An assessment of the nutrient status of soils in northern East Gippsland

Abstract

Likely nutrient disorders were identified in an omission-type pot trial with white clover. The soils, taken from four virgin sites, were developed on the four main parent materials in the area, viz., tuff, basalt, shale, and granite. All were deficient in phosphorus and sulphur; three were deficient in molybdenum (the exception was the granitic soil), but only the granitic soil was deficient in copper. No other nutrients were deficient or in toxic amounts for clover growth, but oats responded to nitrogen on all four soils. The variability between soils sharing similar parent materials was studied in four easily defined suites by interpreting the analysis of 12 samples from each suite. Soils derived from acid volcanic rocks were consistently moderately acid, deficient in P, S, and Mo but variable in K and Cu status. Soils derived from basalt were typically less acid than those of the previous suite, had a wide range in P, K and Mo status, contained adequate Cu, but were consistently deficient in S. Soils derived from sedimentary rocks were typically moderately acid, consrstently deficient in P, S and Mo, but were variable in K and Cu status. The granitic soils ranged from moderately acid to neutral in reaction, had a wide range in P status and K status, were consistently deficient in S and often in Mo or Cu. The phosphorus sorption capacity was consistently low in the granitic soils but very variable in the other suites. Estimates of the amount of phosphorus required as a corrective dressing in the field suggest consistently low requirements by the granitic soils (10-30 kg P ha-1) whereas requirements ranged up to 120 kg P ha-1 in the other suites.