Dataset: Exhaustion Land Experiment P test soil P 1974-2023

This dataset contains topsoil (0-23 cm) Olsen phosphorus (P) and total P data for the "P Test" plots (plots 1, 3, 5, 7 and 9) of the Exhaustion Land Experiment, 1974-2023. The plots were divided into four sub-plots testing four rates of P fertilizer 1986-1992. Maintenance applications of P were then applied to all plots except the P0 from 2000 onwards. Olsen-P is a widely used indicator of plant-available soil P.

The residual effects of fertilizer and manures applied in 1876-1901, and the additional P applied in 1986-1992 have resulted in a wide range of plant-available P in the soil. Soil was not sampled every year. This is the soil data reported by Haefele et al. (2025); crop yields and P uptake are published as a separate dataset.