Effect of Deficit Irrigation and Intercrop Competition on Productivity, Water Use Efficiency and Oil Quality of Chia in Semi-Arid Regions

Intercropping offers greater scope to introduce new crops. Cultivation of crops with diverse root architecture and different durations enhances the productivity of scarce resources like land and water. This study aimed to determine the effect of intercrop competition and irrigation regimes on yield, competition, land usage, irrigation water use efficiency (IWUE), and fatty acids of chia. The field experiment was conducted in semi-arid India during 2020–2022 with full (I100) and deficit irrigation (I50) and six intercrops. Results demonstrated that chia + fenugreek intercropping in I50 improved the crops’ competitiveness, land equivalent ratio (LER) (1.77), land use efficiency (142.5%), and the IWUE of chia (23.2%). Notably, a chia + radish/spinach system in I50 reduced the seed yield (42.6–45.0%) of chia over I100 monocropping. A chia + fenugreek system in I50 resulted in a higher seed yield (196.2 kg ha−1) than chia monocropping in I100. Further, chia + fenugreek intercropping resulted in higher omega-3 content (56.68%) under I100. Therefore, a chia + fenugreek system under I100 may be suggested over monocropping for better yield and oil quality. However, during water scarcity situations, growers can adopt a chia + fenugreek system under I50 which can give a similar chia equivalent yield and a higher LER and IWUE compared to chia monocropping under I100.