التفاصيل البيبلوغرافية
| العنوان: |
Critical phosphorus values from the Better Fertiliser Decisions for Pastures project: early insights from validation trials. |
| المؤلفون: |
Rogers, David, Weaver, David, Summers, Robert, Dobbe, Eric, Master, Ronald, McFerran, Robert, Mussell, Graham, Dawson, Luke, Mercy, Justin, Richards, Peta, Holtham, Deborah |
| المصدر: |
Crop & Pasture Science; 2021, Vol. 72 Issue 9, p731-741, 11p |
| مصطلحات موضوعية: |
FERTILIZERS, PHOSPHORUS in water, PASTURES, SOIL testing, SOIL acidity, PHOSPHORUS, SOIL sampling, GRASSLAND soils |
| مصطلحات جغرافية: |
WESTERN Australia |
| مستخلص: |
Phosphatic fertilisers have made grazing in the south-west of Western Australia (WA) viable. However, there is evidence that a large proportion of pasture paddocks exceed soil test critical values at which 95% of maximum yield is achieved as identified in the national Better Fertiliser Decisions for Pasture (BFDP) project. Of 22 000 soil samples collected between 2009 and 2020, 56% exceeded the critical value for phosphorus (P), although there were constraints to potassium (K) and sulfur (S) and from soil acidity. Soils with available P exceeding the critical value are expected to lead to excessive losses of P to waterways, resulting in eutrophication. A trial program was established to validate the critical P values from BFDP so that concerns can be addressed about the relevance of these critical P values to WA conditions and to contemporary pasture varieties. Measured relative yields for 19 trials in the first year were mostly within 10% of that predicted from BFDP for soils with a P buffering index (PBI) >10. Soils with PBI <10 had measured relative yields up to 25% greater than predicted by BFDP, suggesting response calibrations for low PBI soils may require adjustment in the BFDP dataset. Some pasture yield gaps occurred when soil pH and P were low. Application of nitrogen (N), K and S almost doubled the yield when P was limiting or sufficient. Agronomic advice and practice should seek to optimise these multiple inputs, thereby optimising P use rather than applying P to levels above the critical value. An Australia-wide collaboration (Better Fertiliser Decisions for Pastures, BFDP) previously estimated critical soil test phosphorus (P) values for pastures based on a collation of data from historical fertiliser trials. Soil test critical values are essential to planning fertiliser applications and minimising environmental impacts off-site. We describe early results from trials aimed at validating critical soil test P values from BFDP, using contemporary pasture swards, in order to improve the quality of, confidence in, and uptake of evidence-based P fertiliser advice. [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
