Water-Table and Irrigation Effects on Corn and Sugarbeet

Abstract

THE effects of four shallow constant water-table depths and three surface irrigation levels on corn and sugarbeet yields and actual evapotranspiration (ET), were evaluated in a field-installed nonweighing lysimeters experiment. Corn total dry matter and corn grain yields were uniformly high for all three irrigation levels at the 101-cm water-table depth. At the 155-cm and 210-cm water-table depths, corn yields usually increased with greater surface irrigation. Sugarbeet yields varied considerably between water-table depths and among irrigation levels within a given water-table depth. Both corn and sugarbeet yields were much lower for the shallowest (46 cm) water table treatment. Average seasonal ET was about 519 mm for corn and was about 591 mm for sugarbeet after combining data from all water-table depths and irrigation levels. About 63% of total ET was provided by subirrigation in one lysimeter with the lowest surface irrigation level and 155-cm water table. Subirrigation from shallow water tables (101, 155, and 210 cm) contributed to ET in sizable quantities if rainfall and surface irrigation were inadequate..