Yields and nitrogen uptake of grain sorghum in various rotations, including lucerne, annual legume and long fallow

1989 ◽  
Vol 40 (2) ◽  
pp. 255 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Nitrogen Uptake ◽  
Grain Sorghum ◽  
Grazing Management ◽  
First Year ◽  
Red Clay ◽  
Beneficial Effects ◽  
South Wales ◽  
Establishment Method ◽  
Soil Evidence

Long-term yields, nitrogen uptake and responsiveness of grain sorghum following three lucerne rotations, an annual legume rotation, long fallowing, and continuous wheat growing were measured on a black earth and red clay in northern New South Wales. The three lucerne rotations compared two methods of lucerne establishment (with or without a cover crop) and two methods of grazing management (short or extended grazing).There were large beneficial effects of lucerne leys on the first grain sorghum crop, whether they were measured as grain yield, nitrogen content of the foliage and grain, or nitrogen uptake. The effect was much smaller in the second year but it increased in the third and fourth years, in direct relation to the rainfall during the sorghum flowering period. The effect was larger on the black earth than on the red clay, reflecting the much higher lucerne yields on the former soil. Evidence indicated that the nitrogen contribution from lucerne after the first year was no greater than the nitrogen accumulated by long fallowing, and this was attributed to very low rainfall and lucerne yields during the four year ley period.The annual legume rotation suffered from drought and insect damage in most years, and following sorghum yields tended to be lower than those achieved by long fallowing.Differences in the effects of establishment method and grazing management on total lucerne yields were reflected in the differences in subsequent grain sorghum yields. Largest differences were on the black earth where extended grazing lowered the total yields of lucerne and subsequent grain sorghum. Sowing lucerne under wheat had little effect on total yields of lucerne or sorghum.

Effects of duration of grazed lucerne on long-term yields and nitrogen uptake of subsequent wheat

1980 ◽  
Vol 31 (2) ◽  
pp. 239 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Nitrogen Uptake ◽  
New South ◽  
Growth Yield ◽  
Soil Types ◽  
Wheat Crop ◽  
Grain Protein ◽  
Long Term Effects ◽  
Beneficial Effects ◽  
South Wales

The long-term effects of varying durations of lucerne Icy, extended fallowing, and continuous wheat growing on the growth, yield, and nitrogen uptake of subsequent wheat crops were determined on two contrasting soils in northern New South Wales. Durations of lucerne ley were 3+, 2+ and 1+ years on a black earth and 5+, 3+ and 1+ years on a red-brown earth. With the exception of the first wheat crop, wheat production for several years following lucerne exceeded that following extended fallow or continuous wheat growing, whether measured as vegetative yield at anthesis, grain yield, nitrogen uptake, or grain protein. The beneficial effects of lucerne on vegetative yield, nitrogen uptake, and grain protein reached a maximum in the second crop after lucerne, and the effects of 2+ or more years of lucerne remained significant for the next five crops on the black earth and the next two crops on the red-brown earth. Grain yields fluctuated widely with season, the magnitude of the lucerne effect being much more dependent on rainfall, but the duration of the effect was similar for grain and vegetative parameters. The shorter duration of the lucerne effect on the red-brown earth appeared to be associated with its more freely draining nature and consequent loss of accumulated nitrogen. The optimum duration of lucerne for maintaining nitrogen-dependent wheat yields was 3+ years on both soil types. It eliminated the need for nitrogen fertilizer for the following five wheat crops on the black earth and three wheat crops on the red-brown earth. Extended fallowing also had a beneficial effect on all parameters, particularly in the first and second crops after the fallow ended. Its effect was generally significantly smaller than the lucerne effect except in the first crop after fallow.

Sydney rock oyster farming in Australia.

2020 ◽  
Author(s):  
John Nell
Keyword(s):  
New South ◽  
Quality Assurance Program ◽  
First Year ◽  
Water Sampling ◽  
Time To Market ◽  
Profit Margins ◽  
Rock Oyster ◽  
South Wales ◽  
Sampling Programme

Abstract The 120-year-old Sydney rock oyster industry in New South Wales (NSW) and southern Queensland is one of the oldest aquaculture industries in Australia. The industry has been forced to adapt to competition from other species, tighter harvesting and oyster storage and handling requirements as well as eroding profit margins. Recent changes in farming practices include the move away from stick culture to single seed culture, as the half-shell market demands a more uniformly shaped oyster. When selective breeding demonstrated that it could reduce time to market (50 g whole weight) by nearly a year out of an industry average of 3.5 years, the industry wanted to try hatchery technology. Although the industry had never used hatchery technology before, it purchased 10 million spat or 8% of its annual spat requirement from hatcheries in 2003-2004, the first year that they were made available to farmers. The industry also embraced the Australian Shellfish Quality Assurance Program, which requires that shellfish harvest areas be classified on the basis of a sanitary survey and the results of an ongoing strategic water-sampling programme. This programme ensures product safety for the consumers and helps to provide the industry with a long-term future.

A Decade of Mark-Recapture of Platypuses on The Duckmaloi River: Any New Insights into Population Dynamics?

1998 ◽  
Vol 20 (2) ◽  
pp. 302
Author(s):  
D. Goldney
Keyword(s):  
Sex Ratio ◽  
New South ◽  
First Year ◽  
Mark Recapture ◽  
South Wales ◽  
Adult Status ◽  
Second Year ◽  
Gill Netting ◽  
Population Numbers

A long-term mark-recapture program has been carried out on the Duckmaloi Weir (near Oberon, New south Wales) and associated river over the period 1986 to the present. The pipehead weir creates a long shallow ·pool' about 2.5 ha in area, ideal for gill-netting platypuses. One hundred and eighty-two (182) individual animals have been captured in excess of 500 times. The majority of animals have been captured in the weir pool. A very dynamic situation exists with new adults and juveniles being captured on a regular basis and conversely captured animals "disappearing" on a regular basis from the system. Some individuals exhibit both transience and site attachment characteristics. However, relatively few animals remain site attached for long periods of time. Sixty nine percent of individuals are captured two or fewer times. Band loss cannot account for this phenomenon. Of the captured animals, 11.3% have been caught more than 5 times. The sex ratio of the population favours females in first capture adults (1:1.72) but males in first capture juveniles (1:0.73). Females are more likely to be recaptured than males. The sex ratio of juveniles varies significantly from year to year. The period between recaptures varies greatly and can be up to 6 years. Four animals have been captured over nine years (3 females/1 male) but no animal has been captured every year of the study. Recruitment has occurred at levels able to maintain the current population numbers. Thirty percent of available adults have been found lactating, including second year females. Seventy one percent of first year capture juveniles and 89.9% of first capture adults "disappear" within two years of first capture. Forty two percent of juvenile animals reach adult status before "disappearing".

Sustainable grazing systems for the Central Tablelands of New South Wales. 5. A bioeconomic framework for assessing the long-term economic benefits of grazing management tactics and implications for sustainability

2006 ◽  
Vol 46 (4) ◽  
pp. 495 ◽  
Author(s):  
R. E. Jones ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
W. McG. King
Keyword(s):  
Programming Model ◽  
New South ◽  
New South Wales ◽  
Economic Benefits ◽  
Grazing Management ◽  
South Wales ◽  
Grazing Systems ◽  
Sustainable Grazing ◽  
Management Tactics

There have been significant declines in the perennial grass (PG) content in native and sown pastures across temperate Australia. Not only has this reduced agricultural productivity, it has contributed to more serious degradation, such as loss of soil and biodiversity, decreasing water quality, and dryland salinity caused by rising watertables. Results from the Sustainable Grazing Systems Key Program (SGS) research undertaken at Carcoar on the Central Tablelands of New South Wales were reported by Michalk et al. (2003). This research indicated that grazing management tactics can be used to manipulate pasture composition, thereby changing animal production and water-use patterns. The main grazing tactic investigated was termed a summer grazing rest, where resting was imposed in late spring if PG composition was <50%. Reported in this present paper is an economic framework for valuing the long-term benefits of grazing management tactics. The framework involves the development of a bioeconomic modelling system that links a dynamic programming model with biophysical models for water and environmental processes, soil fertility, pasture growth, livestock energy requirements and the change in pasture species composition. The study concludes that long-term economic returns are improved by strategies, e.g. a summer rest, that lead to an increase in PG composition over time. The study also determined that environmental factors, such as deep drainage, runoff and soil loss, are reduced as perenniality is increased.

Effect of tillage practice on the persistence of atrazine in two contrasting soils in northern New South Wales

1989 ◽  
Vol 29 (6) ◽  
pp. 849 ◽  
Author(s):  
IG Ferris ◽  
WL Felton ◽  
JF Holland ◽  
MS Bull
Keyword(s):  
Surface Soil ◽  
Initial Rate ◽  
New South ◽  
New South Wales ◽  
Grain Sorghum ◽  
Tillage Practice ◽  
Red Clay ◽  
Post Harvest ◽  
Tillage Practices ◽  
South Wales

Grain sorghum was sown at 2 sites at Tamworth in northern New South Wales in 1980 in order to examine the influence of fallow tillage practices and post harvest cultivation on the persistence of atrazine. In a non-cracking red clay (pH 5.7) atrazine (3.2 kg/ha) was applied both to the sorghum fallow and at sowing (1.8 kg/ha). The concentration of carryover atrazine 3 months after sorghum harvest was 0.11 µg/g in the 0-5 cm mil layer and 0.06 µg/g in the 5-15 cm layer. By contrast, the same treatment resulted in 0.61 and 0.52 µg/g in the 0-5 and 5-15 cm zones of a grey clay (pH 7.5). Cultivation after the sorghum was harvested reduced the atrazine residue in the surface soil (0-5 cm) by 20-40%, depending on the initial rate of application. There was no associated increase in the 5-15 cm zone. Despite the reduction in the amount of atrazine residue, cultivation increased the severity of atrazine injury to wheat sown at the grey clay site. There was no evidence of phytotoxicity at the red clay site.

The impact of livestock grazing on the persistence of a perennial forb in a temperate Australian grassland

2003 ◽  
Vol 9 (4) ◽  
pp. 302 ◽  
Author(s):  
Josh Dorrough ◽  
Julian Ash
Keyword(s):  
Plant Species ◽  
Management Practices ◽  
Livestock Grazing ◽  
Grazing Management ◽  
Population Growth Rates ◽  
Perennial Plant ◽  
South Wales ◽  
Recent Occurrence ◽  
The Impact

The presence of perennial plant species in grazed habitats may be an imperfect predictor of their long-term ability to persist under grazing by livestock. This is particularly the case in landscapes where grazing by livestock is a relatively recent occurrence or where management practices are leading to intensification of grazing. This paper investigates the impacts of grazing on the native perennial inter-tussock forb Leptorhynchos elongatus (Asteraceae) in grasslands on the Monaro Tablelands of New South Wales. Although the species persists in grazed habitats, exclosures indicate that current grazing management can lead to severe depletion of seed, largely due to selective removal of flowers and seed heads by livestock. A population model suggests that under current grazing management, population growth rates may be negative. Removal of livestock during flowering and seed set may assist long-term persistence of this species in grazed habitats. Despite almost 200 years of livestock grazing on the Monaro Tablelands, recent intensification of grazing management could result in the future loss of some plant species in grazed habitats.

Effects of eight year rotations of grain sorghum with lucerne, annual legume, wheat and long fallow on nitrogen and organic carbon in two contrasting soils

Soil Research ◽  
1990 ◽  
Vol 28 (2) ◽  
pp. 277 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Nitrogen Fixation ◽  
Organic Carbon ◽  
Total Nitrogen ◽  
Soil Nitrogen ◽  
Grain Sorghum ◽  
Grazing Pressure ◽  
Red Clay ◽  
Positive Effects ◽  
South Wales ◽  
Sparing Effect

Soil nitrogen and organic carbon levels during 8-year rotations of grain sorghum (4 years) with lucerne (4 years), annual legume (faba beans or cowpeas in alternate years), wheat (4 years) and long fallow (alternate years) were measured on a black earth and a red clay in northern New South Wales. Total soil nitrogen (0-15 cm) increased at about 100 kg ha-1 yr-1 in the lucerne leys, but it maximized after 2 years on the red clay and then declined at about the same rate, suggesting that nitrogen fixation had ceased in response to heavy grazing pressure and drought conditions. The positive effects of lucerne on total nitrogen and organic carbon were maintained during 4 years of subsequent sorghum growth on the black earth, but effects on the red clay were not significant. Sorghum, when its residues were incorporated, had a much larger effect than lucerne in raising soil organic carbon. Concentrations of soil nitrate were much higher immediately after the lucerne than after continuous cereal, and they remained higher in the lucerne rotations after 2 years of sorghum. Accumulation of nitrate during long fallows was much larger after sorghum, with incorporated residues, than after no-tilled wheat, and the magnitude of this difference suggested biological nitrogen fixation by free-living bacteria during the sorghum long fallows. Fluctuations in nitrate were generally larger in the red clay than in the black earth, but sorghum yields and nitrogen uptake were less responsive to high nitrate in the red clay, apparently because of its lower nitrate buffering capacity and poorer soil structure. In comparison with continuous cereal growing, the annual legume rotation had no significant effect on organic carbon or total nitrogen, but it sometimes increased nitrate during the sorghum rotation, probably by a nitrate sparing effect during the cowpea crop.

Effects of sorghum ergot on grain sorghum production: a preliminary climatic analysis

1997 ◽  
Vol 48 (8) ◽  
pp. 1241 ◽  
Author(s):  
Holger Meinke ◽  
Malcolm Ryley
Keyword(s):  
Southern Oscillation ◽  
Warning System ◽  
Grain Sorghum ◽  
Climatic Conditions ◽  
Hybrid Seed Production ◽  
Breeding Programs ◽  
South Wales ◽  
Claviceps Africana ◽  
Sorghum Production

Until 1996 the disease ‘sorghum ergot’ (Claviceps africana and Claviceps sorghi) was unknown in Australia. Following an outbreak near Gatton, the disease was found throughout most of the sorghum-producing areas in Queensland within 4 weeks. A climatic risk analysis was conducted to assess the likely timing and frequencies of further outbreaks of the disease across the main sorghum-producing regions of Australia. Based on the information available, likely conditions that could lead to a disease outbreak were formulated and a computer program developed to interrogate an existing database of long-term, daily weather records. Case studies were conducted for 10 key sorghum-producing locations, ranging from Narromine in central New South Wales to Mareeba in far North Queensland and Kununurra in Western Australia. For grain sorghum production, crops flowering in January and February are unlikely to be affected, regardless of location. However, in up to 30% of years, late-sown grain sorghum crops and crops flowering before January could be affected, depending on climatic conditions prior to and around anthesis. The frequency and timing of these events differed strongly temporally and spatially and appeared highest in high rainfall years and in regions with relatively cooler temperatures and more frequent autumn rains. Hybrid seed production (i.e. breeding programs) and forage sorghum production are likely to be more affected due to their inherently low pollen generation, again with strong regional variation. Further applications of the methodology, such as the development of an early warning system, based on phases of the Southern Oscillation Index, are discussed.

Importance of mineral nitrogen in the subsoil to yield and uptake of nitrogen by wheat in southern New South Wales

1988 ◽  
Vol 28 (2) ◽  
pp. 215
Author(s):  
AC Taylor ◽  
WJ Lill ◽  
AA McNeill
Keyword(s):  
Nitrogen Uptake ◽  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Mineral Nitrogen ◽  
Soil Mineral ◽  
Soil Mineral Nitrogen ◽  
South Wales ◽  
Nitrogen Concentrations

Dry matter and nitrogen uptake of wheat tops at flowering, dry matter and nitrogen of wheat grain at maturity, and soil mineral nitrogen (0-90 cm) at sowing and flowering, were measured at 68 sites (1 experiment per site in 5 Shires) in southern New South Wales to test the hypotheses that: (i) mineral nitrogen below 30 cm would improve the prediction of wheat yields, (ii) soil mineral nitrogen would be better indicated by wheat yields at flowering than those at maturity, and (iii) soil mineral nitrogen would be better indicated by nitrogen uptake by wheat than by dry matter yields. Mineral nitrogen concentrations in soil at depths greater than 30 cm did not improve the prediction of wheat attributes, but hypotheses (ii) and (iii) were validated. Curvilinear regressions, significant (P< 0.05) on 2 occasions, were not important in this study. The best regression of wheat dry matter at flowering against soil mineral nitrogen at sowing was a single straight line, but the best models for the other 3 wheat variables were all bilinear. The best of the latter related the uptake of nitrogen by wheat at flowering to mineral nitrogen in the soil at sowing as follows: FNUH = (31.6 � 5.9) + (0.892 � 0.110) TMNS30 and FNUL = (9.7 � 7.3) + (0.892 � 0.110) TMNS30 where FNUH is nitrogen uptake by wheat at flowering (kg/ha) in 1960, 1964 and 1966 (when Shire wheat yields were above the Shire's long term average), FNUL is nitrogen uptake by wheat at flowering (kg/ha) in 1961, 1965 and 1974 (when Shire wheat yields were below the Shire's long term average), and TMNS30 is total mineral nitrogen (0-30 cm) (kg/ha) at sowing.

scholarly journals Sowing methods for successful pasture establishment - a review

2011 ◽  
Vol 15 ◽  
pp. 31-37
Author(s):  
E.R. Thom ◽  
T.J. Fraser ◽  
D.E. Hume
Keyword(s):  
Seedling Growth ◽  
Seedling Survival ◽  
First Year ◽  
No Tillage ◽  
Research Attention ◽  
Establishment Method ◽  
Long Term Monitoring ◽  
Term Monitoring ◽  
Suitable Environment

Methods of achieving successful pasture establishment have been broadened over the last 50 years by the introduction of no-tillage technologies, providing a viable alternative to cultivation. Parallel developments in drill technologies for seed and fertiliser placement, and methods to control competition from the existing pasture have ensured the success of no-tillage methods. This review focuses on the effects of the establishment method on seedling growth over the establishment period, defined for the purposes of this paper as the year after sowing. Undersowing existing pasture is the establishment method least likely to provide a suitable environment for seedling growth and development. New pastures must receive different management to existing pastures for at least 1 year after sowing to increase their chances of becoming persistent and productive. Long-term monitoring (5-10 years) of new pastures has received little research attention, making assessments of effects of different establishment methods on persistence difficult. Factors likely to affect seedling establishment and plant survival are discussed. Keywords: competition control, cultivation, directdrilling, first year management, Lolium perenne, ryegrass, seedling survival, Trifolium repens, white clover

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