Improved estimation of micro nutrients in hectare plots of the Sonning Series.

SUMMARY The form and degree of spatial dependence in readily extractable iron, manganese, copper and zinc in the topsoil of 1 ha plots on the Sonning Series near Reading have been determined. The results have been used to calculate the sampling effort required to estimate mean values with specified precision. They show that two- to three-fold economies can be achieved for iron and manganese, at least, by taking account of the known spatial dependence and optimally configuring the sampling. [ABSTRACT FROM AUTHOR]