Energy Efficiency Analysis of Wheat Crop under Different Climate- and Soil-Based Irrigation Schedules

Use of energy in the agriculture sector has directly or indirectly been intensified to increase crop production to fulfill the food demand of the growing population. Considering the energy and water scarcity in Pakistan, the present study was carried out to assess wheat production efficiency with regard to energy consumption. For this purpose, a field experiment was conducted at the Water Management Research Centre (WMRC), University of Agriculture Faisalabad, to compare two irrigation scheduling techniques (climatic- and soil moisture-based) and farmers’ practice. All the inputs, except volume of irrigation water, were the same for all treatments. Energy equivalents (extracted from a scientific source) were used to calculate the energy balance and indices (energy use efficiency, energy productivity (kg MJ−1), specific energy (MJ kg−1), net energy (MJ ha−1) and water productivity (kg m−3)). The results show that soil moisture-based treatment (at 30% management allowable depletion (MAD)) gave 7.94% and 27.94% more yield compared to climate-based treatments (20 mm cumulative pan evaporation (CPE)) and farmers’ practice respectively. Pumping water for irrigation was the highest energy consumption input for wheat production after chemical fertilizers. T1 = 30% MAD and T4 = 20 mm CPE treatments saved 33.71% and 35.72% energy, respectively, compared to farmers’ practice, due to water being saved. T1 and T4 treatments increased energy output by 11.40% and 6.38%, respectively, compared to farmers’ practice, in terms of grain yield and biological yield. The highest net energy (155,557.95 MJ ha−1), energy use efficiency (7.478), energy productivity (0.181 kg MJ−1) and water productivity (1.875 kg m−3) were achieved with T1 (30% MAD); however, the highest specific energy (8.148 MJ kg−1) was achieved with farmers’ practice. The results thus obtained help the farmers, stakeholder agencies and researchers to make informed decisions when choosing different treatments.