Volume 18, Issue 69 (fall 2014)                   jwss 2014, 18(69): 237-250 | Back to browse issues page

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Dept. of Soil Sci., Ramin Univ. of Agric. Sci. and Natur. Res. Khuzestan, Iran. , pishgir88@yahoo.com
Abstract:   (12230 Views)

This study was done to compare K+ and NH4+ fixation in different agricultural systems in Khuzestan province. Soil samples were collected from Shushtar and Abadan. Samples were collected from depths of 0-30 and 30-60 cm in sugarcane, multi cropping, palm and uncultivated land. Then, 0-50-100-200-400-600-800-1000 mg kg-1 K+ or NH4+ concentrations were added to 0.5 gram of clay separated from these soil samples. These clay samples were kept for 24 h at room temperature. Then, they were extracted with 0.5 M magnesium acetate, and K+ and NH4+ were determined by flame photometer and micro diffusion methods, respectively. Fixed K+ or NH4+ was determined from added and extracted cations. Also, XRD studies were done in some samples. Kaolinite, palygoreskite, illite, chlorite, smectite and quartz were identified by XJRD. Statistical analysis showed that K+ or NH4+ fixation and rate were increased by increasing the concentration. Maximum K+ or NH4+ were fixed in surface layer’s clay in Shushtar multi cropping and Abadan Palm cultivation. The results showed that K+ and NH4+ fixation were increased by increasing the concentration. But, under increasing concentration for a cation, fixation decreased for others and vice versa. NH4+ fixation was more than K+. This may be due to smectite clay mineral in these samples. Smectite group tend to cause NH4+ fixation more than K+. These results can be applied for K+ or NH4+ fertilizers management.

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Type of Study: Research | Subject: Ggeneral
Received: 2015/01/11 | Accepted: 2015/01/11 | Published: 2015/01/11

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