TITLE:
Evapotranspiration, Grain Yield, and Water Productivity of Spring Oat (Avena sativa L.) under Semiarid Climate
AUTHORS:
Koffi Djaman, Michael O’Neill, Curtis Owen, Komlan Koudahe, Kevin Lombard
KEYWORDS:
Spring Oat, Genotypes, Evaluation, Grain Yield, Water Productivity, High Elevation, Semiarid Climate
JOURNAL NAME:
Agricultural Sciences,
Vol.9 No.9,
September
28,
2018
ABSTRACT: Spring oat (Avena sativa) is produced for grain, hay, and green manure and can be integrated into a cropping system as a cover crop. Twenty-eight oat genotypes (G1, G2, G3, …., G28), selected for their adaptability to the Southwestern United States, were evaluated for their yield performance under sprinkler irrigation during four growing seasons (2005-2008) at the Agricultural Science Center at Farmington, New Mexico State University. The genotypes were arranged in randomized complete blocs design with four replications. Irrigation scheduling was based on evapotranspiration and the depletion criterion of 40% to 45% total available water (TAW) was practiced to prevent the plants from experiencing any water stress. Crop evapotranspiration estimated by the FAO crop coefficient and reference evapotranspiration approach was low about 2 mm/day during crop initial stage and increased with plant growth and reached the maximum during crop mid-season or reproductive stage. It decreased during crop late season. Daily crop evapotranspiration varied from 0.5 to 12.6 mm in 2008 and the seasonal Spring oat evapotranspiration varied from 535.8 to 591 mm. Averaged across the four growing seasons, oat evapotranspiration was 570.4 mm. The results showed that Spring oat plant height varied significantly with genotypes and ranged from 59.1 to 100.8 cm. Oat grain yield significantly varied with years and genotypes. Grain yield varied from 3386 to 6498 kg/ha and average yield was 4245, 4265, 5477, and 4025 kg/ha during the 2005, 2006, 2007 and 2008, respectively. The best performing genotypes were G1, G2, G7, G19, G20, G21 and G23 with average yield greater than 4800 kg/ha while G3, G13, G17 and G27 showed the lowest yield among the genotypes. Oat crop water use efficiency (CWUE) varied with genotype and years and ranged from 0.53 to 1.07 kg/m3 and averaged 0.65, 0.78, 0.91 and 0.70 kg/m3 in 2005, 2006, 2007 and 2008, respectively. The highest CWUE was achieved by G19 and the lowest CWUE was obtained by G13. Irrigation water use efficiency (IWUE) which represents the quantity of yield produced per cubic meter of water, varied from 0.57 to 1.20 kg/m3 while evapotranspiration water use efficiency (ETWUE) varied with genotype and year and ranged from 0.57 to 1.21 kg/m3 with the overall IWUE mean of 0.83 kg/m3 and ETWUE mean of 0.81 kg/m3.