Phosphorus status of pastoral soils where reactive phosphate rock fertilisers have been used

K.W. Perrott, B.E. Kerr, J.H. Watkinson, J.E. Waller
1995 Proceedings of the New Zealand Grassland Association  
The dissolution rate of Sechura phosphate rock (particle size 75-150 pm) was determined at 95 New Zealand sites with a range of soil and environmental properties. Rates ranged from 0 to 70% of the phosphate rock dissolved per year with an average dissolution rate of 3 1 %/year. An initial model based on stepwise linear regression analysis indicated that the rate of dissolution was negatively associated with soil pH and positively associated with rainfall and exchangeable soil magnesium. There
more » ... magnesium. There was also an effect of soil type and drainage. The amount of residual RPR accumulated from previous fertiliser application can be determined by a new soil test. This, together with the dissolution rate estimated from the nature of the RF'R and the soil and site factors, can be used to indicate likely soil P status. Keywords: dissolution, fertiliser, phosphorus, reactive phosphate rock, soil test
doi:10.33584/jnzg.1995.57.2171 fatcat:57pajfgpxnaz3el4dqgreeb7rm