High Precision Weighing Lysimeters for Evapotranspiration Measurements of Sugarcane Pre-Sprouted Plantlets

Abstract

Sugarcane pre-sprouted plantlets (PSP) production system is an innovative method to enhance crop multiplication rate. Determination of crop evapotranspiration (ETc) is crucial for water requirement identification throughout the plant cycle for irrigation management. ETc can be satisfactorily measured by weighing lysimeters. The objective of the study was to construct and calibrate three low-cost weighing lysimeters to measure ETc of PSP. The built lysimeters had 0.6909 m² area (1179 mm x 586 mm), with 400 mm depth supported by 3 load cells. Lysimeters calibration showed excellent precision measurements, due to high linear correlation (R² = 1.0000) between electric signal and equivalent mass, high accuracy, confirmed by mean absolute error between 0.0272 and 0.0382 mm, mean square error between 0.0011 and 0.0024 mm² and Willmott's index of agreement (d) equal to unit. Maximum hysteresis (0.1951 mm) and hysteresis at full scale (0.4492%) did not compromise the evaluations. Daily ETc measurements showed variation of 0.27 mm among lysimeters and were coincident with daily course of reference evapotranspiration (ETo). The cost of the equipment was low, except for the data acquisition system. Therefore, lysimeters presented low cost and were adequate to measure ETc of PSP in greenhouse-grown.

Comparison of some evapotranspiration models using lysimeter measurements in arid climate conditions

“…The essence of the system in a weighing lysimeter is that it has a mechanism that measures the change in mass. Thus, the methodology of weighing lysimeters is considered a standard in studies of water consumption of crops (Hagenau et al, 2015; Mariano et al, 2015; Libardi et al, 2018). Nevertheless, determining ET c for each region and crop is complex, time‐consuming and costly.…”

Predictive Models of Chlorophyll Content in Sugarcane Seedlings Using Spectral Images

“…An example of this is sugarcane planting using pre-sprouted seedlings (PSS). Such a technique improves plant physiological traits and speeds up the production process, associating phytosanitary quality, plant vigor, and planting uniformity (Almeida et al, 2020;Libardi et al, 2018;Aquino et al, 2018).…”