Improvement of Irrigation Scheduling Techniques for Corn with Variable Crop Maturity Range, Plant Population and Water Supply Availability

摘要

Research was carried out to develop improved crop coefficient (CC) functions to assist calculation of evapotranspiration (ET) in the scheduling of corn irrigation. Hydraulic lysimeters were installed and were seeded to three maturity ranges of corn, with four populations of each maturity during several growing seasons. The ratio of crop ET to potential ET (ETP) was calculated to estimate points on the CC function at different growth cycle stages. The ETP was computed by a modified Penman equation calibrated in the region. Comparison was made with ET by alfalfa planted in two lysimeters. Partitioning of water use between evaporation and transpiration (T) was altered as populations increased, with more water use attributed to T.