Water Requirements, Soil Moisture Availability, and Their Effects on Quinoa (Chenopodium quinoa Willd.) Development and Yield

Throughout the world, about 70% of the total water is used for irrigation. Reports show that there will be a significant increase in irrigation requirements, as irrigation is an important factor affecting water footprint and productivity worldwide [45]. The experiment described in this article was carried out at the Agricultural Research Station, Ministry of Agriculture, Iraq, in 10 kg pots to evaluate the effects of soil moisture availability on water requirements, water productivity, and quinoa crop productivity under different irrigation treatments. These treatments maintained the soil at different levels of soil water tension (-0.05, -0.10, -0.15, -0.30, and -0.40 MPa) during the vegetative and/or reproductive periods of growth. The study analyzed water consumption, plant growth, yield components, and water productivity of the quinoa crop. The data showed that evapotranspiration decreased with increasing soil moisture tension during both the vegetative and reproductive periods of development. The maximum water productivity was consistently recorded at the lowest soil moisture tension, highlighting moisture efficiency. It was concluded that quinoa is relatively tolerant to soil moisture stress during the vegetative period compared to the reproductive period. The number of grains per ear was identified as a limiting factor for grain yield.