Comparison of the Pi, Colwell, Bray 1, calcium acetate lactate (CAL) and Truog soil phosphorus test for predicting growth of oats, barley, triticale and clover in the field in lateritic soils fertilised with superphosphate and rock phosphate
1994
Kumar, V. | Bolland, M.D.A. | Gilkes, R.J.
The Pi soil test for phosphorus (P), which uses an iron oxide impregnated paper, was evaluated in three field experiments on lateritic soils in south-western Australia fertilised with triple superphosphate, North Carolina rock phosphate, Queensland rock phosphate, and in one experiment, Caliphos. Soil samples were collected February to March from 1985 to 1988. The Pi, Colwell, Bray1, calcium acetate lactate (CAL) and Truog soil P tests were used. Soil test P values were related to yields of triticale (X Triticosecale) or oats (Avena sativa), barley, (Hordeum vulgare) or dry herbage yields of subterranean clover (Trifolium subterranean). The Colwell soil test, which is commonly used in Australia, and the Pi soil test were almost equally predictive, but showed considerable error in prediction of yield. For each soil test and plant species the relationship between yield and soil test P differed with fertilizer type and year. For combined data for all sites, fertilizers and years, the CAL soil test was the most predictive and the Truog soil test was least predictive of plant yield. uog soil P tests; triple superphosphate, North Carolina rock phosphate, Queensland rock phosphate and Calciphos fertilizers; oats (Avena sativa), barley (Hordeum vulgare), triticale (x Triticosecale), and subterranean clover (Trifolium subterraneum) plant species
显示更多 [+] 显示较少 [-]