Kebede Nigusie, Ayana Mekonen, Mekonnen Boja, Beri Habtamu
Department of Water Resources Engineering, Adama Science and Technology University Adama, Ethiopia.
School of Mechanical, Chemical and Materials Engineering, Adama Science and Technology University Adama, Ethiopia.
Heliyon. 2024 Aug 27;10(17):e36968. doi: 10.1016/j.heliyon.2024.e36968. eCollection 2024 Sep 15.
A simple weighable lysimeter was designed, constructed, and calibrated for measuring the water requirements and crop coefficients of shallow-rooted crops. It has a portable weighing mechanism to quantify changes in soil moisture content. The weighing mechanism consists of a horizontal steel bar, a hydraulic car jack, both ends hooked vertical steel bars, a stand, and a digital weighing balance. As the lysimeter's inner tank, a plastic drum with a 55 cm diameter that yields 0.24 m of internal area was used. A performance test was conducted, and a rating curve was developed at the beginning of the growing seasons in 2023 and 2024 to evaluate the sensitivity of the weighing mechanism in determining crop water use. Linearity, repeatability, and measurement uncertainty tests were conducted. The linearity error was ±0.04 kg and ±0.03 kg for the years 2023 and 2024, respectively, which is within the allowable limit. The weighing system repeats the measurement perfectly with no error (repeatability error was zero). The combined uncertainty of the measurements was 0.023 kg, representing the cumulative effect of individual errors. The lysimeter weighing system is capable of detecting variations in mass as small as 0.2 mm of moisture content. Therefore, the developed lysimeter can be used to determine water requirements and crop coefficients of shallow-rooted crops for the design and management of irrigation in data-scarce areas of Ethiopia.
设计、建造并校准了一种简单的可称重蒸渗仪，用于测量浅根作物的需水量和作物系数。它有一个便携式称重装置来量化土壤含水量的变化。称重装置由一根水平钢条、一个液压汽车千斤顶、两端带钩的垂直钢条、一个支架和一个数字秤组成。作为蒸渗仪的内槽，使用了一个直径55厘米、内部面积为0.24平方米的塑料桶。在2023年和2024年生长季节开始时进行了性能测试，并绘制了评级曲线，以评估称重装置在确定作物用水方面的灵敏度。进行了线性度、重复性和测量不确定度测试。2023年和2024年的线性误差分别为±0.04千克和±0.03千克，在允许范围内。称重系统完美地重复测量，没有误差（重复性误差为零）。测量的合成不确定度为0.023千克，代表了各个误差的累积效应。蒸渗仪称重系统能够检测到小至0.2毫米含水量的质量变化。因此，开发的蒸渗仪可用于确定埃塞俄比亚数据匮乏地区浅根作物的需水量和作物系数，以用于灌溉设计和管理。
