Document Type : Research Article

Authors

University of Urmia

Abstract

Introduction: Multiple biological and physiological processes in the plant, including carbohydrates and proteins formation, activation of 50 enzymes for energy transmission as well as reducing water losses from leaf pores, are mostly affected by the presence of potassium in the plant. In order to test this hypothesis, five soil subgroups (TypicCalcixerepts, FluventicHaploxerepts, TypicEndoaquepts, TypicHalaquepts and VerticEndoaquepts) belonging 15 series of gardened and adjoining virgin soils were described and sampled. The studied soils had been influenced under horticultural practices for over five decades.
Materials and Methods: The soil samples were analyzed for different K forms, K adsorption and physico- chemical properties after air drying and grinding to pass through a 2 mm-sieve. The particle-size distribution was determined by the hydrometer method (Bouyoucos, 1962). The total carbonate in the soil expressed as the calcium carbonate equivalent (CCE) was determined by a rapid titration method (Nelson, 1982). Organic matter (OM) was measuredby the Walkley and Black (1934) dichromate oxidation method. The pH of the soil was analyzed in 2:1 CaCl2/soil suspension using glass electrode pH meter (Crockford and Norwell, 1956) and EC was detected in a saturated extract. The cation exchange capacity (CEC) was measured using sodium acetate (1 M NaOAc) at pH 8.2 (Chapman, 1965). Water soluble K was extracted with deionized water (1: 5 w/v) after shaking for 30 minutes on a mechanical shaker and later contents were centrifuged to separate clear extract (Jackson 1973). Exchangeable K was determined by extracting the soil with neutral normal ammonium acetate, Non-exchangeable K was estimated as the difference between boiling 1N HNO3 –K and neutral normal ammonium acetate K (Thomas 1982).
Results and Discussion: The result showed that for most of the studied soils, long-terms horticultural practices decreased the amount of different K forms as a result of changes in soils types, agricultural practices and soil properties. In Comparing to the virgin soils, long-term horticultural and irrigation activities caused a decrease?? in soluble K from 0.05 (a drop of 15% with depletion factor of 0.85) to 1.48 mmol l-1(a drop of 95% with depletion factor of 0.05), potassium absorption ratio (PAR) from 0.08 (a drop of 31% with depletion factor of 0.69) to 1.17 mmol l-1(a drop of 97% with depletion factor of 0.03), exchangeable K from 12.01 (a drop of 3% with depletion factor of 0.97) to 285.98 mg kg-1 (a drop of 97% with depletion factor of 0.43),exchangeable potassium percentage(EPP) from 0.49 (a drop of 12% with depletion factor of 0.88) to 3.47% (a drop of 59% with depletion factor of 0.41), available K from10.42 (a drop of 3% with depletion factor of 0.97) to 180.65 mg kg-1(a drop of 53% with depletion factor of 0.47) and non-exchangeable potassium from 43.05 (a drop of 8% with depletion factor of 0.92) to 114.65 mg kg-1 (a drop of 19% with depletion factor of 0.81). Isotherm studies showed that the uptake of potassium in gardened series were more than virgin soils. The highest adsorption values were observed in VerticEndoaquepts (gottape) subgroup.In this series of soil, amount of available k (potassium soluble + exchangeable K) and expandable clay increased by long-term horticultural practices which can be effective in increasing K buffering capacity.
Conclusion: long-term horticultural practices decreased K in soil solution and potassium adsorption ratio. The main reasons for the decline of soluble K can be explained by possible movement of K into the depths, dense cultivation and harvesting crops as well as high levels of calcium and magnesium in irrigation water of study area.In comparison with adjoining virgin soils, horticultural practices caused significant decrease in the amount of exchangeable K, exchangeable K percentage (EPP) and available K. The most important cause of reduced exchangeable potassium may be related toK uptake by apple trees (The study area is generally under the apple orchard user) which had the great need for K. Consequently, due to lack of fertilizers application and agricultural practices,the amount of available K declined in soils about 80percent. On the other hand, In the Non-exchangeable K amount with long-term horticultural practices non- significant reduction occurred. Since the amount of exchangeable and available k in these soils is high, it seems to be enough to satisfy the needs of the regional products.

Keywords

1- Balali M.R. 1997. Buffering capacity review potential potassium (PBCK) in Paddy Soil of Northern Iran. M.Sc. Thesis Soil science, Faculty of Agriculture, Tarbiat Modares University, 124p. (In Persian).
2- Bouyoucos G.J. 1962. Hydrometer method improved for making particle size analysis of soil. Agron. Journal. 54: 464-465.
3- Chapman H. D. 1965. Cation exchange capacity. In ‘Methods of Soil Analysis Part 2.’ (Ed C. A. Black). American Society of Agronomy, Madison, Wisconsin, USA. Pp: 891-900.
4- Dobermann A., and Fairhurst T. 2000. Rice Nutrient Disoders & Nutrient Management. Hand book series. Potash and Phosphate Institute (PPI), Potash and Phosphate Institute of Canada (PPIC) and International Pice Research Institute. 191p.
5- Dovlati B., Samadi A., and Oustan SH. 2010. Effects of Long-Term Continuous Cropping of Sunflower on K Forms in Calcareous Soils of Western Azarbaijan Province Iran. Journal Agriculture Science. 16: 71-82. (in Persian)
6- Dovlati B., Samadi A., and Oustan SH. 2005. Relations of K forms and Q/I in soils cultivated sunflower (khuy area). Journal Agriculture Science. Nat. Resource. Pp: 623-636. (in Persian).
7- Rezapour S., and Samadi A. 2011. Soil quality response to long-term wastewater irrigation in Inceptisols from a semi-arid environment. Nutrient Cycle Agroecosyst. 91: 269-280. (in Persian with English abstract)
8- Gaemiyan N. 2000. Review and update the semi-detailed soil plains south of Lake Urmia and effects of Lake water level. Agriculture. Resource. Center of West Azerbaijan.
9- Huang P.M. 2005. Chemistry of potassium in soils. p. 975- 1050. In: Chemical processes in soils. M.A. Tabatabai and D.L. Sparks (eds.) Soil Science Society of America, WI. USA.
10- Jalali M. 2005. Release kinetics of non-exchangeable potassium in calcareous soils. Commun. Soil. Science. 36: 1903–1917. (in Persian with English abstract).
11- Jalali M., and Zarabi M. 2006. Kinetics of nonexchangeable-potassium release and plant response in some calcareous soils. Journal. Plant Nut and Soil Science. 169: 194–204.
12- Khandegale M. T. 1977. Effect of various levels of nitrogen, phosphorus and potassium on growth, yield and quality of Thomas on seedless grape (Vitis vinifera L). M. Sc. Thesis. Mahatma Phule krishi Vishwa Vidyolaya, Rahur.
13- Khormali F., and Mahmudabadi Sh. 2009. Micromorphological study and examine the evolution of loess soils under the influence of vegetation in the area Aq Su in golestan. Proc. Conserv. Soil Science. Gorgan. Iran. (In Persian).
14- Kittrick J. A., and Hope E. W. 1971. A procedure for particale size separation of soil for X-ray diffraction. Soil. Science. Society of America. Jornal. 35: 621-626.
15- Kunze G., W and Dixon J. B. 1996. Pretreatment for mineralogical analysis. In: Klute, A. (Eds). Methods of soil analysis. Part 1. Soil Sci Society of America. Madison WI. USA.
16- Le Roux J., and Sumner M.E. 1968. Labile potassium in soils. I. Factors affecting the quantity-intensity (Q/ I) parameters. Soil. 106: 35–41.
17- Lee R. 1973. The K/Ca and Q/I relation and preferential adsorption sites for potassium. New Zealand Soil Bureau Scientific Repot II.
18- Loeppert R.H., and Sparks D.L. 1996. Carbonate and gypsum. In D.L. Sparks (Ed.), Methods of Soil Analysis. Part 3, chemical methods. SSSA, Madison, Wisconsin, USA. pp. 437-474.
19- Mahdavi Ardecani S.R., and Jafari M. 2009. Gaz plant impact on soil properties well Afzal Region, Yazd (Case Study).Proc. Conserv. Soil Science. Gorgan. Iran. (in Persian).
20- Marschner H. 1995. Mineral Nutrition of Higher Plants. 2nded., Academic Press., London
21- Merbach W., Schmidt L., and Wittenmayer L. 1999. Die Dauerdungungsversuche in Halle. B.G. Teubner, Stuttgart- Leipzig, pp. 56-65.
22- Najafi Ghiri M., Abtahi A., Jaberian F., and Owliaie H. R. 2010. Relationship between soil potassium forms and mineralogy in highly calcareous soils of southern Iran. Aus. Jornal and Application Science. 4: 434–441. (in Persian with English abstract).
23- Olk D.C., and Cassman K.G. 1995. Reduction of potassium fixtion by two humic acid fraction in vemicollite soils. Soils Science. American. Journal. 59: 1250-1258.
24- Rezapour S., and Samadi A. 2012. Assessment of inceptisols Soil quality following long-term cropping in a calcareous environment. Envirement. Science. 184:1311-1323. (in Persian with English abstract).
25- Rezapour S. 2013. Response of some soil attributes to different land use types in calcareous soils with Mediterranean type climate in north-west of Iran. Envir. Earth Science. DOI 10.1007/s12665-013-2625-3. (in Persian with English abstract).
26- Samadi A., Dovlati B., and Barin M. 2008. Effect of continuous cropping on potassium forms and potassium adsorption characteristics in calcareous soils of Iran. Aus. Journal of Soil Research, 46: 265-272. (in Persian with English abstract).
27- Sharpley A. N. 1989. Relationship between potassium forms and mineralogy. Soil. Science. Society. American. Journal. 52: 1023–1028.
28- Srinivasan C., and Muthukrishnan C. R. 1970. Effect of potassium on the development of buda in grape varieties Anab-e-shahi Madra. Agriculture. Journal. 57: 700-703.
29- Thomas G. W. 1996. Soil pH and soil acidity, pp. 475–490, in D. L. Sparks et al., eds., Methods of soil analysis, Part III, 3rd ed. American Society of Agronomy, Madison, Wisconsin, USA.
30- Thomas G. W. 1982. Exchangeable cation. In: Methods of Soil Analysis Part2 (Page, AL. (ED.)), chemical and microbiological properties. ASA Monograph. 9: 159-165.
31- Tondon H. L. S. 1998. Methods of Analysis of Soils, Plant, Waters and Fertilizers Development and Consultation organization. New Delhi, India.
32- Walkley A. Y., and Black T.A. 1982. An examination of the method for determining soil organic matter and a proposed modification of the chromic acid titration method. Soil Science 37: 29-38.
CAPTCHA Image