S.j Hosseinifard, H Khademi, M Kalbasi,
Volume 13, Issue 50 (1-2010)
Abstract
This study was conducted to determine the effect of 3 extractants on K release from biotite, phlogopite and muscovite. The minerals were grouped to <60 and 60-100 µm size classes. Particles CEC were saturated with calcium. Sequential extraction up to 30 times was carried out using 0.01M HCl, 1M NH4OAc and 0.05M BaCl2 solutions and cumulative concentration of K was calculated for each extractant. There was a difference among the 3 extractants in cumulative K release values from the three minerals. The highest values of cumulative K release were obtained by 0.01M HCl and 1M NH4OAc for less than 60 and 60-100 µm particle sizes, respectively. The amount of K release from muscovite was even higher when 1M NH4OAc and 0.05M BaCl2 solutions were used as extractants. This might indicate that muscovite cannot be considered as an ineffective source of available K in soils. Furthermore, particle size had a great impact on nonexchangeable K release from micaceous minerals. Coarser particles released higher quantity of K as compared to that of finer particles. Therefore, particle size distribution of different micaceous minerals in soils may be a factor that causes a difference in the amount of K release from soils.
Z. Naderizadeh , H. Khademi ,
Volume 15, Issue 56 (7-2011)
Abstract
Many studies have been carried out on the effect of organic matter on soil physical, chemical, biological, and nutritional properties, including the effect of organic matter on the availability of such elements as P, N and heavy metals. There is, however, no information on the effect of organic matter on potassium uptake from micaceous minerals. The objective of this study was to investigate the effect of organic matter on potassium uptake from micaceous minerals released by alfalfa. An experiment was laid out in a completely randomized design with factorial combination and three replicates. Growth medium was a mixture of quartz sand, micaceous mineral (muscovite or phlogopite) and organic matter (0, 0.5 and 1 %). Rehnani cultivar of alfalfa was used in the experiment. During 120 days of cultivation, plants were irrigated with either complete or K-free nutrient solution and distilled water as needed. At the end of cultivation, plant shoots and roots were separately harvested and their K concentration was measured by flame photometer following dry ash extraction. Under the K-free nutrient solution, a significant increase in biomass occurred in pots containing phlogopite and organic matter as compared to those with no organic matter amendment. Also, under K-free condition, potassium concentration in shoot was above the threshold value only in phlogopite amended pots. There was no significant difference in K concentration among different levels of organic matter in control treatment as well as in muscovite added treatment. Under both nutrient solutions treatments, significant increase of K uptake occurred in pots containing phlogopite and organic matter, as compared to those without it. In contrast, under K free nutrient solution, organic matter amendment could not enhance the K uptake in pots containing dioctahedral mica (muscovite). Root activities and organic matter decomposition appear to have increased rhizosphere acidity which, in turn, facilitate the K release from trioctahedral mica (phlogopite) in K deficient medium. Thus, the effect of organic matter on K release greatly depends on the type of micaceous mineral.
M. S. Mousavi Dastenaei, H. Khademi,
Volume 18, Issue 70 (3-2015)
Abstract
Few investigations have been carried out on the ability of different plants to take up non-exchangeable potassium (K). The objective of this investigation was to examine the ability of different alfalfa cultivars to absorb K from phlogopite. An experiment was carried out with a completely randomized design with 3 alfalfa cultivars including Pickseed 2065 (MF), Rehnani (R) and Hamadani (H) grown in a quartz sand medium containing <53 micron sized phlogopite under complete and K-free nutrient solutions for a period of 6 months. During the growth period, the shoot was harvested 4 times. At the end of the experiment, the root was also separated from the growth medium and collected. Plant samples were extracted using the dry ash method and their K concentration was determined. Under the K-free nutrient solution, the highest shoot and root K concentration and uptake were found for the MF cultivar. The shoot and root K concentration in this cultivar were respectively 1.6 and 1.5 times higher than those in the R cultivar and 1.8 times greater than those in the H cultivar. The K uptake in the shoot and root of the MF cultivar was respectively 1.6 and 1.9 times higher than that of the H cultivar and 1.6 and 1.5 times higher than that of the R cultivar. Thus, in addition to other parameters, the type of plant variety should be taken into account when K requirement is evaluated.
