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

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.

2000 ◽  
Vol 80 (2) ◽  
pp. 277-285 ◽  
Author(s):  
S. Bittman ◽  
C. G. Kowalenko

An orchardgrass study in which three rates of N (100, 200 and 400 kg ha−1) each distributed in 1/0/0/0, 0.75/0.25/0/0, 0.50/0.25/0.25/0 and 0.25/0.25/0.25/0.25 proportions prior to four cut intervals examined crude-protein-N and nitrate-N concentrations in grass herbage at each cut in three trials. Crude-protein-N concentration frequently increased to a greater degree and in a different pattern (based on cut) than yield as the rate of N application increased. This showed that crude-protein-N by itself cannot be used as a method for determining the N sufficiency status of grass. Both rate and distribution of fertilizer N strongly influenced plant nitrate-N concentration; the degree of change varied considerably among cuts and trials. Plant nitrate-N concentration in the control did not correspond to yield responsiveness to N application, making it a poor indicator of the plant's need for fertilizer applications. Residual effects of N applications on plant nitrate-N were noted into the last cut of the season from a single spring application. The effect of N rate and distribution, then, was a function of immediate and residual effects of the applications. There was some evidence that N present in the soil in nitrate-N form enhanced the potential for high nitrate-N in the plant. Plant nitrate-N concentrations accounted for up to 29% of the total N in the plant with concentrations greater than 4000 mg N kg−1 at the highest N application rates. Plant nitrate-N did not exceed 1000 mg N kg−1, a concentration considered safe for ruminants, when 75 kg N ha−1 or less ammonium nitrate was applied as a single application prior to a growth interval for all cuts. Since grass protein- and nitrate-N concentrations respond differently than yield to N applications, a specific combination of rate and distribution of fertilizer will not necessarily produce maximum herbage quantity and quality simultaneously. Key words: Crude-protein-N, plant nitrate-N, residual effect, split applications


1977 ◽  
Vol 89 (1) ◽  
pp. 53-63 ◽  
Author(s):  
D. Wilman ◽  
M. Daly ◽  
A. Koocheki ◽  
A. B. Lwoga

SummaryThe effect of six intervals between harvests and two levels of N application on the proportion and digestibility of cell wall was studied in two perennial ryegrass (Lolium perenne) varieties in the first and second harvest years in a field experiment. In the oase of four of the six intervals between harvests the proportion and digestibility of cellulose, hemicellulose and lignin and the N content of cell wall were determined. Diets derived from three of the harvesting treatments were fed, at maintenance level, to sheep as a partial in vivo check on the in vitro procedures. The effect of six intervals between harvests and two levels of N application on the proportion of lignified tissue in leaf cross-section was determined in two varieties in the first harvest year.Effects of interval between harvests and time of year on herbage digestibility were due to effects on both proportion and digestibility of cell wall, particularly the latter. Hemicellulose digestibility appeared to be rather more affected by interval between harvests and rather more closely associated with the proportion of lignin than was cellulose digestibihty. The proportion of cell wall was particularly low and its digestibility particularly high in April and early May.The N in cell wall accounted for about 10% of total N in harvested herbage on all treatments. The ratio of cellulose to hemicellulose averaged 1:0·88 and hemicellulose was rather more digestible than cellulose. Cellulose and cell wall were less digestible in vitro than in vivo.The application of N tended to reduce the proportion of cell wall and to increase its digestibility in leafy but not in stemmy crops.Interval between harvests and N application had no effect on the proportion of lignified tissue in leaf cross-section.


1992 ◽  
Vol 32 (6) ◽  
pp. 759 ◽  
Author(s):  
DO Huett ◽  
E White

A gamma x cubic response surface model was used to predict the dry matter yield of lettuce cv. Montello over the 8-week growth period in sand culture with nitrogen (N) levels of 2, 5, 11, 18 and 36 mmol/L. At 1, 2, 3, 5, 7 and 8 weeks after transplanting, dry matter yield relative to maximum was plotted against tissue N concentration to derive diagnostic concentrations of petiole sap nitrate-N and leaf total N in youngest fully opened leaf (YFOL), youngest fully expanded leaf (YFEL) and oldest green leaf (OL), and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum yield are presented. Growth was consistently depressed at 2 mmol N/L due to N deficiency, and at 36 mmol N/L due to salt toxicity. Petiole sap nitrate concentrations were more responsive than leaf total N concentrations to N application levels. Leaf N concentrations at N application levels of 18 and 36 mmol/L were often similar. Critical leaf total N concentrations in YFOL and YFEL decreased from 2 weeks after transplanting to maturity, whereas the opposite trend occurred for petiole sap nitrate concentrations. Critical total N concentration ranges in YFEL were 0.30-0.95 g/L for petiole sap nitrate-N, and 4.00-5.30% for leaf total N concentration. Critical leaf total N and petiole sap nitrate concentrations clearly differentiated between inadequate and adequate N application rates. Critical values in most cases, differentiated toxic concentrations. Nitrogen application levels of 2 and 36 mmol N/L reduced (P<0.05) potassium, calcium and magnesium concentrations in all leaves. This confirms the importance of optimising N supply when determining critical levels of these nutrients for lettuce. Petiole sap nitrate-N concentrations, which can be determined rapidly in the field, can be used to distinguish between a deficient and an adequate N supply. The marked increase in critical concentration over the growth period requires consecutive determinations to verify the N status of lettuce.


1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena

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.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yushi Zhang ◽  
Yubin Wang ◽  
Churong Liu ◽  
Delian Ye ◽  
Danyang Ren ◽  
...  

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.


1995 ◽  
Vol 31 (3) ◽  
pp. 333-344 ◽  
Author(s):  
G. Webert ◽  
V. Chude ◽  
J. Pleysier ◽  
S. Oikeh

SummaryNitrate-nitrogen was analysed over two cropping seasons in 57 farmers' fields in the northern Guinea savanna of Nigeria. Differences between fields were at least five-fold and often ten-fold irrespective of fertilization rates. Average concentrations were highest at the beginning of the rainy season. Loamy soils had a later peak for nitrate release and maintained high concentrations for a longer period after the start of the rains than the more sandy soils. Nitrate-N was not correlated with soil organic carbon or total nitrogen content. Grain yield of maize was closely associated with nitrate-N in the soil but not with organic carbon or total N. Four patterns of nitrate-N release over the season could he differentiated using cluster analysis. Soil texture, soil pH, soil organic carbon, stover management and cropping history contributed most to a differentiation of the four cluster groups in a discriminant model. There was wide variability in the inherent soil-nitrate level and in its importance in explaining differences in yield among farmers' fields. The development of technologies resulting in improved nitrogen availability or better nitrogen utilization should be based on research of inherent soil processes. For the transfer of such technologies, recommendation domains should be defined based on different native patterns of soil-nitrogen availability.


2009 ◽  
Vol 39 (8) ◽  
pp. 1484-1497 ◽  
Author(s):  
Robert A. Slesak ◽  
Stephen H. Schoenholtz ◽  
Timothy B. Harrington ◽  
Brian D. Strahm

We examined the effect of logging-debris retention and competing-vegetation control (CVC, initial or annual applications) on dissolved organic carbon (DOC), dissolved organic nitrogen, and nitrate-N leaching to determine the relative potential of these practices to contribute to soil C and N loss at two contrasting sites. Annual CVC resulted in higher soil water nitrate-N concentration and flux, with the magnitude and duration of the effect greatest at the high-N site. Most of the increase in nitrate-N at the low-N site occurred in treatments where logging debris was retained. Dissolved organic nitrogen increased at the high-N site in March of each year following annual CVC, but the contribution of this increase to total N concentration was small (2%–4% of total N flux). There was no effect of logging-debris retention or CVC treatment on soil water DOC concentrations, indicating that DOC inputs from logging debris and competing vegetation were either retained or consumed in the mineral soil. The estimated increase in leaching flux of dissolved C and N associated with the treatments was low relative to total soil pools, making it unlikely that loss of these elements via leaching will negatively affect future soil productivity at these sites.


1988 ◽  
Vol 28 (3) ◽  
pp. 401 ◽  
Author(s):  
DO Huett ◽  
G Rose

The tomato cv. Flora-Dade was grown in sand culture with 4 nitrogen (N) levels of 1.07-32.14 mmol L-1 applied as nitrate each day in a complete nutrient solution. The youngest fully opened leaf (YFOL) and remaining (bulked) leaves were harvested at regular intervals over the 16-week growth period. Standard laboratory leaf total and nitrate N determinations were conducted in addition to rapid nitrate determinations on YFOL petiole sap. The relationships between plant growth and leaf N concentration, which were significantly affected by N application level, were used to derive diagnostic leaf N concentrations. Critical and adequate concentrations in petiole sap of nitrate-N, leaf nitrate-N and total N for the YFOL and bulked leaf N were determined from the relationship between growth rate relative to maximum at each sampling time and leaf N concentration. YFOL petiole sap nitrate-N concentration, which can be measured rapidly in the field by using commercial test strips, gave the most sensitive guide to plant N status. Critical values of 770-1 120 mg L-I were determined over the 10-week period after transplanting (first mature fruit). YFOL (leaf + petiole) total N concentration was the most consistent indicator of plant N status where critical values of4.45-4.90% were recorded over the 4- 12 week period after transplanting (early harvests at 12 weeks). This test was less sensitive but more precise than the petiole sap nitrate test. The concentrations of N, potassium, phosphorus, calcium and magnesium in YFOL and bulked leaf corresponding to the N treatments producing maximum growth rates are presented, because nutrient supply was close to optimum and the leaf nutrient concentrations can be considered as adequate levels.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 584a-584
Author(s):  
Ellen T. Paparozzi ◽  
M. Elizabeth Conley ◽  
Walter W. Stroup

Three cultivars of poinsettia, Freedom Red, Lilo and Red Sails, were grown in a peat:perlite:vermiculite mix according to a commercial production schedule. Twelve selected nitrogen–sulfur fertilizer combinations were applied (125, 150, 175 ppm N with either 12.5, 25, or 37.5 ppm S, 225 and 275 ppm N with either 37.5 or 75 ppm S). The experimental design was a split plot with cultivars as the whole plot and fertilizer levels as the split-plot factor. Mix samples were taken initially, at production week 7 and at the end of the experiment. Nitrate-nitrogen, sulfate-sulfur and total nitrogen were determined. Data were analyzed using SAS PROC MIXED. Visually all cultivars responded similarly to all treatments and were salable. Thus, levels of N as low as 125 or 150 with 12.5 ppm S produced quality plants. Sulfate-S tended to accumulate in the mix while nitrate-N and total N did not. Both nitrate-N and sulfate-S concentrations were affected by an interaction between the cultivar and the amount of S applied with `Freedom' better able to utilize available sulfur. `Lilo' removed more nitrate-N and total N from the mix than `Freedom' which removed more than `Red Sails', but only at specific levels of sulfur. There was no cultivar by nitrogen interaction for any variable measured.


1994 ◽  
Vol 119 (3) ◽  
pp. 446-451 ◽  
Author(s):  
Richard J. McAvoy

`Rose Grenadine' and `Buckaroo' garden chrysanthemums [Dendranthema ×grandiflorum (Ramat.) Kitamura] were produced in 15-cm pots in the greenhouse and fertilized with either 550 or 1000 ml of a 15 mol·m-3 N solution at each irrigation. The nutrient solution applied to half the pots contained a wetting agent (WA), and the remaining pots received no WA. Core samples were removed at 15-cm increments to a depth of 90 cm from the soil beneath the pots. The average leaching fraction (LF) from pots receiving a WA was 0.29 but was 0.26 from pots receiving no WA. However, WA did not affect the leachate NO3-N concentration or the total NO3-N deposited on the soil beneath; these were most influenced by LF. After week 2, NO3-N concentration in the upper 15 cm soil layer was 3.4 times higher with a high LF than with a low LF (30 and 8.8 g·m-3 respectively). At week 10, the NO3-N concentration in the 30 to 45 cm soil layer averaged 71.9 g·m-3 under the high LF and 35.5 g·m-3 under the low LF. Total N and NO3-N in the potting medium was higher in the low LF pots than the high LF pots, while NO3-N was higher in the medium of pots irrigated without WA than with WA. Final plant shoot mass was higher in pots irrigated to a high LF or without WA than in pots irrigated to a low LF or with WA.


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