A. G. Smajstrla's research while affiliated with Instituto Agronômico do Paraná and other places

Publications (44)

Article
Full-text available
DEVELOPMENT AND TESTING OF A COMPUTER MODEL TO SIMULATE WATER TABLE RESPONSE TO SUBIRRIGATION Jadir Aparecido RosaPólo Regional de Ponta Grossa, Instituto Agronômico do Paraná , Caixa Postal 129, CEP 84001-970, Ponta Grossa – PR, E-mail: jrosa@pr.gov.brAllen George Smajstrla (deceased)Kenneth Leonard Campbell Agricultural and Biological Engineering...
Article
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1 ABSTRACT A two-dimensional finite difference model (WATABLE) was developed to simulate water movement from a buried microirrigation line source, and the response of the water table to irrigation, precipitation, evapotranspiration, deep percolation, and runoff. The water uptake by plant roots was simulated by an extraction function with a root dis...
Article
This document is Bulletin 333, one of a series of the Agricultural and Biological Engineering department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication: March, 1999. Please visit the EDIS Web site at http://edis.ifas.ufl.edu
Article
For three crop seasons, potatoes (Solanum tuberosum L.) were grown in the field to evaluate the use of an automatically controlled subsurface drip (SDI) irrigation system with conventional semi-closed seepage irrigation (subirrigation). Both the SDI irrigation system and the automated irrigation control system performed well, and crop yields produc...
Article
Time-domain reflectometry (TDR) is a technique that indirectly measures soil volumetric water content based on the effect of changing dielectric properties of the medium on applied electromagnetic waves. A calibration equation that has been developed and widely used, based on the relationship between fast-rise electromagnetic properties and water c...
Article
A simple water level indicator was developed for rapid evaluation of the saturated hydraulic conductivity in soils with a high water table. Components of the observation wells and level indicators are readily available, durable, and low-cost. The device was tested under field conditions using both filtered and non-filtered wells, and results were c...
Article
Two-year-old, container-grown rabbiteye (Vaccinium ashei Reade) and highbush (Vaccinium corymbosum L.) blueberry plants were used in a 3-year study of water requirement for blueberry production in Florida. The rabbiteye cultivars Powderblue and Premier and the highbush cultivar Sharpblue were grown under three irrigation regimes. Irrigation events...
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Water management practices involve complex decisions and daily operations that are affected by water and nutrient requirements of the crop, temporal distribution of rainfall, and weather conditions. The Citrus Irrigation Management System (CIMS) was developed to assist citrus microirrigation, cold protection, and fertigation management. The system...
Article
A methodology was developed to quantify long-term temporal variability of monthly total precipitation. Ninety-three years of data from four weather stations on the Florida peninsula were used. This peninsula, covered by a single 8°x 10°grid of the NASA/GISS atmospheric GCM, is a transitional climatological region, influenced on a seasonal basis by...
Article
A three-year study of water use by two species of cultivated blueberry was conducted. The experiment was performed on two rabbiteye (Vaccinium ashei Reade) varieties, Premier and Powderblue, and one highbush (Vaccinium corymbosum L.) variety, Sharpblue. Water was applied to the plants using a microirrigation system. Irrigations were triggered at th...
Article
A numerical simulation model (E-RAIN) was developed to estimate long-term average and extreme values of monthly and annual effective rainfall for both seepage (seep) and fully-enclosed seepage (FES) irrigation systems. The model calculates effective rainfall as the difference between rainfall and runoff. Runoff is calculated from the SCS runoff equ...
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A methodology was developed to quantify the uncertainty associated with maximum likelihood parameter estimates used in the wet day amount component of stochastic rainfall models. Traditional point parameter estimates were combined with interval estimates to construct a probabilistic region of parametric uncertainty. Regions of model uncertainty wer...
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Tomatoes (Lycopersicon esculentum Mill.) were grown on a fine sandy soil using drip irrigation and polyethylene mulch to evaluate the effects of irrigation scheduling on irrigation requirements and yields under typical Florida production conditions. Tensiometers were used to automatically schedule irrigations whenever the soil matric potential reac...
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Studies were conducted for three production seasons between 1988 and 1991 to measure water use of dripirrigated strawberry plants and to evaluate the effects of soil tension management level on fruit yield and drip irrigation water requirement. Water balance lysimeters were designed and installed to measure monthly water requirements of dripirrigat...
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A low cost, computer-based irrigation control system is presented. The system uses readily available components that result in a reliable and highly flexible controller. The system has been used in a variety of field conditions including mist, sprinkler, and microirrigation systems. Commercial installations have successfully used this system for a...
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Strawberry ( Fragaria × ananassa Duch.) was grown for two seasons with microirrigation. Preplant fertilizer treatments of zero, one, two, three, and four times the basic N and K rate of 17 and 15 kg·ha –1 , respectively, were applied each season. Additional N and K were applied twice weekly through the microirrigation system at 1.12 and 0.92 kg·ha...
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A microcomputer-based data acquisition system for continuous soil water potential measurements was developed from commercially available components. The system consisted of tensiometer-mounted pressure transducers, a work station data acquisition and control device, and a portable microcomputer. The system was installed and tested in a set of lysim...
Article
A mathematical model was developed to simulate soil water infiltration, redistribution, and extraction in a bedded soil profile overlaying a shallow water table and irrigated by a line source drip irrigation system. The model uses an implicit finite difference scheme with explicit linearization of soil parameters. Its accuracy was verified by compa...
Article
This paper describes a software package that includes: computer-aided irrigation scheduling, computer-aided field uniformity information manipulation, an expert emulation program for diagnosis and treatment of slime clogging problems, and real time control software for the operation of trickle irrigation systems. This package of programs enables th...
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Fruit production and juice quality were measured during a 5-yr study of trickle irrigation. Irrigation treatments included no irrigation control, 2 or 4 drippers and 1 or 2 spray jets per tree. Fertilization treatments included dry fertilizer, 15 and 30% of the N and K supplied through the irrigation systems (fertigation). Irrigation increased frui...
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A five-year study of the production of 'Valencia' orange in response to amount of water applied and method of trickle irrigation was conducted. Irrigation scheduling was based on 100 per cent, 50 per cent and 25 per cent of potential evapotranspiration. Citrus yield was not influenced by the amount of irrigation applied. Yields were strongly relate...
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Penman, pan evaporation, Thornthwaite, Blaney-Criddle, and water budget methods were used to estimate basinwide monthly evapotranspiration (ET) in the Everglades Agricultural Area (EAA).The Penman method gave predictions closest to monthly basinwide water budgets and the Thornthwaite method had the largest deviations. However, based upon the data a...
Article
Tensiometers are useful instruments for measuring soil water status in the field. Tensiometers measure soil water potential or tension, which is a measure of the amount of energy required for a plant to overcome capillary and gravitational forces to extract water from a soil. Thus, tensiometers can be used to schedule irrigations when the soil wate...
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Full-text available
For efficient water application, lawn irrigation systems must apply water uniformly over the entire irrigated surface. High uniformity means that all parts of the irrigated lawn receive about the same amount of water. This requires proper sprinkler selection and layout. Sprinkler patterns of coverage must overlap to provide uniform water applicatio...
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Water table monitoring can improve irrigation and drainage management for agricultural production in the high water table areas of Florida. A large portion of Florida's agricultural land, notably the Everglades Agricultural Area (EAA) and surrounding sandlands, is irrigated and drained using water table management (including forms of seepage and su...
Article
Irrigation efficiency is a measure of (1) the effectiveness of an irrigation system in delivering water to plants or (2) the effectiveness of irrigation in increasing plant production. From definition (1), irrigation efficiency may be expressed as the ratio of the volume of water used or available for use in plant production to the volume pumped or...
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Full-text available
The water content increase in the clay soil was similar in many ways to that of the loamy soil. Water content increase was moderate compared to the two previous soil types. In addition, all points started to increase in water content at the same time with the exception of the 0-cm point. The slope of increase in the water content was much smaller t...
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Full-text available
The Institute of Food and Agricultural Sciences (IFAS) is an Equal Employment Opportunity -Affirmative Action Employer authorized to provide research, educational information and other services only to individuals and institutions that function without regard to race, creed, color, religion, age, disability, sex, sexual orientation, marital status,...
Article
Nursery production in Florida requires irrigation. The majority of the systems found in container and field nurseries are pressurized irrigation systems, which are sprinklers or some type of microirrigation. Most microirrigation systems are found in field nurseries or in the larger, 3 gallon and more, container production systems. The majority of F...
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Proper irrigation scheduling is the application of water to crops only when needed and only in the amounts needed; that is, determining when to irrigate and how much water to apply. With proper irrigation scheduling, crop yields will not be limited by water stress from droughts, and the waste of water and energy used in pumping will be minimized. O...

Citations

... Strawberry growing in Norway is mainly extensive cultivation of June bearing cultivars on matted row on low beds and to some extent double row on polyethylene mulched high beds. Growers give granulated fertilizers before planting, a practice supported by research [1,2]. However, it is shown that broadcasted NO 3 -N given in April/May and late August of the harvest years increased fruit yield of 'Bounty' compared with none or one fertilization incidence [3]. ...
... The instantaneous potential evapotranspiration rates (mm h −1 ) ET r , are calculated by distributing the daily potential evapotranspiration rate ET p (mm day −1 ) over a 24-h period (Vellidis and Smajstrla 1992;. The daily potential evapotranspiration ET p was partitioned into daily potential evaporation E p and daily potential transpiration T p , so that the ratio E p =ET p has a value around 0.14 as an approximation to the average real conditions for a fully developed crop in semiarid regions. ...
... The use of the YW in irrigation had a significant effect on different ecological parameters of weed communities inhabiting the area. Several studies indicated an increase in weed growth when irrigated with wastewater (Smajstrla and Koo 1984;Zekri and Koo 1993;Maurer et al. 1995), and these coincide with the present study. The results of monthly botanical surveys conducted in Al-Rusiefa Park in the three study sites indicated a significant increase in number of weeds/m 2 for all studied months in the site irrigated with YW compared to the two other sites. ...
... One of the main irrigation drawbacks is having very sandy soils (more than 90% sand) in most of the berry production area [5]. Sandy soils not only have a lower water-holding capacity but also significant downward water movement [6,7]. Farmers seek to maximize berry production, because of the relatively small impact of the emptying phase of the distribution system on the overall distribution uniformity. ...
... The use of water table management practices to help maintain agricultural productivity and profitability, without causing any degradation of water quality, is important in most areas in the United States. Water table control has been practiced for many years in various locations, such as Florida, in both the sandy flatwoods soils (Campbell et al., 1974;Pitts et al., 1993) and the organic soils near the Everglades (Snyder et al., 1978), in the Lower Mississippi Valley (Bengtson et al., 1993), in the Georgia Flatwoods (Shirmohammadi et al., 1991;Johnson Junior et al., 1993), in the Coastal Plain Soils of Virginia and North Carolina (Evans & Skaggs, 1989), in the organic soils of the Great Lake States of Michigan, Indiana, Ohio, and Minnesota, and in the Sacramento-San Joaquin Delta, in Central California (Fouss et al., 1990). Some of these applications date back to the 1920's. ...
... However, the PM equation requires numerous meteorological variables: air temperature, wind speed, relative humidity and solar radiation. Several authors highlighted the problem of the data availability due to the scarcity of in situ weather vari- ables measurements ( Shih et al. 1983;Remesan et al. 2008) and proposed simplified empirical methods (Droogers and Allen 2002;Pereira 2004;Gavilan et al. 2006), which vary in complexity and data requirements. ...
... These beneficial changes are usually ascribed to the effect of mixing of mineral soil with less dense organic material. It is distinctly evident just after compost application in fine-textured soils (Aggelides and Londra, 2000) and in coarse-textured soils (Turner et al., 1994), especially when high rates of compost were applied (Giusquiani et al., 1995). ...
... The batch calibration method is perhaps the most common method and achieves a uniform SWC throughout the test column; however, it is time consuming and difficult to repack the soils to a consistent dry BD with each increase in SWC (Topp et al., 1980;Dirksen and Dasberg, 1993;Evett et al., 2005;Western and Seyfried, 2005;Kelleners et al., 2009). A volume of water was added, mixed thoroughly with the <2-mm soil, and stored overnight in an airtight plastic bag to equilibrate. ...
... However, climate-induced fluctuations in temperature, solar radiation, and precipitation not only affect crop productivity but also impact water use. The effect of changing weather patterns on the temporal and spatial variation of water requirements, consumption, and deficit has been investigated; however, most studies on strawberry irrigation have been conducted in California and Florida, where open-field cultivation is standard (Clark et al., 1996, Grattan et al., 1998, Hanson and Bendixen, 2004, Trout and Gartung, 2004. In Europe, strawberries are grown in greenhouses (Gavilán et al., 2015), similar to the experimental environment in this study; therefore, an equation was used that did not consider precipitation as a factor. ...
... There are various approaches of crop water measurements deal with soil, plant, atmospheric or microclimatic parameters. However within all parameters soil related measurements; soil moisture sensing is more viable which uses dielectric properties of the soil as it is auto-dynamic as it is not affected by the environmental manipulations and easy accessible [3] Evidence are documented that they were Therefore switching tensiometers were in the usage to find out the soil moisture state and to automate the irrigation in between two different predetermined matrix potentials in tomatoes, citrus, and Bermuda grass [4,5]. But there are some drawback in using these tensitometers, were demonstrated by Smajstrla and Koo (1986) such as entrapped air in the tensiometers, organic growth on the ceramic cups, and the need for recalibration [4]. ...