Exploring the potential for site specific nitrogen management in grazing systems

Abstract

The application of site-specific nutrient management (SSNM) in grazing systems may offer considerable benefits in terms of optimised nutrient use efficiency and pasture productivity. There is significant variability in soil nutrients and plant growth potential across pasture paddocks, suggesting that SSNM may prove viable (Virgona and Hackney, 2008). Research has led to increasing uptake of SSNM in cropping systems. Despite this, there has been little research into the value of SSNM strategies within more complex grazing systems and even less is know about how producers might implement these techniques. This experiment examines the value of SSNM of nitrogen (N) in a pasture using soil EM38 mapping to guide paddock zoning for variable rate fertiliser application. Soil EM38 is strongly linked to soil moisture characteristics and this study explores how variability in soil water may influence nutrient use efficiency at the sub paddock scale.