Refining foliage sampling protocols for white clover

White clover (Trifolium repens) foliar ‘grab’ samples were taken pre-grazing from two irrigated experiments at Lincoln University ~6 week intervals August 2019 to May 2021. Clover leaves divided into lamina and petiole before analysis. The results for nitrogen (N), phosphorous (P), potassium (K) sulphur (S) concentrations are reported.
 While there seasonal variations, N% S% consistently higher in the white than petiole, K% was mostly P% during winter/early spring period. With increasing sward height, DW ratio declined 4, a height of 5 cm, 1 20 cm. lamina+petiole sample had lower N S alone. Over time, relatively stable but P, K showed ~ two-fold variation may have been affected by low soil moisture.
 diagnosis nutrient status should be based on lamina-only spring, when plant growth is fastest, just prior grazing sufficient herbage. foliage sampling routinely used inform fertiliser recommendations rather relying development visual symptoms deficiency.