There has been an increasing interest in the stratification of soil nutrients and pH, and the need to revise sampling depths to better diagnose soil surface and subsurface constraints to crop and pasture production. Twenty-three commercial paddocks were sampled in the Australian Capital Territory (ACT) to diagnose soil chemical constraints to 30 cm. There was little evidence of pH stratification, but strong evidence of phosphorus (P), sulfur (S) and potassium (K) accumulation in the surface (0-5 cm) soil. Nutrient concentrations were highest at 0-5 cm and declined significantly with depth, consistent with the trend in soil organic matter (indicated by total carbon and nitrogen concentration). Sixty six percent of paddocks had available P (0-10 cm) in excess of the critical value, while 61% were deficient in S (0-10 cm). There was no evidence of S accumulation in subsurface soil layers to 30 cm and overall 61% of paddocks were deficient in S in the 0-30 cm profile sampled. Therefore, even if S has accumulated deeper in the profile (>30 cm) it is likely to be below the root zone of most annual species until late in the growing season. Our results indicate nutrient stratification may limit pasture production more than pH stratification in the ACT.
|Title of host publication||Proceedings of the 19th Australian Society of Agronomy Conference|
|Place of Publication||Australia|
|Publisher||Australian Society of Agronomy|
|Number of pages||4|
|Publication status||Published - 2019|
|Event||19th Australian Agronomy Conference 2019 - Wagga Wagga Civic Theatre, Wagga Wagga, Australia|
Duration: 25 Aug 2019 → 29 Aug 2019
https://web.archive.org/web/20190122040437/http://agronomyconference.com/ (Conference website)
https://web.archive.org/web/20190625230032/http://www.agronomyconference.com/program (Conference program)
|Conference||19th Australian Agronomy Conference 2019|
|Abbreviated title||Cells to Satellites|
|Period||25/08/19 → 29/08/19|
|Other||The 19th Australian Agronomy Conference will be held in Wagga Wagga, NSW from 25 – 29 August 2019. In the heart of the Riverina, Wagga Wagga has a range of rural industries across the region. Wagga has everything to offer the agronomy conference being surrounded by a mixed farming zone with irrigation to the west and permanent pasture enterprises to the east.|
The conference theme Cells to satellites highlights the integrative nature of agronomy. Each of us work across a range of disciplines to optimise crop or pasture production for productivity and profitability. We have an increasing number of tools available to increase the precision and accuracy of our work; whether it is at the “cellular” level where DNA is mapped and biochemistry is unravelled or using “satellites” for remote sensing or guidance. The opportunities for enhancing our agronomy research is boundless.