Dr Geoffrey Anderson1, Mr David Hall1, Dr Ed Barrett-Lennard1, Mr Glen Riethmuller1, Mr Wayne Parker1, Mr Chad Reynolds1
1Department Of Primary Industries and Regional Development, Northam, Australia
Biography:
I have more than 30 years' experience in agricultural research, mainly in soil management, including fertiliser use (N, P, and S), soil acidity and alkalinity, and soil water repellences. I currently work for the Department of Primary Industries and Regional Development and previously worked for CSIRO, The University of Western Australia, and the University of New England. My experience combines background plant nutrition research in contrasting environments (NSW and WA) and agricultural systems (crops and pastures). Most of my research has focussed on using soil test measurements to define soil constraints and the soil amendments to overcome these constraints.
Abstract:
Growers use soil testing to determine the limitations imposed by soil constraints or the investment required in fertilisers and other soil amendments (lime and gypsum). The soil test value is related to the crop yield by defining a soil test-crop response relationship. These relationships have been well-defined for nutrient constraints (P, K, and S), where increasing soil test values result in an increasing relative yield value presented as a percentage. In contrast, soil testing for managing acidic soil or, more specifically, aluminium toxicity and sodic-alkaline-saline soils is less well defined. We can determine the relative impact of the soil constraint for these two groups by measuring soil pH or the chemical constraint. Recently, the measurement of soil aluminium content has been shown to be a better predictor of lime response than soil pH for acidic soil. In contrast, soil testing for managing sodic-alkaline-saline soil pH is a better predictor than various chemical measurements and other soil chemical measurements and indices. We can combine these new soil tests–crop relationships for acidic and alkalinity with existing nutrient soil test–crop response relationships to improve the grower's soil management investment decisions.