The present study was carried out to assess the salinity of the soil along the banks of the Krishna river in the state of Maharashtra for which soil samples were collected at 10 spots covering 562 km' area and studied for pH, conductance, moisture, organic matter, alkalinity, chloride, sulphate, sodium, potassium, calcium and total microflora. Study indicated an increasing trend of salinity with increase in down stream distance from the source and soil salinity was higher in deep black soil with distinct patches of salt affected land in very recent past.

INTRODUCTION

The irrigation projects, particularly diversion of the river water by construction of weirs etc. enhance the process of salt build up in the river water (Masters, 1974; Skogerboe, 1975). This water which is rich in salinity when used in agriculture accelerates the salt accumulation process in the soils as a result of evapotranspiration thereby polluting the soils and making them unfit for crop growth for ever. The conditions get aggravated when coupled with poor drainage facilities. Such problems have been studied by many workers (Paliwal, 1971; Pringle et al, 1975; Naik, 1975; Kovda, 1978). The present study was carried out to assess the salinity of the soil along the banks of the Krishna river in this state.

MATERIALS AND METHODS

Important features of the sampling area are described in Table 1. Soil samples, 2 cm below the surface were collected randomly from five places

© The Academy of Environmental Biology, India. Printed in India.

SAMPLING AREA AND METHODS

Table 1 : IMPORTANT FEATURES OF THE SAMPLING SPOTS ALONG THE KRISHNA RIVER IN THE STATE OF MAHARASHTRA.

S.N.	Name	Distance from the source(km)	Remarks
1.	Dhom	20	A dam is constructed on the Krishna river.Agricultural practices along the banks but less of sugarcane.
2.	Mahuli	45	Situated at the confluence of the Krishna and the Venna river. Little agriculture nearby.
3.	Rahimatpur	60	Little irrigation facility and less agriculture. Soil rich in gravel.
4.	Umbraj	80	Situated at the confluence of the Krishna and Tarale river. Little agriculture but some sugarcane cultivation. Soil with gravels.
5.	Karad	100	Situated at the confluence of the Krishna and Koyna. Extensive sugarcane cultivation. Weir is constructed. Sewage of the city is discharged frequently.
6.	Takari	125	Weir is constructed. Extensive sugarcane cultivation. Effluents of sugar and alcohol industry are discharged.
7.	Bbilawadi	170	Extensive sugarcane cultivation. More than 250 hectares of land affected by salinity in last two years.
8.	Sangli	214	Extensive sugarcane cultivation.Industrial and city wastes discharged in the river.
9.	Gbalwad	244	Extensive sugarcane cultivation. More than 400 hectares of land is affected due to salt build-up in last two years.
10.	Narsinhawadi	261	Extensive sugarcane cultivation, popular piligrimage center.

at each spot and mixed. They were air dried and passed through 6 mm mesh. Organic matter was estimated as per method of Misra(1968). 1:5 soil extract was used for the estimation of pH (Systronics Gnph pH meter, Model, 303); conductivity (Systronics Direct Reading Conductivity Meter,Model,303); alkalinity, chloride and sulphate (ISI, 1974) and sodium, potassium and calcium (Elico Flame photometer, Model CL 22 A) of the soil. Soil extract-agar medium was used for the determination of standard palte count for bacteria. All the analyses were done atleast for five times for each sample and mean of five estimations are presented in the table 2.