Search

Nitrogen is the most limiting nutrient for turfgrass growth. Instead of pursuing the maximum yield, most turfgrass managers use nitrogen (N) to maintain a sub-maximal growth rate. Few tools or soil tests exist to help managers guide N fertilizer decisions. Turf growth prediction models have the potential to be useful, but the currently existing turf growth prediction model only takes temperature into account, limiting its accuracy. This study developed machine-learning-based turf growth models using the random forest (RF) algorithm to estimate short-term turfgrass clipping yield. To build the RF model, a large set of variables were extracted as predictors including the 7-day weather, traffic intensity, soil moisture content, N fertilization rate, and the normalized difference red edge (NDRE) vegetation index. In this study, the data were collected from two putting greens where the turfgrass received 0 to 1,800 round/week traffic rates, various irrigation rates to maintain the soil moisture content between 9 and 29%, and N fertilization rates of 0 to 17.5 kg ha–1applied biweekly. The RF model agreed with the actual clipping yield collected from the experimental results. The temperature and relative humidity were the most important weather factors. Including NDRE improved the prediction accuracy of the model. The highest coefficient of determination (R2) of the RF model was 0.64 for the training dataset and was 0.47 for the testing data set upon the evaluation of the model. This represented a large improvement over the existing growth prediction model (R2= 0.01). However, the machine-learning models created were not able to accurately predict the clipping production at other locations. Individual golf courses can create customized growth prediction models using clipping volume to eliminate the deviation caused by temporal and spatial variability. Overall, this study demonstrated the feasibility of creating machine-learning-based yield prediction models that may be able to guide N fertilization decisions on golf course putting greens and presumably other turfgrass areas.

This study develops a framework that quantifies golf course pesticide risk, explores environmental and economic factors that may be responsible for the observed risk, develops a method to compare golf course pesticide risk to other agricultural crops and investigates how pesticide risk on golf courses can be most effectively reduced. To quantify pesticide risk, we adapt the Environmental Impact Quotient (EIQ) and hazard quotient models for use on golf courses. The EIQ model provides an estimate of overall environmental risk, while the hazard quotient model, as applied here, provides an estimate of pesticide risk to mammals. This novel framework was applied to twenty-two courses in Wisconsin and New York, USA. Using both pesticide risk models, all twenty-two golf courses showed a high coefficient of variation of pesticide risk (

A novel coronavirus, termed COVID‐19, spread worldwide and become a global pandemic in 2020. Forecasts show that COVID‐19 will cause substantial economic contraction affecting almost every industry. Managed turfgrass, particularly in urban settings, has many positive societal and environmental benefits. In a contracted economy, will resources be available to manage turfgrass to achieve these benefits? In this paper, we outline the benefits of managed turfgrass on golf courses, playing fields, recreational parks, and urban landscapes to assist decision makers with resource allocation in the COVID‐19 era.

The objective of this research was to evaluate bentgrass quality, growth, and disease incidence over a range of soil and tissue potassium levels. ‘Penn A4’ creeping bentgrass (Agrostis stolonifera L.) on a sand root zone was maintained as a putting green. The treatments included four levels of liquid potassium sulfate, ranging from 0 to 249 kg ha−1 yr.−1 K and one level of granular gypsum at a rate of 100 kg ha−1 yr.−1 Ca. No differences in vegetative or quality parameters were observed over the 6 year study period. Tissue K, Mehlich-3 extractable K, and Microdochium patch infection were all affected by treatment, with high-K treatments being greater than control and Ca treatments in all three instances. Near-daily turfgrass harvest resulted in much greater K removal than was estimated to be available from the pools extracted by Mehlich-3 and 1 M HNO3, suggesting that K became plant-available from more recalcitrant pool. Traditional soil testing methods may be inadequate for determining plant-available K in sand root zones. Total soil K analysis of the 0-K treatment indicated an increase in K during the study period, likely as a result of regular additions of sand via topdressing. Weathering of mineral K likely provided sufficient K to compensate for the lack of fertilizer.

There is a widely-held belief in the turfgrass industry that irrigating with water high in bicarbonate will result in carbonate accumulation in the soil, despite a lack of evidence for this claim. While water quality problems are traditionally associated with arid regions, water quality recommendations are being applied to more humid regions where there is a lack of research to correlate water chemistry with soil properties. The objective of this study was to investigate the relationships among soil properties, climate, and irrigation water quality for golf courses across the United States. This study examines the vertical distribution of soil inorganic carbon (SIC) in 28 sand putting green soils across a range of geographic locations and climates. Soils below a pH of 7.8 had very little inorganic carbon, and soils above this pH had variable levels of inorganic carbon. There was no relationship between SIC and the estimated bicarbonate load from irrigation water, mean annual precipitation (MAP), or annual potential evapotranspiration (ETp). Our findings from this study do not provide evidence that bicarbonate from irrigation will cause formation of layers or zones of accumulation in putting green soils, contrary to this widely-held belief in the turfgrass industry.

article i nfo Article history: Layerscementedbyiron andmanganese havebeenobserved insoilsof puttinggreensatgolfcoursesthroughout the USA. Theyresultinreduced waterinfiltration,saturated conditionsintherootzone, and a declineinturfgrass density and quality. The physical and chemical properties of these layers have not been investigated nor described in detail. Here we present a detailed analysis of the physicochemical properties and a conceptual pedogenetic model for the formation of Fe-cemented layers in soils of golf putting greens across the USA. These man-made soils have an A horizon of about 5 to 10 cm over 20 to 30 cm sand (C horizon) over gravel. TheFe-cementedlayeriscommonlyfoundattheinterfaceoftheAandChorizons,ortheChorizonandthegravel layer. Levels of total Fe in the cemented layers range from 0.41 to 16.21 g kg �1 and these are accompanied by accumulations of SOC and sometimes high levels of Mn and Al. The downward movement of water (irrigation), high levels of Fe (fertilization), and a textural discontinuity are key factors in the formation of the Fe-cemented layer. The layers may form at rates as high as 1.5 mm per year depending on Fe content and redox conditions in the root zone, and may become cemented in 10 years. These cemented layers meet the criteria of the placic horizon in Soil Taxonomy.

Oxygen-18-labeled phosphate (OLP) and natural abundance 18O have been used as tools for elucidating the dynamics of phosphorus (P) in soils, yet much remains poorly understood. The objective of this research was to determine the extent of preferential soil sorption across the range of species contained within OLP. A variety of soils were shaken with water containing 65.5 mg L−1 OLP-P for a 24-h period. Following shaking, the OLP species remaining in the solution were determined. Increasing the oxygen-18 atoms in the phosphate molecule by one resulted in a 1.8% increase in the amount of that OLP species sorbed to the soil, and this increase in sorption was uniform across soils. A strong correlation (r2 = 0.94) was found between the amount of phosphate sorbed and the Mehlich 3 P saturation ratio of the soil. These results will be useful for studies using natural abundance and enriched 18O-phosphate in soils.

There is an increasing demand to develop a means to trace phosphorus (P) movement through the environment as excessive inputs of P have led to the eutrophication of many fresh water bodies. 18 O labeled phosphate has been suggested as a potential tool for tracing P, and other researchers are using information from natural abundance 18 O levels of phosphate to study phosphorus cycling. The objective of this research was to determine the rate of biological de-labeling of 18 O in soils. This objective was achieved using a laboratory incubation study in which three silt-loam textured soils were incubated with 250 mg kg − 1 P 18 O 4 -P for a period of 3, 10, 30, or 50 d. The incubations were conducted on both sterilized and unsterilized soils. Following incubation, phosphate from soils was extracted with a modified Bray extractant and analyzed using electrospray ionization mass spectrometry to determine the distribution of labeled phosphate species. The half-life of P 18 O 4 in the non-sterile soils ranged from 15 to 22 d, while there was no observed P 18 O 4 de-labeling in sterile soils after 50 d. A parameterized numerical model was developed which provided insight into the dynamics of the individual labeled phosphate species, including their half-lives and relative concentrations across the incubation period. The use of P 18 O 4 may be useful in areas where use of radioisotopes of P is restricted, and P 18 O 4 has potential to be useful to elucidate the dynamics of the P cycle in soils.

Evaluation of turfgrass performance at low nitrogen fertility levels is important because many home lawns are fertilized below common recommendations. The objective of this study was to evaluate visible quality and weed susceptibility of common and alternative cool season grasses under multiple management regimes in Wisconsin. A split-split plot completely randomized block design was used to evaluate ‘Kingfisher' Kentucky bluegrass (Kentucky bluegrass), ‘Kenblue' Kentucky bluegrass, ‘Victory II' chewings fescue, ‘Grande II' tall fescue, and ‘Jiffe II' perennial ryegrass. Each species was mowed at 3.5, 6.0, or 8.5 cm, and fertilized with 0, 98, or 196 kg ha−1yr−1of nitrogen. Visible quality and weed cover were evaluated four times annually for 3 yr. Tall fescue had the greatest turf quality across all treatments. Kingfisher Kentucky bluegrass, an improved variety, responded most dramatically to nitrogen fertilization, with quality rating improved from 5.1 to 7.1 when annual nitrogen applications totaled 196 kg ha−1compared to the nonfertilized control. Kenblue Kentucky bluegrass, a common variety, had the greatest weed cover at all mowing heights and fertilizer rates. Assessment of common dandelion flowers by digital image analysis revealed that improved and common Kentucky bluegrass had greater common dandelion cover than fine or tall fescue when herbicides were withheld for 2.5 yr. Background soil fertility was found to have a significant impact on visible quality and weed cover. In an area with eroded, low-fertility soil, improved Kentucky bluegrass required 196 kg N ha−1yr−1to maintain high quality and limit weed invasion. These results suggest that tall fescue is best suited to low and high input conditions, while improved varieties of Kentucky bluegrass performed acceptably only under high inputs.

The Mehlich-3 soil test is extensively used to determine available soil P; however, calibration studies for sand greens are lacking. The purpose of this field study was to evaluate turfgrass response to different soil test P (STP) levels and application of trinexapac-ethyl (TE) (0.1 kg a.i. ha⁻¹ every 200 growing degree days). A creeping bentgrass (Agrostis stolonifera L. ‘Penn A4’) putting green was constructed at the O.J. Noer Turfgrass Research and Education Facility in Madison, WI, using 30 cm of calcareous sand overlaying pea gravel. A factorial of four STP levels, 0 to 95 mg P kg⁻¹, was established with monopotassium phosphate (MKP) with or without TE was arranged in a randomized complete block design with four replicates. Mehlich-3 STP level, clipping yield, tissue P content, and visual turfgrass quality were quantified monthly for two growing seasons. Nonlinear regression analysis was used to calculate STP and tissue P content critical points. Although a wide range of initial STP was established, STP levels in all treatments declined substantially during the two season study, eventually stabilizing to approximately 3 to 5 mg P kg⁻¹. Turfgrass quality was the most sensitive to both STP and tissue P content and provided clear critical values with linear plateau regression. The Mehlich-3 STP and tissue P content critical points for visual turfgrass quality ranged from 6 to 11 mg kg⁻¹ and 1.5 to 4.4 g kg⁻¹, respectively. While TE sometimes statistically altered the STP critical point, the difference was not substantial enough to suggest different STP recommendations for turf maintained with or without TE.

The plant growth regulator trinexapac-ethyl (TE) [4-(cyclopropyl-a-hydroxymethylene)-3,5dioxo-cyclohexanecarboxylic acid ethylester] reduces turfgrass clipping yield and enhances turfgrass color and density. Typically, such responses are achieved through alteration of N application rate, yet few have comprehensively investigated the effect of TE on turfgrass N requirements. We hypothesized that TE reduces putting green N requirements without sacrifi cing turfgrass quality. A three year study was conducted on a creeping bentgrass (Agrostis stolonifera L.) putting green with treatments consisting of three N application rates (5, 10, and 20 kg N ha–1 14 d–1) with or without TE application. To sustain season-long growth suppression, TE was applied at 0.10 kg a.i. ha–1 every 200 growing degree days (GDD; base 0°C). Turfgrass yield and color were quantifi ed every other week, and clipping tissue N content was analyzed monthly. Clipping yield, tissue N content, N removal, and color index increased with N rate. All attributes responded linearly to N application rate. Trinexapac-ethyl enhanced color while suppressing clipping yield and nutrient removal from mowing. As a result, TE reduced creeping bentgrass putting green N requirements by 25% conservatively and on several occasions by greater than 50%. W.C. Kreuser, Department of Horticulture, Cornell University, Ithaca, NY 14853; D.J. Soldat, Department of Soil Science, University of Wisconsin-Madison, Madison, WI 53706. Received 18 July 2011. *Corresponding author (wck38@cornell.edu). Abbreviations: GDD, growing degree days; TE, trinexapac-ethyl. Published in Crop Sci. 52:1348–1357 (2012). doi: 10.2135/cropsci2011.07.0364 © Crop Science Society of America | 5585 Guilford Rd., Madison, WI 53711 USA All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permission for printing and for reprinting the material contained herein has been obtained by the publisher.

Fall fertilization of turfgrass in northern climates is often considered to be agronomically beneficial, although research on nitrogen (N) uptake during cold temperatures is sparse and environmental concerns exist regarding nitrate leaching. Therefore, the objective of this study was to evaluate N uptake potential, use, and plant metabolic response in a climate-controlled environment evaluating the responses of various cool-season turfgrass species to variable N rates and temperature regimens. Creeping bentgrass (Agrostis stolonifera L.), kentucky bluegrass (Poa pratensis L.), and annual bluegrass (Poa annua var. reptans L.) were seeded and grown for 3 months and then acclimated in a growth chamber to one of three climate regimens corresponding to 15 Sept., 15 Oct., and 15 Nov. in Madison, WI. Grasses were fertilized at 0, 25, 49, or 98 kg·ha−1 N with 15N-labeled ammonium sulfate (10 atom % 15N) by applying a liquid solution of 75 mL per pot (1 cm of solution in depth). Data collected included verdure biomass, root mass, net canopy photosynthesis, and 15N fertilizer uptake. For all turfgrass species, shoot growth increased in response to N application in the September regimen, but not in October or November regimens. N uptake was significantly lower in the November regimen compared with September with an average of 73% of fertilizer recovery in September compared with 57% and 38% in October and November, respectively. Root mass and net canopy photosynthesis were greatest in the November treatments, although these responses were generally unaffected by N application rate. The results of this study indicate that N uptake capacity is greatly reduced as average daily temperatures approach 0 °C. Nitrogen application rates should be adjusted downward to maximize uptake efficiency in cold temperatures.

Trinexapac-ethyl (TE) is a widely used growth regulator in the turfgrass industry. Poor summer effi cacy has been related to more rapid metabo- lism in the plant. The purpose of this study was to determine if a growing degree day (GDD) model could be used to identify the optimum TE reappli- cation interval for putting greens. This objective was accomplished through model development and validation. Model development was con- ducted on a creeping bentgrass (Agrostis stolon- ifera L.) golf putting green in Madison, WI, during 2008. The treatments consisted of fi ve TE reap- plication intervals (100, 200, 400, 800 GDD, and 4 wk) and a control. Growing degree days were calculated in degrees C with a base temperature of 0°C. Trinexapac-ethyl was applied at the rate of 0.05 kg a.i. ha -1 . Clippings were collected daily. The 100- and 200-GDD reapplication intervals provided consistent 20 and 12% yield suppres- sion, respectively. Other reapplication intervals had alternating periods of yield reduction fol- lowed by yield enhancement. Model valida- tion occurred on a different creeping bentgrass green in 2009 and 2010. The experiment was a 3 × 2 factorial CRD with three TE rates (0.00, 0.05, and 0.10 kg a.i. ha -1 ) and two reapplication frequencies (200 GDD and 4 wk). The 200-GDD interval consistently suppressed clipping yield. Application rate had no effect on the duration of suppression. Reapplying TE every 200 GDD pro- vides more consistent growth regulation than a calendar-based application schedule.

Accurate determination of turfgrass yield via clipping harvest can be problematic on closely mowed research putting greens because sand often contaminates samples. Scientists reporting putting green clipping yields rarely mention if or how sand was removed from clippings. The two objectives were: (i) evaluate the efficacy of three clipping cleaning methods (water decantation, forced air, and a vibrating pan method) and (ii) evaluate the effect of sand contamination on field data variability. All three clipping cleaning methods effectively removed coarse sand from the sample while only the vibrating pan method effectively removed the fine sand fraction. Turf clippings were collected from four different research putting greens, dried, weighed, cleaned, and reweighed to calculate percent sand and treatment variability. Debris mass ranged from 0.01 to 0.92 kg kg ―1 (0.001-0.535 cm 3 cm ―3 ) and averaged 0.26 kg kg ―1 sand with a standard deviation of 0.18 kg kg ―1 . Cleaning clippings reduced the standard deviation and coefficient of variation of all treatments (n = 104) by 0.92 g m ―2 and 15%, respectively. Sand debris varied spatially across each green regardless of sand topdressing. Sand debris in golf putting green clipping samples constitutes a large enough percentage of total mass to justify its removal.

Water repellency and related localized dry spots are common problems on sand-based root zones often used for golf putting greens. The objective of this study was to quantify the effect of three commonly used surfactants applied to a sand-based root zone on turfgrass visual quality and drought symptoms, soil water content and uniformity, and soil water repellency. In 2007 and 2008, a study was conducted in Wisconsin on a creeping bentgrass golf putting green with a water-repellent sand soil. Prolonged periods of drought occurred in both years. Treatments included three surfactants and two controls, one irrigated at 30% of potential evapotranspiration (ETp) and a second irrigated at 100% of ETp. The surfactant treatments were irrigated at 30% of ETp. Soil moisture was measured weekly in each plot on a 5 × 5 30-cm grid pattern, along with visual estimates of area exhibiting drought symptoms and turfgrass visual quality. Soil water repellency was measured before and at the conclusion of each growing season. In 2007, the surfactant treatments maintained visual quality lower than the well-irrigated control treatment but greater than the reduced-irrigation control treatment. In 2008, substantial drought symptoms appeared on all surfactant treatments, which recovered faster than the reduced-irrigation control treatment. Soil water contents of surfactant treatments were similar to each other and the reduced-irrigation control on most testing dates. During periods of drought, surfactant-treated soils had the greatest uniformity of moisture content and lowest water repellency at the end of each growing season. These results indicate that use of these surfactants can reduce water use while improving visual quality compared with untreated areas, prevent localized dry-spot development, and increase moisture uniformity in sand-based golf putting green root zones.

Phosphorus losses from turfgrass areas are perceived to contribute to water quality prob- lems, yet a comprehensive review of P fate in turfgrass ecosystems is lacking. According to available data in the literature, phosphorus fer- tilizer inputs (2-10 kg ha -1 ) slightly exceed the estimated outputs of phosphorus in clippings (0.4-7.5 kg ha -1 ). Sediment losses from turf areas are negligible, generally limited to estab- lishment, but runoff and leaching losses of P vary from inconsequential to severe depending on rate, source, and timing of fertilizer applica- tion. Soil properties were found to have a larger effect on runoff volume than vegetative prop- erties. Highest runoff and leaching losses of P occurred when rainfall occurred or was simu- lated shortly after P fertilizer application. Leach- ing losses of P have historically been considered relatively minor; however, the limited research results available indicate that annual P leach- ing losses from mineral soils (0.2-0.7 kg ha -1 ) are similar in magnitude to runoff-P losses from turfgrass systems. One major gap in the knowl- edge is how P sources other than fertilizer (i.e., soil and plant tissue) and irrigation affect runoff and leaching losses of P.

Phosphorus (P) loss from urban areas has been identified as a major contributor to declining surface water quality. The objective of this study was to determine the relationship between extractable soil P, depth of soil sampling, and dissolved reactive P (DP) concentration in runoff from turfgrass areas. At each site, runoff was generated on turfgrass and adjoining areas where turfgrass cover was removed. Across all six locations and the wide range of nutrient management schemes, variation of extractable soil P concentration and saturation ratios of 0–2cm samples accounted for 49–59% (r 2 = 0.49–0.59, n = 92) of variation of DP concentration in runoff from bare soil and soil with turfgrass cover. Despite a high degree of soil P stratification, changing sampling depth generally did not improve the relationship between soil test P and runoff DP concentrations. Across the narrower range of soil P levels common to lawns in New York (0–50mg kg−1 Morgan extractable soil P), none of the soil tests or P saturation levels (for 0–2cm depth) could accurately predict runoff P concentrations from soil with turfgrass cover (r 2 = 0.02 to 0.23, n = 72). For bare soil plots, restricting the analysis to the same range (

Little information exists that describes how soil P levels and vertical distribution throughout the soil profile are influenced by fertilization practices and the addition of composted manures. Two field studies were designed to provide more information on how adding P fertilizer or compost influences the concentration and distribution of P in turfgrass soils. Application of P fertilizer at rates of 19, 38, or 72 kg P 2 O 5 per ha/year over a period of 4 or 5 years increased soil P in the upper 0 to 5 cm of soil by a factor of 2.7 to 3.3. Applying P at a rate of 10 kg P 2 O 5 per ha did not increase soil P in the upper 0 to 5 cm of soil. With one exception, soil P levels at depths of 5 to 10 or 10 to 15 cm were not increased by fertilizer applications over a period of 4 or 5 years. In contrast, adding composted poultry or dairy manures to plots at rates of 12 to 24 mm/year resulted in 8 to 333-fold increases in soil P in the upper 5 cm of soil. Soil P levels also increased substantially in deeper layers as a result of poultry compost application, but not for dairy. These findings indicate that common fertilization practices have a much smaller influence on soil P levels compared to composted manures. The benefits of using composted manures must be weighed against the potentially negative environmental impacts that could result from a large increase in soil P layer where runoff occurs.

Phosphorus (P) has only one stable isotope and therefore tracking P dynamics in ecosystems and inferring sources of P loading to water bodies have been difficult. Researchers have recently employed the natural abundance of the ratio of (18)O/(16)O of phosphate to elucidate P dynamics. In addition, phosphate highly enriched in oxygen-18 also has potential to be an effective tool for tracking specific sources of P in the environment, but has so far been used sparingly, possibly due to unavailability of oxygen-18 labeled phosphate (OLP) and uncertainty in synthesis and detection. One objective of this research was to develop a simple procedure to synthesize highly enriched OLP. Synthesized OLP is made up of a collection of species that contain between zero and four oxygen-18 atoms and, as a result, the second objective of this research was to develop a method to detect and quantify each OLP species. OLP was synthesized by reacting either PCl(5) or POCl(3) with water enriched with 97 atom % oxygen-18 in ambient atmosphere under a fume hood. Unlike previous reports, we observed no loss of oxygen-18 enrichment during synthesis. Electrospray ionization mass spectrometry (ESI-MS) was used to detect and quantify each species present in OLP. OLP synthesized from POCl(3) contained 1.2% P(18)O(16)O(3), 18.2% P(18)O(2) (16)O(2), 67.7% P(18)O(3) (16)O, and 12.9% P(18)O(4), and OLP synthesized from PCl(5) contained 0.7% P(16)O(4), 9.3% P(18)O(3) (16)O, and 90.0% P(18)O(4). We found that OLP can be synthesized using a simple procedure in ambient atmosphere without the loss of oxygen-18 enrichment and ESI-MS is an effective tool to detect and quantify OLP that sheds light on the dynamics of synthesis in ways that standard detection methods cannot.

Turfgrass managers are in need of low-input turfgrass species options. We have previously identified a number of species that do well as low-input, sustainable turf in the north central United States. The objective of this study was to evaluate multiple cultivars of turfgrass species with known adaption to low-input environments in the North Central Region. Twenty-five turfgrass cultivars and selections, representing ten grass species, were evaluated at eight locations. Plots were established in late summer 2007, and after establishment were maintained at 7.6 cm without inputs of pesticides, fertilizer, or supplemental irrigation. Tall fescue, Chewings fescue, hard fescue, and colonial bentgrass performed well at most locations. Sheep fescue, tufted hairgrass, and prairie junegrass all performed adequately at some locations, and poorly at others. Texas bluegrass hybrids and the single Idaho bentgrass entry were not well adapted to most of the region.

In recent decades, several standard colorimetric reactions for chemical analysis have been miniaturized to microwells on microplates, including methods useful for environmental measurements. Advantages of method miniaturization include a reduction in reagents required, improved safety, reduced waste stream, and increased sample throughput. However, the widespread use of microscale techniques employing microplates in classroom settings is likely limited by the high cost of microplate readers. Although spectrophotometers read peaks of specific wavelengths, absorbance spectra tend to be relatively broad and measurements at specific wavelengths are highly autocorrelated with those of nearby neighbors, which implies that broadband intensity data of red, green, and blue channels may indeed be adequate for digital colorimetric quantification. In this article, we demonstrate that digital image analysis of a scanned microplate image can substitute for a spectrophotometer for several common quantitative microscale procedures. This finding allows for cost effective and microscale quantification of several compounds to be demonstrated in the laboratory. Additionally, popular teaching and learning activities such as water quality monitoring can now be performed accurately and inexpensively using digital image analysis.