The effect of biosolids on cereals in central New South Wales, Australia. 1. Crop growth and yield

2005 ◽  
Vol 45 (4) ◽  
pp. 435 ◽  
Author(s):  
J. L. Cooper

Two forms of biosolids, with and without lime, were applied to acid soils at 2 sites in central New South Wales. Wheat and triticale were then grown on these sites to determine the effect of biosolids on crop growth and yield. The forms of biosolids used were dewatered sewage sludge cake, and N-Viro Soil which is a lime amended sewage sludge. Dewatered sewage sludge cake was applied at rates of 0, 6, 12 and 24 dry Mg/ha, and N-Viro soil at 0, 1.5, 3.0 and 4.5 dry Mg/ha. Biosolids produced grain yield increases of over 50% at both sites, with the largest yield increases at the highest rate of dewatered sewage sludge. Continued cropping at 1 of the sites showed that significant yield increases were still obtained 3 years after the initial application. The addition of lime and N-Viro Soil raised soil pH, and produced small but long lasting yield increases. However, the main benefit of biosolids seems to have come from the nutrients they supplied rather than changes in soil pH.


1991 ◽  
Vol 31 (2) ◽  
pp. 211 ◽  
Author(s):  
J Brockwell ◽  
A Pilka ◽  
RA Holliday

Measurements were made of soil pH, frequency of occurrence of annual species of Medicago (medics) and populations of Rhizobium meliloti at 84 sites on 7 dominant soil groups of the Macquarie region of central-western New South Wales. Over all sites, soil pH (0-10 cm; 1:5 soil: water) ranged from 5.26 to 8.07, medic frequency from 0 to 100% and most probable numbers of R. meliloti from undetectable to 675 000/g soil. There was a highly significant (P<0.001) relationship between soil pH and number of R. meliloti. Above pH 7.0, the mean soil population of R. meliloti was 89000/g; below pH 6.0, it was 37/g. Medics occurred most frequently on the more alkaline soils and with least frequency on the more acid soils, but the relationship between soil pH and medic frequency was weaker than between pH and R. meliloti number. Medics were more tolerant of low soil pH than their rhizobia were; at 2 sites, of pH 5.49 and 5.35, medics occurred at 100% frequency but R. meliloti was undetected. There was an indication of some acidification in these soils over a period of 35 years but this remains to be confirmed.



2005 ◽  
Vol 45 (4) ◽  
pp. 445 ◽  
Author(s):  
J. L. Cooper

Two forms of biosolids, with and without lime, were applied to acid soils at 2 sites growing wheat and triticale in central New South Wales. The forms of biosolids used were dewatered sewage sludge cake, and N-Viro Soil which is a lime-amended sewage sludge. Dewatered sewage sludge cake was applied at rates of 0, 6, 12 and 24 dry Mg/ha, and N-Viro soil at 0, 1.5, 3.0 and 4.5 dry Mg/ha. The soil was sampled and analysed at 2 points in time to determine the effect of the biosolids on heavy metal concentrations. Vegetative plant material and grain were also analysed for heavy metal and organo-chlorine pesticide levels. Zinc and copper concentrations increased significantly with the addition of biosolids, especially with the highest rates of dewatered sewage sludge cake. However, all soil heavy metals were below the maximum allowable soil contaminant concentrations set by Environment Protection Authority, NSW. Cereal species, the addition of lime, and biosolids each affected heavy metal concentrations in plant material, but the responses differed between sites. Also, the changes in heavy metal concentrations in plant material were smaller and less consistent than the changes in soil heavy metal concentrations. The maximum heavy metal concentrations in grain were all below the maximum permitted concentrations of Food Standards Australia New Zealand. There were no detectable changes in the levels of organo-chlorine pesticides in the grain.



1996 ◽  
Vol 39 (4) ◽  
pp. 619-621 ◽  
Author(s):  
P. M. Dowling ◽  
D. L. Garden ◽  
D. A. Eddy ◽  
D. I. Pickering


1994 ◽  
Vol 34 (7) ◽  
pp. 921 ◽  
Author(s):  
DC Godwin ◽  
WS Meyer ◽  
U Singh

Evidence exists that night temperatures <18�C immediately preceding flowering in rice crops can adversely affect floret fertility and, hence, yields. It has been suggested that sterility induced by low temperature is also influenced by floodwater depth and nitrogen (N) rate. In southern New South Wales, low night-time temperatures are believed to be a major constraint to the achievement of consistently high yields. The availability of a comprehensive model of rice growth and yield that is sensitive to this constraint would aid the development of better management practices. CERES RICE is a comprehensive model that simulates the phasic development of a rice crop, the growth of its leaves, stems, roots, and panicles, and their response to weather. It also simulates the water and N balances of the crop and the effects of stresses of water and N on the yield-forming processes. The model has been extensively tested in many rice-growing systems in both tropical and temperate environments. However, the original model was unable to simulate the level of chilling injury evident from yield data from southern New South Wales. This paper reports modifications made in the model to simulate these effects and the evaluation of the model in environments of low night temperature. Inclusion of the chilling injury effect greatly improved the accuracy of estimated yields from treatments in an extensive field experiment. However, additional testing with a wider range of data sets is needed to confirm the international applicability of the modifications.



1985 ◽  
Vol 25 (1) ◽  
pp. 149 ◽  
Author(s):  
LJ Horsnell

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.



Soil Research ◽  
2003 ◽  
Vol 41 (5) ◽  
pp. 875 ◽  
Author(s):  
Balwant Singh ◽  
I.O.A. Odeh ◽  
A. B. McBratney

Soil acidity has been of major concern in Australia since European settlement. Acidification processes have been accelerated due to agricultural activities such as N fertiliser application and leguminous N-fixation in farm rotations. In this paper, we measured the acid buffering capacity (pHBC) of Vertosols, soils used predominantly for growing cotton in northern New South Wales. The pHBC values were used to calculate decrease in soil pH assuming net acid input due to agricultural practices. We combined the acidification results with geostatistics to spatially simulate the decline in soil pH of surface soils over time. The results indicate that it would take 10–417 years for soil pH to decrease by 1 unit on an assumed acid input of 5�kmol�H+/ha.year. Soil pH will drop by 1 unit within 100 years for 90% of the soils and within 15 years for 10% of the soils. This reflects the variability of the pHBC for the studied soils. In 50 years from present, most of the eastern and north-western parts of the study region may become highly acidic with soil pH declining to 5.5. There may be a potential threat to sustainable agriculture from acidification in the region, although more work needs to be done to corroborate the counter-effects of water fluxes and carbonate dissolution. Sensitivity analysis indicates that even at low levels of acid input, some areas in the study region may experience significant decline in soil pH in the surface layer.



1987 ◽  
Vol 27 (3) ◽  
pp. 411 ◽  
Author(s):  
GM Murray ◽  
BJ Scott ◽  
Z Hochman ◽  
BJ Butler

Lime was applied at rates from 0 to 5.0 t ha-1 at 4 sites in southern and central New South Wales. A root and crown disease characterised by basal stem blackening affected up to 60% of wheat plants and 80% of triticale plants when the soil pH in 0.01 mol L-1 CaCl2 was above 5.0 at all 4 sites. Below pH 4.8, incidence was less than 5%. The take-all fungus, Gaeumannomyces graminis var. tritici, was consistently associated with this symptom. Losses in grain yield from the disease ranged from 26 to 77% depending on site. Regression analysis indicates that each 10% increase in plants with basal stem blackening decreased yield by 0.76%. These results demonstrate that the disease can reverse the expected increase in yield after liming, and that progressive acidification of the soils in the region may have caused the present reduced amount of take-all.



1991 ◽  
Vol 31 (2) ◽  
pp. 221 ◽  
Author(s):  
GJ Crocker ◽  
ICR Holford

The effects of pasture improvement on soil pH, total nitrogen, organic carbon and extractable phosphorus (P) were determined by analysing adjacent soils from improved and unimproved pastures at 67 sites on the Northern Tablelands of New South Wales. Pasture improved sites contained at least 1 clover species, predominantly white clover, and had received at least 125 kg P/ha over periods of 15-45 years. The majority of pasture improved sites contained more soil nitrogen, carbon and phosphorus and were of lower soil pH than adjacent unimproved sites. However, the decreases in pH were not statistically significant and not usually related to the magnitude of the increases in other soil fertility parameters nor to the amounts of superphosphate applied or duration of fertiliser history. The largest decline in soil pH and largest increase in organic carbon were on granitic soils which had received more than 250 kg P/ha. The relatively small decreases in soil pH and lack of relationship with fertiliser history, compared with soils from southern New South Wales, were attributed to: (i) re-cycling of legume-fixed nitrogen by summer-growing grasses; (ii) the naturally lower pH, higher nitrogen content and higher buffering capacity of many northern soils. Soil acidification therefore seems to be much slower and less frequent in the perennial pasture systems of the Northern Tablelands of New South Wales.





1989 ◽  
Vol 29 (3) ◽  
pp. 383 ◽  
Author(s):  
PL Milthorpe ◽  
RL Dunstone

Jojoba (Simmondsia chinensis [Link] Schneider) was tested at several sites and on various soil types to assess its production potential under rainfed conditions in semi-arid areas of New South Wales. Stands were established using either plants grown from seed or cuttings taken from selected plants. With good nutrition and weed control, plant height increased at a similar rate over the experiment at all but the most sandy site, where growth was consistently poorer despite similar climatic conditions and management. Stands established from seed had extremely variable yields. Some plants failed to produce seed after 8 years while other plants consistently produced fruit after year 4, with yields as high as 1 kg clean seed per bush by year 8. The average yield was well under 200 g plant-1 except at Trangie in 1986-87 (590 g plant-1). At year 3, 50-100% of female plants were unproductive and by year 8, between 8 and 26% of plants remained unproductive. The variation in yield of the sampled population was consistently high irrespective of seasonal conditions, and usually the upper quartile yield was only marginally higher than the mean. However, the maximum yielding plant produced up to 10 times the mean yield. By contrast, the variation in yield of individuals within a clone was low regardless of the yield potential of that clone and the maximum yielding plant rarely exceeded twice the mean yield. Some clones (A, B and F) show promise as agricultural lines as they are relatively consistent yielders and show early yield development. The highest yield obtained extrapolates to 1.1 t ha-1 at year 7 at a site which averages 417 mm rainfall per year. Further research is needed to identify the reasons for the high variability and fluctuations in yield.



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