Showing 3 results for Non-Exchangeable Potassium
M. Bahreini Touhan, E. Dordipour, S. A. Movahedi Naeini,
Volume 14, Issue 53 (10-2010)
Abstract
Kinetical study on non-exchangeable potassium (NEK) release is necessary for management, optimum use of soil resources, availability and supplying power of potassium. Information about NEK release rate in Golestan soils is limited. The aim of this study was to investigate the NEK release of saturated soil sample by calcium using acid citric and CaCl2 extractants from 2 to 1844 h duration in 12 dominant soil series in Golestan province. Different soils indicated various responses to continuous extraction. The rate of K released in different soils was lower in CaCl2 than that of Citric acid. Potassium release was faster in earlier periods of the extraction in all soils followed by a lower release rate. Due to high coefficient of determination and low value of the standard error of the estimate, the NEK release kinetic by citric acid and CaCl2 were well described by Elovich and Parabolic diffusion equations and Power, First order and Elovich equations, respectively. Therefore, NEK release rate was controlled by K diffusion from weathered surface of soil minerals.
A. Farshadirad, E. Dordipour, F. Khormali1 ,
Volume 16, Issue 59 (4-2012)
Abstract
Non-exchangeable potassium (NEK) release is necessary to supply potassium for plant in different soils. A few studies on the NEK release have been done in soils and particularly on its components. This study was intended to investigate the NEK release from soil and the components of clay and silt through successive extractions with oxalic acid (0.01 M) over a period of 1844 (h) in 4 soil series of Golestan province. The amount of NEK release from whole soil, silt and clay fractions after 1844 (h) were 242 to 450, 380 to 550 and 105 to 199 mg kg-1, respectively. The cumulative rates of NEK release after 1844 (h) were well described by simplified Ellovich, parabolic diffusion and power function equations. The rate of K release was high initially, and then decreased gradually in all soils and in their silt and clay fractions. The amount of released NEK (with high rate) consisted of lower percentage of total NEK, but in spite of less amount, this K form plays a vital role in K dynamic and soil fertility.
Mh. Rasouli Sadaghiani, S. Sadeghi, M. Barin, E. Sepehr, B. Dovlati,
Volume 20, Issue 78 (1-2017)
Abstract
Potassium is the most abundant nutrition element in the surface soil but most of the potassium is unavailable to the plants. The present study was conducted with the aim of isolation of potassium solubilizing bacteria from rhizosphere soil and evaluation of quantitative ability of released potassium from different sources of silicate by strains. For this propose, laboratory and greenhouse evaluations were carried out on corn (Zea mays L. Cv. single cross 640 (as a factorial in a completely randomized design with three replications. Laboratory factors were potassium sources (four levels), incubation time (seven levels) and microbial inoculation (six strains) and greenhouse factors were potassium sources (five levels) and microbial inoculation (four strains). The results showed that among the bacterial strains KSB13 had maximum dissolution diameter (25 mm) and solubilisation index (SI=3). The highest potassium content (3/32 µg/mL) was released from biotite by strains of KSB10 after ten days incubation. The microbial inoculation increased root dry weight and plant height for 30 and 25 percent, respectively, compared to control treatments. Also the mean shoot dry weight and K content in microbial treatments of silicate minerals were respectively increased 3/75 and 1/57 times higher than control treatment. It can be concluded that microbial inoculation causes potassium release from silicate minerals and improved plant growth.
