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.

Effect of rate of nitrogen fertilizer on the above- and below-ground biomass of irrigated bromegrass in southwest Saskatchewan

1991 ◽  
Vol 71 (4) ◽  
pp. 1057-1067 ◽  
Author(s):  
A. J. Leyshon
Keyword(s):  
N Fertilization ◽  
N Recovery ◽  
Root Mass ◽  
Forage Production ◽  
N Application ◽  
Nutrient Quality ◽  
N Concentration ◽  
Below Ground ◽  
Use Efficiency ◽  
N Rates

A 9-yr study was conducted on an alluvial clay loam at Swift Current, Saskatchewan to determine the effect of annual applications of urea-N (46-0-0) fertilizer on production, nutrient quality, N use efficiency, root mass, and root distribution of bromegrass (Bromus inermis Leyss.). Nitrogen was applied annually at the rates of 0, 50, 100, and 200 kg ha−1 N to an established stand of bromegrass. Plots were flood irrigated. Forage DM yields increased linearly with rate of N applied. In all years, the slope of the response was similar and averaged 24 kg DM kg−1 N. The average y-intercept value was 1794 kg DM ha−1. In years 1–4, the N concentration in the grass was depressed at low N rates but after 5 yr the N concentration increased at all N rates. Tissue [Formula: see text] levels over 100 ppm occurred at the 200 kg N rate after 3 yr. Applications of N reduced plant P in all years; the extent depended on N rate. Uptake of N increased with increasing N rate as did the apparent N recovery. Nitrogen rate had no effect on root mass or distribution. Root mass totalled 13 888 kg DM ha−1 to 105-cm depth. Approximately 36% of the root mass was in the top 7.5 cm, 11.9% in the 7.5- to 15-cm depth and 16.9% in the 15-to 30-cm depth. Estimates of the soil space occupied by roots indicate that they would occupy a large proportion of the available pore volume. It was concluded that producers growing bromegrass under irrigation on medium- to heavy-textured soils in southern Saskatchewan can consistently expect considerable increases in hay yield of good quality with N fertilizer at rates up to 200 kg N ha−1. While forage production increased linearly in response to N fertilization, root accumulation remained at a constant level. Further studies are needed to establish maximum yields and economic rates of N application. Key words: N rate, N recovery, roots, forage N, forage P

Utilisation de l'engrais azoté marqué au 15N par le maïs selon les modes d'application et les doses d'azote

1997 ◽  
Vol 77 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Thi Sen Tran ◽  
Marcel Giroux ◽  
Michel P. Cescas
Keyword(s):  
Field Experiments ◽  
N Uptake ◽  
Field Trials ◽  
N Fertilization ◽  
N Fertilizer ◽  
N Recovery ◽  
Split Application ◽  
N Application ◽  
Application Methods ◽  
N Rates

The main objective of this study was to compare the recovery of 15N-labelled fertilizer by different methods of N application and N rates. Field experiments were carried out for 3 yr at Saint-Hyacinthe (Saint-Damase, Du Contour, Sainte-Rosalie soils) and at Saint-Lambert, Lévis (Le Bras soil). Grain corn (cv. Pride K228, 2700 CHU) and silage corn (cv. Hyland 3251, 2300 CHU) were grown at Saint-Hyacinthe and Saint-Lambert, respectively. In 1988 and 1989, field trials were arranged in a randomized complete bloc design consisting of five treatments in three replications: control 0 N and four split application methods of N fertilizer. Labelled 15NH4 15NO3 fertilizer was applied either banded at planting as starter (D), broadcast and incorporated before planting (Vs) or sidedressing between rows at V6 to V8 stages of corn (Bp). In 1990 field trials, treatments consisted of four N rates (0, 60, 120 and 180 kg N ha−1) labelled with 15NH4 15NO3. The effect of N rates on yield and N uptake by corn was significant in all years. However, the effect of application methods was significant only on the soil Du Contour in 1989 where corn grain yield was highest when N fertilizer was split as starter and sidedress band. The CUR of N fertilizer applied broadcast before planting (42 to 48%) was generally lower than sidedressing band application (43 to 54%). N fertilizer recovery in the starter showed also high CUR values (45 to 60%). Consequently, it is recommended to split N fertilizers and apply in band to increase efficiency for grain corn. The CUR values decreased with N rates only in Le Bras soil in 1990. Residual N fertilizer increased from 27 to 103 kg N ha−1 for 60 and 180 kg N ha−1 rates, respectively. Consequently, the environmental impact of N fertilization may increased with high N rate. Key words: Grain corn, silage corn, 15N recovery, fertilizer N split application

scholarly journals 349 Determining Nitrogen Requirements of Lettuce through Presidedress Soil Nitrate Testing (PSNT)

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 452C-452 ◽  
Author(s):  
T.K. Hartz ◽  
S. Breschini
Keyword(s):  
Application Rate ◽  
N Fertilization ◽  
Fertilizer Efficiency ◽  
Test Technique ◽  
N Application ◽  
Central California ◽  
Iceberg Lettuce ◽  
N Concentration ◽  
N Application Rate ◽  
Salinas Valley

High rates of N fertilization of cool-season vegetables has contributed to NO3-N pollution of groundwater in the Salinas Valley of central California. Ten field demonstrations were conducted in 1999 to document the utility of presidedress soil NO3-N testing in maximizing N fertilizer efficiency in iceberg lettuce (Lactuca sativa L.). In each demonstration, a plot 36 beds wide × the entire field length was established in a commercial lettuce field. The cooperating growers applied 1 to 3 N sidedressings in these fields. Before each sidedressing the soil NO3-N concentration in the top 30 cm of the plot was determined by an on-farm quick test technique. If NO3-N was >20 mg·kg-1, no N was applied at that sidedressing; for NO3-N <20 mg·kg-1, ≈4 kg N/ha was applied for each milligram per kilogram below the 20 mg·kg-1 threshold. Plot yields, harvested by commercial crews, were compared to the yield of adjacent areas of the field that received the growers' full sidedress N regime. Across fields, seasonal sidedress N application in the PSNT plots averaged N only at 86 kg·ha-1, almost 60% less than the average N (212 kg·ha-1) applied by the growers. Yields in the PSNT plots averaged 1824 boxes/ha, compared with 1829 boxes/ha in the companion field plots. Whole leaf N concentration at heading was above published sufficiency standards in all PSNT plots. Evaluation of heads after 10 days of storage at 5 °C showed that sidedress N application rate did not affect visual quality, decay, or midrib discoloration. We conclude that PSNT can reliably be used to minimize wasteful sidedress N applications in lettuce.

NLEAP Computer Model and Multiple Linear Regression Prediction of Nitrate Leaching in Vegetable Systems

2002 ◽  
Vol 12 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Hudson Minshew ◽  
John Selker ◽  
Delbert Hemphill ◽  
Richard P. Dick
Keyword(s):  
Linear Regression ◽  
Multiple Linear Regression ◽  
Nitrate Leaching ◽  
Cover Crops ◽  
N Uptake ◽  
N Leaching ◽  
Residual Soil ◽  
Vegetable Crops ◽  
Crop N Uptake ◽  
Mlr Model

Predicting leaching of residual soil nitrate-nitrogen (NO3-N) in wet climates is important for reducing risks of groundwater contamination and conserving soil N. The goal of this research was to determine the potential to use easily measurable or readily available soilclimatic-plant data that could be put into simple computer models and used to predict NO3 leaching under various management systems. Two computer programs were compared for their potential to predict monthly NO3-N leaching losses in western Oregon vegetable systems with or without cover crops. The models were a statistical multiple linear regression (MLR) model and the commercially available Nitrate Leaching and Economical Analysis Package model (NLEAP 1.13). The best MLR model found using stepwise regression to predict annual leachate NO3-N had four independent variables (log transformed fall soil NO3-N, leachate volume, summer crop N uptake, and N fertilizer rate) (P < 0.001, R2 = 0.57). Comparisons were made between NLEAP and field data for mass of NO3-N leached between the months of September and May from 1992 to 1997. Predictions with NLEAP showed greater correlation to observed data during high-rainfall years compared to dry or averagerainfall years. The model was found to be sensitive to yield estimates, but vegetation management choices were limiting for vegetable crops and for systems that included a cover crop.

scholarly journals PLANT DENSITY AND NITROGEN FERTILIZATION ON COMMON BEAN NUTRITION AND YIELD

2017 ◽  
Vol 30 (3) ◽  
pp. 670-678 ◽  
Author(s):  
ROGÉRIO PERES SORATTO ◽  
TIAGO ARANDA CATUCHI ◽  
EMERSON DE FREITAS CORDOVA DE SOUZA ◽  
JADER LUIS NANTES GARCIA
Keyword(s):  
Grain Yield ◽  
Common Bean ◽  
Nitrogen Fertilization ◽  
Dry Matter ◽  
Plant Density ◽  
N Fertilization ◽  
N Concentration ◽  
Plant Densities ◽  
N Rates ◽  
Lower Plant

ABSTRACT The objective of this work was to evaluate the effect of plant densities and sidedressed nitrogen (N) rates on nutrition and productive performance of the common bean cultivars IPR 139 and Pérola. For each cultivar, a randomized complete block experimental design was used in a split-plot arrangement, with three replicates. Plots consisted of three plant densities (5, 7, and 9 plants ha-1) and subplots of five N rates (0, 30, 60, 120, and 180 kg ha-1). Aboveground dry matter, leaf macro- and micronutrient concentrations, yield components, grain yield, and protein concentration in grains were evaluated. Lower plant densities (5 and 7 plants m-1) increased aboveground dry matter production and the number of pods per plant and did not reduce grain yield. In the absence of N fertilization, reduction of plant density decreased N concentration in common bean leaves. Nitrogen fertilization linearly increased dry matter and leaf N concentration, mainly at lower plant densities. Regardless of plant density, the N supply linearly increased grain yield of cultivars IPR 139 and Pérola by 17.3 and 52.2%, respectively.

scholarly journals Optimizing Nitrogen Application for Growth and Productivity of Pomegranates

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 366
Author(s):  
Silit Lazare ◽  
Yang Lyu ◽  
Uri Yermiyahu ◽  
Yehuda Heler ◽  
Alon Ben-Gal ◽  
...  
Keyword(s):  
N Uptake ◽  
N Fertilization ◽  
Field Conditions ◽  
Nitrogen Application ◽  
N Application ◽  
Environmentally Responsible ◽  
Irrigation Solution ◽  
Vegetative Indices ◽  
Leaf N ◽  
Usage Efficiency

Quantification of actual plant consumption of nitrogen (N) is necessary to optimize fertilization efficiency and minimize contamination of earth resources. We examined the performance of fruit-bearing pomegranate trees grown in soilless media and exposed to eight N-fertigation treatments, from 5 to 200 mg N L−1. Reproductive and vegetative indices were found to be optimal when 20 to 70 mg N L−1 was supplied. Nitrogen application levels over 70 mg L−1 reduced pomegranate development and reproduction. N uptake in low-level treatments was almost 100% and decreased gradually, down to 13% in 200 mg N L−1 treatment. N usage efficiency was maximized under 20 mg N L−1, in which case 80% to 90% of added N was taken up by the trees. At high N application, its efficiency was reduced with less than 50% utilized by the trees. Leaf N increased to a plateau as a function of increasing irrigation solution N, maximizing at ~15 to 20 mg N g−1. Therefore, analysis of diagnostic leaves is not a valid method to identify excessive detrimental N. The results should be valuable in the development of efficient, sustainable, environmentally responsible protocols for N fertilization in commercial pomegranate orchards, following adaptation and validation to real soil field conditions.

scholarly journals Yield performance of upland rice cultivars at different rates and times of nitrogen application

2012 ◽  
Vol 36 (2) ◽  
pp. 475-483 ◽  
Author(s):  
José Hildernando Bezerra Barreto ◽  
Ismail Soares ◽  
José Almeida Pereira ◽  
Antonio Marcos Esmeraldo Bezerra ◽  
José Aridiano Lima de Deus
Keyword(s):  
Upland Rice ◽  
Oryza Sativa L ◽  
Block Design ◽  
N Fertilization ◽  
Rice Cultivars ◽  
Nitrogen Application ◽  
N Application ◽  
Yield Performance ◽  
Randomized Block Design ◽  
N Rates

Nitrogen is the most important nutrient for rice (Oryza sativa L) yields. This study aimed to evaluate the response of upland rice cultivars to N rate and application times in a randomized block design, in subdivided plots with four replications. The studied factors were five rice cultivars (BRS MG Curinga, BRS Monarca, BRS Pepita, BRS Primavera, and BRS Sertaneja), three application times (100 % at planting, 50 % at planting - 50 % at tillering and 100 % at tillering) and four N rates (0, 50, 100, and 150 kg ha-1). All cultivars responded to increased rates and different times of N application, especially BRS Primavera and BRS Sertaneja, which were the most productive when 50 % N rates were applied at sowing and 50 % at tillering. The response of cultivar BRS Monarca to N fertilization was best when 100 % of the fertilizer was applied at tillering.

scholarly journals Ethephon Reduces Maize Nitrogen Uptake but Improves Nitrogen Utilization in Zea mays L.

2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
N Uptake ◽  
Utilization Efficiency ◽  
N Application ◽  
Total N ◽  
N Concentration ◽  
High Plant Density ◽  
Ethephon Treatment ◽  
N Use

Increasing use of plant density or/and nitrogen (N) application has been introduced to maize production in the past few decades. However, excessive planting density or/and use of fertilizer may cause reduced N use efficiency (NUE) and increased lodging risks. Ethephon application improves maize lodging resistance and has been an essential measure in maize intensive production systems associated with high plant density and N input in China. Limited information is available about the effect of ethephon on maize N use and the response to plant density under different N rates in the field. A three-year field study was conducted with two ethephon applications (0 and 90 g ha−1), four N application rates (0, 75, 150, and 225 kg N ha−1), and two plant densities (6.75 plants m−2 and 7.5 plants m−2) to evaluate the effects of ethephon on maize NUE indices (N agronomic efficiency, NAE; N recovery efficiency, NRE; N uptake efficiency, NUpE; N utilization efficiency, NUtE; partial factor productivity of N, PFPN), biomass, N concentration, grain yield and N uptake, and translocation properties. The results suggest that the application of ethephon decreased the grain yield by 1.83–5.74% due to the decrease of grain numbers and grain weight during the three experimental seasons. Meanwhile, lower biomass, NO3- and NH4+ fluxes in xylem bleeding sap, and total N uptake were observed under ethephon treatments. These resulted in lower NAE and NUpE under the ethephon treatment at a corresponding N application rate and plant density. The ethephon treatment had no significant effects on the N concentration in grains, and it decreased the N concentration in stover at the harvesting stage, while increasing the plant N concentration at the silking stage. Consequently, post-silking N remobilization was significantly increased by 14.10–32.64% under the ethephon treatment during the experimental periods. Meanwhile, NUtE significantly increased by ethephon.

scholarly journals Variability for Nitrogen Management in Genetically-Distant Maize (Zea mays L.) Lines: Impact of Post-Silking Nitrogen Limiting Conditions

Agronomy ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 309 ◽  
Author(s):  
Isabelle Quilleré ◽  
Céline Dargel-Graffin ◽  
Peter J. Lea ◽  
Bertrand Hirel
Keyword(s):  
N Uptake ◽  
Predictive Marker ◽  
N Fertilization ◽  
High Yield ◽  
N Content ◽  
Whole Plant ◽  
Large Level ◽  
N Remobilization ◽  
N Management ◽  
The Impact

The impact of nitrogen (N)-limiting conditions after silking on kernel yield (KY)-related traits and whole plant N management was investigated using fifteen maize lines representative of plant genetic diversity in Europe and America. A large level of genetic variability of these traits was observed in the different lines when post-silking fertilization of N was strongly reduced. Under such N-fertilization conditions, four different groups of lines were identified on the basis of KY and kernel N content. Although the pattern of N management, including N uptake and N use was variable in the four groups of lines, a number of them were able to maintain both a high yield and a high kernel N content by increasing shoot N remobilization. No obvious relationship between the genetic background of the lines and their mode of N management was found. When N was limiting after silking, N remobilization appeared to be a good predictive marker for identifying maize lines that were able to maintain a high yield and a high kernel N content irrespective of their female flowering date. The use of N remobilization as a trait to select maize genotypes adapted to low N input is discussed.

scholarly journals How Nitrogen Supply Affects Growth and Nitrogen Uptake, Use Efficiency, and Loss from Citrus Seedlings

1996 ◽  
Vol 121 (1) ◽  
pp. 105-114 ◽  
Author(s):  
John D. Lea-Cox ◽  
James P. Syvertsen
Keyword(s):  
Plant Growth ◽  
N Uptake ◽  
Single Application ◽  
N Application ◽  
N Supply ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Use Efficiency ◽  
Complete Nutrient Solution ◽  
Leaf N

We examined how N supply affected plant growth and N uptake, allocation and leaching losses from a fine sandy soil with four Citrus rootstock species. Seedlings of `Cleopatra' mandarin (Citrus reticulata Blanco) and `Swingle' citrumelo (C. paradisi × P. trifoliata) were grown in a glasshouse in 2.3-liter pots of Candler fine sand and fertilized weekly with a complete nutrient solution containing 200 mg N/liter (20 mg N/week). A single application of 15NH415NO3(17.8% atom excess 15N) was substituted for a normal weekly N application when the seedlings were 22 weeks old (day O). Six replicate plants of each species were harvested at 0.5, 1.5, 3.5, 7, 11, and 30 days after 15N application. In a second experiment, NH4 NO3 was supplied at 18,53, and 105 mg N/week to 14-week-old `Volkamer' lemon (C. volkameriana Ten. & Pasq.) and sour orange (C. aurantium L.) seedlings in a complete nutrient solution for 8 weeks. A single application of 15NH415NO3 (23.0% 15N) was substituted at 22 weeks (day 0), as in the first experiment, and seedlings harvested 3,7, and 31 days after 15N application. Nitrogen uptake and partitioning were similar among species within each rate, but were strongly influenced by total N supply and the N demand by new growth. There was no 15N retranslocation to new tissue at the highest (105 mg N/week) rate, but N supplies below this rate limited plant growth without short-term 15N reallocation from other tissues. Leaf N concentration increased linearly with N supply up to the highest rate, while leaf chlorophyll concentration did not increase above that at 53 mg N/week. Photosynthetic CO2 assimilation was not limited by N in this study; leaf N concentration exceeded 100 mmol·m-2 in all treatments. Thus, differences in net productivity at the higher N rates appeared to be a function of increased leaf area, but not of leaf N concentration. Hence, N use efficiency decreased significantly over the range of N supply, whether expressed either on a gas-exchange or dry weight basis. Mean plant 15N uptake efficiencies after 31 days decreased from 60% to 47% of the 15N applied at the 18,20, and 53 mg N/week rates to less than 33% at the 105 mg N/week rate. Leaching losses increased with N rate, with plant growth rates and the subsequent N requirements of these Citrus species interacting with residual soil N and potential leaching loss.

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