scholarly journals Nitrogen requirement and critical N content of stevia grown in two contrasting soils of Bangladesh

2016 ◽  
Vol 3 (1) ◽  
pp. 87-97 ◽  
Author(s):  
Md Maniruzzaman ◽  
Md Akhter Hossain Chowdhury ◽  
KM Mohiuddin ◽  
Tanzin Chowdhury

Nitrogen is recognized as one of the most limiting nutrient for crop growth in Bangladesh and can be supplemented with inorganic fertilizers like urea. The experiment was conducted in the net house of the Department of Agricultural Chemistry, Bangladesh Agricultural University during March to July 2012. The objective was to examine the effects of different levels of N on the growth, leaf biomass yield, N content and to estimate minimum N requirement and critical N content of stevia. The treatments included six N rates (0, 100, 150, 200, 250 and 300 kg ha-1). Plant sampling was done at 15, 30, 45 and 60 days after planting (DAP) to measure plant height, number of branches and leaves, fresh and dry weight of leaves, leaf area and N concentration. The results revealed that all the characters were significantly affected by different N rates. The highest values of all parameters except plant height and N concentration were obtained from 250 kg N ha-1 and the lowest values from N control. Nitrogen application at all levels increased leaf dry yield at harvest by 99 to 505% in acid soil and 69 to 438% in non-calcareous soil, respectively over control. The growth of most parameters was rapid at the later stages (30 to 60 DAP). Leaf N content proportionately increased with the increasing rates of N. The highest N concentration was obtained from its highest application (300 kg N ha-1). The minimum amount of N for maximum leaf biomass production in the plants grown in acid and non-calcareous soils was estimated to be ca 273 and 257 kg ha-1, respectively. The critical N concentration to achieve 80% of the maximum production of stevia leaf was also estimated to be ca 1.43 and 1.50% in the leaves of stevia plants grown in acid and non-calcareous soils, respectivelyRes. Agric., Livest. Fish.3(1): 87-97, April 2016

HortScience ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Xiaojie Zhao ◽  
Guihong Bi ◽  
Richard L. Harkess ◽  
Jac J. Varco ◽  
Tongyin Li ◽  
...  

Tall bearded (TB) iris (Iris germanica L.) has great potential as a specialty cut flower due to its fragrance and showy, multicolor display; however, limited research has been reported on optimal nitrogen (N) nutrient management for TB iris. The objectives of this study were to investigate the effects of N fertilizer rate on plant growth and flowering of ‘Immortality’ iris and determine the influence of both stored N and spring-applied N fertilizer on spring growth and flowering. On 14 Mar. 2012, rhizomes of ‘Immortality’ iris were potted in a commercial substrate with no starter fertilizer. Plants were fertigated with 0, 5, 10, 15, or 20 mm N from NH4NO3 twice per week from 28 Mar. to 28 Sept. 2012. In 2013, half of the plants from each of the 2012 N rate were supplied with either 0 or 10 mm N from 15NH415NO3 twice per week from 25 Mar. to 7 May 2013. Growth and flowering data including plant height, leaf SPAD, number of fans and inflorescence stems, and length of inflorescence stem were collected during the growing season. Plants were harvested in Dec. 2012 and May 2013 to measure dry weight and N concentration in leaves, roots, and rhizomes. Results showed higher 2012 N rates increased plant height, leaf SPAD reading, and number of inflorescence stems at first and second blooming in 2012. Greater 2012 N rates also increased plant dry weight and N content in all structures, and N concentration in roots and rhizomes. Rhizomes (58.8% to 66.3% of total N) were the dominant sink for N in Dec. 2012. Higher 2012 N rates increased plant height, number of fans, and the number of inflorescence stems at spring bloom in 2013. In May 2013, N in leaf tissue constituted the majority (51% to 64.3%) of the total plant N. Higher 2012 N rates increased total dry weight, N concentration, and N content in all 2013 15N rates; however, leaf dry weight in all plants was improved by 2013 15N rate. Percentage of tissue N derived from 2013 15N (NDFF) decreased with increasing 2012 N rate. New spring leaves were the dominant sink (56.8% to 72.2%) for 2013 applied 15N. In summary, ‘Immortality’ iris is capable of a second blooming in a growing season, this second blooming dependent on N fertilization rate in current year. A relatively high N rate is recommended to produce a second bloom.


HortScience ◽  
2012 ◽  
Vol 47 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Yun-wen Wang ◽  
Bruce L. Dunn ◽  
Daryl B. Arnall ◽  
Pei-sheng Mao

This research was conducted to investigate the potentials of normalized difference vegetation index (NDVI), a Soil-Plant Analyses Development (SPAD) chlorophyll meter, and leaf nitrogen (N) concentration [% dry matter (DM)] for rapid determination of N status in potted geraniums (Pelargonium ×hortorum). Two F1 cultivars were chosen to represent a dark-green leaf cultivar, Horizon Deep Red, and a light-green leaf cultivar, Horizon Tangerine, and were grown in a soilless culture system. All standard 6-inch (15.24-cm) pots filled with a medium received an initial top-dress application of 5 g controlled-release fertilizer (15N–9P–12K), then plants were supplemented with additional N in the form of urea at 0, 50, 100, or 200 mg·L−1 N every few days to produce plants ranging from N-deficient to N-sufficient. The NDVI readings of individual plants from a NDVI pocket sensor developed by Oklahoma State University were collected weekly until the flowering stage. Data on flower traits, including number of pedicels (NOP), number of full umbels per pot (NOFU), total number of flowers per pot (TNF), number of flowers per pedicel (NOF), and inflorescences diameter (IFD), were collected 3 months after initial fertilizer treatment. After measuring flower traits, pedicels were removed from each pot, and SPAD value, NDVI, and leaf N concentration (g·kg−1 DM) were measured simultaneously. Cultivar and N rate significantly affected all but two flower and one N status parameters studied. The coefficient of determination R2 showed that NOP, NOFU, and TNF traits were more related to the N rates and the status parameters studied for ‘Horizon Tangerine’ than for ‘Horizon Deep Red’. For the latter cultivar, NOP and TNF traits were highly related to NDVI and SPAD values than N rates and leaf N content parameters. Correlation analysis indicated that the NDVI readings (R2 = 0.848 and 0.917) and SPAD values (R2 = 0.861 and 0.950) were significantly related to leaf N content (g·kg−1 DM) between cultivars. However, sensitivity of the NDVI and chlorophyll values to N application rate in geranium was slightly less than leaf N content. Strong correlations (R2 = 0.974 and 0.979, respectively) between NDVI and SPAD values were found within cultivars. The results demonstrated NDVI and SPAD values can be used to estimate N status in geranium. Because the pocket NDVI sensor will be cheaper than the SPAD unit, it has an advantage in determining N content in potted ornamentals.


2016 ◽  
Vol 6 (2) ◽  
pp. 46
Author(s):  
Nurhayati D. Purwantari

Leucaena leucocephala leaves are nutritious and palatable for ruminants. However, the plant is poorly adapted on acid soil, water logged, and susceptible to psyllid (Heteropsylla cubana). Leucaena favours soils with pH >5. It performs best on calcareous soils. This study aimed to evaluate adaptability of several Leucaena species on acid soils. The study was conducted at the experimental field in Ciawi, Bogor, altitude 500 m above sea level, rainfall 1500-2000 mm year-1, on Latosol soil with pH 5.2. Leucaena species evaluated were L. leucocephala K28, L. leucocephala (local type), Leucaena KX2 hybrid, L. collinsii, L. trichandra, and L. diversifolia. Experiment was designed in a randomized complete block, four replications. All the seedlings were grown in the nursery for 2.5 months before being transplanted to the field. The plants were grown in row plots of 5 m x 1 m with planting distance 0.5 m and spacing between row plot was 3 m. One unit replicate was 5 m x 21 m. In wet season, the plants were pruned at 50 cm height every 3 months, whilst in dry season pruning was done every 5 months. Parameter measured were plant regrowth and forage production (edible part and non-edible part of the plant), as well as N and P content of the edible part. The result showed that Leucaena KX2 hybrid was superior to other leucaenas. Regrowth of KX2 hybrid was the fastest and produced highest forage. The highest fresh weight forage production for 1 year (four times harvests), i.e. 33.93 t ha-1 year-1 equal to 12.48 t ha- 1 year-1 of dry weight, was obtained from Leucaena KX2 hybrid, whereas the lowest was produced by L. diversifolia, i.e. 3.12 t ha-1 year-1 of fresh weight or 1.01 t ha-1 year-1 of dry weight. Production of non-edible part followed the pattern of production of edible part. N and P content in the edible part of all Leucaena species did not show any significant difference except for L. trichandra which contained the lowest. This study implies that Leucaena KX2 hybrid is adaptable to acid soil; therefore it can be grown in wider areas throughout Indonesia.


2016 ◽  
Vol 6 (2) ◽  
pp. 46
Author(s):  
Nurhayati D. Purwantari

Leucaena leucocephala leaves are nutritious and palatable for ruminants. However, the plant is poorly adapted on acid soil, water logged, and susceptible to psyllid (Heteropsylla cubana). Leucaena favours soils with pH >5. It performs best on calcareous soils. This study aimed to evaluate adaptability of several Leucaena species on acid soils. The study was conducted at the experimental field in Ciawi, Bogor, altitude 500 m above sea level, rainfall 1500-2000 mm year-1, on Latosol soil with pH 5.2. Leucaena species evaluated were L. leucocephala K28, L. leucocephala (local type), Leucaena KX2 hybrid, L. collinsii, L. trichandra, and L. diversifolia. Experiment was designed in a randomized complete block, four replications. All the seedlings were grown in the nursery for 2.5 months before being transplanted to the field. The plants were grown in row plots of 5 m x 1 m with planting distance 0.5 m and spacing between row plot was 3 m. One unit replicate was 5 m x 21 m. In wet season, the plants were pruned at 50 cm height every 3 months, whilst in dry season pruning was done every 5 months. Parameter measured were plant regrowth and forage production (edible part and non-edible part of the plant), as well as N and P content of the edible part. The result showed that Leucaena KX2 hybrid was superior to other leucaenas. Regrowth of KX2 hybrid was the fastest and produced highest forage. The highest fresh weight forage production for 1 year (four times harvests), i.e. 33.93 t ha-1 year-1 equal to 12.48 t ha- 1 year-1 of dry weight, was obtained from Leucaena KX2 hybrid, whereas the lowest was produced by L. diversifolia, i.e. 3.12 t ha-1 year-1 of fresh weight or 1.01 t ha-1 year-1 of dry weight. Production of non-edible part followed the pattern of production of edible part. N and P content in the edible part of all Leucaena species did not show any significant difference except for L. trichandra which contained the lowest. This study implies that Leucaena KX2 hybrid is adaptable to acid soil; therefore it can be grown in wider areas throughout Indonesia.


2016 ◽  
Vol 8 (5) ◽  
pp. 86
Author(s):  
G. O. S. Ojo ◽  
S. A. Ayuba

<p>Experiments in acid sand culture, acid and neutral soil fields were carried out in 2003 with the objective of studying genetic variability and correlation among seedling and mature plant traits with a view of guiding breeders on appropriate selection options in breeding for aluminium/acid stress tolerant soybean in Nigeria. Genotypic variance was high for all the sand culture traits (root dry weight, shoot dry weight and relative root surface area), leading to the high heritability estimates of 77.85% to 83.72%. Genetic advance as a percentage of the mean (GA) was very high (85.51%-155.84%) for the sand culture traits. As expected, a better performance in terms of grain yield and yield components was observed for the neutral soil field compared to the acid soil field. However, higher heritability estimates were observed for the field traits measured on the acid soil field compared to the neutral soil field. Heritability estimates for the days to flowering and plant height were high (66.44%-79.63%) compared to the moderate heritability (47.42%-58.89%) observed for the number of pods/plant and grain yield on both soils. Conversely, the GA for days to flowering and plant height was lower (12.08%-26.49%) compared to the values (27.27%-41.56%) observed for number of pods/plant and grain yield on both fields. Higher genotypic and phenotypic coefficients of variation (GCV and PCV) were observed for the sand culture traits compared to the field traits. On the acid and neutral soil fields GCV and PCV values were lower for the days to flowering and plant height compared to the values observed for the number of pods/plant and grain yield, with highly significant correlation between/within the sand culture traits and the field traits. These results indicate that selection of soybean genotypes with high seedling root dry weight and relative root surface area in acid sand culture at 450 μM Al<sup>3+</sup> will enhance progress in the selection of high yielding acid tolerant tropically adapted genotypes of soybean on acid soils of Nigeria.</p>


2020 ◽  
Vol 36 (5) ◽  
Author(s):  
Marcela da Silva Flores ◽  
Willian Meniti Paschoalete ◽  
Fabio Henrique Rojo Baio ◽  
Cid Naudi Silva Campos ◽  
Ariane de Andréa Pantaleão ◽  
...  

Precision agriculture is a set of techniques that assist the monitoring of the agronomic performance of the maize crop by using vegetation indices. This study aimed to verify the relationship between vegetation indices, plant height, leaf N content, and grain yield of three maize varieties, grown under high and low N as topdressing. The experiment was carried out at the Fundação de Apoio à Pesquisa Agropecuária de Chapadão (Fundação Chapadão), located in the municipality of Chapadão do Sul, during the 2017/2018 season. The experiment consisted of a randomized block design with four replications, arranged in a 3x2 split-plot scheme. The first factor (plots) corresponded to three open-pollinated maize varieties (BRS 4103, BRS Gorotuba, and SCS 154), and the second factor (subplots) consisted of two N rates applied as topdressing (80 and 160 kg- 1). All the evaluated variables showed varieties x N interaction. Vegetation indices in maize varieties were influenced by the N rate applied as topdressing. Normalized Difference Vegetation Index (NDVI) and Soil-adjusted Vegetation Index (SAVI) showed a higher correlation with plant height. At the same time, Normalized Difference Red Edge (NDRE) had a stronger association with leaf N content.


Jurnal Agro ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 130-141
Author(s):  
Salamet Ginandjar ◽  
Budy Frasetya Taufik Qurrohman ◽  
Panji Rahmatullah

Tanaman selada merupakan sayuran yang dikonsumsi dalam bentuk segar. Karakteristiknya sebagai tanaman akumulator nitrat perlu diimbangi pemupukan N dan aplikasi Silika (Si) sesuai kebutuhan tanaman. Penelitian ini bertujuan untuk mempelajari interaksi ekstrak silika sekam padi (ESSP) dan N-total, serta memperoleh konsentrasi  ESSP dan N-total yang tepat untuk menghasilkan panen selada yang tinggi tetapi aman bagi kesehatan. Rancangan penelitian yang digunakan adalah Rancangan Acak Lengkap Faktorial, faktor pertama adalah konsentrasi ESSP (0 ppm, 30 ppm, 60 ppm, 90 ppm) dan faktor kedua adalah konsentrasi N-total (100 ppm, 200 ppm, 300 ppm), setiap kombinasi perlakuan diulang 3 kali. Parameter yang diamati yaitu tinggi tanaman 35 hari setelah tanam (HST), luas daun, berat kering tanaman, berat segar tanaman, kandungan nitrat pada daun selada. Data dianalisis dengan analisis varians taraf 5% dilanjutkan dengan Uji Jarak Berganda Duncan pada taraf nyata 5%, sedangkan parameter kandungan nitrat dianalisis secara deskriptif. Berdasarkan hasil analisis varians konsentrasi ESSP dan konsentrasi N-total berinteraksi pada tinggi tanaman dan berpengaruh mandiri terhadap berat kering tanaman dan berat segar tanaman. Aplikasi ekstrak silika sekam padi 30 ppm meningkatkan hasil panen 28% lebih tinggi dan menurunkan 12% kandungan nitrat tanaman selada pada N total 100-300 ppm.AbstractLettuce is a freshly consumed vegetable. Its characteristics as a nitrate accumulator plant need to be balanced with N fertilization and Silica (Si) applications according to the plant required. This research aimed to study the interaction between rice husk silica extract (ESSP) and total N to obtain the right ESSP and total N concentrations to produce high yield lettuce and safely consumed it. This study used a factorial completely randomized design. The first factor was ESSP concentrations (0 ppm, 30 ppm, 60 ppm, 90 ppm) and the second factor was total N concentrations (100 ppm, 200 ppm, 300 ppm). Each treatment combination was repeated 3 times. The parameters observed were plant height in 35 days after planting, leaf area, plant dry weight, fresh plant weight, and nitrat e content in lettuce leaves. The  data  were  analyzed  by analysis of variance at the 5%, and post-test by DMRT at the 5% significant level, the nitrate content used descriptive analysis. Based on the analysis of variance, ESSP concentration and total N concentration interacted on plant height. The ESSP concentration and total N concentration independently affected plant dry weight and fresh plant weight. Application of 30 ppm rice husk silica extract increased 28% higher yield and decreased 12% nitrate content of lettuce plants at N-total of 100-300 ppm.


2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Jorge Atílio Benati ◽  
Gilberto Nava ◽  
Newton Alex Mayer

Abstract The objective of this research was to evaluate the technical feasibility of SPAD index in the diagnosis of N status in ‘Esmeralda’ peach. The field trial, with five N rates applied to the soil (0, 40, 80, 120 and 160 kg ha-1 of N as urea form) was conducted in a randomized block design with four replications. During the years 2014, 2015, 2016 and 2017, SPAD readings were carried out with a Minolta SPAD-502 chlorophyll meter, in the leaf middle part, in 40 leaves per plot. The leaf N content determination was performed in CHN-S Elemental Analyzer. SPAD index and leaf N content increased in a linear way in response to increasing N rates applied in soil. There was a positive linear correlation between SPAD index and N concentration in leaves (0.652; 0.756; 0.762 and 0.767, p<0.05). SPAD index can be used for nutritional N diagnosis purpose in peach when readings are taken between the 13th and 15th weeks after full bloom. In the range between 39 and 49, the SPAD index indicates the leaf N content is included in “normal” class (33 – 45 g kg-1) of agronomic interpretation for the States of Rio Grande do Sul and Santa Catarina, Brazil.


HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1173c-1173
Author(s):  
David N. Sasseville ◽  
Rufus Jones

Tomato cv. 'Show Me' were grown in the greenhouse for six weeks in a 50%;50% (v:v) soil:sand mixture and provided weekly with a quarter-strength Hoagland solution with nitrogen provided as 100%:0% 50%;50% 0%:100% nitrate:ammonium ratios at rates of 0, 10, 20, 40, 80 mg N/kg medium with and without 5 mg/kg nitrapyrin. Nitrapyrin induced plant phytotoxic symptoms of stunted growth, curled leaves and deformed terminal buds. These effects were reduced with increasing amount of applied nitrogen and greater percent of nitrate. A second similar experiment using 0, 80, 160, 240, 320 mg N/kg medium and 1 mg/kg nitrapyrin showed no phytotoxic effects and also induced no significant changes in dry weight, tissue nitrogen content or residual medium nitrogen content regardless of nitrogen treatment. N concentration and N form effects were similar to previously reported research with an accumulation of nitrates in tissues with higher nitrate nutrition.


Revista CERES ◽  
2012 ◽  
Vol 59 (3) ◽  
pp. 399-405 ◽  
Author(s):  
Maria do Carmo Lana ◽  
Janaína Dartora ◽  
Deniele Marini ◽  
João Elias Hann

The biological nitrogen fixation is an alternative to supply the nitrogen needed for maize. The objective of this study was to evaluate the development and yield of maize in response to inoculation with Azospirillum associated with nitrogen fertilization. We conducted two field experiments in the summer harvest, the first in the 2000/2001 crop year in the region of Marechal Cândido Rondon, under conventional tillage, and second in the 2002/2003 agricultural year in the region of Cascavel, under no tillage. The experimental design in both experiments was a randomized complete block, with four replications, 2x2x2 factorial, with two levels of nitrogen at sowing (zero and 20 kg ha-1), two levels of inoculum (zero and 200 g ha-1) and two levels of nitrogen in topdressing (zero and 100 kg ha-1). There was evaluated the height of ear insertion, total plant height, leaf N content, shoot dry biomass and grain yield. The height of ear insertion and total plant height were not influenced by the factors under study. Nitrogen fertilization at sowing increased the leaf N content, causing the opposite effect when combined with inoculation. Inoculation with Azospirillum in the absence of nitrogen, provide productivity increases of 15.4% and 7.4% for 2000/2001 and 2002/2003 crops, respectively. The inoculation provided productivity similar to that obtained with 100 kg ha-1 in topdressing in crop 2000/2001, while in association with the topdressing, reduced productivity and shoot dry biomass in crop 2002/2003.


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