scholarly journals EVALUATION OF HORIBA CARDY COMPACT METERS FOR MONITORING GROWING MEDIA EXTRACT AND CELL SAP pH, E. C., NO3, NA AND K CONCENTRATION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 670a-670
Author(s):  
Jill Larimer ◽  
John C. Peterson
Keyword(s):  
Electrical Conductivity ◽  
Standard Deviation ◽  
Nutritional Status ◽  
Excellent Agreement ◽  
Nutrient Content ◽  
Growing Media ◽  
Good Relationship ◽  
Potting Media ◽  
K Concentration ◽  
Saturated Extract

Horiba Cardy compact pH, Electrical Conductivity (E.C.), Nitrate (NO3), Sodium (Na), and Potassium (K) meters were used to monitor the nutrient content of solutions extracted from five organic potting media. Solution extracts were collected using the Saturated Extract Method (SEM). Duplicate samples were sent to three analytical labs for comparative purposes. The meters proved to be quick and easy to use and there was good to excellent agreement with lab value for pH, E.C., Na and K. The NO3 meter did not provide good values below 80 ppm. For higher values there was a good relationship to lab values. The standard deviation for meter values was low, as were lab values for all parameter. Results of cell sap measurements as a method for evaluating the nutritional status of plants will be presented.

scholarly journals 493 PB 169 VARIATION ASSOCIATED WITH TESTING PROCEDURES FOR PH AND ELECTRICAL CONDUCTIVITY OF SOILLESS POTTING MEDIA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 502a-502
Author(s):  
Harvey J. Lang
Keyword(s):  
Electrical Conductivity ◽  
Nutritional Status ◽  
Solution Phase ◽  
Equilibration Time ◽  
Testing Procedures ◽  
Potting Media ◽  
Saturated Media

Analysts of potting media for pH and electrical conductivity (EC) can be a useful tool for monitoring the nutritional status of greenhouse grown plants. This research examined the variability associated with procedures involved in the determination of pH and EC in greenhouse potting media. Three commonly used methods, the 1:5 dilution, the 1:2 dilution and the saturated media extract, were examined on several different commercial potting media. Because of the different dilution volumes used, there were significant differences in pH and EC between the three methods for all media tested. Within each method, results varied baaed on whether readings were taken in the slurry, solution phase, or extract, with extracts resulting in consistently higher pH, but lower EC values. There was a significant effect of medium-solution equilibration time on both pH and EC, with variability decreasing after 30 minutes of equilibration. Samples taken from the upper half of pots had higher EC readings than those collected from the bottom half of pots only on plants fertilized with N concentrations greater than 200 ppm. There was also slight variability between the different calibrated instruments used in determining pH and EC. Details of each study along with grower recommendations will be discussed.

scholarly journals Physio-chemical properties and dynamic of the surface sediment in riparian mangroves along the Tien river, Tien Giang province

2019 ◽  
Vol 2 (5) ◽  
pp. 50-58
Author(s):  
Hung Duc Nguyen ◽  
Ngot Van Pham ◽  
Duy Van Nguyen
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Surface Sediment ◽  
Chemical Properties ◽  
Total Sulfur ◽  
Mean Sea Level ◽  
Factors Affecting ◽  
Sediment Samples ◽  
Mesohaline Zone ◽  
Saturated Extract

This study was conducted to investigate the physio-chemical properties and vertical dynamic of the surface sediment (0–5 cm) in riparian mangroves along the Tien river, Tien Giang province. The distribution of riparian mangroves located from the polyhaline zone (transect S1 and S2) to the mesohaline zone (transect S3 and S4) and the oligohaline zone (transect S5). Three plots (10x10 m) per transect were set based on the elevation of the mangrove floor (cm + mean sea level) and dominant plants. A total of 28 sediment samples were collected in December 2016 and April 2017. Seasonal variation of pH, redox potential (Eh), electrical conductivity of saturated extract (ECse), bulk density, sediment organic matter (SOM) and total sulfur (TS) were measured in accordance with the standard protocols. Seasonal trends of vertical erosion and accumulation were tested by the tracer stick method. The ECse values and TS concentrations were higher in the dry season and in transects closed to the estuary (S1, S2 and S3) but these trends weren’t found for pH, Eh, and SOM. In most of the riparian mangroves along the Tiền river, low elevation (0–50 cm) was one of important factors affecting the Eh and ECse. In the rainy season, major changes in vertical erosion and acumulation have occurred in the transects near the mouth of the river.

scholarly journals Response of Weeping Lantana (Lantana montevidensis) to Compost-Based Growing Media and Electrical Conductivity Level in Soilless Culture: First Evidence

Plants ◽  
2018 ◽  
Vol 7 (2) ◽  
pp. 24 ◽  
Author(s):  
Giuseppe Cristiano ◽  
Gjok Vuksani ◽  
Vincenzo Tufarelli ◽  
Barbara De Lucia
Keyword(s):  
Electrical Conductivity ◽  
Soilless Culture ◽  
Growing Media

scholarly journals Leachate Nutrient Content and Growth of Two Hollies As Influenced by Controlled Release Fertilizers

1992 ◽  
Vol 10 (3) ◽  
pp. 162-166
Author(s):  
John M. Ruter
Keyword(s):  
Electrical Conductivity ◽  
Controlled Release ◽  
Growth Response ◽  
Nutrient Content ◽  
Good Growth ◽  
Linear Relationships ◽  
Ilex Cornuta ◽  
Source Rate ◽  
Liquid Fertilization ◽  
Controlled Release Fertilizers

Abstract An experiment was conducted to evaluate the effects of fertilizer source, rate of application, and method of application on the release of nutrients over time using the pour-through method and to determine the growth response of Ilex cornuta Lindl. & Paxt. ‘Burfordii’ and Ilex × ‘Nellie R. Stevens’ holly to different multicoated controlled release fertilizers (CRF). Depending on the rate of application used, the three CRFs used in this study [Osmocote 17N-3P-9.9K (17-7-12), Sierrablen 17N-3P-8.3K (17-7-10), and High-N 24N-1.7P-5.8K (24-4-7)] provided adequate concentrations of nutrients for a minimum of 90 days after treatment. Fertilizer source had no effect on the growth of either holly used in this study. Good growth of ‘Burfordii’ and ‘Nellie R. Stevens’ holly was obtained at the rate of 1. 5 kg N/m3 (2. 5 lb N/yd3). Linear relationships between NO3-N and electrical conductivity using the pour-through method were established for ‘Burfordii’((NO3-N = 414 (electrical conductivity)) and ‘Nellie R. Stevens’ ((NO3−N =−11.4 + 425 (electrical conductivity)). Results of this study indicate that the nutrient sufficiency values for liquid fertilization programs with the pour-through method need to be adjusted for use with multicoated CRFs.

scholarly journals Date of Potting and Fertilization Affects Plant Growth, Mineral Nutrient Content, and Substrate Electrical Conductivity

2002 ◽  
Vol 20 (2) ◽  
pp. 104-109
Author(s):  
R. Lee Ivy ◽  
Ted E. Bilderback ◽  
Stuart L Warren
Keyword(s):  
Electrical Conductivity ◽  
Plant Growth ◽  
Dry Weight ◽  
Nutrient Content ◽  
Mineral Nutrient ◽  
Stem Cuttings ◽  
P Content ◽  
Winter Temperatures ◽  
Highly Correlated ◽  
One Year

Abstract The landscape industry uses containerized plant material throughout the year. Thus, traditional spring potting at many nurseries has changed to potting throughout the year. The objective of this study was to determine the effect of potting date and rate of fertilization on plant growth and mineral nutrient content, substrate electrical conductivity (EC) and pH, and winter injury. To complete this objective, rooted stem cuttings of Ilex crenata Thunb. ‘Compacta’ and Viburnum awabuki K. Koch. ‘Chindo’ were potted in Raleigh, NC, July 17, 1998; September 7, 1998; October 29, 1998; March 25, 1999; and May 13, 1999. Two controlled-release fertilizers [Wilbro/Polyon 15N–1.8P–7.5K (15N–4P2O5–9K2O) and Scotts 23N–1.8P–6.6K (23N–4P2O5–8K2O)] were applied at four rates: a split application with 0.5X incorporated at potting and surface application of the remaining 0.5X six months after potting date [X = manufacturers' recommended rate per 3.8 liter (4 qt) container], and 1X, 1.5X, and 2X incorporated at potting. Plant growth and mineral nutrient content were determined one year after initial potting date. Substrate EC and pH were measured monthly. ‘Compacta’ holly and ‘Chindo’ viburnum potted in September or October were larger than plants potted in March regardless of fertilizer and rates of fertilization. In general, holly and viburnum were smaller when fertilized with 0.5/0.5X compared to 1X regardless of fertilizer and date of potting. Within each rate of fertilization, viburnum potted in September had significantly greater N and P content compared to viburnum potted in March or May. Nitrogen and P content were highly correlated to plant dry weight (r > 0.79, P = 0.0001). Mineral nutrient content of holly responded similarly. No plants were injured by winter temperatures regardless of potting date or rate of fertilization throughout the study period. Plants potted in July, September, or October had the highest substrate EC values in March, whereas plants potted in March or May had highest EC values in August regardless of species, fertilizer or rate of fertilization. Substrate pH was unaffected by date of potting, but pH decreased with increasing rates of fertilization.

scholarly journals The pH, Electrical Conductivity, and Primary Macronutrient Concentration of Sphagnum Peat and Ground Parboiled Fresh Rice Hull Substrates Over Time in a Greenhouse Environment

2011 ◽  
Vol 21 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Michael R. Evans ◽  
Johann S. Buck ◽  
Paolo Sambo
Keyword(s):  
Electrical Conductivity ◽  
Primary Objective ◽  
Iron Sulfate ◽  
Rice Hull ◽  
Second Grade ◽  
Hammer Mill ◽  
Sphagnum Peat ◽  
P Concentration ◽  
K Concentration ◽  
Sampling Times

The primary objective of this research was to compare the pH, electrical conductivity (EC), and primary macronutrient status of three ground parboiled fresh rice hull (PBH) products to sphagnum peat when used as a root substrate over 56 days in a greenhouse environment. The three grades of ground rice hull products were produced by grinding PBH and passing the ground product through different screens. One grade (P3) was passed through a 2.00-mm screen and captured on a 1.00-mm screen. The second grade (P4) was passed through a 1.00-mm screen and captured on 0.50-mm screen. A third ground rice hull product (RH3) was a commercially available, ground PBH material that was ground in a hammer mill until it passed through a screen with 1.18-mm-diameter openings and was collected on a screen with 0.18-mm openings. The pH of sphagnum peat ranged from 3.4 to 3.7 across time. The pH of RH3 and P3 increased from 4.7 to 7.1 on day 5 and 14, respectively, before decreasing to 6.3 and 6.7, respectively, on day 56. The pH of P4 increased from 4.8 to 6.9 on day 6 before decreasing to 6.6 on day 56. The P4 had an EC of 1.2 dS·m−1, which was higher than that of peat, RH3, and P3, which had similar EC of 0.7 to 0.8 dS·m−1 regardless of time. The ammonium (NH4+) concentration was unaffected by time. Peat had an NH4+ concentration of 6.4 mg·L−1, which was lower than that of the ground rice hull products. The P3 had an NH4+ concentration of 14.6 mg·L−1, which was higher than that of RH3 and P4. The RH3 and P4 had similar NH4+ concentrations of 11.8 and 10.8 mg·L−1, respectively. The nitrate (NO3−) concentration was unaffected by time. The RH3 had a NO3− concentration of 8.2 mg·L−1, which was significantly higher than that of peat, P3, and P4, which had similar NO3− concentrations of 0.5 mg·L−1. The phosphorus (P) concentration in peat ranged from 1.3 to 2.5 mg·L−1 across the sampling times, and peat had a lower P concentration than all rice hull products, which ranged from 57.4 to 104.4 mg·L−1. The potassium (K) concentration in peat ranged from 2 to 5 mg·L−1 across the sampling times and was always lower than that of the rice hull products, which had a K concentration ranging from 195 to 394 mg·L−1. Because pH, P, and K concentrations were above recommended concentrations, ground rice hull products would not be suitable as a stand-alone substrate but might be amended with materials such as elemental sulfur or iron sulfate to adjust the pH or blended with other components to reduce the P and K concentrations to within recommended concentrations.

scholarly journals In Situ Probes for Measurement of Electrical Conductivity of Soilless Substrates: Effects of Temperature and Substrate Moisture Content

HortScience ◽  
2006 ◽  
Vol 41 (1) ◽  
pp. 210-214 ◽  
Author(s):  
Holly L. Scoggins ◽  
Marc W. van Iersel
Keyword(s):  
Electrical Conductivity ◽  
Water Content ◽  
Pore Water ◽  
Nutrient Content ◽  
Extraction Methods ◽  
Temperature Sensitive ◽  
Greenhouse Production ◽  
Growing Medium ◽  
Added Water

Growing medium electrical conductivity (EC) is used in laboratory analysis and greenhouse production as a measure of the nutrient content of the growing medium. Fast, accurate ways to measure growing medium EC will make it easier to determine EC and maintain it within a suitable range for a particular crop. Several probes have been developed that can be inserted directly into the growing medium of container-grown crops for measurement of EC. We tested the sensitivity of four in situ EC probes (Field Scout, HI 76305, WET sensor, and SigmaProbe) at a range of temperatures, substrate volumetric water contents (VWC), and fertilizer concentrations. The HI 76305 probe was highly sensitive to temperature, while the WET sensor was temperature-sensitive at high ECs above its normal operating range. The probes responded differently to increasing VWC. The SigmaProbe and WET sensor measure the EC of the pore water specifically and show a decrease in EC with increasing water content, as the fertilizer ions in the pore water become more diluted as VWC increases. EC readings of the HI 76305 and Field Scout probes, which measure the EC of the bulk substrate (growing medium, water, and air combined) increased with increasing water content as the added water helps conduct the current of these meters. At a VWC above 35%, there was little effect of VWC on EC readings of all probes. The EC measured with the various in situ probes differed slightly among the probes but was highly and positively correlated with all three of the standard solution extraction methods [pour-through, 1:2 dilution, and saturated media extract (SME)] over the range of fertilizer concentrations at a given temperature and VWC. These results make it possible to convert substrate EC guidelines that have been established for any of the three standard methods for use with the in situ probes, though our results indicate the substrate VWC must be above 35% for the interpretation to be valid. The in situ probes are a viable alternative for measurements of substrate EC and eliminate the step of substrate solution extraction, thus simplifying data collection.

scholarly journals Effect of Root Substrates and Nutrient Solution Electrical Conductivity on Tomato Transplant Characteristics

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 982A-982
Author(s):  
Paolo Sambo ◽  
Franco Sannazzaro ◽  
Michael Evans
Keyword(s):  
Electrical Conductivity ◽  
Nutrient Solution ◽  
Dry Weight ◽  
Nutrient Content ◽  
Stem Diameter ◽  
Dry Matter Accumulation ◽  
Hypocotyl Length ◽  
Rice Hulls ◽  
Main Plot ◽  
Shoot Weight

In order to evaluate alternative rooting media as a substitute to sphagnum peat in tomato transplant, fresh rice hulls (2 and 4 mm particle size), perlite, and peat were compared. In the same experiment, four nutrient solutions differing in electrical conductivity [(EC) 2.5, 3.5, 4.5 and 6.0 mS/cm], but not in nutrient content, were used. Seed of tomato (Lycopersium esculentum L.) `Brigade' (ASGROW) were sown in 55 × 35 × 6.5 cm polystyrene transplant trays containing 336 cells (15 mL) and filled with the root substrates. The trays were placed in a glass-glazed greenhouse. Trays were kept under intermittent mist for 6 days and then fertilized twice per week with 2.6 L per tray of solution. A split-plot design with three replications was used with nutrient solution serving as the main plot and root substrates serving as the subplots. During the growing cycle (once a week) and when plants were ready to transplant (16 cm tall, with an average of five to seven true leaves), stem diameter, hypocotyl length, plant height, number of true leaves, fresh shoot weight, and dry shoot weight were measured. Also at transplant, root fresh and dry weight and above- and below-ground biomass were analyzed to determine N, P, K, Ca, Mg, Fe, and Mn content. Plants grown in rice hulls were as marketable as those in peat, but showed a higher content in N, K, and Mn. Increased nutrient solution affected not only dry matter accumulation, but also stem diameter and plant hight, which were greater in plants grown with high EC.

scholarly journals Portable meters for nutritional assessment in plants of gerbera fertigated with electrical conductivity levels

2014 ◽  
Vol 18 (3) ◽  
pp. 258-262 ◽  
Author(s):  
Poliana R. D'A. Mota ◽  
Roberto L. Villas Bôas ◽  
Fernanda Ludwig ◽  
Dirceu M. Fernandes ◽  
Marcos V. Folegatti
Keyword(s):  
Electrical Conductivity ◽  
Nutritional Status ◽  
Plant Tissue ◽  
Nutritional Assessment ◽  
Block Design ◽  
Rapid Testing ◽  
Substrate Solution ◽  
Chlorophyll Meter ◽  
Randomized Block Design ◽  
Rapid Tests

Rapid tests to assess the nutritional status of plants gerbera can make easier the decision of any adjustments in the fertilization of the substrate. The study was conducted to evaluate nutritionally fertigated gerbera plants with increasing levels of electrical conductivity (EC), using portable meters nitrate and potassium, and chlorophyll. For this, two experiments were conducted. A randomized block design with five levels of EC (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1) and four replications was used. Cherry cultivar was used in the first experiment. In the second experiment, two cultivars (Cherry and Salmon Rose) were used. In the first experiment, the sap of the leaves was subjected to rapid testing of N-NO3- (equipment Cardy Horiba C -141). N-NO3- and K+ (C-131) were determined in the substrate solution. The intensity of the green leaf, in the second experiment was evaluated with portable Chlorophyll Meter. The N content in the indicator leaf in the first and N and K contents in the plant in the second experiment were determined. Rapid tests are presented as good indicators of the level of N-NO3- and K+ in plant tissue, with the advantages of convenience and speed of determination, facilitating monitoring of fertilization of the substrate by producers and technicians.

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