture and total farm production its use was encouraged with subsidies available for remoter regions.
Today, phosphorus remains an essential input however there is little land that is phosphorus responsive as higher than maintenance inputs have been applied for many years.
Maintenance only is required and research at Lincoln University showed that, “In a well-designed system the addition of phosphorus can be minimised and set to match the true level of loss of P. In a typical sheep and beef operation this may be around 4 to 8kg P/ha and in dairying 10 – 16kg P/ha…”
Were the current soil fertility models to incorporate this information there would be little if any concern around the relatively high cadmium content in available rock. It also brings into focus the use of steady release direct application rock regardless of its solubility as there are compound fertilisers available for situations, such as for crop establishment, where there may be a benefit.
The argument then is whether superphosphate plants here are necessary given their age and location at or close to harbours. The cost-effectiveness argument may also be used for the manufacture of urea as there may be a long-term subsidy required given the availability and cost of local gas supply. The steadily increasing levels of Nitrate-N in groundwater also highlights environmental considerations of commonly used fertility models.
Clover can and does meet all the nitrogen requirements of pastures growing as much as 20 tonne of DM/ha annually with minimal impact on water quality. The driver of the alternative systems is calcium, and this country is well endowed with many high-quality deposits.
There’s a brave new world to be explored when the farming industry is prepared to break free from decades old nutrient input models based on lowest cost. And the benefits from making the changes necessary in a timely fashion before they are forced on us by offshore purchasers are numerous.
For more information call Peter on 0274950041.