scholarly journals Effects of nitrogen on accumulation and partitioning of dry matter and nitrogen of vegetables. 3. Spinach

1996 ◽  
Vol 44 (3) ◽  
pp. 227-239
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Leaf Age ◽  
High Yield ◽  
Organic N ◽  
N Accumulation ◽  
N Application ◽  
N Concentration ◽  
Application Techniques ◽  
High Yields

Four greenhouse and 2 field experiments (the latter on a sandy soil) were carried out with different amounts and dates of N application to analyse the dynamics of dry matter and N accumulation in spinach (cv. Trias). Frequent measurements were carried out on dry matter and N accumulation in leaf blades, petioles and stems. The total accumulation of dry matter and N differed largely among and within experiments. Increasing N application increased yield of dry matter and N accumulation, whereas splitting N applications had much smaller effects. However, the partitioning of dry matter and N proved insensitive to N treatments. Harvest indices for dry matter (about 0.67) or N (about 0.74) of crops at a marketable stage were fairly constant over treatments and experiments. Increasing or splitting the N application affected N accumulation more than dry matter production, resulting in large effects on N concentrations. The lack of variation in response to N for different N regimes facilitates the development of N application techniques aimed at high yield, high quality and reduced emissions. The organic N concentration of leaf blades and petioles decreased with leaf age, although in most experiments this decrease was smaller at higher leaf numbers. The nitrate-N concentration decreased with increasing leaf number at any sampling date; it was higher when N was abundant. High yields in autumn crops were associated with high nitrate concentrations but also with potentially high losses of N.

scholarly journals Establishment of Critical Nitrogen Concentration Models in Winter Wheat under Different Irrigation Levels

Agronomy ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 556
Author(s):  
Bin-Bin Guo ◽  
Xiao-Hui Zhao ◽  
Yu Meng ◽  
Meng-Ran Liu ◽  
Jian-Zhao Duan ◽  
...  
Keyword(s):  
Field Experiments ◽  
Nitrogen Concentration ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
High Yield ◽  
N Application ◽  
N Concentration ◽  
Whole Plant ◽  
Critical Nitrogen Concentration ◽  
Critical N Concentration

The aim of this study was to verify the applicability of the critical nitrogen concentration dilution curve (Nc) of wheat grown under different irrigation conditions in the field, and discuss the feasibility of using the N nutrition index (NNI) to optimize N fertilizer application. The high-yield, medium-protein wheat varieties Zhoumai 27 and Zhoumai 22 were used in field experiments in two different locations (Zhengzhou and Shangshui) in Huang-Huai, China. Plants were grown under rainfed and irrigation conditions, with five N application rates. Nc models of the leaves, stems, and whole plant were constructed, followed by establishment of an NNI model and accumulative N deficit model (Nand). As previous research reported, our results also showed that the critical N concentration and biomass formed a power function relationship (N = aDW−b). When the biomass was the same, the critical N concentration was higher under irrigation than rainfed treatment. Meanwhile, the fitting accuracy (R2) of the Nc model was also higher under irrigation than rainfed treatment in both sites, and was higher in the stems and whole plant. The NNI calculated using the Nc model increased with increasing N application, reflecting N deficiency. Moreover, there was a significant negative linear correlation between NNI and Nand, and both indices could be uniformly modeled between locations and water treatments. The accuracy of the Nand model was highest in the whole plant, followed by the leaves and stems. The models constructed in this paper provide a theoretical basis for accurate management of N fertilizer application in wheat production.

Dynamics of nitrogen and dry-matter partitioning and accumulation in broccoli (Brassica oleracea var. italica) in relation to extractable soil inorganic nitrogen

1999 ◽  
Vol 79 (2) ◽  
pp. 277-286 ◽  
Author(s):  
P. A. Bowen ◽  
B. J. Zebarth ◽  
P. M. A. Toivonen
Keyword(s):  
Dry Matter ◽  
N Fertilization ◽  
N Fertilizer ◽  
Organic N ◽  
Soil N ◽  
Inorganic N ◽  
N Accumulation ◽  
Spring Planting ◽  
Extractable Soil ◽  
Soil Inorganic

The effects of six rates of N fertilization (0, 125, 250, 375, 500 and 625 kg N ha−1) on the dynamics of N utilization relative to extractable inorganic N in the soil profile were determined for broccoli in three growing seasons. The amount of pre-existing extractable inorganic N in the soil was lowest for the spring planting, followed by the early-summer then late-summer plantings. During the first 2 wk after transplanting, plant dry-matter (DM) and N accumulation rates were low, and because of the mineralization of soil organic N the extractable soil inorganic N increased over that added as fertilizer, especially in the top 30 cm. From 4 wk after transplanting until harvest, DM and N accumulation in the plants was rapid and corresponded to a rapid depletion of extractable inorganic N from the soil. At high N-fertilization rates, leaf and stem DM and N accumulations at harvest were similar among the three plantings. However, the rates of accumulation in the two summer plantings were higher before and lower after inflorescence initiation than those in the spring planting. Under N treatments of 0 and 125 kg ha−1, total N in leaf tissue and the rate of leaf DM accumulation decreased while inflorescences developed. There was little extractable inorganic soil-N during inflorescence development in plots receiving no N fertilizer, yet inflorescence dry weights and N contents were ≥50 and ≥30%, respectively, of the maxima achieved with N fertilization. These results indicate that substantial N is translocated from leaves to support broccoli inflorescence growth under conditions of low soil-N availability. Key words: N translocation, N fertilizer

scholarly journals Factors affecting the herbage iodine content.

1974 ◽  
Vol 22 (3) ◽  
pp. 195-206 ◽  
Author(s):  
J. Hartmans
Keyword(s):  
Soil Type ◽  
Dry Matter ◽  
Field Experiments ◽  
Iodine Content ◽  
Single Species ◽  
Residual Effects ◽  
Grass Species ◽  
Yield Response ◽  
N Application ◽  
Factors Affecting

In pot and field experiments, N application somewhat increased the I content of the harvested crop, although I concentrations in the herbage decreased considerably (diluting effect of increased dry matter yields). Herbage I contents were not consistently affected by chemical fertilizers which produced no yield response. I contents were up to 13 times higher in dicotyledenous pasture species than in grasses. I contents varied between grass species and to less extent between varieties of a single species. Contrary to earlier New Zealand data, good quality grasses were lower in I content than medium-value and inferior grasses. Small I dressings were less effective than larger amounts in terms of percentage return in the harvested crop; residual effects in later cuts were always small. The effectiveness of I dressings depended on soil type and tended to be lowest on soils of low natural I content. ADDITIONAL ABSTRACT: Studies were with ryegrass in pots and pastures. N dressing increased I uptake by the crop but reduced the I content considerably because of the diluting effect of higher DM yields. Dressing with fertilizers which did increase yield did not affect herbage I content consistently. Dicotyledonous species in pasture had I contents up to 13 times that of grasses. The I content of grasses varied over a 2-fold range but variation was smaller in a given species. Good quality grasses had a lower I content than inferior grasses. Smaller I dressings gave a smaller percentage return in the crop than larger amounts; the efficiency depended on soil type and tended to be less for soils with the lowest natural I content. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Effects of nitrogen accumulation and partitioning of dry matter and nitrogen of vegetables. 1. Brussels sprouts

1995 ◽  
Vol 43 (4) ◽  
pp. 419-433
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik
Keyword(s):  
Dry Matter ◽  
Leaf Number ◽  
Nitrogen Accumulation ◽  
N Accumulation ◽  
Total N ◽  
Brussels Sprouts ◽  
Apical Buds ◽  
Nitrate N ◽  
N Concentration ◽  
Final Harvest

Three greenhouse trials and one field trial were carried out on Brussels sprout cv. Icarus SG2004 in which the treatments consisted of different N amounts and application dates. DM and N accumulation in stems, apical buds and groups of leaf blades, petioles and sprouts were measured frequently throughout crop growth. Total amounts of accumulated DM and N were affected by amount of N applied and date of application, but the final harvest indexes for DM and N (0.10-0.35 and 0.20-0.55, respectively) were not significantly affected by treatments in most experiments. Nitrate N concentrations were only high (up to about 2%) shortly after planting. The total N concentration of leaf blades and petioles increased with increasing leaf number. This increase resulted from a decreasing N concentration during the leaf's life. The total N concentration in sprouts changed little with leaf number.

Nitrogen fixation in field beans (Vicia faba) as affected by population density, shading and its relationship with soil moisture

1977 ◽  
Vol 88 (2) ◽  
pp. 303-310 ◽  
Author(s):  
Janet I. Sprent ◽  
Alison M. Bradford
Keyword(s):  
Acetylene Reduction ◽  
Field Experiments ◽  
Reduction Technique ◽  
N Fixation ◽  
N Accumulation ◽  
Total N ◽  
Nodule Senescence ◽  
Total Plant ◽  
Acetylene Reducing Activity ◽  
High Yields

SUMMARYN fixation data, estimated by the acetylene reduction technique and by total N content are given for the field experiments reported by Sprent, Bradford & Norton (1977).Maximum potential acetylene reducing activity per plant varied little from year to year. At low population densities a maximum rate of activity was observed shortly after flowering. As density increased this maximum became less pronounced and environmental factors (such as water supply) exerted increasing effects on activity. Shading prolonged activity and delayed nodule senescence.Total plant N continued to increase almost to seed maturation. As plants aged, the acetylene reduction technique progressively underestimated N accumulation. Maximum Nfixed/ha/year was over 600 kg. Itis concluded that the potential for N fixation in this crop is sufficient to sustain high yields.

Effects of strobilurin fungicide programmes and fertilizer nitrogen rates on winter wheat: leaf area, dry matter yield and nitrogen yield

2011 ◽  
Vol 150 (4) ◽  
pp. 427-441 ◽  
Author(s):  
S. ISHIKAWA ◽  
M. C. HARE ◽  
P. S. KETTLEWELL
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
N Uptake ◽  
N Fertilization ◽  
Bread Making ◽  
N Accumulation ◽  
N Yield ◽  
Wheat Leaf ◽  
Strobilurin Fungicide ◽  
Nitrogen Rates

SUMMARYFour field experiments were conducted on wheat, using the bread-making cultivar Hereward, over 3 years to study the interactions between nitrogen (N) and strobilurin fungicides with respect to yield and grain N. In one of the field experiments, above-ground dry matter (DM) yield was greater when the plots were treated with a mixture of triazole and strobilurin than when either no fungicide or triazole alone was applied. On plots that received no N fertilizer, above-ground DM and grain yield were lower for the plots treated with fungicides than for plots not treated with fungicide, which implied that the benefit of applying fungicides could only be exploited with N fertilization. There was no difference in above-ground N accumulation between fungicide programmes; however, greater N accumulation in grains was observed following the application of a mixture of triazole and the strobilurin trifloxystrobin compared with plots treated with either no fungicide or triazole alone. This increase in grain N appeared to be attributable more to improved translocation of N to grains rather than to increased N uptake from the soil. The two strobilurin fungicide ingredients kresoxim-methyl and trifloxystrobin, each mixed with a triazole and tested in the present study, performed differently. Better performance, especially with respect to grain N yield, was observed most frequently with trifloxystrobin compared to kresoxim-methyl.

scholarly journals   Effects of nitrogen application stage on grain yield and nitrogen use efficiency of high-yield summer maize

2012 ◽  
Vol 58 (No. 5) ◽  
pp. 211-216 ◽  
Author(s):  
P. Lü ◽  
J.W. Zhang ◽  
L.B. Jin ◽  
W. Liu ◽  
S.T. Dong ◽  
...  
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
High Yield ◽  
Summer Maize ◽  
N Application ◽  
Total N ◽  
Leaf Stage ◽  
Application Method ◽  
Use Efficiency ◽  
Jointing Stage

This study aims to explore the optimum nitrogen (N) application method by analyzing effects of variable N application stages and ratios on the N absorption and translocation of high-yield summer maize (DH661). The study included field experiments and <sup>15</sup>N isotopic dilutions for pot experiments. Results showed that the yield was not increased in a one-off N application at the jointing stage. The uptake of fertilizer-derived N in the grain increased with the increasing of N applied times. Compared to a single or double application, total N uptake (N<sub>up</sub>) and biomass increased significantly by supplying N at the six-leaf stage (V6), ten-leaf stage (V10) and 10 days after anthesis in ratios of 3:5:2 and 2:4:4. The fertilizer-derived recovery rates were 67.5% and 78.1%, respectively. The uptake and utilization of fertilizer-derived N was enhanced by increasing the recovery rate of N supplied after anthesis, and reducing the absorption of soil-derived N. Therefore, the 2:4:4 application ratios was the optimal N application method. &nbsp;

Effects of Azospirillum inoculation on root infection and nitrogen incorporation in wheat

1983 ◽  
Vol 29 (8) ◽  
pp. 924-929 ◽  
Author(s):  
Vera L. D. Baldani ◽  
José Ivo Baldani ◽  
Johanna Döbereiner
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Nitrogen Accumulation ◽  
Root Infection ◽  
Wheat Roots ◽  
N Accumulation ◽  
Total N ◽  
Total Plant ◽  
Chloramine T ◽  
Heading Stage

In two field experiments, wheat was inoculated with various strains of Azospirillum spp. The two A. brasilense nir− strains isolated from surface-sterilized wheat roots increased the number of Azospirillum in surface-sterilized roots, plant dry matter, and percent N. The total N accumulated in plant tops at heading stage was increased by 30% in the first experiment (strain Sp 107 st) and by 51 and 89% (strains Sp 107 st and Sp 245, respectively) in the second experiment. The Azospirillum numbers (MPN) in chloramine-t treated roots were correlated with total nitrogen accumulation in plant tops (r = 0.92**). Numbers of Azospirillum in nonsterilized roots did not correlate with total plant N accumulation.

scholarly journals Dry Matter and Nitrogen Accumulation During Vegetative and Grain Filling of Lentil (Lens culinaris Medic.) as Affected by Nitrogen Rates

2011 ◽  
Vol 39 (2) ◽  
pp. 196 ◽  
Author(s):  
Nurdilek GULMEZOGLU ◽  
Nihal KAYAN
Keyword(s):  
Dry Matter ◽  
Field Experiments ◽  
Block Design ◽  
Growth Yield ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Grain Filling ◽  
Nitrogen Accumulation ◽  
N Accumulation ◽  
N Rates

This research aimed to determine the effect of different levels of nitrogen (N) on the growth, yield and the N accumulation of lentil plants grown under rain-fed conditions. The two-year field experiments with lentil were arranged in a randomised complete block design. Nitrogen was applied at four rates (0, 20, 40 and 60 kg ha-1) and all of the plots received half of the N rates before sowing in October and the remaining N rate in spring. The plants were harvested in the following stages: the first multifoliate leaf unfolding at the fifth node (V5) full seed or seed on nodes 10-13 that fill pod cavities (R6) and maturity (R8). The dry weight and N concentration of the shoot (leaf+stem), pod wall, and seed were then measured. It has been found that N application significantly affected the lentil characteristics. The maximum biomass accumulation and N accumulation were obtained at R6, and the N fertiliser had a positive effect on the seed weight and N accumulation. It can be suggest that 20 kg N ha-1 will increase the per-plant dry matter and N accumulation of the seeds under rain-fed conditions.

scholarly journals Use of a Chlorophyll Meter to Diagnose Nitrogen Status of ‘Fuyu’ Persimmon Leaves

HortScience ◽  
2011 ◽  
Vol 46 (5) ◽  
pp. 821-824 ◽  
Author(s):  
Seong-Tae Choi ◽  
Doo-Sang Park ◽  
Seong-Mo Kang ◽  
Soo-Jeong Park
Keyword(s):  
Field Experiments ◽  
Regression Line ◽  
Coefficient Of Determination ◽  
Regression Equations ◽  
N Application ◽  
Reference Guide ◽  
N Concentration ◽  
Old Trees ◽  
Spad Readings ◽  
Leaf N

A possible relationship between leaf SPAD readings and nitrogen (N) concentrations was evaluated at different growing stages of ‘Fuyu’ persimmon trees under different N regimes in pots and in the field. When 5-year-old trees grown in pots received 0 to 40 g N over the growing season, leaf SPAD reading, N concentration, and specific leaf weight tended to increase with increasing N rate. The correlation between leaf SPAD reading and N concentration was statistically significant from late April to early November (R2 = 0.72 to 0.97). It was noted that the slope of regression line decreased as the season progressed. Similar significant correlations were found from pot-grown 4- to 7-year-old trees grown under various nutrient regimes (R2 = 0.67 to 0.96). Significant correlations were also confirmed with the leaves collected from 31 commercial orchards at different locations. The highest coefficient of determination was observed from the leaves collected at harvest time in both the pot and field experiments. Although the regression equations differed depending on the growing stage of trees, SPAD readings were found useful in estimating leaf N status at a specific time and in quickly judging the need for N application at that time. Seasonal changes of leaf SPAD readings from five well-managed orchards are presented as a reference guide for practical use.

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