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.

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 Nitrogen Leaching and Nitrogen Balance under Differing Nitrogen Fertilization for Sugarcane Cultivation on a Subtropical Island

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 740
Author(s):  
Ken Okamoto ◽  
Shinkichi Goto ◽  
Toshihiko Anzai ◽  
Shotaro Ando
Keyword(s):  
N Uptake ◽  
Fertilizer Application ◽  
Application Rate ◽  
N Fertilizer ◽  
N Leaching ◽  
N Recovery ◽  
N Application ◽  
Fertilizer Application Rate ◽  
Sugarcane Yield ◽  
Cropping Seasons

Fertilizer application during sugarcane cultivation is a main source of nitrogen (N) loads to groundwater on small islands in southwestern Japan. The aim of this study was to quantify the effect of reducing the N fertilizer application rate on sugarcane yield, N leaching, and N balance. We conducted a sugarcane cultivation experiment with drainage lysimeters and different N application rates in three cropping seasons (three years). N loads were reduced by reducing the first N application rate in all cropping seasons. The sugarcane yields of the treatment to which the first N application was halved (T2 = 195 kg ha−1 N) were slightly lower than those of the conventional application (T1 = 230 kg ha−1 N) in the first and third seasons (T1 = 91 or 93 tons ha−1, T2 = 89 or 87 tons ha−1). N uptake in T1 and T2 was almost the same in seasons 1 (186–188 kg ha−1) and 3 (147–151 kg ha−1). Based on the responses of sugarcane yield and N uptake to fertilizer reduction in two of the three years, T2 is considered to represent a feasible fertilization practice for farmers. The reduction of the first N fertilizer application reduced the underground amounts of N loads (0–19 kg ha−1). However, application of 0 N in the first fertilization would lead to a substantial reduction in yield in all seasons. Reducing the amount of N in the first application (i.e., replacing T1 with T2) improved N recovery by 9.7–11.9% and reduced N leaching by 13 kg ha−1. These results suggest that halving the amount of N used in the first application can improve N fertilizer use efficiency and reduce N loss to groundwater.

Total nitrogen concentration in leaves of potatoes (Solanum tuberosumL.) as an index of nutritional status

1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena
Keyword(s):  
Total Nitrogen ◽  
Tuber Yield ◽  
Critical Concentration ◽  
Nitrogen Concentration ◽  
Curvilinear Relationship ◽  
N Application ◽  
Total N ◽  
Potato Plants ◽  
N Concentration ◽  
Total Nitrogen Concentration

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.

A new approach for determining rice critical nitrogen concentration

2011 ◽  
Vol 149 (5) ◽  
pp. 633-638 ◽  
Author(s):  
R. CONFALONIERI ◽  
C. DEBELLINI ◽  
M. PIRONDINI ◽  
P. POSSENTI ◽  
L. BERGAMINI ◽  
...  
Keyword(s):  
Nutritional Status ◽  
Cropping Systems ◽  
Nitrogen Concentration ◽  
Simulation Models ◽  
Crop Models ◽  
N Concentration ◽  
Alternative Approach ◽  
Using Data ◽  
The University ◽  
Critical N Concentration

SUMMARYA reliable evaluation of crop nutritional status is crucial for supporting fertilization aiming at maximizing qualitative and quantitative aspects of production and reducing the environmental impact of cropping systems. Most of the available simulation models evaluate crop nutritional status according to the nitrogen (N) dilution law, which derives critical N concentration as a function of above-ground biomass. An alternative approach, developed during a project carried out with students of the Cropping Systems Masters course at the University of Milan, was tested and compared with existing models (N dilution law and approaches implemented in EPIC and DAISY models). The new model (MAZINGA) reproduces the effect of leaf self-shading in lowering plant N concentration (PNC) through an inverse of the fraction of radiation intercepted by the canopy. The models were tested using data collected in four rice (Oryza sativaL.) experiments carried out in Northern Italy under potential and N-limited conditions. MAZINGA was the most accurate in identifying the critical N concentration, and therefore in discriminating PNC of plants growing under N-limited and non-limited conditions, respectively. In addition, the present work proved the effectiveness of crop models when used as tools for supporting education.

Effects of method, rate and time of application of nitrogen fertilizer on seed production of tall fescue

1998 ◽  
Vol 78 (3) ◽  
pp. 453-458 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch
Keyword(s):  
Seed Yield ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
N Fertilizer ◽  
N Application ◽  
Seed Crop ◽  
Grass Seed ◽  
Yield And Quality ◽  
Whole Plant ◽  
Clean Seed

The production of seed of tall fescue (Festuca arundinacea Schreber) provides an opportunity to diversify the agriculture of the Peace region with a new, un-subsidized, soil-conserving, cash-crop. Nitrogen fertility and nutrition are major components of the production of any grass-seed crop. A field study was conducted on the nitrogen (N) fertilizer requirements for optimizing seed yield and quality of tall fescue grown in the Peace region. Row-crop stands (30-cm spacing) were established at four sites in two consecutive seeding years (1993 and 1994), with two consecutive seed crops being harvested from each stand. A total of 18 N fertilizer treatments was applied to the first seed crop, a factorial combination of two methods (surface-broadcast, granular, ammonium nitrate 34–0–0, and soil-injected 28–0–0 solution), three times (early- to mid-September, early- to mid-October, and early- to mid-April prior to the first seed harvest), and three rates (50, 100, and 150 kg ha−1 N). The second seed crop received 68 kg ha−1 of surface-broadcast N applied in mid-September after removal of the harvest crop residue. Seed yield and quality were not affected by the time of N application. When compared with broadcast application, soil-injection of N fertilizer significantly reduced whole-plant dry matter (DM) yield and seed yield/seedhead by 7 and 9%, respectively, but the two methods of N application had no differential effect on clean seed yield ha−1, fertile tiller density, harvest index, thousand-seed weight, specific seed weight, germination, or on the proportion of clean seed. When compared with N at 50 kg ha−1, whole-plant DM yield was increased by 6 and 8%, and clean seed yield/seedhead by 15 and 14%, with the 100 and 150 kg ha−1 rates of N, respectively. The first- and second-year seed yields averaged 1319 and 952 kg ha−1, respectively, for the 1993 seeding year, and 1630 and 716 kg ha−1, respectively, for the 1994 seeding year. The cumulative seed productivity over the 2 production years was similar for the two seeding years, being 2271 kg ha−1 for 1993 and 2346 kg ha−1 for 1994. Each seed crop of tall fescue requires an available N supply from the soil in the range of 100 to 150 kg ha−1 N to maximize seed yield and quality. Key words: Tall fescue, Festuca arundinacea Schreber, nitrogen fertility, grass seed production, grass seed quality

Managing inoculation failure of field pea and chickpea based on spectral responses

2002 ◽  
Vol 82 (2) ◽  
pp. 273-282 ◽  
Author(s):  
J. T. McConnell ◽  
P. R. Miller ◽  
R. L. Lawrence ◽  
R. Engel ◽  
G. A. Nielsen
Keyword(s):  
Spectral Reflectance ◽  
Crop Production ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Field Pea ◽  
Yield Potential ◽  
Shoot Biomass ◽  
Fertilizer N ◽  
Logistic Regression Models ◽  
N Concentration

Pulse crop production is expanding in semiarid regions of the Northern Plains, and depends on successful biological N2-fixation. Inoculation failure, resulting in plant N deficiency and economic crop loss, might be alleviated by remedial N fertilizer application. The experiment was conducted using no-till management at two dryland sites in Montana in 1999 and 2000, where field pea and chickpea were grown in cereal stubble. Shoot biomass, shoot biomass N concentration, seed yield and seed N concentration were measured for uninoculated and inoculated controls and compared with remedial fertilizer N applied 0, 4, 6, and 8 wk after seeding. Spectral reflectance was compared for the inoculated and uninoculated controls. For field pea and chickpea, the critical period for fertilizer N application to prevent yield loss occurred within 6 wk of seeding (P ≤ 0.05). Logistic regression models derived from spectral reflectance had overall accuracies of 84 and 60% for detecting uninoculated control treatments in field pea and chickpea, respectively. The field pea model had a high degree of accuracy 6 wk after seeding, indicating it was capable of assisting a decision to apply remedial N fertilizer. Spectral reflectance provided a window of opportunity of 1 wk to apply remedial N fertilizer to attain full yield potential. Key words: Chickpea, field pea, inoculant failure, nitrogen, spectral reflectance

scholarly journals Nitrogen Requirements and N Status Determination of Lettuce

HortScience ◽  
2012 ◽  
Vol 47 (12) ◽  
pp. 1768-1774 ◽  
Author(s):  
Thomas G. Bottoms ◽  
Richard F. Smith ◽  
Michael D. Cahn ◽  
Timothy K. Hartz
Keyword(s):  
N Uptake ◽  
N Fertilization ◽  
Fertilizer Efficiency ◽  
Residual Soil ◽  
N Application ◽  
Fresh Biomass ◽  
N Concentration ◽  
Whole Plant ◽  
Crop N Uptake ◽  
N Rates

As concern over NO3-N pollution of groundwater increases, California lettuce growers are under pressure to improve nitrogen (N) fertilizer efficiency. Crop growth, N uptake, and the value of soil and plant N diagnostic measures were evaluated in 24 iceberg and romaine lettuce (Lactuca sativa L. var. capitata L., and longifolia Lam., respectively) field trials from 2007 to 2010. The reliability of presidedressing soil nitrate testing (PSNT) to identify fields in which N application could be reduced or eliminated was evaluated in 16 non-replicated strip trials and five replicated trials on commercial farms. All commercial field sites had greater than 20 mg·kg−1 residual soil NO3-N at the time of the first in-season N application. In the strip trials, plots in which the cooperating growers’ initial sidedress N application was eliminated or reduced were compared with the growers’ standard N fertilization program. In the replicated trials, the growers’ N regime was compared with treatments in which one or more N fertigation through drip irrigation was eliminated. Additionally, seasonal N rates from 11 to 336 kg·ha−1 were compared in three replicated drip-irrigated research farm trials. Seasonal N application in the strip trials was reduced by an average of 77 kg·ha−1 (73 kg·ha−1 vs. 150 kg·ha−1 for the grower N regime) with no reduction in fresh biomass produced and only a slight reduction in crop N uptake (151 kg·ha−1 vs. 156 kg·ha−1 for the grower N regime). Similarly, an average seasonal N rate reduction of 88 kg·ha−1 (96 kg·ha−1 vs. 184 kg·ha−1) was achieved in the replicated commercial trials with no biomass reduction. Seasonal N rates between 111 and 192 kg·ha−1 maximized fresh biomass in the research farm trials, which were conducted in fields with lower residual soil NO3-N than the commercial trials. Across fields, lettuce N uptake was slow in the first 4 weeks after planting, averaging less than 0.5 kg·ha−1·d−1. N uptake then increased linearly until harvest (≈9 weeks after planting), averaging ≈4 kg·ha−1·d−1 over that period. Whole plant critical N concentration (Nc, the minimum whole plant N concentration required to maximize growth) was estimated by the equation Nc (g·kg−1) = 42 − 2.8 dry mass (DM, Mg·ha−1); on that basis, critical N uptake (crop N uptake required to maintain whole plant N above Nc) in the commercial fields averaged 116 kg·ha−1 compared with the mean uptake of 145 kg·ha−1 with the grower N regime. Soil NO3-N greater than 20 mg·kg−1 was a reliable indicator that N application could be reduced or delayed. Neither leaf N nor midrib NO3-N was correlated with concurrently measured soil NO3-N and therefore of limited value in directing in-season N fertilization.

scholarly journals Low N Fertilizer Application and Intercropping Increases N Concentration in Pea (Pisum sativum L.) Grains

2018 ◽  
Vol 9 ◽  
Author(s):  
Falong Hu ◽  
Yan Tan ◽  
Aizhong Yu ◽  
Cai Zhao ◽  
Jeffrey A. Coulter ◽  
...  
Keyword(s):  
Pisum Sativum ◽  
Fertilizer Application ◽  
N Fertilizer ◽  
Pisum Sativum L ◽  
N Concentration

scholarly journals Long-Term Effects of Different Nitrogen Levels on Growth, Yield, and Quality in Sugarcane

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 353 ◽  
Author(s):  
Xu-Peng Zeng ◽  
Kai Zhu ◽  
Jian-Ming Lu ◽  
Yuan Jiang ◽  
Li-Tao Yang ◽  
...  
Keyword(s):  
Fertilizer Application ◽  
Sugar Yield ◽  
N Fertilizer ◽  
Cane Yield ◽  
Sugar Accumulation ◽  
Production Cycle ◽  
Long Term Effects ◽  
N Application ◽  
Yield And Quality

Nitrogen (N) plays an important role in sugarcane (Saccharum spp. hybrids) growth and development; however, long-term effects of N application levels on cane and sugar production in different sugarcane cultivars under field conditions remain unclear. In this study, we investigate the agronomic, yield, and quality traits in three sugarcane cultivars (GT11, B9, and ROC22) under different N levels (0, 150, and 300 kg/ha urea) from 2015 to 2019. Continuous four-year field experiments of plant and ratoon crops were carried out by using two-factor split-plot design. The results showed that N fertilizer application improved the tillering rate, stalk diameter, plant height, stalk weight, millable stalks/ha, cane yield, sugar yield and juice rate of cane, and the difference between N application and non-N application was significant. The cane yield, millable stalks/ha, juice rate, and juice gravity purity increased with the increase of N application, but the milled juice brix and sucrose % cane decreased with the increase of N application. The sugar yield was the highest at 150 kg/ha urea application, while the cane yield was the highest at 300 kg/ha urea application. Different N fertilizer application levels significantly regulated the activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) and the contents of chlorophyll and nitrate N in plant leaves, which reflected the regulation in nitrogen metabolism and alteration in dry matter production and distribution, cane yield and sugar accumulation in different sugarcane cultivars. During the four-year experiment duration, the cane yield and sugar yield generally showed ROC22 > B9 > GT11. These data suggested that 300 kg/ha urea application was suitable for the plant and first ratoon crops, and 150 kg/ha urea application was suitable for the second and third ratoon crops. Both cane and sugar yields could be the highest in a four-year production cycle under this circumstance.

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