EFFECTS OF N AND K FERTILIZATION ON THE PROTEIN, NITRATE AND NONPROTEIN REDUCED N FRACTIONS OF TIMOTHY AND BROMEGRASS

1974 ◽  
Vol 54 (2) ◽  
pp. 331-341 ◽  
Author(s):  
L. B. MacLEOD ◽  
J. A. MacLEOD
Keyword(s):  
Field Experiments ◽  
Application Rate ◽  
Phleum Pratense ◽  
Bromus Inermis ◽  
N Application ◽  
Nitrate N ◽  
N Concentration ◽  
Phleum Pratense L ◽  
K Fertilization ◽  
N Fractions

Timothy (Phleum pratense L.) and bromegrass (Bromus inermis Leyss.) were grown in field experiments to evaluate the effects of N and K fertilization on protein, nitrate and nonprotein reduced N concentration in the forage. Concentrations of all N fractions studied generally increased as the rate of N application was increased. At high rates of N application (448 and 896 kg N/ha) nitrate N concentrations increased when rates of K application were increased from 56 to 440 kg/ha. Highest nitrate N concentrations were 0.37 and 0.43% for timothy and bromegrass, respectively. These were obtained at highest rates of N and K application (896 kg N/ha and 440 kg K/ha). Highest concentrations of nonprotein reduced N were 1.20 and 1.11% for timothy and bromegrass, respectively. Although the highest concentrations of nonprotein reduced N were obtained at highest rates of N and K application, rate of K application had no significant effect on this fraction.

NITROGENASE ACTIVITY OF ALFALFA GROWN ALONE AND IN MIXTURE WITH GRASS UNDER GREENHOUSE CONDITIONS

1985 ◽  
Vol 65 (3) ◽  
pp. 787-791
Author(s):  
H. A. BURITY ◽  
B. E. COULMAN ◽  
M. A. FARIS
Keyword(s):  
Medicago Sativa ◽  
Nitrogenase Activity ◽  
Dactylis Glomerata ◽  
Phleum Pratense ◽  
Bromus Inermis ◽  
Smooth Bromegrass ◽  
Medicago Sativa L ◽  
Dactylis Glomerata L ◽  
Phleum Pratense L ◽  
Nodule Tissue

A greenhouse experiment has shown that total nitrogenase activity of alfalfa (Medicago sativa L.) is not significantly affected when grown in association with timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis Leyss) or orchardgrass (Dactylis glomerata L.) except after initial harvest when decreased alfalfa activity was associated with smooth bromegrass or orchardgrass. It was concluded that mixed cultures of alfalfa with timothy, smooth bromegrass or orchardgrass have no effect on alfalfa N2 fixation. The results also suggest the occurrence of N transference from alfalfa to associated grasses. It is speculated that this transfer is not primarily due to the death of roots and nodule tissue (after harvest), but involves some degree of N excretion during the period before initial harvest.Key words: Alfalfa-grass mixtures, N2-fixation, nodule activity, N-transference

NITROGEN ENHANCEMENT OF SURFACE APPLIED FERTILIZER PHOSPHORUS UPTAKE BY FORAGE SPECIES

1974 ◽  
Vol 54 (1) ◽  
pp. 89-104 ◽  
Author(s):  
R. W. SHEARD
Keyword(s):  
Phosphorus Uptake ◽  
Phleum Pratense ◽  
Grass Species ◽  
Similar Data ◽  
Forage Grasses ◽  
Efficient Utilization ◽  
N Application ◽  
P Utilization ◽  
Medicago Sativa L ◽  
Phleum Pratense L

Nitrogen, supplied as NH4NO3 to timothy (Phleum pratense L.) and bromegrass (Bromus inermis L.) or as N derived from alfalfa (Medicago sativa L.) growing in association with timothy, enhanced the utilization of surface applications of pelleted, 32P-labelled calcium phosphate. The proportion of the P in timothy derived from a single application of 60 kg P/ha increased from a range of 16% to 21% without N to a range of 38% to 43% with an application of 60 kg N/ha before spring growth and repeated after the first and second harvests. At the first two harvests, growing timothy in association with alfalfa further increased the proportion. The increase was greater at the second harvest and at the lower rates of N, amounting to an increase of one-third at applications of 15 and 30 kg N/ha. The proportion of P in the first harvest of bromegrass which was derived from a surface application was increased 17% to 26% as the rate of P was increased from 40 to 120 kg P/ha; however, N fertilizer as NH4NO3 increased fertilizer P utilization from 17% to 32% as the rate of N was increased from zero to 120 kg N/ha at the 40 kg P/ha rate, and from 26% to 57% with increasing N at the 120 kg P/ha rate. Similar data were obtained when the rates of N application were repeated for the second and third harvests. A relationship, developed between the N concentration in the grass species and the percent utilization of fertilizer P, would suggest that enhancement in utilization of P was, in part, the result of an increase in the assimilated N in the plant. The experiments illustrate that it is imperative to provide adequate N for efficient utilization of surface-applied P by perennial forage grasses.

scholarly journals 647 Effects of Nitrogen Application Rates on Leachate Nitrogen Concentrations and Leatherleaf Fern Establishment

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 509B-509
Author(s):  
Robert H. Stamps
Keyword(s):  
Controlled Release ◽  
Application Rate ◽  
Contamination Level ◽  
N Leaching ◽  
Nitrogen Application ◽  
N Application ◽  
Controlled Release Fertilizer ◽  
Nitrate N ◽  
Application Rates ◽  
N Application Rate

One of the most difficult times to balance crop nitrogen (N) requirements with concerns about nitrate-N leaching occurs during crop establishment, when root systems are poorly developed and not widely distributed in the growing medium. This dilemma can be exacerbated when producing a slow-growing plant such as leatherleaf fern (Rumohra adiantiformis [Forst.] Ching) on sandy soils in shadehouses in areas with significant rainfall. Rhizomes were planted in 36 drainage lysimeters containing Tavares fine sand located in a shadehouse. Nitrogen fertilizer was applied at nine rates using liquid and/or controlled-release fertilizer. Nitrogen application rates were varied as the rhizomes became established and spread into unplanted areas of the lysimeters. Irrigation and rainfall were monitored and the amount of water not lost to evapotranspiration was determined. Nitrogen (ammoniacal, nitrate/nitrite, total Kjeldahl) concentrations in leachate collected below the rootzone were determined. Stipe sap nitrate and frond total Kjeldahl nitrogen (TKN) were determined to try to develop a production monitoring technique. Initially, only leachate samples from controlled-release fertilizer plots treated at 21 and 42 kg of N/ha per year and liquid fertilizer at 28 kg of N/ha per year were consistently below the maximum contamination level (MCL) of 10 mg·L–1. As the fern became established, leachate nitrate/nitrite-N concentrations from higher N application rate treatments also remained below the MCL. Leachate N concentrations decreased as rainfall increased. Fern growth increased with increasing N application rate. Stipe sap nitrate-N and frond TKN concentrations were not well-correlated during establishment.

scholarly journals 291 Effect of Nitrogen Fertilization Time on Nitrogen Storage and Return Bloom of Pecan

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 492D-492
Author(s):  
Laura E. Acuña-Maldonado ◽  
Michael W. Smith
Keyword(s):  
Nitrogen Fertilization ◽  
Nitrogen Storage ◽  
Nitrogen Application ◽  
Application Time ◽  
Split Application ◽  
Single Application ◽  
N Application ◽  
Nitrate N ◽  
N Concentration ◽  
Return Bloom

A study was conducted to compare a single nitrogen application in March (125 kg N/ha) vs. a split application in March (75 kg N/ha) and October (50 kg N/ha) on 15-year-old `Maramec'. After one season, N application time did not affect return bloom. A split N application increased trunk wood Kjeldahl-N but decreased Kjeldahl-N in the current season's reproductive shoots and 1-year-old branches compared to a single application in March. Kjeldahl-N concentration was not affected by treatment in current season's vegetative shoots, trunk bark or roots. Nitrate-N concentration was not affected by treatment in any tissue sampled. Between the first week of October and the first killing frost in November, Kjeldahl-N increased 29% in current season's shoots, 21% in trunk bark, 32% in roots >1 cm in diameter, and 15% in roots <1 cm in diameter but decreased 42% in trunk wood and 5% in 1-year-old branches. Roots <1 cm in diameter accumulated more nitrate-N than other tissues during November.

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.

The effect of stubble management and N-fertilization practices on the nitrogen economy under intensive rice cropping

Soil Research ◽  
1989 ◽  
Vol 27 (4) ◽  
pp. 685 ◽  
Author(s):  
PE Bacon ◽  
LG Lewin ◽  
JW McGarity ◽  
EH Hoult ◽  
D Alter
Keyword(s):  
Field Experiments ◽  
Oryza Sativa L ◽  
N Uptake ◽  
Application Rate ◽  
N Fertilization ◽  
Rice Crop ◽  
Soil N ◽  
Fertilizer N ◽  
N Application ◽  
Total N

The fate of 15N-labelled fertilizer applied to rice (Oryza sativa L) was studied in microplots established within two field experiments comprising a range of stubble levels, stubble management techniques, N application rates and times. The first experiment investigated uptake of soil and fertilizer N in plots where application of 0 or 100 kg N ha-1 to the previous rice crop had produced 11.5 and 16.1 t ha-1 of stubble respectively. The stubble was then treated in one of four ways-burn (no till); burn then cultivated; incorporated in autumn or incorporated at sawing. Microplots within these large plots received 60 kg ha-1 of 5% 15N enriched urea at sowing, just prior to permanent flood (PF), or just after panicle initiation (PI) of the second crop. The second experiment was undertaken within a field in which half of the plots had stubble from the previous three rice crops burned, while the other plots had all stubble incorporated. In the fourth successive rice crop, the two stubble management systems were factorially combined with three N rates (0, 70 or 140 kg N ha-1) and three application times (PF, PI or a 50 : 50 split between PF and PI). Nitrogen uptake and retention in the soil were studied within 15N-labelled microplots established within each of these large plots. Only 4% of the 15N applied at sowing in the first experiment was recovered in the rice crop, while delaying N application to PF or PI increased this to an average of 20% and 44% respectively over the two experiments. The doubling of N application rate doubled fertilizer N uptake and also increased uptake of soil N at maturity by 12 kgN ha-1. Three years of stubble incorporation increased average uptake of fertilizer and soil N in the second experiment by 5 and 12 kg N ha-1 respectively. In both experiments, the soil was the major source of N, contributing 66-96% of total N uptake. On average, in the fourth crop, 20% of fertilizer N was in the grain, 12% in the straw and 3% in the roots, while 23% was located in the top 300 mm of soil. A further 3% was in the soil below 300 mm. The remaining 39% was lost, presumably by denitrification.

Selection for nitrogen use efficiency and N concentration in timothy

1998 ◽  
Vol 78 (4) ◽  
pp. 611-613 ◽  
Author(s):  
R. Michaud ◽  
G. Bélanger ◽  
A. Brégard ◽  
J. Surprenant
Keyword(s):  
Nitrogen Use Efficiency ◽  
N Uptake ◽  
Genetic Selection ◽  
Phleum Pratense ◽  
N Use Efficiency ◽  
Nitrogen Use ◽  
N Concentration ◽  
Use Efficiency ◽  
Phleum Pratense L ◽  
N Use

Improvement of N use efficiency of timothy (Phleum pratense L.) involves higher DM yield but, for feeding purposes, N concentration should also be considered. Differences in N use efficiency were found among 40 genotypes of timothy. The analysis of residues of the linear regression between N uptake and DM yield of all genotypes allowed for the selection of genotypes with both high N use efficiency and contrasted N concentrations. Key words: Phleum pratense L., timothy, genetic selection, nitrogen use efficiency

The effect of interval between harvests and nitrogen application on the concentration of nitrate-nitrogen in the total herbage, green leaf and ‘stem’ of grasses

1986 ◽  
Vol 106 (3) ◽  
pp. 467-475 ◽  
Author(s):  
D. Wilman ◽  
P. T. Wright
Keyword(s):  
Field Experiment ◽  
Perennial Ryegrass ◽  
Nitrate Nitrogen ◽  
Italian Ryegrass ◽  
Green Leaf ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Time Of Year

SummaryThe effect of six intervals between harvests and three levels of N application on the concentration of nitrate-N and total N in total herbage, green leaf and ‘stem’ was studied in two varieties of perennial ryegrass during 30-week periods in each of the first two harvest years of a field experiment. The effect of two intervals between harvests on the concentration of nitrate-N in Italian ryegrass total herbage was studied in the same experiment. The effect of two intervals between harvests and three levels of N application on the concentrations of nitrate-N and total N in total herbage was studied in five grasses during a 32-week period in a second field experiment.Increasing the interval between harvests tended to increase the concentration of nitrate-N in herbage; however, this seemed due mainly to the average date of harvest being later in the year with the longer intervals. The concentration of nitrate-N in herbage increased from June to September. Italian and hybrid ryegrass and tall fescue were much higher than perennial ryegrass in nitrate-N concentration at the highest level of applied N (525 kgN/ha per year). Apart from the species and time of year effects, the nitrate-N concentration seemed to be determined mainly by the amount of N applied divided by the number of days between the date of application and the date of sampling. The ‘stem’ of perennial ryegrasa tended to be slightly higher in nitrate-N concentration than green leaf. The proportion of nitrate-N in total N was increased by increasing the interval between harvests and by applying N and was nearly twice as high in ‘stem’ as in green leaf. Both the nitrate-N and the total N concentration of herbage, particularly the latter, seemed to be inversely related to solar radiation receipt.

Relationship between P and N concentrations in timothy

1999 ◽  
Vol 79 (1) ◽  
pp. 65-70 ◽  
Author(s):  
G. Bélanger ◽  
J. E. Richards
Keyword(s):  
N Fertilization ◽  
Phleum Pratense ◽  
Growth And Yield ◽  
Shoot Biomass ◽  
P Deficiency ◽  
P Concentration ◽  
N Concentration ◽  
Critical P Concentration ◽  
The Relationship ◽  
Phleum Pratense L

Tools quantifying the status of N and P in plants may help to achieve efficient management of these nutrients and to optimize crop growth and yield. The objective of this study was to establish the relationship between P and N concentrations during the regrowth of timothy (Phleum pratense L.) and, in particular, to estimate the critical P concentration required to diagnose P deficiency. The relationship between P and N concentrations was determined for timothy grown in two experiments conducted with early- and late-maturing cultivars under non-limiting N conditions in spring of 1991 and 1992, and in two experiments with four rates of N fertilization conducted in the spring of 1993 and the summer of 1994. Shoot biomass and P and N concentrations were determined weekly during each regrowth cycle. The P and N concentrations decreased with time in all four experiments. The decrease in P concentration with increasing shoot biomass was generally similar to the decrease in N concentration. The relationship between P concentration and shoot biomass was not different for early- and late-maturing timothy cultivars. This relationship, however, was affected by N fertilization. For a given shoot biomass, increasing N fertilization rates increased P concentration. The relationship between P and N concentrations under non-limiting N conditions is described by a linear relationship (P = 1.46 + 0.069N, R2 = 0.79, P < 0.001, n = 48) in which P concentration (P) and N concentration (N) are expressed in g kg−1 DM. The relationship between P and N concentrations was different under N limiting conditions. For a given N concentration, the P concentration was greater under limiting N conditions than under non-limiting N conditions. Our results show that the critical P concentration for shoot growth is a function of the N concentration in the shoot biomass and the level of N deficiency. The present study provides the relationship required to estimate the critical P concentration which is essential for quantifying levels of P deficiency in timothy, and in developing models to predict the quantity of fertilizer P needed to correct that deficiency. Key words: Phleum pratense L., timothy, nitrogen, phosphorus, grasses

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