|Allen R R,|
|Musick J T,|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 9, 1995
Publication Date: N/A
Interpretive Summary: Much of the irrigated winter wheat in the Southern High Plains is managed with furrow irrigation. Improved methods are needed to efficiently manage the irrigation water that is available because supplies are limited. By blocking the ends of wheat furrows and eliminating irrigation water from running off ends of fields, the amount of irrigation water used to grow a crop was reduced by 22% without reducing grain yield on fields with moderate slope. This method saved 7,800 gallons of irrigation water per acre and provided irrigation water use efficiency comparable to that with well managed sprinkler irrigation. This method of furrow irrigating wheat on moderate slopes offers growers an opportunity to improve irrigation efficiency without the expense of purchasing sprinkler equipment.
Technical Abstract: A study was conducted to determine the effectiveness of blocking furrow ends and cutting-off furrow inflow earlier to eliminate runoff and save water, rather than using the common practice of 4 to 6 h runoff to wet the lower ends of fields. Earlier cutoff is feasible with irrigated wheat because wetting of beds closely follows furrow advance. Both adequate (3-4 applic.) and deficit (1-2 applic.) irrigation regimes were evaluated during the 3-year study. With adequate irrigation, the elimination of runoff with blocked furrows and earlier cutoff reduced average gross irrigation applications from 430 to 335 mm (16.9 to 13.2 in) or 22% without reducing grain yield. Seasonal water use savings averaged 95 mm (3.75 in) with adequate irrigation. With deficit irrigation, water savings were 17% of 48 mm (2 in). Grain yields averaged 5.6 Mg/ha (83 bu/ac) and 4.2 Mg/ha (63 bu/ac), respectively, with adequate and deficit irrigation on blocked furrows. An average seasonal water use efficiency of 0.88 kg/m**3 (3.3 bu/ac-in) with adequate irrigation on blocked furrows compared favorably with efficiencies obtained with low-pressure spray nozzles or level basins.