The uptake of nitrogen by wheat, its agronomic efficiency and their relationship to soil and fertilizer nitrogen

1993 ◽  
Vol 44 (6) ◽  
pp. 1245 ◽  
Author(s):  
AD Doyle ◽  
ICR Holford
Keyword(s):  
New South ◽  
N Uptake ◽  
Soil Nitrate ◽  
Fertilizer N ◽  
Agronomic Efficiency ◽  
Rooting Zone ◽  
The North ◽  
South Wales ◽  
Protein Response ◽  
North Western

Nitrogen uptake by wheat from both soil and fertilizer, and the efficiencies of fertilizer N (up to 116 kg/ha) for increasing yield and protein, were measured in 53 wheat fertilizer experiments during 1985-89 on the north-western slopes and plains of New South Wales. There was a highly significant (r2> 0.70) and common relationship between N uptake in unfertilized wheat (tops and grain) and soil nitrate to 90 cm depth for 4 of the 5 years of the study. A different but significant relationship occurred in 1988 when heavy rainfall before sampling leached some of the soil N beyond the sampled depth but within the rooting zone. The uptake and recovery of fertilizer N were lower in 1989, when in-crop rainfall was much lower than in the other 4 years. However, there was greater transfer of N from the herbage to the grain than in the wetter years. With increasing increments of fertilizer N. there was a much larger average decline in agronomic efficiency than in the recovery of fertilizer N or in physiological efficiency. Consistent with this, the average protein efficiency of fertilizer N tended to increase with increasing increments in every year except 1989. Although the highest increment of fertilizer N was always the least efficient for increasing grain yield, it exceeded the level required for profitability (8 kg grain/kg fertilizer N) in 20% of experiments. In experiments in which agronomic efficiency of the highest fertilizer increment was too low for profitability, there were at least 10 experiments in which the protein response was probably sufficient to make the highest increment profitable. The agronomic, protein and physiological efficiencies of fertilizer N in at least 10% of these experiments were higher than previously recorded in Australia and are comparable with the highest values recorded for wheat in other regions of the world.

Yield responses and nitrogen fertilizer requirements of wheat in relation to soil nitrate levels at various depths

Soil Research ◽  
1992 ◽  
Vol 30 (5) ◽  
pp. 683 ◽  
Author(s):  
ICR Holford ◽  
AD Doyle
Keyword(s):  
New South ◽  
Soil Nitrate ◽  
Sampling Depth ◽  
The North ◽  
South Wales ◽  
Nitrate Concentrations ◽  
Optimum Sampling ◽  
Yield Responses ◽  
North Western ◽  
Very High

Wheat grain yield responses and estimates of fertilizer nitrogen requirements in 57 experiments over five years (1985-9) were related to soil nitrate values at various depths (to 90 cm) in the soil profile. These experiments were on representative soils of the north western slopes and plains of New South Wales. Profile distributions of nitrate differed in the first three years, when nitrate concentrations at 15 or 30 cm intervals declined regularly with depth, to the last two years, when it was much more uniformly distributed and much lower in the top 30 cm. This was apparently caused by very high mid-fallow (pre-sampling) rainfall that occurred in the last two years but not in the earlier years. There were large differences in relationships of N fertilizer responsiveness and requirements to soil nitrate values between the two time periods. For each period, responsiveness and requirements were closely related to soil nitrate values at 0-15 cm and deeper depths, but not at 0-10 cm, with >50% of the variance being accounted for. The optimum sampling depth was 0-15 or 0-30 cm. Fertilizer responsiveness and requirements in relation to soil nitrate values (0-90 cm) were much lower in the last two years than in the first three years. This was attributed to very low in-crop rainfall in the last year and excessive rainfall in the penultimate year causing significant nitrate leaching beyond 90 cm depth. The critical nitrate concentrations varied from 24 mg N/kg at 0-15 cm down to 12 mg N/kg at 0-90 cm depth for 1985-7 and from 6 to 7 mg N/kg for all sampling depths in 1988-9. It was concluded that relationships obtained for the first three years were representative of years when normal or above average (but not excessive) rainfall occurred in the fallow and crop growth periods, while those for the last two years represented years when excess pre-sampling rainfall leached soil nitrate beyond the sampled depth or when yield responses to fertilizer were limited by in-crop conditions such as low rainfall.

Soil and vegetation response to thinning White Cypress Pine (Callitris glaucophylla) on the North Western Slopes of New South Wales, Australia

2006 ◽  
Vol 285 (1-2) ◽  
pp. 245-255 ◽  
Author(s):  
M. T. McHenry ◽  
B. R. Wilson ◽  
J. M. Lemon ◽  
D. E. Donnelly ◽  
I. G. Growns
Keyword(s):  
New South ◽  
New South Wales ◽  
Vegetation Response ◽  
The North ◽  
South Wales ◽  
Callitris Glaucophylla ◽  
North Western ◽  
Cypress Pine

The nutrient status and cultivation practices of the soils of the North-West wheat belt of NSW.

1954 ◽  
Vol 5 (3) ◽  
pp. 422 ◽  
Author(s):  
EG Hallsworth ◽  
FR Gibbons ◽  
TH Lemerle
Keyword(s):  
Organic Carbon ◽  
New South ◽  
Nutrient Status ◽  
North West ◽  
Nitrogen Levels ◽  
The North ◽  
South Wales ◽  
Cultivation Practices ◽  
North Western ◽  
Available Phosphate

A study has been made of the nitrogen, organic carbon, phosphate, and pH levels of the wheat soils of north-western New South Wales, and the cultivation practices adopted. They are found generally to be high in both total and available phosphate, and particularly high figures for available phosphate, over 1000 p.p.m., were found in limited areas. The nitrogen levels of the virgin chernozemic soils are distinctly higher than those of the red-brown earths and red solodic soils, but soils of all groups show a decline with cultivation, which is most rapid in the first 10 years. The introduction of periods under lucerne raises the nitrogen level, but the wheat/grazed fallow or wheat/grazing oats appear to cause the same nitrogen losses as are encountered under continuous wheat, in spite of the prevalence of stubble burning which inevitably accompanies this practice. The average yields of wheat on the chernozemic soils are distinctly higher than those obtained on the red-brown earths and red solodic soils, on some of which nitrogen appears to be limiting.

Yield and protein responses to nitrogen, and nitrogen fertiliser requirements of grain sorghum, in relation to soil nitrate levels

1997 ◽  
Vol 48 (8) ◽  
pp. 1187 ◽  
Author(s):  
I. C. R. Holford ◽  
J. F. Holland ◽  
A. J. Good ◽  
C. Leckie
Keyword(s):  
Yield Response ◽  
N Recovery ◽  
Soil Nitrate ◽  
Soil N ◽  
Response Curves ◽  
The North ◽  
Nitrate N ◽  
South Wales ◽  
Yield Responses ◽  
Protein Response

Sorghum fertiliser experiments at 40 sites on the north-western slopes andplains of New South Wales demonstrated that many soils are severely deficientin nitrogen (N), but most yield responses to fertiliser N occurred on sites inthe southern part of the region. Grain yields responded to fertiliser in fewerthan half of the experiments but protein concentrations responded in about75%.There were 4 distinct types of protein response curve, and the type of curvewas related to the degree of N deficiency. In the most deficient experiments(mean protein 6·1% or less), response curves were convex to thex -axis or linear; at intermediate deficiency (mean protein7·2%), response curves were sigmoid; and at low deficiency (meanprotein 9·7%), response curves were Mitscherlich. Yield responsenever occurred where grain protein was >10%.Maximum grain yield responses and amounts of fertiliser N for maximum profit,estimated by fitting the Mitscherlich equation to response curves, weresignificantly correlated with soil nitrate N levels at various depths in thesouthern experiments, but not in the northern experiments. This difference inN responses appeared to be caused by lower rainfall and higher soil N in mostof the northern experiments. Nitrate-N levels in soils sampled to 15 or 30 cmdepth were better correlated with yield response ( r> 0·81) and fertiliser requirement (r >0·72) than N levels to deeper depths.There was little or no fertiliser N recovery in the grain in the northern experiments but substantial recovery in the south where it was generallygreater than recovery by wheat in earlier experiments in the same region.Fertiliser requirement in relation to soil nitrate-N levels was lower thanthat of these wheat experiments. This was attributed to mid-spring soilsampling for sorghum which underestimates the soil N available to the sorghum

Genetic affinities of a remnant population of the brush-tailed rock-wallaby (Petrogale penicillata) in Mt Kaputar National Park, northern New South Wales

2018 ◽  
Vol 40 (1) ◽  
pp. 112
Author(s):  
Mark D. B. Eldridge ◽  
Linda E. Neaves ◽  
James Faris ◽  
Todd Soderquist
Keyword(s):  
Dna Sequences ◽  
National Park ◽  
New South ◽  
Term Survival ◽  
The North ◽  
South Wales ◽  
North Western ◽  
Remnant Population ◽  
Semiarid Conditions

The brush-tailed rock-wallaby (Petrogale penicillata) is now extinct west of the Great Dividing Range, apart from remnant populations in the Warrumbungles and at Mt Kaputar. Previous genetic analysis has identified deep genetic subdivisions within P. penicillata, but samples from Mt Kaputar were not included. Mitochondrial DNA sequences obtained from Mt Kaputar and the Warrumbungles clustered within the Central ESU, extending its distribution north of the Hunter River onto the north-western slopes adjacent to populations of the Northern ESU. These highly threatened western populations are the only P. penicillata persisting in semiarid conditions. This makes them of particular value to the long-term survival of the species and their conservation should be a priority.

Anthracnose and seedling blight of Bathurst Burr caused by Colletotrichum xanthii Halst

1951 ◽  
Vol 2 (4) ◽  
pp. 401 ◽  
Author(s):  
FC Butler
Keyword(s):  
New South ◽  
Economic Value ◽  
New South Wales ◽  
Summer Rainfall ◽  
Seedling Blight ◽  
The North ◽  
Weed Host ◽  
South Wales ◽  
Stem Lesions ◽  
North Western

In the summer rainfall regions of New South Wales during the past three seasons, a disease caused by the fungus, Colletotrichum xanthii, has caused widespread destruction of Bathurst burr, which ranks as one of the most serious weeds of pasture land in these areas. The disease, previously unrecorded in this State, was first observed on the Central Tableland but has since become established throughout the North-western and Central Western Slopes and Plains. It appears to be restricted to the genus Xanthium and is characterized by anthracnose-type stem lesions which tend to produce a 'ring-bark' effect. A seedling blight condition may also occur. The disease carries over from season to season on old burr remains. Since 1947-48 it has occurred naturally in 50 different districts of the State. During 1949-50 it was artificially established in 16 districts where it had not been observed previously. Disease development is favoured by prolonged periods of wet weather in the summer and autumn. It is difficult on the basis of three seasons' observations to assess the economic value of the disease as a means of biologically controlling Bathurst burr. During these three seasons, however, it has largely removed the necessity for weedicide spraying and hand cutting of burrs on many properties in northern New South Wales and thereby proved to be the most useful parasitic disease of a weed host ever encountered in this State.

Relative drought tolerance of three grass species from the Northwestern slopes of New South Wales.

1979 ◽  
Vol 1 (3) ◽  
pp. 244 ◽  
Author(s):  
AR Harradine ◽  
RDB Whalley
Keyword(s):  
Water Stress ◽  
Native Species ◽  
New South ◽  
New South Wales ◽  
Moisture Stress ◽  
Grass Species ◽  
The North ◽  
South Wales ◽  
Native Pastures ◽  
North Western

On the north-western slopes of New South Wales, native pastures are subjected to frequent and often severe moisture stress during the summer growing season (Daniel and Watt 1967) so the relative drought tolerances of the component species may be important in determining pasture composition. Survival of three common native species from this area, Aristida ramosa R.Br., Danthonia linkii Kunth and Dichanthium sericeum (R.Br.) A. Camus, when subjected to water stress was compared in a glasshouse pot trial. The use of cycles rather than a single water stress in drought resistance studies, to simulate field conditions more closely, has been emphasised by Gates (1974). This experiment was designed to determine the relative tolerance of the above three species to repeated, increasing periods of water stress in a limited volume of soil. Pots of different sizes were used to determine the effect of differences in the rate of development of water stress on plant survival.

scholarly journals A group of viruses isolated from naturally infected mosquitoes collected in the Murray Valley area of Victoria and New South Wales

1954 ◽  
Vol 52 (4) ◽  
pp. 551-562 ◽  
Author(s):  
E. L. French ◽  
W. C. Reeves
Keyword(s):  
Small Area ◽  
New South ◽  
New South Wales ◽  
The Other ◽  
Chick Embryos ◽  
The North ◽  
South Wales ◽  
Valley Area ◽  
North Western

By the inoculation of suspensions of mosquitoes on the chorio-allantoic membrane of chick embryos, seven pock-producing viruses have been isolated. The mosquitoes were collected in a small area of the Murray Valley situated in the north-western corner of Victoria and southern New South Wales. Six of the viruses were isolated from pools ofC. fatigansand one from a pool ofC. annulirostris. Five of the viruses were found to be members of the bird pox group and related to fowl-pox virus. Two of the viruses differed in the type of pock they produced on the chorio-allantoic membrane and appeared to be serologically unrelated to the other five.The interest and criticism of Sir Macfarlane Burnet, F.R.S., throughout the conduct of this work is gratefully acknowledged.

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