Seasonal variation of pH, aluminium, and manganese in acid soils from north-eastern Victoria

1992 ◽  
Vol 32 (8) ◽  
pp. 1105 ◽  
Author(s):  
WJ Slattery ◽  
GR Ronnfeldt

Seasonal variation in pH (measured in H2O or 0.01 mol CaCl2/L) and in Al and Mn extracted by 0.01 mol CaCl2/L are reported for north-eastern Victoria. Seasonal variation in pH(H2O) was significantly (P<0.05) greater than either the spatial variation or laboratory error. There was no significant (P<0.05) seasonal variation in pH(CaCl2). For pH (H2O), values were observed to increase after the autumn break, to peak at or near midwinter, and to decrease slowly over the spring and summer months to lowest values in late summer. Seasonal changes for pH(H2O) were significantly (P<0.05) related to the ionic strength of the 1 : 5 soil : water extract. Significant seasonal variations (P<0.05) occurred for extractable Al and Mn in a podsolised red earth and a red podsolic. Seasonal effects were a significant (P<0.05) source of variation for the methods used in this study and should, therefore, be considered in any comparative or predictive studies using these methods.

2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA

Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula) at Gran Canaria Island (eastern Atlantic) via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds) within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula) with the most conspicuous species (D. africanum) in the study area.


2013 ◽  
Vol 41 (1) ◽  
pp. 255 ◽  
Author(s):  
Ercan YILDIZ ◽  
Mustafa KAPLANKIRAN ◽  
Turan Hakan DEMIRKESER ◽  
Celil TOPLU

The study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey during the 2010 and 2011 growing seasons. The aim of this study was to investigate the effect of ‘Troyer’ and ‘Carrizo’ citranges (Poncirus trifoliata Raf. × Citrus sinensis Osb. var. ‘Troyer’ and ‘Carrizo’), and common sour orange (Citrus aurantium L. var. common), rootstocks on the seasonal variation of carbohydrate content in the leaves of cvs. ‘Fremont’, ‘Nova’, and ‘Robinson’ mandarin. The seasonal variation of carbohydrate content of the three cultivars budded on different rootstocks was nearly same. Soluble carbohydrate concentration showed a continuous decrease from January to mid or late-summer, and then slowly began to increase after early autumn till winter. The sucrose was the dominant soluble carbohydrate in leaves. The seasonal evolution of starch content in leaves increased initially during January to March, and then decreased in April. The starch concentration showed a continuous decrease slowly until the mid-autumn, and then accumulation began during late-autumn and winter. The total carbohydrate content differences among the rootstocks were significant, but the content was changed among the cultivars and according to the season. The change in the total carbohydrate content of leaf tissues showed a strong similarity in cultivars budded on different rootstocks throughout the year. The total carbohydrate content reached their lowest levels in July for cv. ‘Robinson’, in August for cv. ‘Fremont’ and cv. ‘Nova’. The total carbohydrate content in leaves increased from the mid- or late-summer to winter. It is suggested that the seasonal variation of carbohydrate content in plant tissues can be considered during fertilization program in mandarin trees.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
E Atkins ◽  
Q Pilard ◽  
K Rogers ◽  
A Salam ◽  
A Rodgers

Abstract Background There is evidence that blood pressure (BP) levels vary considerably from season to season, due principally to variation in ambient temperature. This gives the potential for both under- and over-treatment if BP lowering medications are not varied seasonally, but is not acknowledged in clinical guidelines. We will describe the seasonal variation in BP and assess the association between systolic blood pressure (SBP) and outdoor maximum ambient temperature in Australia. Methods The primary care data is an extract from MedicineInsight, a national general practice data program developed and managed by NPS MedicineWise, which extracts deidentified data from almost 10% of all Australian general practices. We included patients aged 30–90 years with at least one BP measure recorded from 1 Jan 2010 to 1 Aug 2017. Australian Bureau of Meteorology daily max temperature is linked by matching observation dates and location to nearest weather station. Decomposition of the mean will determine seasonal variation. Multiple linear regression was used to estimate the associations between max temperature and SBP with adjustment for age, sex, socioeconomic index, current smoking, comorbidities, BP lowering medication use, lipid lowering medication use and year of BP measurement. Results The study population includes 2.6 million people, mean age 55 years (standard deviation [SD] 16.3). Fifty-five percent are female, over a third of the cohort reside in New South Wales, and 62.4% reside in major Australian cities. The mean (SD) temperature was 23°C (6.6). There was a mean (SD) of 7 (11.4) BP measurements per person over the study period, median 3 measures (interquartile range 1–8). A quarter had a history of hypertension, 8% had a history of cardiovascular disease, and 8% had a history of diabetes. Twenty-six percent had at least one prescription for BP lowering therapy. The average monthly SBP for the cohort demonstrated strong seasonal variation with higher values in winter. The population mean varies by 3mmHg SBP between seasons across Australia, ranging from 1.7mmHg in the Northern Territory to 3.5mmHg in South Australia (range of mean maximum temperature 3°C [30–33] and 14°C [15–29] for the capital cities respectively). Each 10°C increase in max outdoor temperature was associated with a 1.8mmHg [95% CI 1.80–1.83] lower mean SBP. The proportion of people with SBP>140mmHg varied by season, irrespective of age, sex and use of BP lowering treatment. For example, among those treated control rates varied between 70 and 81%, and among those not treated between 78 and 85% (Figure). Blood pressure seasonality in Australia Conclusions BP control rates vary considerably by season. These findings have implications for the reliable diagnosis of hypertension, and suggest seasonal adjustments in treatment should be considered for some patients. The clinical and public health relevance of this phenomenon is expected to increase with increasing climate variability. Acknowledgement/Funding National Health and Medical Research Council Australia, National Heart Foundation Australia


2006 ◽  
Vol 46 (4) ◽  
pp. 439 ◽  
Author(s):  
W. McG. King ◽  
P. M. Dowling ◽  
D. L. Michalk ◽  
D. R. Kemp ◽  
G. D. Millar ◽  
...  

Temperate perennial grass-based pastures dominate the high rainfall zone of south-eastern Australia and support a major livestock production industry. This area has experienced a recent change in overall pasture condition, however, typified by a reduction in the abundance of perennial grasses and an increasingly prominent winter-annual grass weed component. Improving the condition and productivity of these pastures can be achieved by improved management but this requires better knowledge of the interactions between management options and pasture species composition and of the interaction between pasture vegetation and the complex effects of a heterogeneous landscape. This paper reports the results of an intensive survey of a 60-ha paddock that was designed to identify the species present, determine their patterns of distribution and examine the relationships between pasture vegetation and the environment. The survey of species present in late summer was supplemented by the identification of seedlings that later emerged from extracted soil cores and by soil physical and chemical analyses. Data were analysed using ordination and interpreted with GIS software so that topographic features could be considered. The most frequently identified taxa were Hypochaeris radicata, Austrodanthonia spp. and Bothriochloa spp. (in late summer) and Vulpia spp., Bromus molliformis and Trifolium subterraneum (winter-annual species). Austrodanthonia spp. were commonly found on the drier ridges and more acid soils with lower phosphate levels. These were also the areas dominated in spring by Vulpia spp. and were generally lower in plant species richness overall. The most species-rich areas occurred downslope where soil fertility was higher and less moisture stress was presumably experienced. The measured environmental factors explained a substantial proportion of the variation in the vegetation dataset, which underlined the importance of considering landscape effects in the management of typical tablelands pastures.


1976 ◽  
Vol 16 (81) ◽  
pp. 532 ◽  
Author(s):  
RF Isbell ◽  
RK Jones ◽  
GP Gillman

Eleven complete profiles and an additional 112 surface soils of deep sandy yellow and red earths in the far northern part of Cape York Peninsula have been sampled for laboratory studies. Chemical analyses showed that these acid soils are very low in organic carbon, nitrogen, phosphorus, potassium, sulphur, copper, zinc, manganese, cobalt, exchangeable basic cations, and base saturation. They have relatively high contents of exchangeable aluminium. The variability of surface soil chemical properties is relatively low. Glasshouse experiments with Stylosanthes humilis cv. Gordon conducted on soils from the 11 profile sites showed responses to sulphur, potassium, zinc and lime on all soils and to copper on about half the sites. Considering the results of both the laboratory and glasshouse studies, it is suggested that responses to nitrogen, phosphorus, zinc and probably calcium and copper are likely in the field. Responses to sulphur may be transitory because of the presence of appreciable levels of phosphate-extractable sulphur at depth.


1927 ◽  
Vol 18 (1) ◽  
pp. 63-65
Author(s):  
C. B. Williams

In the course of the beekeeping work of this Department we have had a number of hives weighed at regular intervals of about a week by means of a steelyard and tripod, and two permanently standing on platform weighing machine and weighed every day. The information obtained from these has been of great value in showing the seasonal variation in activity, the periods of honey flow, and the effect on the hives of the presence of enormous numbers of hornets in the late summer.There were, however, many problems, such as the daily periods of activity and honey-collecting, the effect of high midday temperature, etc., that could only be dealt with by more frequent weighings, and it was felt that a machine to record continuously the weight of the hive by means of a rotating clock drum and pen would be a most valuable instrument of research.


Clay Research ◽  
2020 ◽  
Vol 39 (1) ◽  
pp. 31
Author(s):  
Sonalika Sahoo ◽  
Duraisamy Vasu ◽  
Ranjan Paul ◽  
Tarun Kanti Sen ◽  
Sanjay Kumar Ray ◽  
...  

Author(s):  
M. A Ansar ◽  
B. U Choudhury ◽  
S. S. Roy ◽  
S. K. Sharma ◽  
P. K. Saraswa ◽  
...  

TPerformance of 27 improved groundnut cultivars were assessed for agronomic and physiological traits associated to improve the productivity in degraded acid soils under rainfed hilly ecosystem. The cultivars ICGS- 76 and ICGV-86590 produced significantly p less then 0.05 higher pod yield with more than 39% improvement over JL-24. The study also identified five more promising cultivars viz. ICGS-5, TKG-19 A, TG-37-A, GG-11 and GG-21 with 19-38% higher yield over the check. The low productivity of cereals in the acidic and moisture stressed Jhum degraded upland soils of rainfed hilly ecosystem of Eastern Himalayan Region is a major concern for socio-economic improvement of resource poor farmers. Adoption of these cultivars is expected to increase the productivity and net income to a tune of 93.2% without incurring any additional costs to the prevailing production system.


1989 ◽  
Vol 29 (2) ◽  
pp. 209 ◽  
Author(s):  
DR Coventry ◽  
BR Walker ◽  
GR Morrison ◽  
MT Hyland ◽  
JC Avery ◽  
...  

Liming experiments were conducted at 13 sites (soil pH range 4.99-6.27, 0-10 cm depth) in the dryland cropping region of north-eastern Victoria with wheat grown at all sites and barley at 3 sites. Lime increased wheat yields at 9 of the 13 sites with the acid sensitive cultivar Oxley, but the yield increase was not correlated (r2=0.07) with exchangeable Al. Exchangeable A1 was closely related to pH (in 0.01 mmol/L CaCl2). The acid-tolerant wheat cultivars (Matong and Millewa) out-yielded Oxley at a soil pH (CaCl2) of 4.7 and the acid-tolerant cultivars were less responsive to liming. The barley responded to the lime treatment at each of the 3 sites. The use of acid tolerant crop species is recommended on these soils, but an improvement in the predictability of a lime response is required before liming is widely recommended.


1995 ◽  
Vol 46 (3) ◽  
pp. 617 ◽  
Author(s):  
SH Hooker ◽  
RG Creese

An examination of the reproductive condition of a population of paua, H. iris, at Leigh in north-eastern New Zealand during 1986-87 revealed a long breeding season extending from late summer through autumn and winter and into early spring. Within this period, a sharp decrease of over 60% in the gonad index for both males and females indicated major spawning events in July and October. A smaller decrease in the gonad index in March suggested a third, minor spawning. These spawning events were confirmed by regular examination of histological sections of gonadal material. This breeding pattern is different from that previously described for southern localities in New Zealand, where spawning activity is limited to a four-month period from late summer into autumn. Paua in this northern population had a sex ratio slightly biased towards males (1 female to every 1.3 males) and achieved reproductive maturity between the sizes of 48 and 60 mm shell length. These features are also different from those described for southern populations of H. iris. These findings highlight the need to take regional differences in reproductive pattern into account when describing the population dynamics of marine gastropods.


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