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Trends in Olsen P test over time for the Waikato region

TR 2004/09

Report: TR04/09
Author: DM Wheeler, Agresearch


Olsen P data extracted from database of soil fertility data obtained from commercial soil testing lab for the period 1988-2001. Samples were categorised according to land use or soil group (sedimentary, volcanic, pumice, peat).

Olsen P measurements lend themselves to monitoring change over time. This report gives trends in Olsen P levels over time for different land use and soil types for the Waikato region.

Trends In Olsen P Test Over Time For The Waikato Region
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Table of Contents

Executive Summary iii
1 Background 1
2 Methods 1
2.1 Database 1
2.2 Classification of records 2
2.3 Bias 3
2.4 Analysis 3
3 Results 4
3.1 Olsen P over time 4
3.2 Distribution of samples 6
4 Discussion 6
References 11