Powdered granite is not an effective fertilizer for clover and wheat in sandy soils from Western Australia

Citation
Mda. Bolland et Mj. Baker, Powdered granite is not an effective fertilizer for clover and wheat in sandy soils from Western Australia, NUTR CYCL A, 56(1), 2000, pp. 59-68
Citations number
19
Categorie Soggetti
Agriculture/Agronomy
Journal title
NUTRIENT CYCLING IN AGROECOSYSTEMS
ISSN journal
13851314 → ACNP
Volume
56
Issue
1
Year of publication
2000
Pages
59 - 68
Database
ISI
SICI code
1385-1314(200001)56:1<59:PGINAE>2.0.ZU;2-W
Abstract
Granite (silicate) rock dust, a by-product of quarry operations, is being a dvocated and used as a fertilizer in the wheatbelt of south-western Austral ia (WA). The dust is insoluble and based on its nutrient element content (1 .9% K and 0.3%P and negligible N) it is not expected to be a useful fertili zer. Previous laboratory studies and glasshouse experiments in WA suggest t he dust is a slow release K fertilizer. This paper extends the previous stu dies to consider the dust as an NP or K fertilizer in the year of applicati on in a field experiment on a soil deficient in N, P and K. In addition, th e effectiveness of the dust as a K fertilizer was compared with the effecti veness of KCl (muriate of potash), the K fertilizer used in WA at present, in glasshouse experiments using K deficient soils. In the field experiment, compared with NP fertilizer or NPK fertilizer (urea, supplying N; superpho sphate, providing P, S, Ca, Cu, Zn and Mo; KCl providing K), the dust had n o effect on grain yield of wheat ( Triticum aestivum); in fact dust applied at 20 t ha(-1), for unknown reasons, reduced yields by about 65% compared to the nil (no fertilizer, no dust) treatment. Relative to the nil treatmen t, applying NPK fertilizer increased yields about threefold, from 0.54 to 1 .79 t ha. The glasshouse experiments showed that, relative to KCl, the dust was from about 0.02 to 14% as effective in K deficient grey sandy soils fo r producing dried tops of 30-day old wheat plants or 42-day old clover (Tri folium subterraneum) plants. In soils with adequate K (yellow sands, sandy loams or clays, loamy clays, clay loams and clays), neither KCl nor the dus t affected yields of 30 to 42-day old wheat or clover plants grown in the g lasshouse. In the glasshouse experiments, no yield depressions were measure d for the dust applied up to 17 g dust per kg soil (equivalent to 17 t dust ha(-1) mixed into the top 10 cm of soil in the field). It is concluded tha t the dust has no value as a fertilizer.