Comparing a Smartphone Irrigation Scheduling Application with Water Balance and Soil Moisture-based Irrigation Methods: Part II—Plasticulture-grown Watermelon

Abstract

<jats:p>A new smartphone irrigation scheduling application (VegApp) was compared with current irrigation scheduling recommendations and an automated soil moisture sensor (SMS)–based irrigation system in southern Georgia during Spring 2016 and 2017. Plants were grown using plastic mulch and drip irrigation following standard production practices for watermelon (<jats:italic>Citrullus lanatus</jats:italic>) in Georgia. The VegApp irrigation regime was based on evapotranspiration (ET<jats:sub>o</jats:sub>) values calculated from real-time data collected from a nearby weather station. Current irrigation scheduling recommendations use a water balance (WB) method. The WB method uses historic averages for determining ET<jats:sub>o</jats:sub> rates for the season. Water applied, soil water tension at 6-, 10-, and 14-inch depths, yield, and fruit quality were evaluated. In 2016, the SMS-based irrigation plots applied the least water. In 2017, the lowest amount of water was applied to plants grown using the VegApp. Total marketable yields were not significantly affected by irrigation regime. However, 45-count fruit yields were affected by irrigation in 2017. Plants grown using SMS-based irrigation had significantly higher yields of 45-count fruit than those grown using the WB method. Irrigation water use efficiency (IWUE) was affected by irrigation treatment and year. The SMS-irrigated plants had the greatest IWUE, although it was not significantly different from plants grown using the VegApp irrigation program. Internal quality parameters including, firmness, hollow heart, and total soluble solids (TSS) were not significantly affected by irrigation scheduling during the study. The results suggest that overall water applications may be reduced and yields maintained when using VegApp compared with traditional WB methods of irrigation scheduling.</jats:p>

Increasing Air Temperatures and Its Effects on Growth and Productivity of Tomato in South Florida

“…and Nakai) [ 37 ]. The SI scheduling method has not only been reported to significantly increase water savings but also increase crop yield [ 32 , 37 ] and improve iWUE [ 35 , 38 ] as well as increase in crop nutrient recovery by maintaining nutrient within the root zone [ 35 ]. More detailed information on SI technology is available at .…”

Development of a Pilot Smart Irrigation System for Peruvian Highlands

“…Assuming an efficiency of 85% for the smart irrigation setup, 308 liters were estimated to be delivered to the trees in one and a half hours compared to the application of 2,000 liters in five minutes offered by flood irrigation. Considering the soil in the Arequipa region is well known for its high drainage capabilities, the use of the proposed smart irrigation system allows farmers to effectively provide water to the root zone in a constant manner, saving water and as demonstrated in past work, maintaining yield (Miller et al 2018).…”

Automatic Irrigation Scheduling on a Hedgerow Olive Orchard Using an Algorithm of Water Balance Readjusted with Soil Moisture Sensors

“…In this relationship, ETo represents the demand imposed by the meteorological conditions while Kc integrates the physical and biophysical differences between the reference crop and the crop which is to be estimated for evapotranspiration [14]. Irrigation scheduling based on WB presents the advantage of anticipating crop water requirements at certain times during the growing season and the possibility of planning irrigation accordingly [15]. However, this method presents the disadvantage that predicted ETc values could be inaccurate because of changes in annual weather patterns and differences in the production practices for which the Kc was developed [16].…”

“…This information can then be deployed to identify and solve problems, and make optimized decisions. The simplest DSS designed to carry out automated irrigation consists of activating or deactivating irrigation when the sensor measurements are above or below predefined threshold values [15,[20][21][22][23]. A more complex proposal is a DSS which combines the WB method with soil or plant sensors to readjust the ETc [24][25][26][27].…”