Simulation of irrigation requirements for major crops in south western Quebec

Supplemental irriga tion is important in south western Quebec to ensure maximum crop production. This study was conducted to determineirrigationrequire ments for major crops grown in this area. Soil moisture simulations were performed using the Versatile Soil Moisture Budget version IV in order to quantify irrigation requirements for nine crops and three soil types using meteorological records from ten stations. Weekly water deficits were determined at five probability levels. Results showed that crops grown on loamy sand exhibit a wider range of variation in year to year irrigation requirements when compared to cropsgrownon clay loam.Maximumrooting depth androot develop ment affect the magnitude and distribution of water deficits within the growing season. Tables of peak and seasonal irrigation requirements that can be used for irrigation system design are presented.