Design and analysis for spatial effects in pasture trials

Abstract

Measurements made on pasture plots in field evaluation studies are affected by the spatial heterogeneity of the field due to local influences of paddock history, moisture drying order and fertility gradients. Statistical models to account for these inherent and ephemeral effects can markedly enhance the accuracy of comparisons among test lines or treatments so that interpretation of the results is objective, accurate and reliable. This paper reports on statistical methods for the field evaluation of white clover breeding lines in the development of locally adapted white clover cultivars for New South Wales dry-land pastures.