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Gönül (Bilgehan) Aydın, Saime Seferoğlu ADU. Agicultural Faculty Soil Science Dept. Cakmar AYDIN ABSTRACT Soil and plant boron content of irrigation water was researched on Great Menderes Basin. It was tried to determined that accumulation of boron, come from irrigation water, in the soil profile, its effect on some soil characteristics, and its relation with the amount of boron in plant. According to results, it was obtained that boron content of irrigation water was so high in particular Germencik where there was a ground thermal water reservoir. Boron has been accumulated more than plant requirement in the areas irrigated by this water. High boron content in soil was led to toxic effects as dried plant. Besides, there was a direct relationship between soil and plant boron content. Boron content of irrigation water was relatively low in rainy season while it was high in dry season. INTRODUCTION Some irrigation water resources ,especially those in areas where geothermal waste waters are discharged, have high boron concentrations .Some of the branches of B.Menderes river contain great amounts of Boron up to 21.1 mg /lt Since Boron is considerably less mobile in soil, it accumulates there and then unproductivity occurs because of over use of water which is in boron. Plants need Boron in different concentrations as a nutrient. While some plants need much more Boron, others are less tolerant of Boron. For example, cereal plants need much more Boron, grass plant, potato and strawberry require Boron less than 1.0 ppm; tobacco, cotton. Tomato, carrot, onion and some fruits need Boron between 0.1-0.5 ppm; apple, clover, peppermint, beet, and cabbage need Boron more than 0.5 ppm (Kovancy,1979) When 21.1 ppm Boron concentration which some irrigation waters contain are considered, it is seen that this concentration is even much more than the need of the highest Boron demanding plants. Therefore , toxic effect is extensively encountered in citrus fields, which are less tolerant of Boron , of study area Because waters with high Boron content flow into B:Menderes river over years, Boron concentrations of irrigation waters, soils irrigated with those irrigation waters and plants have been determinate with this study. This research results will enable us to take measure for currently threatened areas and to predict future changes, determine probable changes in these concentrations levels in coming years MATERIAL AND METHOD B.Menderes Basin is located between 37°and 38°northern latitudes and 27° and 29° eastern longitudes. Its an important agricultural source for Aydyn province and lies from Denizli border to Aegean sea. The basin has 23900 km2 of area.In the research area from east to west (Aegean Sea) of the basin, 36 sampling points have been selected among citrus fields where Boron toxicity is seen, From selected points, 142 soil samples in 0-30 and 30-60 cm depths in two different periods (before and after irrigation), 44 water samples from irrigation waters in these fields and 36 plant samples after irrigation have been taken. METHOD After having brought to laboratory, 146 soil samples, 44 water samples and 36 plant samples have been prepared to analyse. Soil samples have been sieved with 2 mm sieve after drying water laboratory conditions. Plant samples firstly have been washed with demineralized water, then dried at 60-70 °C for 24 hours and ground and finally sieved with 2 mm sieve (KACAR,1972) Analysis (Method / Instrument) In soil samples . Texture (Hydrometer, Bouyoucos,1951), pH, (pH meter glass electrode within a suspension of 1 / 2,5 soil water ratio Anonim 1980) CaCO3, (Calsimeter Allison and Moode 1965) Total soluble salts, (Electrical resistance of Saturated soil ) Organic matter, (Walkey-Black Anonim 1980), Available phosphorus, (spectrometer using Olsen method Anonim 1980), Exchangeable Potassium,, Calcium, Sodium, (Flame photometer in an extract obtained with 1 N NH4OAC pH 7,1 Richard 1954), Exchangeable Magnesium, (Atomic Absorption Spectrophotometer Kacar 1962), Boron, (Azomethin-H Wolf 1936) In Water Samples : pH, (pH meter glass electrode), Electrical Conductivity, (EC meter microsiemens / cm),NaCl, (EC meter mg/l), Boron, (Azomethin-H Wolf 1936) In Plant Samples : pH, (ph meter glass electrode), Electrical conductivity, (EC meter microsiemens/ cm),NaCl, (EC meter mg/l),Boron, (Azomethin-H Wolf 1936) RESULTS AND DISCUSSIONS Some physical and chemical analysis belonging to soil samples are given in Table 1. Some soil properties such as texture ,lime content and organic material content are of great importance, since they affect the movement of Boron in soil. When the results of analysis are examined, it can be seen that pH values are neutral on surface but increase from surface to deeper strata due to increase in alkalinity. According to EC values, there is no salinity problems in soil. Organic materials of soils were found low in general. Lime contents were generally found high in both 0-30 cm and 30-60 cm in strata . When relationships between Boron contents of the soils and some soil characteristics were examined, some statistically significant relationships were found. Negative relationship sat 0,05 significance level between sand contents and Boron concentrations were found. This situation shows that Boron coming with irrigation water can easily seep downward in soil profile because sand is incapable to hold any element and is highly permeable. A positive relationship at 0.05 level between clay and silt contents and boron concentrations were observed. Statistically positive relationships were obtained between electrical conductivity values and Boron concentrations at 0.01 level and between lime and Ca and Mg contents of soils at 0.05 level. Assesements of Results of Analysis of Water and Plant Samples : Because Aydın has abundant geothermal resources and these resources contain high concentrations of Boron, great amounts of Boron containing waters flow into B.Menderes river, especially from geothermal power plants. Moreover, Boron pollution in domestically used waters which originates from ground waters supplies or from industrial effluents through irrigation waters is threatening both human and animal health. It has been previously shown in researches carried out by State Hydraulic Works (DSY) that Boron concentrations in both some streams and some ground waters of the region have reached hazardous levels According to some research results, high Boron concentrations up to 11.8 ppm have been detected in some branches of B.Menderes river. Some analysis results on water and plant samples are given in Table 2 pH' s of water samples were determinate between neutral and average alkaline. It is given in literature that permissible pH values for drinking water is between 7.0 -8.5 for agricultural irrigation and animal watering. Electrical conductivity (EC*106 ) values were measured between 392-2420 ms / cm Referring to u.s.s. salinity Lab. Staff (1954), water samples of 750 - 2250 micromhos / cm are accepted as high saline water and those of 250 - 750 micromhos / cm as average saline water NaCl contents of water samples ranged from 212 to 1237 mg /l.  Boron concentrations of water samples ranged from 0.33 to 6.41 ppm Scofield (1936) classified irrigation water in terms of their Boron concentrations in such away that waters containing Boron less than 0.33 ppm is "very good" for plants which are susceptible to Boron, the range 0.33 - 0.67 ppm is " good",the range 0.67-1.0 ppm is "usable" (for unsusceptible plants), the range 1.0-2.0 ppm is "inadvisable" and finally those greater than 2.0 ppm is "unusable ".When compared to criteria given above, none of samples have a quality to fall in "very good" category. Referring to Kovancy (1979), principally waters which contain Boron more than 1.0 ppm can cause pollution in soils resulted from Boron depending on permeability of soils. Therefore, it has been found that 50% of samples taken from research area is good, approximately 29% of them can be used in unsusceptible plants and the rest 21% in unusable for irrigation. Boron concentrations fluctuate throughout year, higher in some months and lower in some months. For example, some of samples taken in September had higher Boron concentrations than those taken in June. It has been seen that from The irrigation water analysis of DSY for years. Boron concentrations of irrigation waters from June to September were higher than those of other months in a year. Boron contents show higher values in summer that irrigation intensifies due to intense use of irrigation waters with Boron content in summer months, too much boron accumulates in soil. Because this application is contiuned every year, accumulated boron in soil firstly causes toxicity in plants, then in later years makes soils unproductive and completely unproductive. Boron contents of plants taken from research area were found between 61-957 ppm. Referring to Reuter and et al., Boron concentrations above 260 ppm in plants are considered toxic. Based on explanations given above and result of analysis, Wery few of plant samples had enough Boron, but approximately 19% of them had high amounts of Boron and 80% had Boron at toxic level As a result , it has been observed that almost all citrus fields which has been studied in this project is suffering from intense Boron toxicity. A statistically positive relationship at 0.05 level has been obtained between Boron content of soils and of plants. A similar relationship between irrigation water, soil and plant Boron contents was obtained in a study carried out by (Akba? 1998) in Söke and Menemen plains Since citrus is one of the plant which are susceptible to Boron, the damage which is currently seen in citrus fields will likely be observed in coming years in cherry, fig vineyard, cotton and wheat fields which are important for the region. That the mobility of Boron in soils is very slow makes hard its removal from soil Conseqently, because the region has abundant geothermal water resources which contain high amounts of Boron and these ground waters are brought to surface and used for various purposes such as power generation, heating or thermal spring and then discharged to B. Menderes river, it is being exposed to intense Boron pollution therefore, in order to prevent Boron pollution and hence unproductivity in soils, it is necessary not to discharge waters with high Boron content to irrigation waters. REFERENCES Akbaş F.(1998). Değ. Bor Kons.lu Sul. Sularının Menemen ve Söke Ovası Topraklarında Yetiştirilen Pamuk Bitkisine Etkileri. Ege Bölgesi I. Tarım Kongresi.. Cilt I. 439-445. AYDIN Allıson L. E., Moode, C.D. (1965). Methods of Soil Analysis. Part 2. Agronomy Series. No. 9. American Society of Agronomy. Wisconsin Series. 1379-1396. Anonymous 1. (1971). Köy İşleri Bşk. Toprak-Su Genel Müd. Aydın İli Toprak kaynağı Env. Haritası. No 16. Toprak Etüdleri ve Haritalama Dairesi, Arazi Tasnif Şub.. ANKARA, Anonymous 2 (1997-1998). İnt. Office for Water. French-Turkish Co. Agree.an Rivers Integrated Water Resour Use Planning and Management. Integr. Develop and Pollution Control. Anonymous 3. (1980).Soil and Plant Testing and Analysis as a Basis of Fertilizer Recommendation, F.A.O. Soils Bulletin 38/2 95. Anonymous 4.(1981). The Analysis of Agricultural Materials.R.B. 427 Replaces Technical Bulletin 27 Her Majesty's Stationary Office, LONDON, Bouyoucus G.J. (1951). A Recalibration of the Hydrometer for Making Mechanical Analysis of Soils. Agron. J. 43.434-438. Kacar B. (1962). Plant and Soil Analysis. Univ. of Nebraska, College of Agriculture. Depth. Of Agronomy, Lincolin, Nebraska, U:S:A: Kellog C.E.(1952). Our Garden Soils. The Macsiltlan Company. NEWYORK, Kovancı İ. (1979). İç Ege Bölgesi Sulama Sularının Bitki Beslenmesi Açısından Kimi Nitelikleri ve Kimyasal İçerikleri Üzerine Bir Araştırma. No. 364. EÜZF. Of. Ü. İZMİR, S: 87. Reuter D.J and Robınson J.B. (1986). Plant Analysis an Interpretation Manual Incata Press. MELBOURNE, SYDNEY. Rıchards L.A. (1954). Diagnosis and Improvement of Saline and Alkali Soils. U.S. Agriculture Handbook. No. 60. 159. Sauchelli V. (1969). Trace Elm. in Agr. Van Nostraned Reinhold Company, NEWYORK. Scofıeld C.S. (1935)., The Sal.of Irrigation Waters. Smith Inst. Ann. Report, 275-287. Wolf B. (1936)., The Determination of Boron in Soil Extrac.Plant Materials, Composts, Manures, Waters and Nutrient Solutions. Soil Sci. and Plant Anl., 2(5):363-374. |