Effects of deficit irrigation and manure application on growth, yield and water use efficiency of onion (Allium cepa L.)

Abstract

With increasing municipal and industrial demands for water, its allocation for agriculture is decreasing steadily. Irrigated agriculture, both now and in the future, will occur in areas with limited water resources. Insufficient water supply for irrigation will become the norm rather than the exception, and irrigation management will move from prioritizing production per unit area to optimizing production per unit of water consumed. To deal with limited resources, deficit irrigation is an integral strategy for minimizing irrigation water consumption. In this study, the growth, yield, water use efficiency, and nutritional content of onion (Allium cepa L.) were evaluated, as well as the interacting effects of deficit irrigation and manure treatment on these factors. The research was carried out utilizing a factorial design that was arranged in split plots and included three replications from each group. Treatments consisted of three irrigation levels (ETc 100%, ETc 75% and ETc 50%) and two manure levels (with and without manure application). When compared to deficit irrigation alone, the results showed that the combination of deficit irrigation with the application of manure resulted in a considerable increase in plant height, stem diameter, number of leaves, bulb weight, bulb diameter, and nutrient content. The treatment with manure and 50% ETc had the highest water use efficiency of all the treatments. Under conditions when there is a limited supply of water, the study demonstrates that a combination of deficit irrigation and the use of manure can improve onion yield.