Determination of growth-stage-specific crop coefficients (KC) of maize and sorghum
Determination of growth-stage-specific crop coefficients (KC) of maize and sorghum
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DOI:
10.1016/j.agwat.2009.06.024
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发表时间:
2009-12
影响因子:
6.7
通讯作者:
G. Piccinni;Jonghan Ko;T. Marek;T. Howell
中科院分区:
文献类型:
--
作者:
G. Piccinni;Jonghan Ko;T. Marek;T. Howell
A ratio of crop evapotranspiration (ETC) to reference evapotranspiration (ETO) determines a crop coefficient (KC) value, which is related to specific crop phenological development to improve transferability of the KCvalues. Development of KCcan assist in predicting crop irrigation needs using meteorological data from weather stations. The objective of the research was conducted to determine growth-stage-specific KCand crop water use for maize (Zea Mays) and sorghum (Sorghum bicolor) at Texas AgriLife Research field in Uvalde, TX, USA from 2002 to 2008. Seven lysimeters, weighing about 14Mg, consisted of undisturbed 1.5m×2.0m×2.2m deep soil monoliths. Six lysimeters were located in the center of a 1-ha field beneath a linear-move sprinkler system equipped with low energy precision application (LEPA). A seventh lysimeter was established to measure reference grass ETO. Crop water requirements, KCdetermination, and comparison to existing FAO KCvalues were determined over a 3-year period for both maize and sorghum. Accumulated seasonal crop water use ranged between 441 and 641mm for maize and between 491 and 533mm for sorghum. The KCvalues determined during the growing seasons varied from 0.2 to 1.2 for maize and 0.2 to 1.0 for sorghum. Some of the values corresponded and some did not correspond to those from FAO-56 and from the Texas High Plains and elsewhere in other states. We assume that the development of regionally based and growth-stage-specific KChelps in irrigation management and provides precise water applications for this region.