Background Both the economic and environmental benefits of using RPR as the source of phosphate on New Zealand’s soils have been deliberately understated by the fertiliser manufacturing industry in the past decade. With no significant independent importation and scientific promotion of RPR, farmers who want to keep using it have found it increasingly difficult to… [Read More]
New, must-read articles
2. How to define a true RPR
Background Any phosphate rock will release some P into plant-available form when applied to acid soils. The question is, in the pastoral context, will it release P at a sufficiently fast rate to maintain the needs of a high production pasture? Most phosphate rocks do not. Even if very large quantities are applied they still… [Read More]
3. Using RPR in low soil P, low rainfall, high pH
or extremely high P retention (>97% PR) situations
Background RPR is a natural, slow-release mineral formed on the sea floor over hundreds of thousands of years. Deposits that have been raised above sea level by changes in sea level or earthquakes are cheaper to mine. When RPR is applied to acid soils, the soil acid attacks the phosphate mineral, releasing plant-available P in… [Read More]
4. What every farmer should know about cadmium (Cd)
Background The cadmium (Cd) issue arose in New Zealand and Australia purely and simply because the manufacturing phosphate rocks both countries originally used to make superphosphate (Nauru and Christmas Islands) contained elevated levels (50-100 ppm) of Cd. All of this Cd ended up in the superphosphate, and therefore in the soil. Cd exists at low… [Read More]
5. The effect of the sulphur form used on the ratio of S to P required
Background Pasture plants need to take up 7 kg of sulphur (S) for every 10 kg of phosphorus (P). So, if both nutrients are being applied in reasonably efficient forms, a fertiliser containing 9% P should only need to contain 9×0.7 = 6.3% S. Near the coast, where there is significant input of sulphate in… [Read More]
Urine Patch Detection & Treatment with Spikey ® – Trial Results
LOW-COST DETECTION AND TREATMENT OF FRESH COW URINE PATCHES Geoff Bates1, Bert Quin1,2 and Peter Bishop2,3 1Pastoral Robotics Ltd, Auckland New Zealand Email: gbates@ateliertech.co.nz, bert.quin@gmail.com 2Advanced Agricultural Additives Ltd, Tokomaru, Manawatu 3Bishop Research Ltd, Tokomaru, Manawatu Abstract Leaching of nitrate-nitrogen (NO3-N) from cow urine patches is the most serious threat facing the future viability –… [Read More]
The start; many, many more to come!
Hue_et_al (1986) Abalos et al (2014) Hart, Quin & Nguyen (2004)
