A rapid and simple field test for phosphorus in Olsen and Bray No. 1 extracts of soil

Abstract

Farmers are increasingly aware of the need for correct fertilizer management, and have developed a keen interest in the rapid and accurate assessment of soil nutrient status. A simple field-based soil test for phosphorus (P), adapted from commonly used laboratory tests would allow the farmer to assess quickly fertilizer requirements. We have adapted the malachite green method for the determination of P in water to a single-solution technique for the determination of inorganic P in Olsen and Bray No. 1 extracts of soil. The method was modified for use in the field. The proposed method is at least four times as sensitive as the commonly-used ascorbic acid method, simpler in application and the reagent is much more stable.

Promoter Analysis of the Barley Pht1;1 Phosphate Transporter Gene Identifies Regions Controlling Root Expression and Responsiveness to Phosphate Deprivation

“…Pi content of plants was determined from leaf tissue taken 5 cm from the tip of the first mature leaf using a modification of the method of Irving and McLaughlin (1990) as described by Schü nmann et al (2004).…”

Linking Development and Determinacy with Organic Acid Efflux from Proteoid Roots of White Lupin Grown with Low Phosphorus and Ambient or Elevated Atmospheric CO2 Concentration1

“…Each tank contained a solution of 1 m KH 2 PO 4 , 0.25 mm CaCl 2 , 0.7 mm KNO 3 , 0.25 mm MgSO 4 , 11 m H 3 BO 3 , 2 m MnSO 4 , 0.35 m ZnSO 4 , 0.2 m CuSO 4 , and 6 m ferric EDTA and was adjusted daily to pH 6.0 (Keerthisinghe et al, 1998). Each day, phosphate levels were assayed using Malachite green dye and replenished to 1 m (Irving and McLaughlin, 1990;Keerthisinghe et al, 1998). The complete solution in the tanks was changed weekly or biweekly.…”

A Metal-Accumulator Mutant of Arabidopsis thaliana

“…The ash solution was heated for 2 h at 70"C, and then distilled water was added to a final volume of 3 mL. Samples were analyzed by flame atomic absorption spectroscopy (Perkin-Elmer Cetus) for Mg, K, Ca, Mn, Fe, and Zn, and P was analyzed using a colorimetric assay (Irving and McLaughlin, 1990). The digestion method could not be used for the analysis of S because of the loss of volatile forms, and Cu concentrations were too low to be analyzed.…”