Estimation of evapotranspiration and single and dual crop coefficients of acai palm in the Eastern Amazon (Brazil) using the Bowen ratio system

Abstract

The acai palm (Euterpe oleracea Mart.) is a fruit from the Amazon that is originally found in flooded areas. Over recent years, its marketability has gained significant interest in Brazil and abroad because of its agronomic, nutritional and economic potential. However, there is a lack of technical-scientific information about crop water requirements for irrigation management during the reproductive phase of acai palm. Therefore, the aim of this research was to estimate the water requirements (crop evapotranspiration (ET c ), single (Kc) and dual (Kcb + Ke) crop coefficients) of acai palm in the Eastern Amazon (Brazil) using the Bowen ratio system. A micrometeorological tower was installed in the center of an experimental area to monitor ET c and meteorological variables. Phenological development was monitored during two growing seasons. Soil water evaporation was determined on a daily scale using weighing microlysimeters. Ke and Kcb values were calculated by the ratio of soil surface evaporation and transpiration to reference evapotranspiration (ET o ), respectively. Total water requirements of the acai palms were 1165 mm, with a daily average of 3.49 mm day −1 for the growing season. The average values of Kc, Ke and Kcb for the acai palm were 1.08; 0.21 and 0.84, respectively. The findings will assist the design of irrigation management protocols for acai trees that are better tailored to satisfy crop water requirements. This will allow improved water use efficiency, ensuring tree crop sustainability.

Comparison of Shuttleworth–Wallace and Dual Crop Coefficient Method for Estimating Evapotranspiration of a Tea Field in Southeast China

“…As for perennial plants, the average K c values (0.86) found for the tea plants in this study were lower than that reported by Pinho Sousa et al [51] for acai palm (=1.08), Meijide et al [52] for palm oil (=1.03), and Flumignan et al [53] for coffee trees (=1.28 for ET 0 < 3 mm d −1 , 0.98 for ET 0 > 3 mm d −1 ). The possible reason for this is that the K c in this study was determined using the dataset in 2015, while the tea plants were transplanted into the field in March 2014, which means the values of K c were at the initial stage of the tea plants.…”

Irrigation Optimization via Crop Water Use in Saline Coastal Areas—A Field Data Analysis in China’s Yellow River Delta

“…The conventional approach to estimating ET C in saline coastal farmlands is subject to many limitations and uncertainties. The observation methods at the farm scale include the lysimeter method [ 9 , 10 ], the Bowen ratio method [ 11 , 12 ], the eddy covariance method [ 13 , 14 ], etc. However, because soil salinity in coastal farmlands leads to erosion and degradation of the sensors and other parts of monitoring equipment, the accuracy and reliability of the data collected can be limited.…”

Energy Partitioning and Latent Heat Flux Driving Factors of the CAM Plant Pineapple (Ananas comosus (L.) Merril) Grown in the South Subtropical China

“…Accurate monitoring of surface energy fluxes is fundamental to the study of energy partitioning and its response mechanisms. Energy fluxes can be measured by a variety of techniques, such as eddy correlation and the Bowen ratio energy balance (BREB) system [ 21 ]. The BREB method has emerged as a standard tool for continuously and conveniently measuring energy fluxes across large, homogenized surface areas.…”

“…This technique has found successful applications in the study of energy fluxes, their distribution, and water–heat exchange in both grassland and agricultural ecosystems [ 22 , 23 , 24 , 25 ]. The Bowen ratio ( β = H / LET ) is a crucial parameter of energy partitioning that reflects the ratio of sensible and latent heat distribution [ 21 ]. LET , which links water consumption in agro-ecosystems to the energy driving evapotranspiration [ 23 ], holds critical importance for agricultural water management, crop growth and yield [ 24 ].…”