Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Is it worth subsoil testing for Nitrogen?

Oliver, Y., Bowden, B., Scanlan, C. and Bell, R.ORCID: 0000-0002-7756-3755 (2013) Is it worth subsoil testing for Nitrogen? In: 2013 WA Agribusiness Crop Updates, 25 - 26 February, Perth, Western Australia

[img]
Preview
PDF - Published Version
Download (149kB)

Abstract

In WA, soil testing for mineral N (ammonium plus nitrate) has traditionally been taken from the top 0-0.1 m. Farmers and advisors are now interested in deeper soil testing, in order to know how much mineral N occurs at depth and what this may mean in terms of fertiliser N application decisions. Accounting for topsoil and subsoil test level in N fertiliser use varies markedly among growers and advisors depending on; their own historic applications; use of nitrogen decision support tools (N-DSS’s) such as Yield Prophet simulations or SYN. Other growers use approximate total soil profile N and then add N fertiliser required to reach target yield (i.e. 45 kg N/ha for 1 t/ha of grain).

The main question this paper is addressing is “Do I need to soil test to depth for better N decisions?”

To answer this we needed to understand: 1. Where in the profile the subsoil N occurs and if it is related to topsoil N, 2. How effective is the subsoil in supplying N for the crop – which depends on root access to subsoil N as affected by subsoil constraints and N leaching, 3. What does this mean for N recommendation systems based on soil testing? and 4. Given the seasonal interaction with yield response, will the subsoil N test results reduce the errors in recommendations enough to justify this extra complexity, cost and effort?

Item Type: Conference Paper
Murdoch Affiliation: School of Environmental Science
URI: http://researchrepository.murdoch.edu.au/id/eprint/20197
Item Control Page Item Control Page

Downloads

Downloads per month over past year