Acidification and Its Evolution under Australian Dryland Cropping Systems
- William J. Slattery and
- Keith R. Helyar
In this chapter, we review the development of acid soils in dryland cropping environments in Australia. These soils have become strongly acid in the surface soil layers, affecting some 90 million hectares of agriculturally important land. The main causes of soil acidification in farmed soils are through the leaching of nitrate nitrogen (NO-3N), removal of excess alkali in farm produce, accumulation and leaching of organic acid anions, and the use of ammonium-based N fertilizers. These processes have accelerated the rate of pH decline and in some cases have reduced surface soil pH by more than 1.5 units. The impact of this acidification being greatest in high rainfall environments. We review the impact of declining soil pH on farm production and discuss amelioration strategies such as liming, lime with gypsum, organic matter additions and the frequency of application of these materials. We also explore economic and management decisions that will provide solutions for the continued use of acid soils in the future.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2004. . Copyright © 2004 by the Crop Science Society of America, American Society of Agronomy, 5585 Guilford Rd., Madison, WI 53711 USA