SUMMER COLOR AND FALL COLOR RETENTION OF KENTUCKY BLUEGRASS RECEIVING VARYING AMOUNTS AND TIMING OF INORGANIC OR INORGANIC-ORGANIC COMBINATIONS OF NITROGEN

1980 ◽  
Vol 60 (3) ◽  
pp. 1015-1021
Author(s):  
S. H. NELSON

Varying levels of N as ammonium nitrate, ammonium nitrate phosphate, ammonium phosphate sulfate, and monoammonium phosphate (0.83–2.51 kg N/100 m2/season) applied in three replications at 6-wk intervals (mid-May to mid-August) did not markedly affect the summer color quality of Kentucky bluegrass turf when the season was warm. When the season had a below-normal number of accumulated degree days, however, there was a positive correlation and linear regression between green color of the turf and the amount of N applied. When organic N (processed sewage) was used in two of the applications and inorganic N in one of the three replications, the green color response of the turf during summer was even more influenced by growing conditions. With a below-normal accumulation of degree growing days in 1975 there was no difference in green color from varying levels of organic N while in 1976 with an above-normal accumulation of degree days there was a better green color development with the higher levels of organic N. In the fall, higher levels of green color were maintained from higher levels of inorganic N. Varying the amount of nitrogen within the three application dates did not affect this correlation. When two applications of organic N were used in combination with one application of inorganic N, however, this correlation between better green color and higher rate of N did not show up until very late when all scores were relatively low. Although the range of scores for inorganic and inorganic-organic combinations had a similar range on any particular date in the fall, the application of inorganic N on the final date gave the best color retention and those receiving organic N on the final date tended to go dormant earlier. Where early spring green color or fall color retention of the turf is desired in northern climates, the inorganic form of N is more suitable than the organic form. The amount of color was positively correlated with the amount of inorganic N applied during the summer fertilizer program.

1977 ◽  
Vol 57 (1) ◽  
pp. 155-158 ◽  
Author(s):  
S. H. NELSON

Total N applied during the main summer fertilizing program influenced the early green color return of Kentucky bluegrass (Poa pratensis L.) the following spring. Where inorganic N was the only source, there was a highly significant positive correlation between the total amount of N and the early green color return in the spring. The results were linear within the range tested (0.83–2.41 kg/100 m2 actual) and all treatments fell within the confidence limits. When two applications of organic N were used with one application of inorganic N, no trend was established within the range of 1.00–1.88 kg/100 m2. In these latter combinations, there was a response to varying amounts of inorganic N, but not with organic N. The high correlations and nature of the fit to the regression line would suggest a "luxury uptake" of inorganic N and overwinter storage by the turf grass similar to that reported in some woody plants. Since the plots receiving organic fertilizer went dormant early in the fall, such uptake is not likely and the early green color return would seem to be dependent on the bacterial release of N from the organic residues within the soil as the temperature increased.


1999 ◽  
Vol 79 (2) ◽  
pp. 277-286 ◽  
Author(s):  
P. A. Bowen ◽  
B. J. Zebarth ◽  
P. M. A. Toivonen

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


2019 ◽  
Vol 34 ◽  
pp. 41-66 ◽  
Author(s):  
Raffaella Balestrini ◽  
Carlo Andrea Delconte ◽  
Andrea Buffagni ◽  
Alessio Fumagalli ◽  
Michele Freppaz ◽  
...  

A number of studies have reported decreasing trends of acidifying and N deposition inputs to forest areas throughout Europe and the USA in recent decades. There is a need to assess the responses of the ecosystem to declining atmospheric pollution by monitoring the variations of chemical species in the various compartments of the forest ecosystem on a long temporal scale. In this study, we report on patterns and trends in throughfall deposition concentrations of inorganic N, dissolved organic N (DON) and C (DOC) over a 20-year (1995–2015) period in the LTER site -Val Masino (1190 m a.s.l.), a spruce forest, in the Central Italian Alps. The same chemical species were studied in the litter floor leachates and mineral soil solution, at three different depths (15, 40 and 70 cm), over a 10-year period (2005–2015). Inorganic N concentration was drastically reduced as throughfall and litter floor leachates percolated through the topsoil, where the measured mean values (2 µeq L-1) were much lower than the critical limits established for coniferous stands (14 µeq L-1). The seasonal temperature dependence of throughfall DOC and DON concentration suggests that the microbial community living on the needles was the main source of dissolved organic matter. Most of DOC and DON infiltrating from the litter floor were retained in the mineral soil. The rainfall amount was the only climatic factor exerting a control on DOC and N compounds in throughfall and forest floor leachates over a decadal period. Concentration of SO4 and NO3 declined by 50% and 26% respectively in throughfall deposition. Trends of NO3 and SO4 in forest floor leachates and mineral soil solution mirrored declining depositions. No trends in both DON and DOC concentration and in DOC/DON ratio in soil solutions were observed. These outcomes suggest that the declining NO3 and SO4 atmospheric inputs did not influence the dynamic of DON and DOC in the Val Masino forest. The results of this study are particularly relevant, as they are based on a comprehensive survey of all the main compartments of the forest ecosystem. Moreover, this kind of long-term research has rarely been carried out in the Alpine region.


1989 ◽  
Vol 69 (3) ◽  
pp. 551-565
Author(s):  
F. SELLES ◽  
A. J. LEYSHON ◽  
C. A. CAMPBELL

Prairie farmers are interested in applying nitrogen (N) in the fall or winter to reduce fertilizer costs and allow a better distribution of labor and machinery use. Two studies were conducted in southwestern Saskatchewan to determine the consequences of applying N in late fall. In the laboratory, fertilizer N barely penetrated into the snow at constant subzero temperatures, but under freeze-thaw conditions, urea and ammonium nitrate descended 27 cm in 3 d. In the field, ammonium nitrate and urea were applied to snow-covered and bare microplots of grass sod and cereal stubble (1981–1982) and grass sod only (1985–1986). Nitrogen from ammonium nitrate penetrated deeper into the snow than N from urea. Nitrogen recovery in April 1982 was 55–59% from ammonium nitrate and 39–51% from urea, but was near 100% for both sources on bare soil treatments in April 1986. More N was recovered when fertilizer was applied to bare than to snow-covered soil, especially during 1985–1986 when all the applied fertilizer was blown off the snow-covered plots. Mineral N generally declined from fall to spring in all treatments, probably because of denitrification and immobilization. In 1985–1986, a period of extremely low temperatures in late fall resulted in no movement or transformation of N until after early December. By late January, periods of above-zero soil temperatures resulted in substantial mineralization of soil organic N, in the fertilized plots. This apparent priming effect was attributed to perturbations in the organic matter and microbial biomass due to fertilizer application and freezing and thawing. Following this period there was a general decrease in mineral N towards spring, as observed in 1981–1982. Producers must consider the benefits of using labor and equipment more efficiently and of lower fertilizer cost in the fall against the risk of large potential N losses over winter. Key words: Urea, ammonium nitrate, N recovery, frozen soils, fertilizing in winter


2021 ◽  
Vol 68 (5) ◽  
pp. 206-211
Author(s):  
Tomohiro Mizutani ◽  
Shigetoshi Yoshikawa ◽  
Katsumi Osawa

1961 ◽  
Vol 41 (2) ◽  
pp. 261-267 ◽  
Author(s):  
C. R. Elliott ◽  
C. H. Anderson ◽  
B. D. Owen

Yields of herbage, animal gains, carrying capacity and TDN production were determined for three pasture swards grown on a Grey Wooded soil (Albright-Hythe series) in the Peace River region of northern Alberta over the period 1953 to 1956 inclusive. Sheep were used as grazing units. Fertilizer treatments of nil, ammonium phosphate (11-48-0) at 300 pounds per acre and ammonium nitrate (33-0-0) at 100 pounds per acre were applied annually to pastures of creeping red fescue, creeping red fescue-alfalfa and bromegrass-alfalfa.Productivity obtained with unfertilized grass-legume mixtures was almost double that for unfertilized grass grown alone. Increased production attributable to alfalfa was also obtained, although to a lesser degree, where fertilizers were used. Pastures of creeping red fescue seeded alone and with alfalfa responded markedly to applications of nitrogen while responses to phosphorus were negligible. Conversely, bromegrass-alfalfa pastures responded strongly to applications of phosphorus and only slightly to nitrogen.


1993 ◽  
Vol 7 (2) ◽  
pp. 322-325 ◽  
Author(s):  
Gunawan Wanamarta ◽  
James J. Kells ◽  
Donald Penner

The influence of adjuvants, inorganic salts, and herbicide formulations on the antagonistic effect of Na-bentazon on sethoxydim absorption was studied in quackgrass. Adjuvant BCH 815 00, at 2.4 L ha−1alone or at 1.2 L ha−1combined with 1.1 kg ha−1of ammonium sulfate, added to the sethoxydim and Na-bentazon spray mixture overcame the antagonism on14C-sethoxydim absorption in quackgrass. Crop oil concentrate at rates up to 9.6 L ha−1did not overcome the antagonism. Adding ammonium phosphate or ammonium nitrate to the spray solution was as effective as adding ammonium sulfate in overcoming the antagonism caused by reduced absorption of sethoxydim even from the combination of Na-bentazon plus Na-acifluorfen. Ammonium salts and NH4-bentazon overcame the antagonism of Na-bentazon by forming readily absorbed NH4-sethoxydim.


2019 ◽  
Vol 99 (4) ◽  
pp. 579-583
Author(s):  
X.M. Yang ◽  
C.F. Drury ◽  
W. Xu ◽  
M. Reeb ◽  
T. Oloya

Mid-infrared spectroscopy in the transmission mode was used to predict inorganic nitrogen (N), organic N, and total N in soil leachate. The developed predictions were accurate and robust for total N, NH4+, NO3−, inorganic N (NH4+ + NO3−), and organic N (total N − inorganic N) with high determination coefficients (R2 = 96.7 − 99.0) and residual prediction deviation (RPD = 5.47 − 9.96). The proposed method simultaneously estimates the concentrations of dissolved nitrogen species in soil leachates accurately and with significant savings in time, cost, and chemicals relevant to conventional methods.


1999 ◽  
Vol 133 (2) ◽  
pp. 125-130 ◽  
Author(s):  
R. J. HAYNES

15N-labelled fertilizer urea was applied at increasing rates (0–200 kg N/ha), in spring, to winter wheat crops in the Canterbury region of New Zealand in three successive seasons (1993/94, 1994/95 and 1995/96). Recovery of fertilizer N by the crop (grain, chaff, straw and roots) ranged from 43–58% (mean 48%). The quantity of fertilizer N retained in the soil (0–40 cm), at harvest, ranged from 26–42%. Of the labelled N present in the soil, over 95% was present in organic form and 60–80% was retained in the surface 0–10 cm layer. Since soil organic matter represents a substantial sink for fertilizer N there is a need to characterize the nature of this organic pool of N more fully. The quantity of inorganic N present in the soil profile at harvest ranged from 20–46 kg N/ha and labelled fertilizer-derived N contributed less than 16% (mean 9·2%) to this inorganic pool. Loss of fertilizer N from the crop/soil system (i.e., labelled N not recovered in the crop or soil at harvest) varied from 12–26% (mean 18%). Losses were attributed mainly to denitrification since conditions were not conducive for ammonia volatilization or leaching of nitrate. In agreement with European research, it was concluded that almost all of the N at risk of leaching over the winter originates from mineralization of soil organic N and not from unused fertilizer-N applied in spring.


2011 ◽  
Vol 48 (1) ◽  
pp. 1-20 ◽  
Author(s):  
G. R. MARUTHI SANKAR ◽  
P. K. MISHRA ◽  
K. L. SHARMA ◽  
S. P. SINGH ◽  
A. K. NEMA ◽  
...  

SUMMARYLong-term field experiments were conducted at Agra, Solapur and Hisar from 2000 to 2008 to identify efficient tillage and nutrient management practices and to develop predictive models that would describe the relationship between crop yields and monthly rainfall for rainfed pearl millet grown on arid and semi-arid Inceptisol, Vertisol and Aridisol soils. Nine treatments comprising a factorial combination of three tillage practices, viz., conventional tillage (CT), low tillage + interculture (LT1) and low tillage + herbicide (LT2) and three fertilizer treatments viz., 100% N from an organic source (F1), 50% organic N + 50% inorganic N (F2) and 100% inorganic N (F3) were tested in a split-plot design at the three locations. Studies revealed that tillage and fertilizer treatments, and their interactions, significantly influenced pearl millet grain yields at the three locations. Prediction models describing the relation between grain yield and monthly rainfall indicated that rainfall occurring in June, July and August at Agra; June and July at Solapur; and June and August at Hisar significantly influenced pearl millet grain yield attained by different treatments. The R2 values of the model ranged from 0.64 to 0.81 at Agra; 0.63 to 0.92 at Solapur, and 0.75 to 0.89 at Hisar. When averaged over all the treatment combinations, mean pearl millet grain yields varied from 1590 to 1744 kg ha−1 at Agra; 1424 to 1786 kg ha−1 at Solapur; and 1675 to 1766 kg ha−1 at Hisar while their corresponding sustainability yield indice (SYI) varied from 35.4 to 42.2%, 19.9 to 45.6% and 64.1 to 68.3%, respectively. At Agra (Inceptisol), CTF3 resulted in significantly higher mean net returns (Rs 11 439 ha−1), benefit-cost ratio (2.33), rainwater use efficiency (RWUE) (3.52 kg ha−1 mm−1) and the second best SYI (39.9%). At Solapur (Vertisol), the LT1F3 resulted in significantly higher net returns (Rs 12 818 ha−1), benefit-cost ratio (3.52), RWUE (3.89 kg ha−1 mm−1) and the fourth best SYI (42.6%). At Hisar (Aridisol), the LT1F3 treatment gave higher net returns (Rs 3866 ha−1), benefit-cost ratio (1.26), RWUE (5.05 kg ha−1 mm−1) and the fourth best SYI (67.8%). These treatment combinations can be recommended for their respective locations to achieve maximum RWUE, productivity and profitability.


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