Mapping soil fertility at Broom's Barn by simple kriging

Simple kriging is a technique for estimating values of continuous random spatial variables from data without bias and with minimum variance. The procedure is illustrated by a case study in which three properties of soil fertility, available phosphorus, exchangeable potassium and pH in the topsoil, are mapped using data from Broom's Barn Experimental Station. The soil on the station, covering 77 ha, had been sampled at 40‐m intervals. Semi‐variograms of the properties were determined from the measurements and kriged values estimated at 10‐m intervals on a square grid. These values were then contoured to produce maps of the properties and also reliability maps showing the estimation variances.