YIELD-BASED, IRRIGATED ONION CROP COEFFICIENTS
YIELD-BASED, IRRIGATED ONION CROP COEFFICIENTS
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DOI：
10.13031/2013.5835
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发表时间：
1999
影响因子：
0.9
通讯作者：
M. Al-Jamal;T. Sammis;S. Ball;D. Smeal
中科院分区：
文献类型：
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作者：
M. Al-Jamal;T. Sammis;S. Ball;D. Smeal
灌溉计划是制定灌溉项目最佳管理实践 (BMP) 的最重要工具之一。适当的灌溉调度可以提高灌溉用水效率，从而保护有限的水资源。有关作物系数 (Kc)、每日参考蒸散量 (Eto) 和每日蒸散量 (Et) 的信息对于灌溉计划非常重要。进行梯度喷水线源灌溉实验以确定灌溉洋葱的 Kc。本研究获得的 Kc 曲线与 Doorenbos 和 Kassam (1986) 描述的典型 Kc 曲线相对应，最大 Kc 为 1.09，与在非水分胁迫条件下获得的最大产量 73 000 kg ha –1 相关。生长度日 (GDD) 与 Kc 值相关，并拟合为三阶多项式。对结果进行积分以确定与最大产量相关的最大 Kc。使用 GDD 和相对峰值 Kc 开发了四次方程来预测选定产量水平的 Kc。该方程的开发是为了帮助洋葱种植者建立特定产量的 Kc 曲线。通过该方法获得的非水分胁迫产量水平 73 000 kg ha –1 的模拟 Kc 曲线与实测曲线相似。这种新方法很实用，可以让农民了解洋葱作物的预测季节性灌溉用水需求。此外，这种方法简单易用，可以安排洋葱的灌溉事件。
Irrigation scheduling is one of the most important tools for developing best management practices (BMPs) for irrigated projects. Proper irrigation scheduling results in the high irrigation water use efficiencies necessary to conserve limited water resources. Information about crop coefficient (Kc), daily reference evapotranspiration (Eto), and daily evapotranspiration (Et) is important for irrigation scheduling. A gradient sprinkler line source irrigation experiment was conducted to determine the Kc for irrigated onion. The Kc curve obtained from this study corresponds to the typical Kc curve described by Doorenbos and Kassam (1986), with a maximum Kc of 1.09 associated with a maximum yield of 73 000 kg ha –1 , obtained under non-moisture-stress conditions. Growing degree days (GDD) were correlated to the Kc values, which were fitted to a third-order polynomial. The results were integrated to determine the maximum Kc associated with maximum yield. A quartic equation was developed using GDD and relative peak Kc to predict a Kc for a selected yield level. This equation was developed to help onion growers to establish the Kc curve for particular yield. The simulated Kc curve obtained from this method for the non-moisture-stress yield level of 73 000 kg ha –1 was similar to the one measured. This new method is practical and gives farmers an idea of the predicted seasonal irrigation water requirements for their onion crop. In addition, this method is simple and easy to use to schedule irrigation events for onion.