The nitrogen status of red and yellow earths in the semiarid tropics as influenced by Caribbean stylo (Stylosanthes hamata) grown at various rates of applied phosphorus

Soil Research ◽  
1986 ◽  
Vol 24 (3) ◽  
pp. 405 ◽  
Author(s):  
ME Probert ◽  
J Williams
Keyword(s):  
Room Temperature ◽  
Soil Analysis ◽  
Nitrogen Supply ◽  
Early Years ◽  
Nitrogen Status ◽  
Mineral N ◽  
Stylosanthes Hamata ◽  
Nitrate N ◽  
Red Earth ◽  
Semiarid Tropics

Changes in the nitrogen status of a red and a yellow earth in the semi-arid tropics of central north Queensland were examined following five years' growth of Stylosanthes hamata pasture under a range of phosphorus inputs. The results highlight the importance of leaching of nitrate-N in these environments. This could be accounted for satisfactorily by a simple water and solute exchange model. Small increases in organic carbon and total nitrogen in soil were restricted to the early years of the pasture phase but were not significantly related to the phosphorus treatments. The nitrogen supply to a test crop of millet, both in the field and for surface 0-10 cm samples cropped in the glasshouse, was enhanced by previous growth of legume, and the magnitude of the effect depended upon the yields of legume grown as influenced by its phosphorus nutrition. In terms of freshly applied ammonium nitrate, the contribution from the legume measured in the field was equivalent to 33 kg N ha-1 for an annual production of 1 t ha-1 of legume dry matter on the red earth, and similarly 38 kg N ha-1 on the yellow earth. Of several methods of soil analysis studied, mineral-N extracted with 1 M KCl, either at room temperature or at boiling point, were the best single predictors of the nitrogen supply as measured by the nitrogen uptake of millet. Evidence is provided to show that forms other than mineral-N also contributed to the nitrogen supply, but none of the methods of soil analysis used was able to quantify this nitrogen arising from mineralisation.

Effect of Nitrogen Electrolytes on Al2021 Alloy by Electrolytic Plasma Processing

2013 ◽  
Vol 378 ◽  
pp. 213-219
Author(s):  
Byunh Hyun Ahn ◽  
Dong Gun Lee ◽  
Je Hyun Lee ◽  
Uk Rae Cho ◽  
Bon Heun Koo
Keyword(s):  
Room Temperature ◽  
Coating Layer ◽  
Plasma Processing ◽  
Nitrogen Supply ◽  
X Ray ◽  
Composition And Structure ◽  
Electrolytic Plasma Processing ◽  
Evolution Of Microstructure ◽  
Wear Tests ◽  
Scanning Electron

AlON-Al2O3coatings were prepared on Al2021 alloy by the electrolytic plasma processing (EPP) method. NaNO2, NaNO3and NH4NO3were chosen as nitrogen supply agents. The nitrogen inducing effect was studied by a combined composition and structure analysis of the coating layer carried out by X-ray diffractometer (XRD), scanning electron microscopy (SEM) for the specimens EPP-treated at room temperature for 15 min under a hybrid voltage of 260V DC plus 200V AC (50Hz) power. Microhardness tests and wear tests were carried out to correlate the evolution of microstructure and resulting mechanical properties.

Residual effects of phosphorus fertiliser in a stylo-native grass pasture on a duplex red earth soil in the semi-arid tropics of North Queensland

1994 ◽  
Vol 34 (2) ◽  
pp. 173
Author(s):  
KA Shaw ◽  
MA Gilbert ◽  
JD Armour ◽  
MJ Dwyer
Keyword(s):  
Soil Analysis ◽  
Residual Effects ◽  
Native Grass ◽  
Soil P ◽  
Initial Application ◽  
Red Earth ◽  
P Application ◽  
Stylosanthes Scabra ◽  
Phosphorus Application ◽  
Establishment Phase

A field experiment was established to define the phosphorus (P) requirement for establishment and maintenance of a mixed legume pasture (Stylosanthes scabra cv. Seca, S. hamata cv. Verano, S. guianensis cv. Graham, Macroptilium atropurpureum cv. Siratro) introduced into a native grass pasture on an infertile duplex red earth. Rates of 0, 5, 10, 20, and 40 kg P/ha were applied to separate plots in year 1 (1982), 2, and 3. In year 5 (1986 growing season), half of each plot that had received 20 and 40 kg P/ha in year 3 was refertilised at the original rate to ensure that maximum yields were defined. Bicarbonate- or acid-extractable soil P concentrations of 8 mg/kg were sufficient for 80% maximum legume yield. The residual value of applied P in the surface soil, as measured by soil analysis, decreased exponentially, but an initial application of 40 kg P/ha was still sufficient to produce near-maximum legume yield after 5 years. Phosphorus application increased the dry matter yield of legume. During the establishment phase (years 1 and 2 after planting) yields reached maximum at 10 and 20 kg P/ha, respectively, but increased linearly in subsequent years. When the original rates were reapplied in year 5, peak yield occurred at 20 + 20 kg P/ha, and there was no difference between this yield and that from plots receiving 40 kg P/ha in year 1. Native grass yields increased with P application only in years 4 and 5 of the experiment. Stylos demonstrated good tolerance to low P supply. In year 1, 80% of the total legume yield consisted of Graham stylo and Siratro, whereas in subsequent years, Seca and Verano made up 70 and 20%, respectively, of the total, irrespective of treatment. Yield of legume at nil P, relative to maximum, increased from 5% in year 1 to 42% in year 5.

Effects of soil nitrogen status and rate of inoculation on the establishment of populations of Bradyrhizobium japonicum and on the nodulation of soybeans

1989 ◽  
Vol 40 (4) ◽  
pp. 753
Author(s):  
J Brockwell ◽  
RR Gault ◽  
LJ Morthorpe ◽  
MB Peoples ◽  
GL Turner ◽  
...  
Keyword(s):  
Glycine Max ◽  
Soil Nitrogen ◽  
Bradyrhizobium Japonicum ◽  
Clay Soil ◽  
Mineral Nitrogen ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Nitrogen Status ◽  
Mineral N ◽  
Glycine Max L

Soybeans (Glycine max [L.] Merrill cv. Forrest) were grown under irrigation on a well-structured grey clay soil, previously free of Bradyrhizobium japonicum and containing relatively high levels of mineral N, at Trangie, N.S.W. There were two soil pretreatments, pre-cropped (which had the effect of reducing the level of mineral nitrogen in the soil) and pre-fallowed, and four rates of inoculation (B. japonicum CB 1809 - nil, 0.01 X, 1.OX [=normal] and 100X).Mineral nitrogen (0-10 cm) initially was higher in pre-fallowed soil than in pre-cropped soil (37.6 v. 18.5 mg N per kg). Depletion of mineral nitrogen occurred more rapidly in pre-fallowed treatments, so that, 7 days after harvest, mineral-N in pre-cropped soil was significantly higher than in pre-fallowed soil (14.4 v. 10.6 mg per kg).With high levels of soil mineral nitrogen, colonization of seedling rhizospheres by rhizobia and plant nodulation were diminished. These effects were ameliorated but not eliminated by increased rates of inoculation. The development of the symbiosis was also impeded by lower rates of inoculation (0.01 X, 1.OX).

Corrigendum to: Piggery pond sludge as a nitrogen source for crops. 1. Mineral N supply estimated from laboratory incubations and field application of stockpiled and wet sludge

2005 ◽  
Vol 56 (12) ◽  
pp. 1415
Author(s):  
Y. J. Kliese ◽  
R. C. Dalal ◽  
W. M. Strong ◽  
N. W. Menzies
Keyword(s):  
Sandy Soil ◽  
Clay Soil ◽  
Lignin Content ◽  
Field Application ◽  
Organic N ◽  
N Availability ◽  
Aerobic Incubation ◽  
Mineral N ◽  
Organic C ◽  
Nitrate N

Piggery pond sludge (PPS) was applied, as-collected (Wet PPS) and following stockpiling for 12 months (Stockpiled PPS), to a sandy Sodosol and clay Vertosol at sites on the Darling Downs of Queensland. Laboratory measures of N availability were carried out on unamended and PPS-amended soils to investigate their value in estimating supplementary N needs of crops in Australia's northern grains region. Cumulative net N mineralised from the long-term (30 weeks) leached aerobic incubation was described by a first-order single exponential model. The mineralisation rate constant (0.057/week) was not significantly different between Control and PPS treatments or across soil types, when the amounts of initial mineral N applied in PPS treatments were excluded. Potentially mineralisable N (No) was significantly increased by the application of Wet PPS, and increased with increasing rate of application. Application of Wet PPS significantly increased the total amount of inorganic N leached compared with the Control treatments. Mineral N applied in Wet PPS contributed as much to the total mineral N status of the soil as did that which mineralised over time from organic N. Rates of CO2 evolution during 30 weeks of aerobic leached incubation indicated that the Stockpiled PPS was more stabilised (19.28% of applied organic C mineralised) than the Wet PPS (35.58% of applied organic C mineralised), due to higher lignin content in the former. Net nitrate-N produced following 12 weeks of aerobic non-leached incubation was highly correlated with net nitrate-N leached during 12 weeks of aerobic incubation (R2 = 0.96), although it was <60% of the latter in both sandy and clayey soils. Anaerobically mineralisable N determined by waterlogged incubation of laboratory PPS-amended soil samples increased with increasing application rate of Wet PPS. Anaerobically mineralisable N from field-moist soil was well correlated with net N mineralised during 30 weeks of aerobic leached incubation (R2 = 0.90 sandy soil; R2 = 0.93 clay soil). In the clay soil, the amount of mineral N produced from all the laboratory incubations was significantly correlated with field-measured nitrate-N in the soil profile (0.1.5 m depth) after 9 months of weed-free fallow following PPS application. In contrast, only anaerobic mineralisable N was significantly correlated with field nitrate-N in the sandy soil. Anaerobic incubation would, therefore, be suitable as a rapid practical test to estimate potentially mineralisable N following applications of different PPS materials in the field.

Effects of long-term straw management and fertilizer nitrogen additions on soil nitrogen supply and crop yields at two sites in eastern England

2002 ◽  
Vol 139 (2) ◽  
pp. 115-127 ◽  
Author(s):  
MARTYN SILGRAM ◽  
BRIAN J. CHAMBERS
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Supply ◽  
Fertilizer N ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
Mineral N ◽  
Plough Layer ◽  
N Rates ◽  
Soil Nitrogen Supply

The effects of straw incorporation (early and late cultivation) and straw burning were contrasted in a split-plot study examining the impact of long-term straw residue management, and six fertilizer nitrogen (N) rates on soil mineral nitrogen, crop fertilizer N requirements and nitrate leaching losses. The experiments ran from 1984 to 1997 on light-textured soils at ADAS Gleadthorpe (Nottinghamshire, UK) and Morley Research Centre (Norfolk, UK).Soil incorporation of the straw residues returned an estimated 633 kg N/ha at Gleadthorpe and 429 kg N/ha at Morley on the treatment receiving 150 kg/ha per year fertilizer N since 1984. Straw disposal method had no consistent effect on grain and straw yields, crop N uptake, or optimal fertilizer N rates. In every year there was a positive response (P<0·001) to fertilizer N in straw/grain yields, N contents and crop N offtakes at both sites. Nitrate leaching losses were slightly reduced by less than 10 kg N/ha where straw residues had been incorporated, while fertilizer N additions increased nitrate leached at both sites.At both sites there was a consistent effect (P<0·001) of straw disposal method on autumn soil mineral N, with values following the pattern burn>early incorporate>late plough. The incorporation of straw residues induced temporary N immobilization compared with the treatment where straw was burnt, while the earlier timing of tillage on the incorporate treatment resulted in slightly more mineral N compared with the later ploughed treatment. Fertilizer N rate increased (P<0·001) soil mineral nitrogen at both sites. At Morley, there was more organic carbon in the plough layer where straw had been incorporated (mean 1·09 g/100 g) rather than burnt (mean 0·89 g/100 g), and a strong positive relationship between organic carbon and fertilizer N rate (r2=93·2%, P<0·01). There was a detectable effect of fertilizer N on readily mineralizable N in the plough layer at both Gleadthorpe (P<0·001) and Morley (P<0·05). At Morley, there was a consistent trend (P=0·06) for readily mineralizable N to be higher where straw had been incorporated rather than burnt, indicating that ploughing-in residues may contribute to soil nitrogen supply over the longer term.

Effects of low nitrogen supply on relationships between photosynthesis and nitrogen status at different leaf position in wheat seedlings

2013 ◽  
Vol 70 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Dandan Li ◽  
Mengyu Tian ◽  
Jian Cai ◽  
Dong Jiang ◽  
Weixing Cao ◽  
...  
Keyword(s):  
Nitrogen Supply ◽  
Leaf Position ◽  
Nitrogen Status ◽  
Wheat Seedlings ◽  
Low Nitrogen

Prediction of Nitrogen Status of Sugarbeets by Soil Analysis 1

1975 ◽  
Vol 67 (4) ◽  
pp. 454-459 ◽  
Author(s):  
J. F. Giles ◽  
J. O. Reuss ◽  
A. E. Ludwick
Keyword(s):  
Soil Analysis ◽  
Nitrogen Status

Differences in natural abundance of 15N in the extractable mineral nitrogen of cropped and fallowed surface soils

1987 ◽  
Vol 38 (1) ◽  
pp. 15 ◽  
Author(s):  
GL Turner ◽  
RR Gault ◽  
L Morthorpe ◽  
DL Chase ◽  
FJ Bergersen
Keyword(s):  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Mineral Nitrogen ◽  
Natural Abundance ◽  
Mineral N ◽  
Plant Nitrogen ◽  
Red Earth ◽  
Time Courses ◽  
Soil Nitrogen Cycle ◽  
Made In

The natural abundances (S15N with reference to atmospheric N2) of the stable isotope of nitrogen (15N) in the total nitrogen and in KCl-extractable mineral nitrogen (typically 96% NO-3-N and 4% NH+4-N) were measured in the surface 10 cm of a transitional red earth at Yanco, N.S.W., and of a grey soil of heavy texture at Trangie, N.S.W. Measurements were made in Autumn (May), prior to planting crops of winter oats, at the time of harvest (October) and in December, using both cropped and continuously fallowed soils. At Trangie, additional measurements were made in September, near the beginning of rapid growth in spring. Despite differences in soil type, pH .and location, both sites showed: (i) S15N in extractable mineral nitrogen varied with time (decreasing from 18.7 to 6.0% in fallowed soil at Yanco, and increasing from 5.8 to 12.0%~ under oats at Trangie), and in cropped versus fallowed treatments (12.0 and 5.3% respectively in December at Trangie), and values were different from those of the total soil nitrogen, in which S15N remained virtually unchanged (over all times and sites, S15N = 8.2 � 0.2 at Trangie); (ii) after removal of the crop, S15N in increments of extractable mineral nitrogen were higher than in the total nitrogen of previously cropped soils, whilst in the continuously fallowed soils, S15N of extractable mineral nitrogen was lower than in the total nitrogen. In addition, at Trangie, S15N in the extractable mineral nitrogen was highest late in growth of the oat crop, and this was reflected in the values for S15N of nitrogen assimilated in the crop. Values of the S15N of plant nitrogen agreed well with the S15N of extractable mineral N when the former were determined in increments of plant N during fixed periods of growth and plotted appropriately (the mid-point between sampling times) in relation to the time courses of changes in the mineral N. These results are discussed in relation to the use of 15N natural abundance techniques for estimating nitrogen fixation by nodulated legumes and in the study of other aspects of soil nitrogen cycle processes.

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