Medium Rainfall Zone Trials Eleven replications of the basic rate of P, rate of SO4-S and S experiments were maintained during 1970 in the 20in - 30 in. rainfall zone. Soil types examined were the very gravelly soils (5 reps, 4 sites), sands or loamy sands over gravel or clay (3 sites) and sandplain soils (3 reps, 2 sites). In all cases except one, fertiliser history was not reliable, but in every case well over one ton of super had been applied. over a period of over 15 years
