ABSTRACT
Water-energy nexus plays a crucial role in addressing the issue of water wasting as well as planning, developing, and optimization of the agricultural product irrigation demands. The objective of this paper is to improve the water and energy use in value crops irrigated by center pivot systems under conventional irrigation planning in southern Algeria. This study is based on the field evaluation of the real water and electrical energy consumption, in two types of center pivot systems, large pivots and traditional Mini-Center Pivot Systems in two different areas (Ouargla and El Oued). Over two years, irrigation campaigns on six pivots systems with six different crops were analyzed to evaluate and characterize their water and electrical energy use. The CROPWAT model was used to determine the crop water requirements and compared with the water volumes currently applied by conventional irrigation planning. The results showed that there was over-consumption of water followed by high electrical energy use due to the poor planning of irrigation, which was generally excessive. In addition, the amount of water applied by conventional irrigation planning and that estimated by CROPWAT do not coincide during the most stages of crop growth. Closer inspection of the results shows that the irrigation water use efficiency for different crops was low and ranged between 0.25 and 3.27 kg/m3 due to the Over-irrigation. Furthermore, the modern pivots presented the most efficient equipment in terms of Energy Use Indicators with 1.1 kW ha−1 while the average of the traditional mini pivots was four times more (4.15 kWh−1). No significant difference was evident between the present specific consumption Es (in the average of 0.274 kWh m−3) and those reported in the literature due to high power installed in the pumping station for Mini-Center Pivot Systems. Therefore, the study findings are expected to draw the attention of decision-makers to the extent of wasting water and energy. Also, these findings reveal the harmful effects of farmers’ incorrect irrigation practices and motivate them to take strong measures toward sustainable agriculture.
Nomenclature
ETC | = | Crop evapotranspiration, mm/day |
ETO | = | Reference evapotranspiration, mm/day |
Es | = | Specific Energy consumption, (kWh m−3) |
Kc | = | Crop coefficient, dimensionless |
E | = | Electrical energy, kWh |
P | = | Power, kW |
Ti | = | Time, h |
Y | = | productivity of the crop, (kg/ha) |
Q | = | Water used by the crop, (m3/ha) |
Abbreviations
CPS | = | Center pivot systems |
CIP | = | Conventional Irrigation Planning |
MCPS | = | Mini-center pivot systems |
CWRs | = | Crop water requirements |
IWUE | = | Irrigation water use efficiency |
FAO | = | Food and Agriculture Organization |
Highlights
Water and energy nexus in the agricultural sector for the arid regions is a major challenge.
Irrigation Water management is paramount to the sustainability of water and energy use.
Assessment of irrigation systems using energy efficiency and crops production indicators.
The good management of water-energy use leads to crops production improvement.
CROPWAT 8.0 software is a good tool for Water-Energy-Food Linkages.
Disclosure statement
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.