Improvement of water saving and economic productivity based on quotation with sugar content of sugar beet using linear move sprinkler irrigation

Abstract

This study was aimed to improve water saving and economic productivity based on quotation with sugar percentage of sugar beet (Beta vulgaris L.) using linear move sprinkler system (LMSS). The experiments were carried out in Western Central Anatolia Region of Turkey during the growing seasons of 2012–2014 for 3 years. The irrigation treatments were applied as I1: full irrigation, I2: I1 × 0.80, I3: I1 × 0.60, I4:I1 × 0.40 and I5: I1 × 0.20 using 4 replications and systematically arranged due to the feature of LMSS. The I1 was based on deficit soil moisture in the soil depth of 90 cm according to the field capacity for each 7 days. Different regulated deficit irrigation levels were, thus, created for each irrigation cycle based on I1. The seasonal yield-response factor (Ky) was 0.50. The main reason of the lower of the Ky could be because of frequent irrigation and climatic characteristics. Full irrigation (842 mm) resulted in the highest sugar beet yield (77.8 t ha−1) but did not provide the highest net margin. The main reason for this was that the sugar content of sugar beet decreased with increasing irrigation water, and the sugar beet sales price was determined according to the sugar content. This also enabled the lower amount of irrigation water (687 mm) of 20% lower than full irrigation (842 mm). Irrigation water, yield, sugar content and net margin were, thus, 687 mm, 73.5 t ha−1, 16.5% and 1221 US $ ha−1, respectively. Sugar beet could be irrigated using LMSS in high profitability in irrigation interval of 7–10 days and applying water of 45–65 mm for each irrigation cycle. An appropriate net margin (1074 US $ ha−1) could be obtained using irrigation water less than 40% of full irrigation in case of limited water because net income was still more than about 40% of total cost. The quotation of the sugar beet sales price according to the sugar content and the increase in the sugar content in the lower irrigation showed that significant water savings can be practiced in irrigation water without much loss of income.