Quantity and Frequency of Trickle and Furrow Irrigation for Efficient Cabbage Production

Trickle irrigation, with its capability of small, frequent irrigation applications, has aroused considerable interest because of possible increased production and decreased water requirements. For this reason, a replicated field investigation was conducted to evaluate quantity and frequency of trickle, modified-furrow, and standard-furrow irrigations on the growth of cabbage (Brassica oleracea capitata), using a moderately saline water on a fine-textured soil. Trickle and modified-furrow irrigations were scheduled to supply various quantities of water based on ratios of the plant's estimated consumptive use at frequencies of 3, 6, and 12 days. The modified furrow was a small furrow constructed in the center of the bed to simulate a field practice comparable to trickle irrigation. The standard-furrow irrigation was based on plant symptoms and on soil-moisture depletaion criteria. Consumptive-use measurements were made by gravimetric soil-moisture sampling on the standard-furrow irrigation. Recorded data included yield, quality of production, and water-use efficiency. Results indicated that the consumptive-use requirement (38 cm of water in 1972) for high production of cabbage was about the same for all irrigation methods. Maximum production was almost identical for all methods, whereas the application of irrigation water at less than the consumptive-use rate decreased production for the trickle and modified-furrow irrigations. Increasing the frequency of trickle irrigations decreased production when the amount of applied irrigation water was near or less than the consumptive-use rate. Therefore, frequent trickle irrigations may not necessarily be advantageous for cabbage on this soil. Trickle and modified-furrow irrigation, however, did reduce the irrigation water requirement as compared with the standard-furrow irrigation, showing that higher irrigation efficiencies can be attained with these new irrigation methods as opposed to conventional methods. Trickle or modified-furrow irrigation methods have the potential to reduce irrigation water requirements but not consumptive use under many field conditions.