Performance Evaluation of Micro Irrigation Management

Principles and Practices

Megh R. Goyal

• Publisher: Apple Academic Press
• Year: 2016
• ISBN:
  9781315342245
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

This new volume in the Innovations and Challenges in Micro Irrigation series covers an array of technologies to estimate evapotranspiration and to evaluate parameters that are needed in the management of micro irrigation, with worldwide applicability to irrigation management in agriculture. Topics include recent evapotranspiration research, performance evaluation of filters and emitters, evaluation of fertigation and ground water with treated wastewater effluent, performance of pulse drip irrigated potato under organic agriculture practices in sandy soils, impact of polyethylene mulch on micro irrigated cabbage, and tree injection irrigation.

PART I

PRINCIPLES OF MICRO IRRIGATION

CHAPTER 1

RECENT EVAPOTRANSPIRATION RESEARCH IN PUERTO RICO

ERIC W. HARMSEN, VICTOR J. REVENTOS, and JOHN MECIKALSKI

CONTENTS

1.1 Introduction

1.2 Early Evapotranspiration Studies in Puerto Rico

1.3 Recent Evapotranspiration Studies in Puerto Rico

1.4 Future Work

1.5 Conclusions

1.6 Summary

Acknowledgements

Keywords

References

1.1 INTRODUCTION

Knowledge of evapotranspiration (ET) is essential for efficient agricultural water management. Efficient use of water for agricultural production has become a moral and ethical issue, considering such factors as increasing global population, dwindling water supplies, widespread degraded water quality, climate variability, and 70% of all water withdrawn is used for agriculture, and most of this is used for irrigation [22, 53]. The purpose of this chapter is to summarize recent ET studies conducted in Puerto Rico. Each of these studies has had at its core, the goal of more accurately estimating crop water requirements and increasing water use efficiency.

Puerto Rico is located in the Greater Antilles between the islands of Hispaniola and the U.S. Virgin Islands and has a land area of approximately 9,100 square kilometers. The climate varies significantly over the island. Rainfall is highly influenced by the Eastern Trades Winds and the orographic effect of the Cordillera Central, a chain of east-west-oriented mountains located along the center of the island. Elevations vary from 0 m mean sea level (msl) along the coasts to approximately 1,300 m msl at Cerro de Punta. Annual rainfall varies from 735 mm at Ponce in Southwest Puerto Rico, to 2,160 mm at Mayaguez in Western Puerto Rico, to 4,370 mm at El Yunque National Forest in Northeast (Pico del Este), Puerto Rico. Puerto Rico has wet and dry seasons. The dry season is from December to April and is caused by a low-level temperature inversion in the easterly trade winds [4]. The wet season is generally from May through October, with some reduction in rainfall during the Caribbean mid-summer drought [5]. Angeles et al. [3] provided insight into the influence of Saharan dust and high level wind shear on the rainfall reduction during mid-summer in Puerto Rico. In much of Puerto Rico, it is difficult to establish a new crop during the dry season without irrigation, while in southern Puerto Rico, irrigation is essentially mandatory for crop production because the annual rainfall is only half of the potential ET.

1.2 EARLY EVAPOTRANSPIRATION STUDIES IN PUERTO RICO

Numerous ET studies have been conducted in Puerto Rico over the years. Harmsen [27] presented a review of ET studies in Puerto Rico prior to 2000, while Goyal and Harmsen [21, 34] reported on several additional studies that have occurred since 2000.

Early efforts to determine crop water requirements in Puerto Rico (1950–1980), by necessity, relied on field measurements based on non-weighing lysimeters or soil water balance methods [10: sugarcane; 51: guinea grass, para grass and guinea grass-kudzu and para grass-kudzu mixtures; 52: sugarcane; 1: plantains; 48: rice]. During the 1980s, meteorological methods were employed to estimate crop water requirements. A number of studies were conducted for various crops using the Blaney Criddle [50] method [13: fifteen different vegetable crops]. See also Goyal and González [15; 14: papaya], Goyal and González-Fuentes [20: sugarcane; 16: sorghum; 18: plantain].

The Hargreaves-Samani [HS, 25] reference ET (ETo) method was employed by González-Fuentes and Goyal [12], in combination with a crop coefficient, to estimate the consumptive use for corn. The HS ETo has been estimated at various locations in Puerto Rico, including: Central Aguirre, Fortuna and Lajas substations [16], Vieques Island [17], and at thirty-four separate locations in Puerto Rico in one study alone [19].

A number of pan evaporation studies were conducted to estimate ETo by Goenaga and his colleagues at USDA-TARS – Mayaguez [1993 – plantains under semiarid conditions, 1994 tanier, 1995 – bananas under semiarid conditions, 1998 – banana under mountain conditions] and Santana Vargas [2000 – watermelon under semiarid conditions].

1.3 RECENT EVAPOTRANSPIRATION STUDIES IN PUERTO RICO

Harmsen and Torres-Justiniano [29] compared estimates from the Penman-Monteith ETo method [PM, 2], based on estimated climate data [30], with estimates of HS ETo for thirty-four locations in Puerto Rico and found reasonably good agreement between the two methods. A user-friendly computer program, available to the public, was developed for the climate parameter estimation procedure called PRET [28].

Harmsen et al. [31] evaluated pan coefficient data for evaporation pans, derived by González and Goyal [11]. The objective of the study was to compare pan coefficients, based on pan evaporation data from 1960–1980 with pan coefficients based on pan evaporation data from 1980–2000. The pan coefficient is derived from the equation: kp = E/ETo, where kp is the pan coefficient, E is pan evaporation. In the González and Goyal [11] kp study, they used the Blaney-Criddle method to estimate ETo. The study of Harmsen et al. [31] concluded that there were significant differences in kp values between the two periods, and presented recommendations for new kp values, based on pan data from the later time period (1980–2000) and use of the Penman-Monteith ETo.

Harmsen et al. [33] developed a field methodology for estimating actual ET. The goal of the project was to develop an instrument that provided accurate ET but at a much lower cost than eddy covariance or weighing lysimeter systems. The “ET station” consisted of a movable temperature and humidity sensor raised and lowered between two vertical positions at two-minute intervals (twelve readings at each position) to obtain the humidity gradient. In the theoretical formulation, a humidity gradient flux equation [38] is equated with the generalized Penman Monteith (GPM) equation (equation 3 in 2) and resolved for the bulk surface resistance (r_s). Once r_s is obtained, all parameters and variables were available for estimating ET using the GPM method. The instrument was compared against an eddy covariance system at the University Florida Agricultural Experiment Station near Gainesville Florida in 2004 and at the University of Puerto Rico Agricultural Experiment Station at Lajas, Puerto Rico in 2005. The ET station compared favorably with the Eddie covariance systems. The advantage of the ET station is that its cost is approximately 1/7 the cost of an Eddie covariance system and about 1/20 of the cost of a weighing lysimeter.

Ramirez-Builes [47] conducted several ET studies for common bean (phaseolus vulgaris) in Puerto Rico, with topics including: development of linear models for non-destructive leaflet area estimation; physiological response of different common bean genotypes to drought stress; ET and crop coefficients for two common bean genotypes with and without drought stress; surface resistance estimates from micro-meteorological data; crop measurements under variable leaf area index and soil moisture; crop water stress indices and yield components for common bean genotypes in greenhouse and field environments; and water use efficiency and transpiration efficiency for the two common bean genotypes. See also Ramirez et al. [46], Ramirez et al. [45], Porch et al. [41], and Ramirez et al. [43, 44]

Collaboration was initiated in 2009 between the University Puerto Rico and the University of Alabama in Huntsville, resulting in the availability of a remotely sensed solar radiation product for the northern Caribbean region [34]. Solar insolation estimates are developed from GOES visible data at 1 and 2-km resolution over Puerto Rico and the Caribbean, respectively, and are provided at 30-min time frequency each day (~5 am through 8 pm Local Time). The methods of Diak and Gautie [6], Diak et al. [7] and Paech et al. [40] are utilized, with validation of the solar insolation provided in Otkin et al. [39] and Mecikalski et al. [37]. These GOES solar radiation data are a critical input parameter for ETo equations, for example the GPM, the Hargreaves radiation [24] and the Priestly-Taylor [PT; 42] methods, among others. As noted, the spatial resolution of the GOES product is 2-km, however, there is a sub-set of data available for Puerto Rico and the US Virgi...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of Contributors
• List of Abbreviations
• List of Symbols
• Preface
• Warning/Disclaimer
• About Senior Editor-in-Chief.
• Book Endorsements
• Other Books on Micro Irrigation by Apple Academic Press Inc
• PART I: PRINCIPLES OF MICRO IRRIGATION
• PART II: EVALUATION OF MICRO IRRIGATION
• PART III: MICRO IRRIGATION PRACTICES IN AGRICULTURAL CROPS
• Appendices
• Index