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 Root Substrate pH, Electrical Conductivity, and Macroelement Concentration of Sphagnum Peat-based Substrates Amended with Parboiled Fresh Rice Hulls or Perlite

2008 ◽  
Vol 18 (4) ◽  
pp. 644-649 ◽  
Author(s):  
Mary M. Gachukia ◽  
Michael R. Evans
Keyword(s):  
Electrical Conductivity ◽  
Crop Production ◽  
Sampling Period ◽  
Practical Significance ◽  
Rice Hulls ◽  
Sphagnum Peat ◽  
Ph Increase ◽  
The Difference ◽  
Substrate Ph ◽  
Sampling Times

Substrates were formulated by blending parboiled fresh rice (Oryza sativa) hulls (PBH) or perlite with sphagnum peat (peat) to produce root substrates (substrates) that contained 20%, 30%, 40%, 50%, or 60% (by volume) PBH or perlite with the remainder being peat. After 0 (initial mixing), 4, or 8 weeks in a greenhouse environment, samples were taken and pH, electrical conductivity (EC), nitrate (NO3−), ammonium (NH4+), phosphorus (P), and potassium (K) were determined. As the amount of PBH or perlite in the substrate was increased, the pH increased. After 0 and 8 weeks, the pH of substrates containing up to 30% PBH or perlite had a similar pH. However, the rate of pH increase at these sampling times was higher than that of perlite so that substrates containing 40% or more PBH had a higher pH than equivalent perlite-containing substrates. At the week 4 sampling period, all substrates containing PBH had a higher pH than equivalent perlite-containing substrates. For all sampling times, the difference in pH between equivalent PBH and perlite-containing substrates was not high enough to be of practical significance. For all sampling times, EC increased as the amount of perlite was increased. Depending upon sampling time, the EC decreased or remained unchanged as the amount of PBH was increased. For all sampling times and substrates, EC was within acceptable ranges for unused substrates. Substrates containing PBH had higher NO3− levels than equivalent perlite-containing substrates. The NH4+ level of the substrates decreased as the amount of PBH or perlite was increased. The levels of NO3− and NH4+ were within acceptable ranges for unused substrates. Substrate P and K increased as the amount of PBH in the substrate was increased, but the concentration of P and K remained unchanged or decreased as the amount of perlite was increased. None of the differences between equivalent PBH and perlite-containing substrates was high enough to be problematic with respect to crop production and all of the chemical parameters were within acceptable ranges for unused root substrates.

scholarly journals Nitrogen, Phosphorus, and Potassium Resorption Responses of Alfalfa to Increasing Soil Water and P Availability in a Semi-Arid Environment

Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 310 ◽  
Author(s):  
Meng Kong ◽  
Jing Kang ◽  
Cheng-Long Han ◽  
Yan-Jie Gu ◽  
Kadambot H.M Siddique ◽  
...  
Keyword(s):  
Soil Water ◽  
Forage Yield ◽  
Nutrient Resorption ◽  
P Availability ◽  
P Fertilization ◽  
Resorption Efficiency ◽  
P Concentration ◽  
K Concentration ◽  
The Relationship ◽  
Semi Arid

In semi-arid areas, alfalfa (Medicago sativa L.) is widely grown, but its growth is often restricted due to limited rainfall and soil nutrients, particularly phosphorus (P). Nutrient resorption is an effective strategy for dealing with nutrient shortages. Alleviation of these limited resources using film mulch and P fertilization—which are common practices in semi-arid areas—can affect the internal recycling of such nutrients. Little is known about such effects in alfalfa and the relationship between resorption efficiency and forage yield. We conducted a two-year field experiment in the semi-arid Loess Plateau of China using film mulch and P fertilization to investigate the response to long-term increasing soil water and P availability on leaf nitrogen (N), P, and potassium (K) concentrations and nutrient resorption characteristics in alfalfa. In green leaves, mulching significantly increased P concentration by an average of 5.5% but it had no significant effect on N concentration over two years, and it decreased K concentration by 16.1% in 2017. P fertilization significantly increased N concentrations to a greater degree in 2018 (8.1%) than 2017 (1.6%). P fertilization also significantly increased P concentrations by an average of 34.1% over two years. In contrast, P fertilization significantly decreased K concentration in the mulched treatment by an average of 17.3% in 2017 and 21.8% in 2018, but it had no effect in the no-mulch treatment. In senescent leaves, mulching significantly increased N concentration by an average of 3.9% and P concentration by an average of 16.7%, but it had no significant effect on K concentration over two years, while P fertilization significantly decreased N and K concentrations over two years by an average of 7.5%, and 32.8%, respectively. P fertilization significantly increased senesced P concentration by an average of 11.9% in 2017 and 17.5% in 2018; and year × mulching × P fertilization had a significant interaction on senesced leaf P concentration. For resorption efficiency, mulching decreased P resorption efficiency by an average of 3.0%, but it had no impact on N or K resorption efficiency, while P fertilization increased the N, P, and K resorption efficiencies in alfalfa by an average of 6.8%, 6.2%, and 76.4% over two years, respectively. Interactive effects of mulching and P fertilization were found on P and K resorption efficiencies over time. In addition, N and K resorption efficiencies were significantly higher in 2018 than in 2017. The application of P fertilizer without mulching resulted in positive correlations between forage yield and N, P, and K resorption efficiencies, but no correlations were observed under film mulch. That is, mulching changed the relationship between forage yield and N, P, and K resorption efficiencies in alfalfa, suggesting that N, P, and K resorption efficiencies may not be related to high yield. Our results provide new insights into the role of nutrient resorption in alfalfa in response to increasing soil water and P availability and the relationship between resorption efficiency and forage yield, which will help us to improve alfalfa yield in semi-arid regions.

scholarly journals Using crop analysis in the precision nutrient supply system of maize

2012 ◽  
pp. 183-186
Author(s):  
Zoltán Izsáki
Keyword(s):  
Grain Yield ◽  
Nutrient Supply ◽  
Limit Values ◽  
Leaf Analysis ◽  
Yield Level ◽  
Limit Value ◽  
P Concentration ◽  
Maize Leaves ◽  
K Concentration

The effect of the N, P and K supplies of soil on the grain yield and N, P and K status of maize was studied in a long-term mineral fertilisation experiment between 2001 and 2008 and nutrient supply limit values were determined to plant analysis. Based on the interaction between the N concentrtion of maize leaves measured at the beginnig of tasseling and grain yield, the satisfactory limit value of N supply to reach 10–14 t ha-1 yield was between 2.0–4.0%. Leaf analysis at the beginning of tasselling indicated that better P and K supplies were associated with a higher P and K concentration in the maize leaves. Correlation analysis on the P concentration of the maize leaves and the grain yield showed that at a grain yield level of 10–14 t ha-1 a P concentration of 0.20–0.37% represented a satisfactory P supply level. The satisfactory K supply limit value to reach 10–14t ha-1 grain yield was 1.5–2.6%.

scholarly journals Correlations between Leaf Nutrient Content and the Production of Metabolites in Orange Jessamine (Murraya paniculata L. Jack) Fertilized with Chicken Manure

2015 ◽  
Vol 2 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Siti Rahmah Karimuna ◽  
Sandra Arifin Aziz ◽  
Maya Melati
Keyword(s):  
Bioactive Compounds ◽  
Dry Weight ◽  
Chicken Manure ◽  
Blood Cholesterol ◽  
Mature Leaves ◽  
P Concentration ◽  
Murraya Paniculata ◽  
K Concentration ◽  
Leaf P ◽  
Very High

Plant secondary metabolites are unique sources for pharmaceuticals and food additives. Orange jessamine (Murraya paniculata) contains secondary metabolite that is beneficial to human health including lowering blood cholesterol levels, anti-obesity, and has the antioxidant capacity. Leaves of orange jessamine have several chemical constituents including L-cadinene, methyl-anthranilate, bisabolene, β-caryophyllene, geraniol, Carene, 5-guaiazulene, osthole, paniculatin, tannins, eugenol, citronelled, coumurrayin and coumarin derivatives. This study aimed to determine the correlation between leaf concentrations of N, P and K with leaf bioactive compounds following chicken manure application to the plants. The experiment was conducted at IPB Experimental Station at Cikarawang, Bogor (6o30' - 6o45' S, 106o30'-106o45' E) from March to November 2014 (250 m above sea level). The study used a randomized block design (RBD) with rates of chicken manure as a treatment, i.e. 0, 2.5, 5 and 7.5 kg per plant. Chicken manure was applied at 30 months after planting (MAP). Leaves were harvested by pruning the plants to a height of 75 cm above the soil surface. The results showed that the optimum rates of chicken manure to produce maximum fresh and dry leaf weight were 3.1 kg and 6.5 kg per plant, respectively. This rate was sufficient for leaf production at the first harvest (34 MAP) but was insufficient for the second harvest (38 MAP). K concentration of the leaves from different positions within the plant and leaf age positively correlated with leaf dry weight (P <0.01), but negatively correlated with total flavonoid content (P <0.01). Leaf P concentration was negatively correlated with dry weight of the 5th young leaves, or mature leaves from all positions. Leaf K concentration was categorized very high (3.59-4.10%), whereas leaf P concentration was high (0.28-0.29%) to very high (0.33-0.35%). The 5th mature leaves determined plant K requirements.Keywords: antioxidant, bioactive compounds, leaf position, organic, NPK leaf concentrations

scholarly journals 368 Effects of Nitrogen Fertilization on Saw Palmetto (Serenoa repens)

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 455F-456
Author(s):  
Mary E. Carrington ◽  
Monica Ozores-Hampton ◽  
J. Jeffrey Mullahey
Keyword(s):  
Plant Height ◽  
N Addition ◽  
Serenoa Repens ◽  
Size Category ◽  
Saw Palmetto ◽  
P Concentration ◽  
Palm Species ◽  
K Concentration ◽  
Leaf P ◽  
Leaf N

Saw palmetto (Serenoa repens), a palm species native to the Southeastern United States, is used in ornamental plantings and landscaping. From Mar. 1998 to Mar. 1999, we conducted an experiment to assess effects of different levels of nitrogen addition on three sizes of containerized saw palmettos in southwest Florida. Palmettos were in 26-L containers (plant height 30 to 50 cm, no above-ground rhizome), 38-L containers (plant height 50 to 80 cm, above-ground, prostrate rhizome), and 170-L containers (three erect above-ground rhizomes 1 to 2 m high). We applied granulated ammonium nitrate (34% N) to the soil surface four times during the year, at 6 yearly rates of N addition for each size category of palmettos (24 palmettos in each size category). We also applied granulated concentrated triple superphosphate (46% P2O5) and potassium chloride (60% K2O) at constant yearly rates for each size category. We measured height and width of plants and length and width of leaves at the beginning and end of the experiment. We quantified leaf N, P and K concentration two days after first fertilizer application, and at the end of the experiment. For 26-L plants, increasing rates of N addition were reflected in higher levels of leaf N concentration two days after the first application. Leaf growth was less, and leaf K concentration at the end of the experiment was lower with increasing rates of N addition. Leaf P concentration at the end of the experiment decreased, and then increased with increasing rates of N addition. Plant growth for 170-L plants decreased and then increased, and leaf P concentration at the end of the experiment decreased with increasing rates of N addition.

scholarly journals Silicon Accumulation and Distribution in Petunia and Sunflower Grown in a Rice Hull-amended Substrate

HortScience ◽  
2018 ◽  
Vol 53 (5) ◽  
pp. 698-703 ◽  
Author(s):  
Jennifer K. Boldt ◽  
James C. Locke ◽  
James E. Altland
Keyword(s):  
Helianthus Annuus ◽  
Dry Weight ◽  
Rice Hull ◽  
Published Data ◽  
Abiotic And Biotic Stresses ◽  
Parboiled Rice ◽  
Biotic Stresses ◽  
Rice Hulls ◽  
Sphagnum Peat ◽  
Silicon Accumulation

Silicon (Si) is a plant beneficial element associated with the mitigation of abiotic and biotic stresses. Most greenhouse-grown ornamentals are considered low Si accumulators based on foliar Si concentration. However, Si accumulates in all tissues, and there is little published data on the distribution of Si in plants. This knowledge may be critical to using Si to mitigate tissue-specific plant stresses, e.g., pathogens. Therefore, we quantified Si accumulation and distribution in petunia (Petunia ×hybrida Hort. Vilm.-Andr. ‘Dreams Pink’), a low Si accumulator, and sunflower (Helianthus annuus L. ‘Pacino Gold’), a high Si accumulator. Plants were grown in a sphagnum peat: perlite substrate amended with 0% (−Si) or 20% (+Si) parboiled rice hulls for 53 (petunia) or 72 days (sunflower). Aboveground dry weight was greater in nonamended petunia (13%) and sunflower (18%), compared with rice hull–amended plants, but days to flower was unaffected. Sunflowers grown in the rice hull–amended substrate had the greatest Si concentration in leaves (10,909 mg·kg−1), whereas roots (895 mg·kg−1), stems (303 mg·kg−1), and flowers (252 mg·kg−1) had lower, but similar Si concentrations. In petunia, Si concentration was greatest in leaves (2036 mg·kg−1), then roots (1237 mg·kg−1), followed by stems (301 mg·kg−1), and flowers (247 mg·kg−1). The addition of rice hulls to the substrate increased Si concentration in sunflower 414% in roots, 512% in flowers, 611% in stems, and 766% in leaves. By contrast, Si concentration in petunia increased only 7% in flowers, 105% in stems, and 115% in leaves, but increased 687% in roots. In rice hull–amended sunflowers, the distribution of Si was 91% in leaves, 3% in stems, 3% in roots, and 3% in flowers, and in petunia, it was 72% in leaves, 17% in stems, 6% in roots, and 5% in flowers.

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 Impact of monovalent cations on soil structure. Part I. Results of an Iranian soil

2018 ◽  
Vol 32 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Elham Farahani ◽  
Hojat Emami ◽  
Thomas Keller ◽  
Amir Fotovat ◽  
Reza Khorassani
Keyword(s):  
Electrical Conductivity ◽  
Hydraulic Conductivity ◽  
Pore Size ◽  
Soil Structure ◽  
Monovalent Cations ◽  
Exchangeable Potassium ◽  
Clay Dispersion ◽  
K Concentration ◽  
The Impact ◽  
Dispersible Clay

AbstractThis study investigated the impact of monovalent cations on clay dispersion, aggregate stability, soil pore size distribution, and saturated hydraulic conductivity on agricultural soil in Iran. The soil was incubated with treatment solutions containing different concentrations (0-54.4 mmol l−1) of potassium and sodium cations. The treatment solutions included two levels of electrical conductivity (EC=3 or 6 dS m−1) and six K:Na ratios per electrical conductivity level. At both electrical conductivity levels, spontaneously dispersible clay increased with increasing K concentration, and with increasing K:Na ratio. A negative linear relationship between percentage of water-stable aggregates and spontaneously dispersible clay was observed. Clay dispersion generally reduced the mean pore size, presumably due to clogging of pores, resulting in increased water retention. At both electrical conductivity levels, hydraulic conductivity increased with increasing exchangeable potassium percentage at low exchangeable potassium percentage values, but decreased with further increases in exchangeable potassium percentage at higher exchangeable potassium percentage. This is in agreement with earlier studies, but seems in conflict with our data showing increasing spontaneously dispersible clay with increasing exchangeable potassium percentage. Our findings show that clay dispersion increased with increasing K concentration and increasing K:Na ratio, demonstrating that K can have negative impacts on soil structure.

Crease (Albedo Breakdown) can be Predicted by Peel Thickness and Peel Nutrient Status as Early as the End of the Cell Division Stage of Fruit Development

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498b-498
Author(s):  
Anwar Ali ◽  
Leslie Summers ◽  
Grant Klein ◽  
Carol Lovatt
Keyword(s):  
Cell Division ◽  
Fruit Development ◽  
Nutrient Status ◽  
Significant Negative Correlation ◽  
Nutrient Concentrations ◽  
Threshold Values ◽  
Citrus Industry ◽  
P Concentration ◽  
K Concentration ◽  
Leaf N

Crease is a rind disorder of economic consequence to the citrus industry. The literature suggests crease is related to the thickness of the peel at maturity and nutrient status of the tree, especially N, P, and K, which are known to influence peel thickness. Our objective was to quantify the interrelationship between the degree of crease in an orchard at harvest and September leaf nutrient concentrations, as well as peel nutrient concentrations at maximum peel thickness. The 2-year experiment was conducted at seven California `Valencia' and navel orange (Citrus sinensis L. Osbeck) orchards with known differences in the incidence of crease. Maximum peel thickness, which occurs at the end of cell division during fruit development, was significantly negatively correlated with percent crease at harvest for all sites in both years. There was no significant correlation between leaf N, P, or K concentrations and maximum peel thickness or crease. There was a significant negative correlation between peel K concentration and percent crease for all sites in both years. There was a weak correlation between the incidence of crease and peel nitrogen content in both cultivars. Peel P concentration was not correlated to the incidence of crease in either cultivar. These data identified threshold values for maximum peel thickness and peel K concentration at maximum peel thickness below which the incidence of crease would be greater than 10% for both cultivars.

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