Jb. Tome et al., EFFECTS OF MOIST STORAGE AND DIFFERENT DRYING TEMPERATURES ON THE EXTRACTABILITY OF IRON, COPPER, MANGANESE, AND ZINC IN SOIL SAMPLES, Communications in soil science and plant analysis, 27(11-12), 1996, pp. 2591-2611
The objective of this study was to investigate the effect of different
pretreatments on the extraction of cationic micronutrients [iron (Fe)
, copper (Cu), manganese (Mn), and zinc (Zn)] from four different soil
s. Samples were either stored in the field-moist state for seven days
before drying or dried immediately. Three drying treatments were used:
air-dried (72 hours), oven-dried at 40 degrees C (48 hours), or oven-
dried at 105 degrees C (24 hours). Micronutrients were then extracted
with 0.1N HCl or diethenetriamine-pentacetic acid (DTPA). Storage, dry
ing temperature, extractant, and soil type all influenced micronutrien
t extractability. In general, a higher temperature increased the level
of micronutrient extracted. However, the reverse effect was also obse
rved. The effect of storage was variable and probably depended on the
sample moisture content. We conclude that the results from routine ana
lysis and experimentally determined indices can only be compared if so
il samples are subjected to the same pretreatments. Hence, rigorous st
andardization of the sample preparations is imperative for accurate de
termination of-plant-available micronutrients.