Agro-Environmental Evaluation of Irrigation Water from Different Sources, Together with Drainage and Escape Water of Rice Irrigation Systems, According to its Impact on Maize (Zea mays L.)

Abstract

The water supply deficit requires agro-environmental rationale for the use of alternative water sources to feed agricultural crops, viz.: industrial wastes, municipal drains, farm animal waste, drainage and escape water of rice irrigation systems. We analyzed the quality of irrigation water from different sources, with regard to the content of cations, anions, water-soluble salts, power of hydrogen (рН), sodium adsorption ratio (SAR), etc. in it. In the course of the greenhouse trial, we diagnosed its impact on the indicator crop (maize) (Zea mays L.) with its herbage crop stage of 10 leaves, supplied with water of varying quality. We proved the viability of improved drainage and escape water from rice irrigation systems in irrigated agriculture, owing to which maize herbage was diminished, on average, by 5.82%. We verified the negative impact of irrigation water, which contains the effluent disposals of metallurgical production, on croppers – it had contributed to diminishing the watered maize herb, on average, by 39.27%. A correlation analysis of the test data proved the closely interrelated feedback between the maize herbage amount and the content of cations, anions and water-soluble salts in irrigation water (coefficient of correlation r varied between 0.88 and 0.98). The worked-out linear regressive model for maize herbage, based on the content of water-soluble salts in irrigation water, together with SAR index (Y=2342.71–1.82×x1+366.78×x2), affirmed the validity of the pattern, discovered by means of the correlation analysis.