Potential evapotranspiration for the south coast of Puerto Rico with the Hargreaves-Samani technique

1969 ◽  
Vol 72 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Megh R. Goyal
Keyword(s):  
Water Management ◽  
Puerto Rico ◽  
Potential Evapotranspiration ◽  
South Coast ◽  
Semiarid Region ◽  
Crop Water ◽  
The South ◽  
Water Requirements ◽  
Vegetables And Fruits ◽  
Maximum Minimum

The Hargreaves and Samani model was used to estimate monthly potential evapotranspiration (PET) for Central Aguirre, Fortuna and Lajas substations and Magueyes Island located on the south coast of Puerto Rico. The model uses maximum, minimum and average temperatures. Daily PET varies from 3.68 to 5.37 mm/day in the region with minimum in December and maximum in July. Annual PET was 1613.3 mm/year for Central Aguirre, 1653.5 for Fortuna, 1846.9 for Lajas, 1857.9 for Magueyes Island, with a regional average of 1704.6. These PET values can be used to estimate crop water requirements for vegetables and fruits, to plan irrigation and water management projects, and to schedule irrigation in the semiarid region of Puerto Rico.

scholarly journals Water Management Using Drones and Satellites in Agriculture

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 874 ◽  
Author(s):  
Javier J. Cancela ◽  
Xesús P. González ◽  
Mar Vilanova ◽  
José M. Mirás-Avalos
Keyword(s):  
Water Management ◽  
Remote Sensing ◽  
Water Status ◽  
Irrigation Management ◽  
Irrigation Efficiency ◽  
Agricultural Systems ◽  
Special Issue ◽  
Crop Water ◽  
Water Requirements ◽  
Remote Sensing Techniques

This document intends to be a presentation of the Special Issue “Water Management Using Drones and Satellites in Agriculture”. The objective of this Special Issue is to provide an overview of recent advances in the methodology of using remote sensing techniques for managing water in agricultural systems. Its eight peer-reviewed articles focus on three topics: new equipment for characterizing water bodies, development of satellite-based technologies for determining crop water requirements in order to enhance irrigation efficiency, and monitoring crop water status through proximal and remote sensing. Overall, these contributions explore new solutions for improving irrigation management and an efficient assessment of crop water needs, being of great value for both researchers and advisors.

SYSTEMS-BASED LAND-USE EVALUATION AT THE SOUTH COAST OF PUERTO RICO

1998 ◽  
Vol 14 (2) ◽  
pp. 191-200 ◽  
Author(s):  
J. W. Hansen ◽  
F. H. Beinroth ◽  
J. W. Jones
Keyword(s):  
Land Use ◽  
Puerto Rico ◽  
South Coast ◽  
The South

scholarly journals Variation in the estimations of ET<sub>o</sub> and crop water use due to the sensor accuracy of the meteorological variables

2013 ◽  
Vol 13 (6) ◽  
pp. 1401-1410 ◽  
Author(s):  
R. Moratiel ◽  
A. Martínez-Cob ◽  
B. Latorre
Keyword(s):  
Water Management ◽  
Wind Speed ◽  
Relative Humidity ◽  
Irrigation Water ◽  
Meteorological Variables ◽  
Crop Water ◽  
Water Requirements ◽  
Crop Water Use ◽  
Irrigation Districts ◽  
Annual Scale

Abstract. In agricultural ecosystems the use of evapotranspiration (ET) to improve irrigation water management is generally widespread. Commonly, the crop ET (ETc) is estimated by multiplying the reference crop evapotranspiration (ETo) by a crop coefficient (Kc). Accurate estimation of ETo is critical because it is the main factor affecting the calculation of crop water use and water management. The ETo is generally estimated from recorded meteorological variables at reference weather stations. The main objective of this paper was assessing the effect of the uncertainty due to random noise in the sensors used for measurement of meteorological variables on the estimation of ETo, crop ET and net irrigation requirements of grain corn and alfalfa in three irrigation districts of the middle Ebro River basin. Five scenarios were simulated, four of them individually considering each recorded meteorological variable (temperature, relative humidity, solar radiation and wind speed) and a fifth scenario combining together the uncertainty of all sensors. The uncertainty in relative humidity for irrigation districts Riegos del Alto Aragón (RAA) and Bardenas (BAR), and temperature for irrigation district Canal de Aragón y Cataluña (CAC), were the two most important factors affecting the estimation of ETo, corn ET (ETc_corn), alfalfa ET (ETc_alf), net corn irrigation water requirements (IRncorn) and net alfalfa irrigation water requirements (IRnalf). Nevertheless, this effect was never greater than ±0.5% over annual scale time. The wind speed variable (Scenario 3) was the third variable more influential in the fluctuations (±) of evapotranspiration, followed by solar radiation. Considering the accuracy for all sensors over annual scale time, the variation was about ±1% of ETo, ETc_corn, ETc_alf, IRncorn, and IRnalf. The fluctuations of evapotranspiration were higher at shorter time scale. ETo daily fluctuation remained lower than 5 % during the growing season of corn and alfalfa. This estimation fluctuation in ETo, ETc_corn, ETc_alf , IRncorn, and IRnalf at daily time scale was within an acceptable range, and it can be considered that the sensor accuracy of the meteorological variables is not significant in the estimation of ETo.

Sequential sampling plan for corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in corn fields on the south coast of Puerto Rico.

1969 ◽  
Vol 92 (3-4) ◽  
pp. 207-214
Author(s):  
Lymari M. Calero-Toledo ◽  
Raúl Macchiavelli ◽  
Ángel L. González
Keyword(s):  
Puerto Rico ◽  
Helicoverpa Zea ◽  
Sequential Sampling ◽  
Corn Earworm ◽  
Sampling Plan ◽  
South Coast ◽  
Effective Control ◽  
The South ◽  
Sequential Sampling Plan ◽  
Corn Fields

The corn earworm, Helicoverpa zea (Boddie), is the major insect pest of corn, Zea mays L., in Puerto Rico. The objective of this study was to design a sequential sampling plan with fixed precision levels for H. zea (Boddie) in corn fields on the south coast of Puerto Rico. For determining the presence (= 1) or absence (= 0) of H. zea eggs, 25 corn plants were randomly sampled from December 2003 to March 2004. Data were analyzed by using the beta binomial distribution. Critical density levels of 0.10 and 0.08 infested plants, before and after the emergence of ear silks, were used for Iwao's and converging lines formulae. A converging line sampling plan is recommended because it selected a smaller average sample size. This plan can be used to make cost effective control decisions on field corn in Puerto Rico.

scholarly journals Estimation of Crop Water Requirements in Irrigated Land of the Khorezm Oasis in the Context of Climate Change

2019 ◽  
Vol 8 (1) ◽  
pp. 94
Author(s):  
Stulina Galina ◽  
Solodkiy Georgy ◽  
Eshtchanov Odilbek
Keyword(s):  
Climate Change ◽  
Water Discharge ◽  
Left Bank ◽  
Crop Water ◽  
The South ◽  
Water Requirements ◽  
Amu Darya ◽  
Crop Water Requirements ◽  
Air Temperatures ◽  
Amu Darya River

Khorezm province is located in the northwest part of Uzbekistan in the basin of one of largest water sources &ndash; the Amu Darya River - and occupies the left bank in the Amu Darya lower reaches. The area of the province is 6,100 km2. The province borders Karakalpakstan in the North, Turkmenistan in the South, and Bukhara province of Uzbekistan in the South-East. Uzbekistan is situated in the territory, where high rates of climate change are expected and observed. According to forecasts, further climate change would cause even higher air temperatures, altered precipitation patterns and severe and prolonged droughts, with consequent lowering of available water resources. More plausible scenarios for Uzbekistan suggest more than 4&deg;С rise in average annual air temperatures by 2080. Water discharge along the Amu Darya River is expected to decrease potentially by 10-15%. Objective of given work is to analyze and assess the positive impacts of climate change through alterations of bioclimatic potential in given terrain and agromelioration parameters of crops, with consequent changes in crop water requirements. Earlier research results showed that the observed growth of thermal potential allows earlier sowing and more rapid accumulation of effective temperatures. This will shorten plant development phases, on the one hand, and, as a result, reduce water use by crops, on the other hand.

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