Effect of leaf nitrogen concentration versus CND nutritional balance on shoot density and foliage colour of an established Kentucky bluegrass (Poa pratensis L.) turf

2006 ◽  
Vol 86 (4) ◽  
pp. 1107-1118 ◽  
Author(s):  
Abdo Badra ◽  
Léon-Étienne Parent ◽  
Guy Allard ◽  
Nicolas Tremblay ◽  
Yves Desjardins ◽  
...  
Keyword(s):  
Poa Pratensis ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Principal Component ◽  
Kentucky Bluegrass ◽  
Shoot Density ◽  
Leaf Nitrogen ◽  
N Concentration ◽  
Randomized Block Design ◽  
N Status

A 3-yr field study was conducted in a loam and a sand site to determine the effects of N, P, and K application rates on N status, shoot density and foliage colour of Kentucky bluegrass clippings and to derive critical N values. The experiment was arranged in a completely randomized block design with four replicates and three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1), equally broadcast six times per growing season. We examined N concentration values, log-transformed N concentration values, and CND values for compositional nutrient simplexes comprising one (VN1), three (VN3), five (VN5), or 11 (VN11) macro- and micro-nutrients. Critical values for N expressions were obtained from linear relationships with targeted visual shoot density and foliage colour ratings that were closely related to each other (R2 = 0.92). The highest coefficients of determination (0.975 to 0.980) were obtained with VN5 and VN11. The VN5 values were consistent with literature data and across experimental sites, and were the most successful (99% success) in diagnosing N sufficiency in 328 qualified specimens from commercial sod farms. Compared with raw concentrations, the CND transformation reduced from 0.6 to 0.1 the degree of inter-correlation among nutrients in principal component analysis and was amenable to a χ2 distribution of CND indices. Using a critical imbalance index (CNDr2) of 5.6as χ2 value, and a critical CND IN2 index of 1.5 for a 5-nutrient simplex, we diagnosed as imbalanced 179 qualified specimens of which 110 specimens presented excessively high N level among the 328 qualified specimens in commercial stands. The proposed five-nutrient CND norms proved to be effective in diagnosing N status in Kentucky bluegrass clippings across experimental, literature, and survey data sets. Key words: Plant tissue nutrient diagnosis, DRIS, CND, Kentucky bluegrass nitrogen fertilization, turfgrass shoot density, turfgrass foliage colour

Quantitative and qualitative responses of an established Kentucky bluegrass (Poa pratensis L.) turf to N, P, and K additions

2005 ◽  
Vol 85 (1) ◽  
pp. 193-204 ◽  
Author(s):  
Abdo Badra ◽  
Léon-Etienne Parent ◽  
Yves Desjardins ◽  
Guy Allard ◽  
Nicolas Tremblay
Keyword(s):  
Poa Pratensis ◽  
Block Design ◽  
Kentucky Bluegrass ◽  
The United States ◽  
Shoot Density ◽  
Qualitative Response ◽  
K Fertilizer ◽  
Soil Test P ◽  
N Rates ◽  
Qualitative Responses

Kentucky bluegrass is a common turf species used on golf courses, sports fields, municipal parks, sod farms, road banks, as well as residential and school yards. Our objective was to determine the effects of N, P, K rates on turfgrass quantitative response (clipping yield and underground turf biomass) and qualitative response (shoot density and foliage colour) under a continuous clipping removal. A 3-yr field study was conducted on two sites, a sand that met the specifications of the United States Golf Association (USGA) and a loam. The factorial experiment was arranged in a randomized complete block design with four replicates and different levels of three nutrients, N (0 or 50 to 300 kg ha-1 yr-1), P (0 or 21.8 to 87.3 kg P ha-1 yr-1), and K (0 or 41.7 to 250 kg K ha-1 yr-1). The maximum clipping yield was produced at the rate of 200 kg N ha-1 yr-1 in the loam and 300 kg N ha-1 yr-1 in the sand. Increasing N rates linearly reduced underground turf biomass. Added P and K had no effect on clipping yield and underground turf biomass. Nitrogen significantly improved shoot density and foliage colour. However, equivalent shoot density and colour ratings required 40 to 80 kg more N ha-1 yr-1 in the sand compared to the loam. Phosphorus and K had no significant effect on shoot density and colour in the loam. Colour response to P and K depended on N rates in the sand. Fertilizer units needed to increase soil test P averaged 6 kg added P ha-1 mg-1 PM-III kg-1 across soil types. To replenish soil K, 7 kg K ha-1 per mg KM-III kg-1 were required in the sand, and 3 kg K ha-1 per mg KM-III kg-1 in the loam. Phosphorus and K fertilizer programmes should account for P and K removals to maintain low to medium fertility levels for P, and medium for K when conditions are similar to those in this research. Key words: Turfgrass clipping yield, underground turf biomass, turfgrass shoot density, turfgrass foliage colour, Kentucky bluegrass fertilization

scholarly journals LEAF TOTAL NITROGEN CONCENTRATION AS AN INDICATOR OF NITROGEN STATUS FOR PLANTLETS AND YOUNG PLANTS OF EUCALYPTUS CLONES

2015 ◽  
Vol 39 (4) ◽  
pp. 1127-1140 ◽  
Author(s):  
Eric Victor de Oliveira Ferreira ◽  
Roberto Ferreira Novais ◽  
Bruna Maximiano Médice ◽  
Nairam Félix de Barros ◽  
Ivo Ribeiro Silva
Keyword(s):  
Total Nitrogen ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Soil N ◽  
Total N ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Total Nitrogen Concentration ◽  
N Status ◽  
Leaf N

The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions.

scholarly journals Rocket plants in response to nitrogen concentration in nutrient solution

2021 ◽  
Vol 39 (3) ◽  
pp. 341-345
Author(s):  
Paulo Henrique S Silva ◽  
Arthur Bernardes Cecílio Filho ◽  
Isaias dos S Reis ◽  
Carolina S Nascimento ◽  
Camila S Nascimento
Keyword(s):  
Nutrient Solution ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Dry Mass ◽  
Nitrate Content ◽  
Hydroponic System ◽  
N Concentration ◽  
Randomized Block Design ◽  
Number Of Leaves

ABSTRACT Nitrogen (N) is the second most accumulated nutrient in rocket. This nutrient greatly affects growth, productivity and quality of the vegetable. Rocket is the second most widely grown leafy vegetable in hydroponic system; however, no studies on how N concentration in nutrient solution affects this crop can be found in literature. We studied four concentrations (79.2; 118.8; 158.4 and 237.6 mg L-1 of N) in a randomized block design with five replicates. Maximum number of leaves, leaf area, dry mass and productivity of rocket cv. ‘Folha larga’ were obtained with the highest N concentration. The rocket quality, evaluated by the nitrate content, was maximum with 210.2 mg L-1 of N and its value in the concentration which maximized productivity is in the acceptable range for vegetables; so, it is recommended to grow rocket with 237.6 mg L-1 of N in the nutrient solution.

Monitoring leaf nitrogen in wheat using canopy reflectance spectra

2006 ◽  
Vol 86 (4) ◽  
pp. 1037-1046 ◽  
Author(s):  
Yan Zhu ◽  
Yingxue Li ◽  
Wei Feng ◽  
Yongchao Tian ◽  
Xia Yao ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Reflectance Spectra ◽  
Nutrition Status ◽  
Nitrogen Accumulation ◽  
Canopy Reflectance ◽  
Leaf Nitrogen Concentration ◽  
Non Destructive ◽  
N Status ◽  
Leaf N

Non-destructive monitoring of leaf nitrogen (N) status can assist in growth diagnosis, N management and productivity forecast in field crops. The objectives of this study were to determine the relationships of leaf nitrogen concentration on a leaf dry weight basis (LNC) and leaf nitrogen accumulation per unit soil area (LNA) to ground-based canopy reflectance spectra, and to derive regression equations for monitoring N nutrition status in wheat (Triticum aestivum L.). Four field experiments were conducted with different N application rates and wheat cultivars across four growing seasons, and time-course measurements were taken on canopy spectral reflectance, LNC and leaf dry weights under the various treatments. In these studies, LNC and LNA in wheat increased with increasing N fertilization rates. The canopy reflectance differed significantly under varied N rates, and the pattern of response was consistent across the different cultivars and years. Overall, an integrated regression equation of LNC to normalized difference index (NDI) of 1220 and 710 nm of canopy reflectance spectra described the dynamic pattern of change in LNC in wheat. The ratios of several near infrared (NIR) bands to visible light were linearly related to LNA, with the ratio index (RI) of the average reflectance over 760, 810, 870, 950 and 1100 nm to 660 nm having the best index for quantitative estimation of LNA in wheat. When independent data were fit to the derived equations, the average root mean square error (RMSE) values for the predicted LNC and LNA relative to the observed values were no more than 15.1 and 15.2%, respectively, indicating a good fit. Our relationships of leaf N status to spectral indices of canopy reflectance can be potentially used for non-destructive and real-time monitoring of leaf N status in wheat. Key words: Wheat, leaf nitrogen concentration, leaf nitrogen accumulation, canopy reflectance, spectral index, nitrogen monitoring

scholarly journals Estimating leaf nitrogen concentration based on the combination with fluorescence spectrum and first-derivative

2020 ◽  
Vol 7 (2) ◽  
pp. 191941
Author(s):  
Jian Yang ◽  
Lin Du ◽  
Wei Gong ◽  
Shuo Shi ◽  
Jia Sun
Keyword(s):  
Fluorescence Spectrum ◽  
Nitrogen Concentration ◽  
Principal Component ◽  
Laser Induced Fluorescence ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Concentration ◽  
Growth Status ◽  
First Derivative ◽  
Fluorescence Characteristics ◽  
The Difference

Leaf nitrogen concentration (LNC) is a major indicator in the estimation of the crop growth status which has been diffusely applied in remote sensing. Thus, it is important to accurately obtain LNC by using passive or active technology. Laser-induced fluorescence can be applied to monitor LNC in crops through analysing the changing of fluorescence spectral information. Thus, the performance of fluorescence spectrum (FS) and first-derivative fluorescence spectrum (FDFS) for paddy rice (Yangliangyou 6 and Manly Indica) LNC estimation was discussed, and then the proposed FS + FDFS was used to monitor LNC by multivariate analysis. The results showed that the difference between FS ( R 2 = 0.781, s.d. = 0.078) and FDFS ( R 2 = 0.779, s.d. = 0.097) for LNC estimation by using the artificial neural network is not obvious. The proposed FS + FDFS can improved the accuracy of LNC estimation to some extent ( R 2 = 0.813, s.d. = 0.051). Then, principal component analysis was used in FS and FDFS, and extracted the main fluorescence characteristics. The results indicated that the proposed FS + FDFS exhibited higher robustness and stability for LNC estimation ( R 2 = 0.851, s.d. = 0.032) than that only using FS ( R 2 = 0.815, s.d. = 0.059) or FDFS ( R 2 = 0.801, s.d. = 0.065).

Proteolysis in alfalfa silages made from different cultivars

2001 ◽  
Vol 81 (4) ◽  
pp. 685-692 ◽  
Author(s):  
G. F. Tremblay ◽  
G. Bélanger ◽  
K. B. McRae ◽  
R. Michaud
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Block Design ◽  
Principal Component ◽  
First Year ◽  
Protein Nitrogen ◽  
Silage Fermentation ◽  
Randomized Block Design ◽  
Alfalfa Silage ◽  
High Forage

During silage fermentation, proteolysis reduces the nutritional value of N, particularly in alfalfa. This study evaluated the proteolysis of 27 alfalfa cultivars seeded in triplicate in 2 consecutive years. Forage from each plot was wilted to a targeted dry matter (DM) content of 250 g kg–1 and ensiled in laboratory silos. Minisilos were made with spring growth and summer regrowth in the first year of production for the first seeding, and with the first 2 yr of production for the second seeding, giving 3 harvest years altogether. Concentrations of NPN, NH3, FAA, DM, TN, and pH were measured in silages, whereas RUP concentration was evaluated in forages. Low NPN concentration indicates low proteolysis during silage fermentation. Spring growth and summer regrowth were analyzed separately by ANOVA as a completely randomized block design replicated over 3 harvest years. A principal component analysis was then performed on the ANOVA means. Silage DM was used as covariate when it was deemed appropriate. There was a significant variation among cultivars for NPN concentration in silages made of summer regrowth; it varied from 612 to 717 g kg–1 of TN. Concentration of NPN was significantly lower for cultivars WL 225, Rangelander, Iroquois, and WL 222, and higher for cultivars Oneida VR, Arrow, Vernal, Spredor 2, and Armor. Oneida VR and Rangelander had respectively high and low silage NPN concentration in both spring growth and summer regrowth. From cultivars with low silage NPN concentration, Rangelander was the only one with high forage RUP concentration in both spring growth and summer regrowth; proteins in this cultivar would be more resistant to microbial degradation during ensiling and in the rumen. Key words: Non protein nitrogen; proteolysis; alfalfa silage; cultivars

scholarly journals Two years of nitrogen and sulfur fertilizations in a signal grass pasture under degradation: changes in the root system

2011 ◽  
Vol 40 (6) ◽  
pp. 1195-1203 ◽  
Author(s):  
Cristiane Prezotto Silveira ◽  
Daniela Alves de Oliveira ◽  
Edna Maria Bonfim-Silva ◽  
Francisco Antonio Monteiro
Keyword(s):  
Root System ◽  
Rainy Season ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Dry Mass ◽  
Brachiaria Decumbens ◽  
Randomized Block Design ◽  
Grass Root ◽  
Signal Grass ◽  
Nitrogen Rates

The objective of this research was to evaluate the effect of combinations of nitrogen and sulfur rates in degraded signal grass (Brachiaria decumbens) pasture on their productive, morphological and nutritional attributes in the root system at four soil depths. The pasture used in the experiment was established over eight years ago in Entisol. Five nitrogen rates (0; 150; 300; 450 and 600 kg/ha/year) and five sulfur rates (0; 15; 30; 45 and 60 kg/ha/year) were combined in a fractionated factorial in a randomized block design, with three replications. Nitrogen was supplied as ammonium nitrate and sulfur as gypsum, and the rates were split into three times in the rainy season. The evaluations occurred at intervals of 35 days during the rainy season and 56 days in the dry season, in two consecutive years. Roots were collected with a 4-cm diameter auger at 0-10; 10-20; 20-30 and 30-40 cm soil depths. It was determined root dry matter, length and surface of the root system and nitrogen and sulfur concentrations in roots. Nitrogen rates applied in two consecutive years in the pasture affected dry mass, length, surface and nitrogen concentration in signal grass root system. Rates of sulfur by themselves or combined with nitrogen rates do not affect attributes of root system.

scholarly journals (140) Salt Tolerance Assessment of Kentucky Bluegrass Cultivars Selected for Drought Tolerance

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1057C-1057 ◽  
Author(s):  
Catherine M. Grieve ◽  
Stacy A. Bonos ◽  
James A. Poss
Keyword(s):  
Salt Tolerance ◽  
Drought Tolerance ◽  
Growth Rates ◽  
Poa Pratensis ◽  
Block Design ◽  
Kentucky Bluegrass ◽  
Saline Control ◽  
Drought Tolerant ◽  
Area Expansion ◽  
Poa Arachnifera

Six selections of Kentucky bluegrass (Poa pratensis L.) cultivars, selected based on their drought tolerance under field and growth chamber conditions in New Brunswick, N.J., were evaluated for salt tolerance based on yield and growth rates at eight soil water salinities [2 (control), 6, 8, 10, 12, 14, 18, and 22 dSm-1] from Apr. to Sept. 2005 in Riverside, Calif. Cultivars Baron and Brilliant were selected as drought sensitive and `Cabernet', `Eagleton', and `Midnight' were selected as drought tolerant. A Texas × Kentucky bluegrass (Poa arachnifera × Poa pratensis) hybrid selection (identified as A01-856) developed for improved drought and heat tolerance was also included. Vegetative clones were established in a randomized complete-block design with three replications, each containing 11 clones. Cumulative biomass and clone diameters were measured over time to evaluate relative yields and growth rates for the six cultivar selections. Based upon maximum absolute biomass production as a function of increasing EC, the order of production was `Baron' > `Brilliant' > `Eagleton' > `Cabernet' ≥ `Midnight' > A01-856. Yield relative to the non-saline control (2 dSm-1) for each cultivar was similar, except that the differences between cultivars were less pronounced, and `Baron' slightly outperformed `Brilliant'. Clone area expansion rates were analyzed with a phasic growth model and beta, the intrinsic growth rate of the exponential phase parameter, significantly varied with salinity. Ranking of cultivars, based on expansion rates, was similar to that based on cumulative biomass. Salinity tolerance in this experiment did not appear to be related to the observed ranking for drought tolerance.

scholarly journals Effects of glutamine and glutamate on nursery piglets fed diets with different digestible lysine content

2021 ◽  
Vol 42 (6supl2) ◽  
pp. 3919-3930
Author(s):  
Maykelly da Silva Gomes ◽  
◽  
Dante Teixeira Valente Júnior ◽  
Francisco Carlos de Oliveira Silva ◽  
Ronaldo Lopes Cunha Júnior ◽  
...  
Keyword(s):  
Immune Response ◽  
Growth Performance ◽  
Block Design ◽  
Nitrogen Concentration ◽  
Daily Weight Gain ◽  
Lysine Content ◽  
Feed Conversion ◽  
Nursery Pigs ◽  
Randomized Block Design ◽  
Better Than

The objective of the study was to evaluate the effects of glutamine and glutamate (Gln/Glu) on the growth performance and immune response of nursery pigs fed different digestible lysine content. Two hundred and sixteen piglets, weaned at 21 days old, were assigned to a randomized block design according to their initial body weight (BW), in a 2 × 2 factorial arrangement with two levels of lysine (control-lys and low-lys) and two levels of Gln/Glu (0 and 12 g kg-1), with nine replicates. At 26 d, piglets consuming the low-lys diet not supplemented with Gln/Glu presented a higher (P < 0.01) incidence of diarrhea than the other treatments. From 21 to 32 d of age, the piglets fed the control-lys diets performed better than those fed low-lys diets (P < 0.01). From 21 to 42 d of age, there was a correlation (P < 0.01) between lysine level and Gln/Glu supplementation for average daily feed intake (ADFI) and feed conversion (FC). Gln/Glu supplementation improved (P < 0.05) the ADFI of pigs fed the low-lys diets, resulting in a higher (P < 0.01) average daily weight gain (ADG) and BW; however, worse (P < 0.05) FC. Piglets consuming control-lys diets had higher (P < 0.05) serum urea nitrogen concentration (SUN) and IgG than low-lys piglets. In addition, Gln/Glu supplementation correlated with higher (P < 0.01) SUN. Dietary supplementation of glutamine and glutamate improved the growth performance of weaned piglets from 21 to 42 days of age, regardless of the diets’ lysine levels. In addition, reducing lysine levels 10% below the requirement negatively affects the growth performance and the immune response of nursery piglets.

scholarly journals Repeatability of biometric and fruit and seed yield traits of sacha inchi

2017 ◽  
Vol 47 (3) ◽  
pp. 195-202 ◽  
Author(s):  
Mágno Sávio Ferreira VALENTE ◽  
Maria Teresa Gomes LOPES ◽  
Francisco Célio Maia CHAVES ◽  
Ariane Mendes OLIVEIRA ◽  
Diego Rodrigo Bilby de FREITAS
Keyword(s):  
Block Design ◽  
Principal Component ◽  
Fruit Weight ◽  
Yield Traits ◽  
Principal Component Method ◽  
Randomized Block Design ◽  
Superior Genotypes ◽  
Sacha Inchi ◽  
Efficient Selection ◽  
Number Of Seeds

ABSTRACT Repeatability allows an estimation of the number of evaluations needed to optimize the selection of superior genotypes, with consequent effects on the research costs in terms of financial and human resources. The objective of this study was to estimate the coefficient of repeatability of biometric and yield traits, related to fruits and seeds of sacha inchi (Plukenetia volubilis), and to define the number of evaluations required for an efficient selection and evaluation of genotypes of the species. A total of 37 non-domesticated accessions were evaluated for 19 months in a randomized block design with 5 replications and 2 plants per plot. The total number of fruits, total number of seeds, total fruit weight, mean fruit weight, and number of seeds per fruit of the accessions were evaluated by monthly sampling. Additionally, seed biometry was assessed in a sample of 30 seeds per accession. Repeatability coefficients were estimated by analysis of variance, principal components and structural analysis. The principal component method based on the covariance matrix was the most appropriate for establishing repeatability estimates of sacha inchi, due to the cyclical nature of the crop. Superior genotypes of the species can be selected for yield-related traits with about 90% accuracy, from 5 harvests (months) onwards. To ensure this accuracy level, it would be necessary to evaluate a minimum of 5 and 25 fruits to determine mean fruit weight and number of seeds per fruit, respectively, and 39 seeds would be required to evaluate the biometric traits.

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