Precipitation and Drip Irrigation Effects on Soil Water Dynamics in a Semi-arid Agrosystem
Discipline: Ecology Environmental and Earth Sciences
Subcategory: environmental science
Session: 2
Room: 2 - International Ballroom North
Yeishmary M. Soto Muñiz - University of Puerto Rico Rio Piedras
Co-Author(s): Dr. Elvira Cuevas Viera and Dr. Solimar Pinto Pacheco
Water deficit poses a threat to plant productivity and growth, especially in semi-arid regions. In Puerto Rico, 53.54% of fruit and vegetable production occurs in the south, where a semi-arid climate limits water availability and agricultural productivity. This research is conducted at Finca Atabey, Santa Isabel, Puerto Rico, on the southern coast of the island of Puerto Rico, characterized by high temperatures, low pulsing precipitation, high winds, and frequent droughts. Crops at our study site almost exclusively rely on drip irrigation. In this ongoing research, we explore how drip irrigation and pulse precipitation affect soil water availability in avocado and pumpkin crops grown in two alluvial soil types: clay-loam (“Jacaguas” series) and clay (“San Antón” series). Meteorological data is collected with an ATMOS41W weather station installed on-site. Simultaneously, soil profile data is gathered via METER Group TEROS 12 sensors, which measure water content, soil temperature, and electrical conductivity at three depths: a) 0 – 15 cm, b) 15 – 30 cm, and c) 35 – 50 cm. We hypothesize that during prolonged rainfall events, soil-water intake will occur at a slower rate in comparison to pulsing precipitation and/or drip irrigation. Additionally, we hypothesize that conductivity and water content will vary between the two soil types. Preliminary results reaffirm semi-arid conditions with a cumulative precipitation of 200.97 mm from March to mid-November. Finca Atabey exhibits high evapotranspiration with only 31 wet days–defined as days with over 6 mm of rainfall–since March. So far, May has been the wettest month. Results also indicate water content differences among soil types: on Jacaguas, soil water content is lower than in San Antón. There are differences in water content among depths where from 0 – 15 cm it was higher in the Jacaguas site (12 – 40%) and from 15 – 30 cm higher in the San Antón site (22 – 35%). Water content also peaked after a significant pulsing event associated with Tropical Storm Ernesto. This was highly relevant in the Jacaguas site where it increased 20% at 0 – 15 cm depth. In contrast, no significant change was observed in San Antón, suggesting that soil texture plays a role in water retention. There is very little data on soil water dynamics in the region, therefore our ongoing study will continue to provide highly relevant information for water use and crop resilience, especially under projected drier conditions due to climate change.
Funder Acknowledgement(s): 1. Puerto Rico Louis Stokes Alliance for Minority Participation ROUSS Program. 2. CREST Postdoctoral Research Program, Award ID 2329343
Faculty Advisor: Dr. Elvira Cuevas Viera, elvira.cuevas@upr.edu
Role: I am a student researcher at the laboratory conducting my senior thesis. I developed a proposal and am in charge of analyzing the data that is obtained from the sensors. This is part of a postdoctoral research study conducted by my co-mentor, Dr. Solimar Pinto Pacheco, at the site.