توانايي سه رقم يونجه در جذب پتاسيم از فلوگوپيت با اندازه ذرات متفاوت و تغييرات كاني شناسي رسي

چكيده انگليسي :

Ability of Three Alfalfa Cultivars to Take up Potassium from Phlogopite with Different Sizes and Consequent Mineralogical Changes Maryam Sadat Mousavi Dastenaei m mousavidastenaei@ag iut ac ir February 19 2012 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Hossein Khademi E mail hkhademi@cc iut ac ir Abstract Soil mineralogical studies have shown that potassium K bearing minerals are dominant in Iranian soils particularly in arid to semiarid regions Numerous investigations on the release kinetics of non exchangeableand structural K have indicated that plants can take up K from K containing minerals in K deficient soils Rhizospheric environments and plant root exudates can cause the releases of K from minerals and makemineralogical changes In addition to soil properties the biochemical characteristics of rhizosphere depend onthe type of plant Among different parameters affecting the K dynamic in soil the effect of particle size ofmicaceous minerals on the K supply and mineralogical alteration has not been studied Besides the role of cropcultivars has not been investigated either Therefore the objectives of this research were 1 to investigate therole of different alfalfa cultivars on the K uptake from phlogopite 2 to understand the effect of phlogopiteparticle size on the K release 3 to examine the influence of alfalfa cultivar on phlogopite mineralogicalchanges and 4 to study the relationship between the K uptake by plant and mineralogical bio weathering Apot experiment was carried out under greenhouse conditions with a completely randomized design and factorialarrangement and 3 replications for a period of 6 months Treatments were consisted of four phlogopite particlesizes including 53 m D1 53 62 m D2 62 260 m D3 250 m 1 mm D4 and control nophlogopite three alfalafa cultivars inclouding Rehnani R Hamedani H and Pickseed 2065 MF and 2 typesof nutrient solutions complete and K free During the growing period shoot was harvested 4 times and the rootwas collected at the end The K concentration in plant samples was measured by flame photometry after dry ashextraction For mineralogical investigations samples were taken from the D 1 treatment and their clay fractionwas examined using an XRD The results showed that the Rehnani cultivar produced the highest amount of bothshoot and root under the K free nutrient solution Growth media containing D1 and D3 treatments produced thehighest level of shoot and root respectively The least quantity of dry shoot and root was obtained in controltreatment under the K free nutrient solution with the MF cultivar The maximum K concentration of both rootand shoot under both nutrient solutions belonged to the MF cultivar The highest K concentration in shoot androot was measured in D1 and D2 treatments respectively In pots treated with K free nutrient solution the MFcultivar could take up the highest amount of K The highest uptake of K by shoot and root was measured in D 1and D3 treatments respectively Under the K free nutrient solution the K concentration in shoot increases up tothe 3rd cut and then decreases The finer the phlogopite diameter the higher the amount of K released Coarsesized phlogopite particles seem to release K much slower but for a longer of time X ray diffraction analysis ofMg saturated phlogopite and its likely weathering products indicated that in all the 3 cultivars under the K freenutrient solution the intensity of the 1 0 nm peak decreases while a new 1 4 nm peak forms The highest ratio of1 4 to 1 0 nm peak intensity was obtained for the MF cultivar supplied with the K free nutrient solution XRDanalyses well show the formation of expandable minerals such as smectite and vermiculate Keywords Release of potassium Phlogopite Alfalfa cultivars Vermiculite XRD

موسوي دستنايي، مريم السادات

توانايي سه رقم يونجه در جذب پتاسيم از فلوگوپيت با اندازه ذرات متفاوت و تغييرات كاني شناسي رسي

رها سازي پتاسيم , ارقام يونجه , ورمي كوليت و xRD