Assessment of Water Quality for Agricultural Cultivation Irrigation Using the Irrigation Water Quality Index: A Case-Study Land Survey and Evaluation from Kampus Polinela II

Abstract

River water has an essential role in irrigation water sources in agricultural cultivation activities on the Polinela II campus land. The availability of water on the land depends not only on river water but also on reservoirs that can be used as a source of irrigation water for cultivation activities. In this study, 21 river and pond water samples were taken during May-September 2021, and hydrochemical and hydrophysical quality tests were carried out. Assessment of the suitability of groundwater for irrigation purposes is carried out with hydrochemical parameters (Ca, K, Ca, Mg, EC, COD and Nitrogen) and different indices (SAR and ESP). Some of the data obtained were studied by geostatistical analysis and the spatial variation in the Kampus Polinela II land. The results of hydrochemical testing have different levels of variation in content so that a concise combination is carried out using the Irrigation Water Quality Index (IWQI) method, which gives the quality of irrigation water for crop cultivation purposes with a single value. IWQI can be used as a basis that irrigation water from river water has better irrigation properties than irrigation water from reservoirs. The IWQI found in cultivated land is divided into two water quality index classes: excellent and moderate. The excellent category from the test results is river water used for agricultural irrigation, while the moderate category is found in ponding water. Long-term irrigation by surface water and neglect of implementing soil quality improvement measures can cause negative impacts on the soil, therefore to avoid soil degradation, appropriate and effective preventive measures are needed.