INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 6, No 2, Copyright by the authors - Licensee IPA- Under Creative Commons license 3.

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1 INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 6, No 2, 2015 Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0 Research article ISSN Standarisation of methodology for obtaining the desired salt stress environment for salinity effect observation in Bibha Rani 1, Sharma V.K 2 1- Research Scholar, Department of Agricultural Biotechnology and molecular Biology, Rajendra Agricultural University, Pusa, Samastipur, Bihar. 2- Associate Professor, Department of Agricultural Biotechnology and molecular Biology, Rajendra Agricultural University, Pusa, Samastipur, Bihar bibha9rani@gmail.com doi: /ijes.6026 ABSTRACT The present investigation has been done to provide the salt stress treatments to rice seeds to observe the salinity effect on varieties under evaluation. The desired treatments of EC having salt concentration as 2, 4, 6, and 8 ds/m. The solutions were prepared on the basis of following established relationship between Total Dissolved Solid (TDS) and Electrical Conductivity (EC). Sodium chloride (NaCl) was used as solute and Distilled Water (D.W.) as solvent to prepare the solutions of desired EC. The calculated amounts of NaCl in g/l were dissolved in distilled water to get the respective EC for each solution. But using above calculation the EC obtained of each solution exceeds 12.5%-21% more than the desired EC. So, distilled water (D.W) was added to minimize the EC for desired value. It was observed that for EC 2 ds/m, 4 ds/m, 6 ds/m and 8 ds/m salt solution 1 gm, 2 gm, 3 gm and 4 gram of NaCl was required respectively. Thus a relationship has heen found that amount of sodium chloride required in terms of gram per litre is half of the desired EC in ds/m. It confirms the statement made in IRRI discussion paper series no. 22 (p7) by Gregorio et.al Key words: Electrical conductivity, sodium chloride, Distilled Water, EC meter. 1. Introduction Electrical conductivity is a measure of the ability of a solution to carry an electric current.the SI unit of electrical conductivity (EC) is ds/m. Conductivity also depends on the temperature of the water. As water temperatures increase, conductivity increases. This is because evaporation takes water away but does not take salts away. Water with salt can conduct electricity. Water with absolutely no salt cannot conduct electricity and thus conductivity will be zero. When we measure conductivity, we are measuring how easily electricity is flowing through the water and we get an indirect estimate of how many salts are in the water (U.S.P.E.A). Plant salt stress (osmotic stress) is a condition where excessive salts in soil solution cause inhibition of plant growth or plant death (Yokoi et.al. 2002). Osmotic stress induced by conditions like drought, salinity and heat etc. impairs plant growth and development by affecting plant physiological processes (Nagar et.al. 2015). On a world scale, no toxic substance restricts plant growth more than does salt. Salt stress presents an increasing threat to plant agriculture. Among the various sources of soil salinity, irrigation combined with poor drainage is the most serious, because it represents losses of once productive agricultural land (Zhu 2007). The deleterious effects of salinity on plant growth are associated with low Received on July 2015 Published on September

2 osmotic potential of soil solution (water stress), nutritional imbalance and specific ion effect (salt stress) (Gregorio et.al. 1997, Moradi and Ismail 2007,). Salinity imposes both ionic and osmotic stresses on plants (Munns et.al. 2006). Soluble salt at higher concentration in growth medium cause hyperosmolality and imbalance of nutrients in most plants that harmfully declines plant growth. many studies have shown that the hight, growth index, and fresh and dry weight of the root and shoot system, relative water content, proline content, chlorophyll content in leaves (Turan et.al. 2010). Conductivity is a very important parameter for determining the water quality for drinking as well as agricultural purposes. Conductivity based on total concentration of various ions (Deshmukh and Urkude, 2014). Nacl is the most predominant and detrimental salt in salt affected soil and water (Li et.al. 2006). Increased NaCl concentration adversely affects the germination, seedling fresh mass, water content (Kakkar et.al. 2000), membrane injury and ion homeostasis in rice roots (Siringam et.al. 2011), grain yield (Dionisio and Tobita,2000), net photosynthetic rate (Amira and Qados 2011). 2. Materials and method Four types of salt solution were prepared using AR grade Sodium Chloride (M.W ) by given relationship i.e. (TDS (g/l) = 0.6 x EC (ds/m)) for EC 2, 4, 6 and 8 ds/m to soak rice seed in the solution to provide salt stress for evaluation of salinity tolerance. salt solutions were prepared for 1000ml and desired amount of NaCl was added in Distilled Water. Now the EC was measured using EC meter (Syntronics). Caliberation of the conductivity meter (EC meter) was done with 0.1N KCl. The meter was now turned on and the reading was recorded after 90 sec. 50 ml of sample was taken from each solution and EC was measured, but the desired EC was not achieved so dilution was made with Distilled Water until the desired EC was achieved. 3. Result and discussion 50 ml of sample was taken from each solution. The experiment were repeated for sample 100ml, 500ml, and 1000ml and EC were observed. Because, EC is strongly dependent on temperature of the sample thus all the measurement taken at room temperature (25 o C), the EC values are automatically corrected to a standard value of 25 C and the values are then technically referred to as specific electrical conductivity. A good EC meter will have ATC (automatic temperature compensation) to get accurate results regardless of sample temperature.the sample taken for measurement (v1) were diluted with distilled water until the desired EC (2, 4, 6, 8) were obtained. The measurement shows EC 2.42 ds/m instead of 2 ds/m, 4.60 ds/m instead of 4 ds/m, 6.70 ds/m instead of 6 ds/m and 9.01 ds/m instead of 8 ds/m having percent increament by 21%, 15%, 11.66% and 12.5% respectively (table 1). Now it was observed that when the sample volume reached to 60 ml (v2) for each sample, the desired EC were achieved (table2). Thus, For EC= 2 ds/m, In 600 ml of sample 0.6 gm NaCl was added, so for 1000 ml, amount of NaCl was : 0.6/ = 1 gm. For EC= 4 ds/m, In 600 ml of sample 1.2 gm NaCl was added, so for 1000 ml, amount of NaCl was : 1.2/ = 2 gm. For EC= 6 ds/m, In 600 ml of sample 1.8 gm NaCl was added, so for 1000 ml, amount of NaCl was : 1.8/ = 3 gm. For EC= 8 ds/m, In 600 ml of sample 2.4 gm NaCl was added, so for 1000 ml, amount of 233

3 NaCl was : 2.4/ = 4 gm. From the above calculations it was observed that the the amount of NaCl required (in gm) was exactly half of desired EC values (table3). It also confirms the statement made by Gregorio et.al Acknowledgment I thank the staff members of soil science department of Rajendra Agricultural University, Pusa, Bihar for technical support. I also thank Sugandh Suman and Anita Kumari for incourage and moral support during my research. Desired EC (ds/m) Table 1: deviation of EC measured from desired EC value. weight of NaCl in gm Volume of D.W in ml Measured value of EC (ds/m) Percent increament from desired EC value % % % % Table 2: Dilution made to get the desired EC EC1(ds/m) V2(ml) EC2(ds/m) V2-V1(ml) Table 3: showing relationship between weight of NaCl(gm) and desired EC(dS/m) Amount of Desired EC Volume of NaCl mm of NaCl Remarks (ds/m) sample(ml) added(gm) Weight of NaCl is exactly half of EC per litre of solution. Table 4: conversion of EC units. = 1 millisiemens per centimetre (ms/cm) = 1000 microsiemens per centimetre (µs/cm or EC 1 decisiemens per metre units) (ds/m) = approx. 640 parts per million in water (ppm or mg/l) 234

4 Source: Gibbs References 1. Amira M.S. and Qados A. (2011), Effect of salt stress on plant growth and metabolism of bean plant Vicia faba (L.),. Journal of the Saudi Society of Agricultural Sciences, 10, pp Deshmukh C.K. and Urkude R.N Physico-chemical and microbial status of malkhed lake at chandur railway, district, Amravati. The bioscan, 9(2), pp Dionisio-Sese M.L. and Tobita S. (2000), Effects of salinity on sodium content and photosynthetic responses of differing in salt tolerance. Journal of Plant Physiology, 157, pp Gregorio G.B., Senadhira D., and Mendoza R.D. (1997), Screening rice for salinity tolerance. IRRI discussion paper series Kakkar R. K., Bhaduri S., Rai V. K., Kumar S.(2000), Amelioration of NaCl Stress by Arginine in Rice Seedlings, Changes in Endogenous Polyamines. Biologia Plantarum, 43, pp Li X. G., Li F. M., Ma Q. F., Cui Z. J. (2006), Interactions of NaCl and Na2SO4 on soil organic C mineralization after addition of maize straws, Soil Biology and Biochemistry, 38, pp Moradi F. and Ismail A.M. (2007), Responses of photosynthesis, chlorophyll fluorescence and ROS-scavenging systems to salt stress during seedling and reproductive stages in rice, Annals of Botany, 99, pp Munns R., James R. A., Lauchli A. (2006), Approaches to increasing the salt tolerance of wheat and other cereals, Journal of Experimental Botany, 57, pp Nagar S.,Arora A., Singh V.P., Ramakrishnan S., Umesh D.K., Kumar S. and Saini R.P Effect of cytokinin analogues on cytokinin metabolism and stress responsive genes under osmotic stress in wheat, The Bioscan 10(1), pp Siringam K., Juntawong N., Cha-um S. and Kirdmanee C. (2011), Salt stress induced ion accumulation, ion homeostasis, membrane injury and sugar contents in saltsensitive rice (Oryza sativa L. spp. indica), roots under iso-osmotic conditions, African Journal of Biotechnology, 10, pp Turan M. A., Elkarim A. H. A., Taban A. and Taban S. (2010), Effect of salt stress on growth and ion distribution and accumulation in shoot and root of maize plant. African Journal of Agricultural Research, 5, pp

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