Energy and environmental impacts of wheat production: a comparative study of diesel and photovoltaic irrigation systems

Abstract

Increasing energy demand and environmental concerns have led to interest in renewable energy for agricultural irrigation to promote sustainable agriculture. Therefore, this research aims to assess and compare the environmental impacts and energy of wheat production in Egypt under diesel-driven (Sc-I) and solar PV-driven (Sc-II) irrigation systems. The data was collected from 181 wheat farms during the 2022–2023 season. The environmental assessment was conducted using a life cycle methodology from cradle to farm gate, and one kg of harvested wheat grains was used as the functional unit. The results showed that total energy inputs reached 108,506.97 MJ ha^{− 1} for Sc-I and 38,480.04 MJ ha^{− 1} for Sc-II, whereas the corresponding energy outputs were 153,735.55 and 144,192.30 MJ ha^{− 1}, respectively. Among the energy sources used for Sc-I, fuel for the irrigation system accounted for 63.2%, followed by fertilizer (17.3%). On the other hand, total fertilizer has the largest share in Sc-II (44.7%), followed by water (24%). Moreover, Sc-II led to a 64.5% reduction in total energy input. The global warming potential is estimated at 1.09 kg CO₂-eq kg^{− 1} for Sc-I and 0.19 kg CO₂-eq kg^{− 1} for Sc-II. Sc-II resulted in lower impacts across most environmental categories; however, slight increases were observed in abiotic depletion and freshwater aquatic ecotoxicity compared with Sc-I. While for agricultural operations, Sc-II led to a reduction in all environmental impact categories. Furthermore, solar PV-powered irrigation systems can substantially reduce energy consumption and emissions, providing a practical pathway towards sustainable agricultural production.