PHYSICO-CHEMICAL ANALYSIS OF COASTAL SOIL SAMPLES IN THE WEST COAST OF KANYAKUMARI DISTRICT, TAMILNADU

S. S. Sajitha 1 , P. Metilda 2 and G. Aldous Jenin 3 . 1. Department of Chemistry, Annai Velankanni College,Tholayavattam.Kanyakumari district,Tamilnadu,India. 2. Department of Chemistry, Nesamony Memorial Christian College,Marthandam.Kanyakumari district,Tamilnadu,India. 3. Department of Bio-Chemistry, Lekshmipuram college of arts and science,Neyyoor Kanyakumari district,Tamilnadu,India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

1640 and a biotic variables (Paudel et al., 2003). The industrialization and development in agriculture are necessary to meet the basic requirement of people, at the same time it is necessary to preserve the environment (Joshi et al., 2011). pH is a most important physical properties of soil. It having great effects on solute concentration and absorption in soil (Akpoveta et al.,2010). At low pH values solubility of micronutrients is high while at high pH solubility and availability of micronutrient to plant is declined (Brady et al.,2002). Variability in soil texture can directly or indirectly influence many other soil functions and soil threats such as soil erosion (Adhikari et al.,2009). A rise in temperature of soil accelerates chemical reaction, reduces solubility of gases and decrease pH of soil (Shirbhate et al.,2012). Soluble salt concentration in soil and is commonly used as a measure of salinity (Wagh et al.,2013) Nitrogen cycle plays an important role in soil system and is influenced by biological processes. It is required for growth of plant and is a constituent of chlorophyll, plant protein and nucleic acid (Jain et al.,2014). Soil nitrogen is also directly related with soil organic carbon (Singh et al.,2013 Supply of nitrogen either through organic and inorganic sources also plays an important role for higher winter sorghum productivity in addition to the moisture conservation (Patil et al.,2005). phosphorus content of the soil was higher in topographic position as compared to soils occurring on lower topographic position (Singh et al.,2013). The soil with high organic matter content have better supplies of organic phosphate for plant uptake than have the soils with low organic content (Miller et al 2001). The soil with minimum leaching are known to contain high amount of phosphorus as compared to the soil with maximum leaching (Ahraf et al.,2012).Potassium is not an integral part of any major plant component but it plays a key role in a vast array of physiological process vital to plant growth from protein synthesis to maintenance of plant water balance (Sumithra et al., 2013). Potassium fixation occurs when soil dry and the potassium is bonded between layers of clay (Wagh et al., 2013). It decreases with an increase in depth of soil (Campbell et al., 1961). Soil organic matter is an important property of soil. If the soil is poor in organic matter then it enhances the process of soil erosion. The presence of higher content of organic matter in the soil can be another reason for lowering of the pH (Hodes et al., 1996). Soil organic matter content has decreased from surface to subsoil due to levelling (Helburg et al., 1978). The decomposition rate of organic matter has a tendency to increase as weather warm and to furnish maximum plant growth conditions (Russell, 1950). Organic matter commonly increases water content at field capacity, increases available water content in sandy soil and increases both air and water flows rates through fine textured soil (Ramulu et al.,2001).

Materials and methods:-Study Area:-
The study area chosen for the present work is kanyakumari district coastal region.Which is covering a distance of 65 Km from Vattakottai to Vallavilai of Tamilnadu coast region. It is shown in Fig.1.Numerous industries, chemical factories and aquaculture farms are also developing along these coastal regions, it makes much attention for present and future research.

Soil collection and preparation:-
The study was conducted at ten different coastal regions of kanyakumari district. Coastal soil sample were collected using Peterson grab at all the designated location during low tide. The samples collected sites under study were labelled as S1, S2, S3, S4, S5, S6, S7, S8, S9 and S10. The distance between each site falls around 6 Kms. the collected soil samples stored in polythene bags immediately; after the soil was withdrawn the colour and texture were identified. The soils were air dried, crushed using pestle and mortar and then passed through a 10 mesh (2mm) screen before analysis. The soil analysis was completed within two months after collection ISSN: 2320-5407 Int. J. Adv. Res. 5(12), 1639-1645 1641 Graphical representations of physico chemical characteristics of various coastal area samples of kanyakumari district.

Results and Discussion:-
The physico-chemical properties of ten different coastal regions of Kanyakumari district is shown in Table 1. Samples site numbers and locations are given below. pH and electrical conductivity of different coastal regions show that pH variation is very less but conductivity is more in Chotthavilai region (S2), in comparison to other nine places very less electrical conductivity in Pattanam (S8). The presence of higher content of organic matter in the soil can be another possible reason for lowering the pH.The organic matter value ranges from 0.4247 to 1.3254.
Nitrogen cycle place an important role in soil system and is influenced by biological process. The results in ten different regions showed least amount of nitrogen in all regions. Phosphorus helps the transformation of solar energy into chemical energy. Among all the samples the least amount of Phosphorus recorded in Rajakkamangalam(S3). Potassium is not an integral part, but it plays a key role in vast array of physiological process like maintaining the plant water balance. The lowest value of potassium recorded in Manavalakurichi and Pattanam(S5& S8). The highest value of potassium in regions Kottilpaadu and Kurumpanai(S6 & S7).Graphical representation of physicochemical parameters in Fig.2. and Fig.3. respectively.
Micronutrients analysis was done in Zinc,Iron ,Copper and Manganese, results showed that Zinc is not an adequate amount in all the regions, it is particularly common in high pH soils. Iron is essential for chlorophyll synthesis, iron deficiency results in regions S5-S10, when compared with regions S1-S4. Copper is a component of some enzymes, copper deficiency results in regions S1-S5, when compared with regions S6-S10 the availability of copper is in significant amount. The availability of manganese is in significant amount in all regions. Compared with all the regions Vattakottai has enriched amount of manganese.