Using Thermal Units for Crop Coefficient Estimation and Irrigation Scheduling Improves Yield and Water Productivity of Corn (Zea mays L.)

作者：Bautista Capetillo C^*; Zavala M; Martinez Cob A

来源：Journal of Irrigation and Drainage Engineering, 2013, 139(3): 214-220.

DOI：10.1061/(ASCE)IR.1943-4774.0000529

• Daily corn crop coefficients
• Water use productivity
• Grain yield
• Economic productivity

Estimates of the daily crop coefficient (Kc) for corn and irrigation scheduling were performed during 2009 and 2010 by means of two approaches: Treatment I, computation of Kc using the Food and Agriculture Organization of the United Nations (FAO) method; and Treatment II, computation of Kc from relative fraction of thermal units. Corn crop water requirements and irrigation gross depth for Treatment I were approximately 25 to 33% lower than those for Treatment II in 2009 and 2010, respectively. However, the performance of Treatment II was better in terms of grain yield, which was 9.2 Mg ha(-1) (in 2009) and 9.4 Mg ha(-1) (in 2010), approximately 37 and 29% higher, respectively, than that for Treatment I. Water productivity was approximately 10% higher for Treatment II during 2009 and practically the same percentage higher than that for Treatment I during 2010. Because of year-to-year variability, water productivity was approximately 25% (Treatment II) and 11% (Treatment I) higher for 2010 than for 2009. Finally, economic productivity for Treatment II was $2,162 ha(-1) for both seasons, much higher than that for Treatment I ($1,575 ha(-1) in 2009 and $1,679 ha(-1) in 2010). These results confirm that using fraction of thermal units to estimate corn crop coefficient has improved the yield and water management of this crop under the conditions of this study. Because of the limitations of the study (only 2 years and one experimental plot), further evaluations under other conditions (e. g., climatic, cultivar) should be performed. DOI: 10.1061/(ASCE)IR.1943-4774.0000529.

• 出版日期2013-3