Suitability of Sugarbeets for Limited Irrigation in a Semi‐arid Climate1

Abstract

AbstractTraditional heavy irrigation of sugarbeets (Beta vulgaris L.) on the Southern High Plains is being questioned because of declining pumping rates and increasing cost of energy for pumping irrigation water. The objective of this work was to determine the suitability of sugarbeets for limited irrigation in a semi‐arid climate. Sugarbeets were flood‐irrigated in level basins enclosed by dikes with water accurately measured onto each plot. Soil was Pullman clay loam (fine, mixed, thermic Torrertic Paleustolls order Mollisols), a very slowly permeable soil representative of the majority of sugarbeet acreage in this region. Irrigation schedules and amounts were varied to produce a wide range of water stress severity, duration, and timing. Weather was typical of this region; erratic precipitation totaled about one‐fourth of pan evaporation, and hot, dry, windy conditions frequently prevailed. Sugarbeets made efficient use of limited rainfall and soil profile water even when subjected to periods of water stress as long as 5 months. Irrigation water was most efficiently used when water application was adequate to maintain a nearly full canopy with no periods of major water stress or excessive water. One irrigation applied prior to onset of major water stress in July promoted high water use efficiency. Sugarbeet response to limited irrigation compares favorably to that of grain sorghum (Sorghum bicolor L.), the major summer crop presently grown on the Southern High Plains with limited irrigation. No unusual production problems have occurred with limited irrigation of sugarbeets. This work indicates that sugarbeets can be efficiently grown under a wide range of irrigation level. Sugarbeets readily adapt to limited irrigation because they utilize deep‐stored soil water and quickly recover growth following major water stress.