Physicochemical Indices of Ground Water and Their Geoponic Management, in Coastal Odisha, India

Agriculture can not exist without water. At present the old practice of arbitrary use of water in irrigation sector has become unethical. Odisha is an agrarian state in east coast of India. For better yield of crops, quality of water is intricately related to the aquifer geometry, ground water flow regime and its quality. Coastal Odisha is having an area of 14700 sqkm and demography of 1.26 million. The land has mostly water logged alluvial crop land, deciduous forests or sandy dunes with an astomosed channels of hexa-deltaic rivers. The edaphic factors demand improvement of quality of ground water which is brackish. The physicochemical properties like pH value, electrical conductivity, inorganic constituents (Na, Mg, Ca, K) of ground water used for lift irrigation have been studied. Data from thousand number of wells from the study area are covered in various seasons during the years 2009-2014 along with the yield of the major crop, i.e., paddy. The indices and parameters like EC, SAR, KI, ESP, SSP, MAR, PI and alkalinity of the ground water are determined to show its fitness for irrigation in the area. The different water management policies and present activities are discussed so that the ground water can be used efficiently for irrigation in coastal Odisha.


Introduction
The coastal Odisha is prone to erratic monsoon rainfall, cyclones, floods, salinity hazards, drought, crop failure and many other natural disasters.Yield in the area is meagre and the quality of water used for agriculture is unsatisfactory.The burgeoning demograophy, snooty energy production, urbanization, denudation, industrialization, food demand and deforestation have deteriorated the quality of water for plants.Under utilisation of irrigation potential, low cropping intensity (140-150% for Khariff and Rabi crops) and poor irrigation quality of water, contamination of Ground Water (GW) by sewage and storm water have drastically reduced the produce (from 30-40 quintals to 12-15 quintals per hectare) in coastal districts of Odisha (Aswini Kumar et al., 2014).Irrigation plays pivotal role in the economy of the agrarian state Odisha, in the east coast of India.Irrigation potential created between 2000-2014 was underutilised inthe state (maximum 80.5% (2007)(2008) and minimum 45.9% (2002-2003)) (Agricultural statistics, Odisha, 2012).East coast of Odisha is a depositional coastal zone of six rivers like the Subarnarekha (S Rekha) in north, the Budhabalanga (B.Balang), the Baitarani, the Bramhani, the Mahanadi and the Rushikulya in south (Figure 1).They are debouching in Bay of Bengal directly or indirectly.The area comprises seven districts, i.e., Balasore (or Baleswar), Bhadrak, Kendrapada, Jagatsinghpur (J. S. Pur), Puri, Khurdha and Ganjam.The prograding nature of the coast has left imprints of 4-5 strand lines, fresh or brackish water bodies like Swamps, lakes, coast parallel channels, estuaries and lagoons and alluvial plains behind the smooth coast line.The coastal region comes under north eastern coastal plateau, east and south eastern plateau.The 480 km coastal tract consists of porous sand and loosely cemented old and new alluvium, paleo channels, sand dunes and gravel layers.The continental self of depth 0-20 km covers an area of 6820 sqkm (DPR ICZM, 2011-2012).The area consists of both shallow and deep brackish aquifers.The depth of shallow aquifers extends up to 8 to 10m.The GW is brackish and covers up to 5-25 km inland.The delta head is at 50-80 km from the coastal interface (Figure 3).The soil being unconsolidated alluvium, is the best repository to form shallow and deep aquifers of thickness from average 8m to 86 m (Choudhury et al., 2000).

Trend in rainfall along Odisha coast
The coast is 140 to 120 million years old and was formed between the Post-Jurassic to Early-Cretaceous era.The water of the coastal zone is brackish and that of estuaries is saline (0.5 Mha from 2.66 Mha of land resources along the coast is composed of saline soil, barely fit for agriculture).The estuaries, Bhitarkanika wetland and other mangroves in Kendrapada, Balasore and Bhadrak districts cover 1435 sqkm.The lands within brackish water lagoon, Chilika in Puri, Khurdha and Ganjam districts are of 1165 sqkm, deprived of surface Irrigation.The soil and agriculture coverage map is shown in Figure 3.a and Figure 3.b.The Odisha coast possesses hot and tropical climate.The average temperature is 22-35 0 C and average annual rainfall up to 1480 mm in the south coast and 1600 mm along the north coast.Rainfall of 70-80% occur during South West monsoon (JJAS months) in the year (Figure 2).The climate is humid and mean monthly PET rate is 45 mm in January and 320 mm in the month of May being highest Choudhury et al. (2000).
The average annual flow through all the rivers is 82.84 Bcum but only 17.24 Bcum of water potential is harnessed by 2385 projects, i.e., large (7numbers), medium (38 numbers) and minor (2340 numbers).The ground water potential explored for lift irrigation is only 0.381 Mha by 2014 out of 16.689 Bcum WR Department, Odisha, Annual Report (2014-2015).The coastal districts Odisha have 2.66 Mha of land (Table 1).The area covered under Khariff and Rabi were 0.4176 Mha and 0.33 Mha (63%) respectively in 2013-2014.The soil, land use and land cover and Ground water coverage map is shown in Figure 3   The water logged areas (unfit for irrigation) of Puriand Jagatsinghpur (J S Pur) districts are 1520 and 1150 km 2 .But partly the land is utilized during Rabi irrigation.The salinity affected areas in Puri and Jagatsinghpur block were 1948 and 7988 Ha respectively in 2013 (http://gopabandhuacademy.gov.in/sites/default/files/CHAPTER-WISE/Jagatsinghpur).The six rivers, the Subarnarekha Budhabalang, the Baitarani, the Bramhani, the Mahanadi and the Rushikulya allow average of 2. 308, 3.111, 7.568, 18.577, 59.155 and 3.949 Mm 3 of water to pass through the coast to the Bay.The irrigation statistics of the state are in Table 1.4).The flood plains and other land cover area are of 3100 km 2 (http://shodhganga.inflibnet.ac.in/bitstream).

Review of Literature
Frank et al. (1935) reported that the concentration (conc.) of Boron>0.5 ppm in irrigation water was observed injurious for boron sensitive crops.Boron sensitive crops can with stand up to 1.0 ppm with reductions in yield under special care and tolerant crops could bear Boron conc.Up to 1.5-2.0ppm in San Joaquín V alley, California.Oster and Rhoades (1977), Oster and Schroer (1979) and Suarez (1981) told that SAR over predicts the sodium hazard and introduced SAR (adjusted) by an 0.5 factor to evaluate more correctly the effects of HCO 3 on calcium precipitation.On the basis of annual average values of water quality parameter in Danube shallow ground water in Danube areas, Russia, Burger et al. (2003) reported the Electrical Conductivity (EC) conc. in groundwater ranges from 600 μS/cm to 2100 μS/cm.SAR values from 1.7<SAR<22.He has classified ground water as low, medium, high to very high salinity/sodicity hazard.Gypsum maintains concentration levels of the electrolyte to maintain both physical and chemical properties of soils better over longer run told by Shainberg and Letey (1984).Alaxander et al. (2011) opted for pilot farm studies before use of polluted tank water whose water quality parameters were exceeding norms.OPCB, MoEF, Government of India (GOI) (2011) studies reveal that increased level of biological oxygen demand (BOD), and coli form counts are alarming to agriculture as untreated domestic surplus water is directly discharged to drains.FAO had reported agriculture water widely vary in quality and parameters.Brouwer et al. (1985) prepared manual for FAO where in reported salts in water>2gms/lit is not fit for use.The usual method for qualifying the water quality standards either based on either SAR or RSC could not be satisfied as per field observations Suarez and Taber (2007).Minhas and Gupta (1992) Mishra et al. (2015) reported that the ground water and surface water in Krushnaprasad, Bramhagiri and few other coastal blocks are saline and at some places contaminated.Optimization of saline canal water is needed to avoid water logging and augment yield in the area.Bhatacharjee et al. (2008) studied the physico-chemical parameters of ground waters of Baleswar and Bhadrak districts and reported that there was change in water quality and presently unfit for irrigation at some places.The reasons were due to salinity intrusion.Bharadwaj et al. (2005) reported CPCB norms for irrigation water quality standards for pH are between 6.0 and 8.5, Electrical conductivity (ECw) <2250 µ mhos/cm, Sodium absorption ratio (SAR) <26 and Boron<2 mg/l.As per CGWB report (2010 and 2014), the electrical conductivity above 3000 µS/cm and Chloride ion concentration >1000mg/l of ground water are in the coastal district, Jagatsinghpur of Odisha.Flouride conc.was >1.5 mg/l in coastal districts of Bales war and Bhadrak was in 2008.The Iron concentration was>1.0mg/l, not fit to be used for Irrigation water.MOEF, GOI, has prescribed as irrigation water needed E-class with safe use limits for different parameters are pH: 6.0-8.5, EC at 25 0 C as<2250 micro mhos/cm, SAR<26 and Boron as<2 mg/lit Cl should be<600 mg/lit, MOEF, GOI (2010  Sagasta et al., FAO (2010).Ground water development is found in the northern coastal districts of Odisha (Balesore-53%, Bhadrak-59%, Kendrapada-57% and Jagatsinghpur-51%), Padhi (2015).Ahamad et al., (2014) have reported ground water in and around Berhampur city is satisfactory except three places where water is hard.
From ground water information booklet, Ganjam district, Odisha, the water quality of the district is suitable for moderate leaching and moderate salt tolerance crops CGWB report (2013).Pati et al. (2015) have reported that the water surface temperature of Gohdahada reservoir (Near coast) area was within ranges of 24.2 0 C to 32.9 0 C (29.49±2.42),from 6.74 to 7.39 for pH, dissolved Oxygen (D.O.) values varied from 3.88 to 5.32 mg/l and BOD from 2.09 to 3.73 mg/l in the year 2013.The soils of coastal tracts of form inland river deltas and consists of alluvium and lateritic formations Ahamad et al. (2015).Mohapatra et al. (2016) reported that excess of bicarbonates and carbonates of sodium in ground water used for irrigation causes suspension of organic matter and cause black strain on soil when it is dry.

Reasons for Study
Generally least problem salinity hazard is encountered in agriculture when water of good and standard quality is available as coastal Ground Water (GW) for irrigation.When GW is under severe restrictions, the physicochemical properties and need a high level of management for lift irrigation become important to have higher yield.The problems related to quality of water are salinity, reduction of water infiltration rate, specificion toxicity and excess nutrients.
Paddy (mostly mono-cropped) is the widely grown crop of coastal Odisha.The delta (Δ) for paddy is about one meter.Constant and prolonged use of brackish ground water for irrigation increases salinity and reduced the agricultural yield of the area.The water quality needs to be assured as quantity of water is a redundant factor in coastal areas.Also the quantity of the Total Dissolved Solid (TDS) is significant (10MT/year) if 1gram/lit of silt enter one hectare of irrigated land.So it is indispensable to study the quantity of sediment and quality of ground water added to the agriculture farms of 26,600 sqkm stretches of coastal districts of Odisha.The irrigation water used along the coast is brackish due to salt incursions in the shallow aquifers.During winter crops (Rabi), the ground water becomes less brackish because of salt dilution and flushing through leaching.The local farmers cultivate winter (Rabi) paddy in common where the land is not fallow.The coastal mono-cropped areas need assured irrigation during winter where SAR values are more than three but less than six.
The reason for study is to find the quality of the ground water available for Irrigation.It is also to find the management of GW and make it fit for plant growth in thickly populated areas of the coast.

Methodology
Most of the data for the study were compiled after collection from Ground Water Department of Govt. of Odisha (GoO), Water Resources Department (GoO) and published research works in various literatures like Bandopadhyay et al. (2008), Das et al. (2013), CGWB, GoI (2014), Bhadra et al. (2014), Nandi et al. (2015), Sahu (2016), and many others.The compiled data were of more than 1000 wells both tube and bore wells.Electrical conductance (EC), TDS, SAR, ESP, SSP, Adj SAR and others were calculated and their effect on the water quality in the ground water of coastal districts of Odisha are discussed.The data for quality of ground water for the districts of Ganjam, Bhadrak and Balasore were scanty.The observations were taken from nearby areas and before the year 2000 as available.

Respondent of Water for Irrigation
Poor irrigation water can be identified when applied in the field.There will be signs with signs of leaf burn, poor growth, reddish oily scale on water surface and moisture stress.The soil is saline if white crusts are found on soil surface; plants are water stressed, species change and exhibit burn leaf tip when applied.The Physical, and Chemical standards required for irrigation water and their effect on crop growth are given in Table 3.
Table 3.The water and soil respondent parameters, their impact and permissible limits of GW for irrigation

Some Important Parameters
The important parameters for good quality water for irrigation are EC, SAR, ESP, SSP, Adj SAR and others.The denotation of the parametric formulae used and their applicability are given in Table 4. or ppm) and Ec of 1 dS/m=800mg/lit (3) Conductivity: 1 dS/m=0.1 S/m=1000 µS/cm=1 mmhos/cm=1000 µmhos/cm and (4) meq/l=(mg/l x Valence) /atomic weight.
Note 2. Dissolution of organic matter in soil occurs by excess concentration of carbonates and bicarbonates which is detrimental to plants.
Note 3. Plants transpire "pure" water for growth leaving salts to remain in soil-if not leached.
Note 4. High SAR value, the soil structure breaks and causes infiltration intricacy as soil turns hard and impervious.At very high values of SAR, the salt is not flushed with the irrigation water and sodium level increases gradually.
Note 5. Alkalinity: At high alkalinity (when pH>8.5),higher % of bicarbonates form insoluble salts of Calcium and Magnesium and sodium left in soil and water.This condition exacerbates a sodic soil condition.This affects phosphorous, iron and zink availability to plants.Where Mg=Mg ion present in meq/L.

Provision of IS Code 1624-1986
Indian Standard Code 1624-1986 (reaffirmed 2001) is followed in India as guide line for Irrigation water.The code recommends the WQP values for chemicals, as TSC (Total Salt Concentration as EC in micro Siemens), SAR (Sodium Adsorption Ratio in meq/lit), RSC (Residual Sodium Carbonate or bicarbonate ion conc.meq/lit) and Boron content in ppm.The values also depend upon the % of clay in the soil sample, quality of ground water and type of crop being tolerant and semi tolerant.The optimum parameters for WQP for irrigation is considered depending upon the % of clay as >10%, 10-20%, 20-30% and >40% but the rainfall must be >600mm (Table 5).

Ranges
The GW i The groun for both d districys o Table 8. T   The districts Puri, Jagatsinghpur and Kendrapada have higher upper range of pH, EC and TDS in their GW.So the areas like Krushna Prasad Block, Mahakalapada in Kendrapada, Raghunathpur and Ersama Blocks in Jagatsinghpur are having high values of those parameters (Table 10).

Water Quality Parameters
The GW is purer than surface water but gets contaminated during process of perpetual motion.The change in GW quality may be due to dissolution (gypsum, calcites, dolomites, silicates anhydrite etc.), addition of CO 2 , hydrolysis, oxidation (pyrites and organic matters), reduction by O -2 , NO 3 -1 and SO 4 -2 etc., ion-exchange, precipitation, adsorption and bio-chemical mediated reactions and addition in the zone of unsaturation.The poor quality was due to (1) Addition of CO 2 gas into the unsaturated zone.( 2 Irrigation water contains both dissolved and suspended contaminants varying in quantities during different seasons in a year.That may create three types of hazards (i) Salinity Hazard (ii) Sodium (sodicity) hazard and (iii) toxicity hazards causing low hydraulic conductivity, reduced infiltration, crusting, potential leaf burn and imbalance in nutrient intake.
Soil containing high sodium percentage makes it impermeable and hard when dry, difficult to plough and when wet, plastic and sticky to reduce germination and growth of plants.Magnesium (Mg ++ ), the 2 nd abundant inorganic alkali metal is essential for growth of plants.It increases the electrical conductivity of water.Consequently the Ca ++ uptake is reduced.But high concentration of both (Ca+Mg) has less effect on plant metabolism Srivastav et al. (2014).In brackish ground water have high concentration of Na and Cl ions that increases EC but have less effect on soil.The presence of HCO 3 + ions if higher than Ca ++ ions, after evapotranspiration HCO 3 + ions tends to precipitate Ca ++ ions which are unfavorable for the yield.If Sodium to Calcium Activity Ratio (SCAR) and Sodium Adsorption Ratio increases (SAR) increases then EC increases with upsurge of Sodium hazard.The electrical conductivity and residual sodium carbonate decides the alkalinity hazard in Ground water used for irrigation.Alkaline irrigation water adds to sodium hazard and causes continual Ca, Mg and Fe deficiency.The problem is aggravated under poor drainage, eutrofication and salt accumulation.
On study of results of ground water samples and their physicochemical parameters from 7 districts of coastal Odisha it is concluded that the upper range limits of all the parameters are far exceeding the standard norms as prescribed by FAO, MOWR (India) and Indian standard specification.Burger et al. (2003) reported that Saline Water for irrigation has been classified as low (EC<250 mmho/cm) for common crops, medium (250<EC<750 mmho/cm) for crops of moderate salt resistant crops, high (750<EC<2250 mmho/cm) for crops of high salt tolerance crops.Under inadequate drainage and very high values of EC (EC>2250 mmho/cm) is not suitable for irrigation.The coastal Odisha have saline soil of estuarine intrusion origin with brackish ground water within a narrow strip of 5-25km from the coast including the Chilika lagoon and its periphery.The water in these districts is rich in salts of chloride, sulphate, bicarbonates of sodium, calcium, potassium and Magnesium.During SW monsoon the subsoil salinity deplete with rise in ground water table and reaches its peak value during summer.The slogan "Salt loves bare soils" refers to the fact that exposed soils have higher Evapo Transpiration (ET) values than those covered by residues.Residues left on the soil surface reduce evaporation.Thus, less salt will accumulate.Rainfall will be more effective in providing for leaching activities and iron segregation as observed in coastal Odisha.

Ground Water Management (GWM) for Lift Irrigation in Odisha
For better Irrigation Water Management (IWM), steps involved in the study area are to (i) know the crop, soil and their limitations.(ii) adopt the suitable salt tolerant crops.(iii) study direct and indirect adverse effects like osmotic, specific ion and soil dispersion effects.(v) pre-plant irrigation and frequent discontinuous irrigation without water logging.(vi) changing irrigation system.(vii) blending irrigation water with canal water.(viii) strict implementation of federal laws.(Viii) keeping the farm uncultivated for some period Doneen et al. (1964).

Management Procedure
(1) Management techniques which can be employed in coastal Odisha to have proper yeild are change in irrigation methods (Stressing on rabi crops in coastal areas), altering to sprinkler with more airification rather than the direct pumped and flow method, alternating the canal and lift water supply, land levelling and instalation of adequate subsurface drainages in coastal areas.
(2) Other important management methods are bed forming, preplant irrigation to augment leaching, frequent irrigation for additional leaching and selection of salt tolerant crops, changing duration of irrigation, proper plant selection.
(3) Consumptive use by using quality of water and proper crop diversification, management of nutrients, ground water, sunken raised bed method may add to improvement.
(4) As a solution to SAR problems it is required to change the irrigation source, blend irrigation water with canal water, lowering of sodium level by applying of lime, gypsum, sulphur or sulphuric acid etc.
(5) As advanced methods that can be adopted are reverse osmosis, desalination with system design, membrane technology and Nano tecnology.
(6) For augmentation of yeild, selection of crop water management to be given importance by indoctrinating Participatory Irrigation Management (PIM) through Water Users Associations (WUA).

Conclusions
The average water quality parameters and indices in coastal Odisha were within the permissible limits.But the upper limits of 20-25% data do not meet the proper GW quality criteria.Proper management policies are to be adopted so as to augment yield and to combat food crisis.
To start with, it is essential to have a field survey about cropping pattern and availability of GW and other sources of irrigation and its suitability in the coastal Odisha.Ample irrigation water should be available during the crop period instantly and to be applied uniformly in the agricultural fields.Adequate drainages are to be provided to discharge the surplus or leached water.Adopt proper tillage procedure so that soil moisture content to be maintained avoiding salinity accumulation on seed bed.Know the tolerance of the crop, soil characteristics and irrigation water quality.Constantly monitor irrigation water quality, adequacy and soil profile.Blending with profusely available canal water is also desired.
From the study of ground water sample it is found that fresh water conductivity values are around 1000 but the electrical conductivity increases as water become brackish or saline.It may be due to dominance of Na or K cat ions and HCO 3 -and Cl -anions.There is gradual deterioration of ground water in the coastal districts of Odisha.

Figure 1 .
Figure 1.Status of fresh and brackish ground water and rivers in coastal Odisha Source: CGWB India.

Figure 2 .
Figure 2. The rainfall in coastal districts of Odisha from the year 2005-2014 a, b and c.
) Dissolution of calcite and dolomite and precipitation of calcite.(3) Cation-exchange.(4) Oxidation of pyrite and organic matter.(5) Reduction of oxygen, nitrate and sulphate with production of supplied.(6) Reductive production of methane.(7) Dissolution of gypsum, anhydrite and halite.(8) Incongruent dissolution of primary silicates with formation of clays and others.
The local government has framed laws to maintain proper irrigation qualities.They are the Odisha IrrigationAct  1959, Odisha Irrigation Rule 1961 (amended 1998), Orissa Pani Panchayat Act 2002 and Orissa Pani Panchayat Rules 2003, registered under Society registration Act, 1860, the Orissa Pani Panchayat Amendment Act, 2008 and Odisha Water Policy, 2007.Other acts intervening water quality are The Environment Protection act 2006, The Insecticides Act, 1968 and the Plastic sale and usage rules 1999.The federal institutions in state government have handed over the management of irrigation water supply by the water user associations (Called Pani panchayats) legally as participatory irrigation management.The quality of ground water and the surface water can be better managed by the water users in the coastal areas of the state Odisha, the Odisha ground water regulation, development and management bill 2011.

Table 1 .
Irrigation (Surface and GW) status in coastal districts of Odisha The GW in Khurdha district which encompasses the west bank of the Chilika lagoonis brackish.Five urban local bodies such as Chandabali, Paradip, Puri, Konark and Gopalpurhave brackish GW near coast except few patches of sweet water.Ground Water of 22 out of 69 blocks in the seven coastal districts in Odisha is brackish and three of them are completely saline and unfit for cultivation.Lift Irrigation schemes available in Odisha were by shallow bore wells, surface lift and dug wells of 15543, 4681 and 1801 in numbers respectively by the year 2010-2011 (Table2).

Table 2 .
Agriculture, demography and Irrigation status of GW table in coastal Odisha (GoO) Suarez (1981)a/Mg value for irrigation use.It is to be taken as one against adjusted SAR values recommended bySuarez (1981).Das Madhumita et al. (2009), reported that the SAR values has underrated the sodium hazard.Nayak et al. (2014) reported large variation in EC values in the ground water of the Chilika area than as fresh water having (Na + +K + )-HCO 3 ion dominance and brackish water are resulting from (Na + +K + )-(Cl+NO3) predominance.Bhadra et al. (2014)reported that the water quality of rivers debouching in Bay of Bengalin the coastal districts is safe and are within permissible limits.
Das et al. (2005)identified 5278 km 2 of poor agricultural area and 12940 km 2 of water logged areas in coastal districts of Odisha.Choudhury et al. (2010) stated coastal tracts can have salinity hazard and non-salinity hazard areas.

Table 4 .
Important formulae, parameters and applications of irrigation water quality