A new soil test for simultaneous extraction of macro‐ and micro‐nutrients in alkaline soils

Abstract

A new soil test was developed for simultaneous extraction of NO 3 , P, K, Zn, Fe, Cu and Mn from alkaline soils. The new extraction solution is 1 M in ammonium bicarbonate (NH 4 HCO 3 ), 0.005 M in Diethylene Triamine Pentaacetic Acid (DTPA) and has a pH of 7.6. The new extracting solution should be stored under mineral oil. Ten grams of soil are weighed out into 125 ml Erlenmeyer flasks. Two 2.5 ml scoops of Fisher G carbon black (to remove color for colorimetric determination of nitrates) are added to each soil, followed by 20 ml extracting solution. The soil mixture is then shaken on an Eberbach reciprocal shaker for 15 minutes at 180 cycles per minute. The extract is then filtered through a Whatman 42 filter paper or its equivalent for NO 3 , P, K, Zn, Fe, Cu and Mn determinations. The results obtained with the new procedure are highly correlated with results obtained with Olsen's P test, ammonium acetate K test, and Lindsay and Norvell's DTPA-Zn, Fe, Cu and Mn test. Regression equations between the levels of nutrients extracted by the 195 196 SOLTANPOUR AND SCHWAB new procedure and those extracted by the procedures mentioned above were developed. These equations were used to calculate index values for nutrients extracted by the new extraction procedure based on values used at the Colorado State University Soil Testing Laboratory for the standard extraction procedures. The new procedure extracted about the same amounts of K and Fe as ammonium acetate and DTPA, respectively, from soils having low to marginal levels of these elements. However, it extracted about half as much P as NaHC0 3 and about 0.5 PPM more Zn, 0.8 PPM more Mn, and 0.3 PPM more Cu from soils having low to marginal levels of these elements.

Contrasting effects of biochar versus manure on soil microbial communities and enzyme activities in an Aridisol

“…Total organic C was determined by difference between total and inorganic C. A 2 mol L À1 KCl extract method was used to determine NO 3 -N and NH 4 -N content (Mulvaney, 1996). Extractable P was determined by ammonium bicarbonate diethylenetriaminepentaacetic acid (AB-DTPA) extraction (Soltanpour and Schwab, 1977).…”

Influence of Incubation Period, Temperature and Different Phosphate Levels on Phosphate Adsorption in Soil

“…Soil texture was analysed by Bouyoucos' hydrometer method, organic matter by Black and Walkley method (Jackson, 1958), lime content by Acid neutralization Purie's method (Kanwar and Chopra, 1967) and electrical conductivity by electrical conductivity meter (1:5 soil water extract). Soil pH was measured (water 1:5 extract) using PHM210 Standard pH meter at 30°C (Jones, 2001) and available phosphorus by AB-DTPA method (Soultanpur and Schwab, 1977).…”

Growth, Yield and Fruit Quality of Strawberry (Frageria ananasa Dutch) under Different Phosphorus Levels

“…The soil samples were analyzed for Nutrients, AB-DTPA extractable Phosphorus (Soltanpour & Schwab, 1977) soil texture, pH and Electro conductivity according to (McClean, 1982;Shrivastava et al, 1993). …”