Conference paper
Is it worth subsoil testing for Nitrogen?
2013 WA Agribusiness Crop Updates (Perth, Western Australia, 25/02/2013–26/02/2013)
2013
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?
Details
- Title
- Is it worth subsoil testing for Nitrogen?
- Authors/Creators
- Y. Oliver (Author/Creator)B. Bowden (Author/Creator)C. Scanlan (Author/Creator)R. Bell (Author/Creator)
- Conference
- 2013 WA Agribusiness Crop Updates (Perth, Western Australia, 25/02/2013–26/02/2013)
- Identifiers
- 991005540645607891
- Murdoch Affiliation
- School of Environmental Science; Centre for Sustainable Farming Systems
- Language
- English
- Resource Type
- Conference paper
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