Spatial and temporal variation in soil Mn2+ concentrations and the impact of manganese toxicity on lucerne and subterranean clover seedlings

2012 ◽  
Vol 63 (9) ◽  
pp. 875 ◽  
Author(s):  
R. C. Hayes ◽  
M. K. Conyers ◽  
G. D. Li ◽  
G. J. Poile ◽  
A. Price ◽  
...  

Spatial and temporal variation in soil Mn2+ was observed over a 12-month period at two field sites near Gerogery and Binalong in southern New South Wales (NSW), Australia. Three pot experiments were then conducted to emulate the range of soil Mn2+ concentrations observed in the field and to determine the effect of different concentrations on lucerne and subterranean clover seedling growth, as well as to determine the effect of heating a soil on pH and Mn2+ concentrations. Concentrations of soil Mn2+ in the surface 0.20 m varied at a given sampling date by up to 288% (2.5–9.7 µg/mL) and 183% (8.7–24.6 µg/mL) across the Gerogery and Binalong field sites, respectively. At both sites, the concentration of soil Mn2+ in a given plot also varied by up to 175% between sampling times. There was little consistency between sites for seasonal fluctuations of soil Mn2+, although in both instances, peaks occurred during months in which newly sown lucerne plants might be emerging in southern NSW. Pot experiments revealed that high concentrations of soil Mn2+ reduced lucerne seedling survival by 35%, and on seedlings that did survive, reduced shoot growth by 19% and taproot length by 39%. Elevated concentrations of soil Mn2+ also reduced subterranean clover seedling survival by up to 55% and taproot length by 25%, although there were few effects on subterranean clover in treatments other than those imposing the highest soil Mn2+ concentrations. The third pot experiment demonstrated that elevated soil temperatures led to increased soil pH and increased soil Mn2+ concentrations, attributable to a decrease in biological oxidation of soil Mn2+. This was in contrast to the commonly anticipated response of a decline in soil Mn2+concentrations as soil pH increased.

Soil Research ◽  
1968 ◽  
Vol 6 (1) ◽  
pp. 131 ◽  
Author(s):  
CH Williams

Seasonal changes in sulphate sulphur were studied in a soil under subterranean clover pasture. Fluctuations in sulphate content were found to be similar to those in nitrate. Both sulphate and nitrate accumulated in the surface soil during summer, immediately after senescence of the pasture. High concentrations were maintained throughout the summer-autumn period and these decreased to low values in winter and spring. The higher values in summer probably resulted from mineralization of soil organic matter under favourable moisture and temperature conditions, and lack of plant uptake. Minor fluctuations were associated with partial leaching by rainwater. The low values in winter and spring were probably brought about by leaching and plant uptake, together with low rates of mineralization at low soil temperatures.


1950 ◽  
Vol 1 (4) ◽  
pp. 374 ◽  
Author(s):  
D Spencer

The mechanism of the action of lime in stimulating nodulation of subterranean clover on some soils of the Southern Tablelands of New South Wales was studied in pot experiments. Increased soil pH or increased calcium supply alone did not markedly improve nodulation. With a combination of both these factors, excellent nodulation resulted. Nodulation was shown to be increased by increasing the amount of the inoculum of Rhizobium added with the seed. It was also increased if the moisture content of the soil was maintained continually at field capacity.


2017 ◽  
Vol 10 (2) ◽  
pp. 203 ◽  
Author(s):  
Aderonke Adetutu Okoya ◽  
Bamikole Walter Osungbemiro ◽  
Temi E. Ologunorisa

The study of the chemical composition of rain water was conducted in Ile – Ife and environs, an agrarian, commercial, residential and semi-industrialised center of Osun state Nigeria. This was with a view to assessing the impact of land use activities on rain water composition and the temporal variation of rainwater chemistry. Physico-chemical parameters such as Turbidity, pH, TDS, Conductivity, Oxygen parameters, Alkalinity, Acidity, Hardness and Major ions (Ca2+, Mg2+, K+, Na+, NO3-, SO4-, HCO3-) were determined, predominant ions were identified. Turbidity, pH, Conductivity, TDS, D.O B.O.D, Alkalinity, Acidity Hardness ranged between 2.90 - 42.84 NTU, 5.65 - 7.40, 6.71 – 122.33 µScm-1, 4.10 –73.27 mg/L, 3.60 – 10.60 mg/L, 0.13 – 7.20 mg/L, 0.33 – 22.0 mg/L, 2.00 – 15.00 mg/L, 0.04 – 1.23 CaCO3mg/l respectively. The dominant ions detected in the study were HCO3-, Mg2+, Na+ and Ca2+. Generally, the mean concentration of ions as expressed in milli-equivalent per Litre showed order of dominance as HCO3- > NO3- > SO42- for the anions and Mg2+ > Na+ > Ca2+ > K+ for cations. The study concluded that land use activities had influence on all the chemical composition of rain water in the study area but more on pH, alkalinity, acidity, bicarbonate. Except sulphate and Nitrate, all other parameters recorded high values in dry season.


1967 ◽  
Vol 7 (27) ◽  
pp. 372 ◽  
Author(s):  
H Philpotts

In two pot experiments at Narrabri, New South Wales, Poona cowpeas (Vigna sinensis) were sown in a black chernozemic soil at 1, 2, and 4 inches, and at 1 1/2 and 4 inches with and without a straw mulch, to give a range of soil temperatures at the depth of sowing. It was found that the higher the soil temperature at sowing depth the lower was the percentage of plants with nodules and the number of nodules per plant.


2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.


1983 ◽  
Vol 23 (121) ◽  
pp. 181 ◽  
Author(s):  
SM Bromfield ◽  
RW Cumming ◽  
DJ David ◽  
CH Williams

Changes in soil pH, manganese and aluminium as a result of long periods under subterranean clover pasture were examined in soils formed on granite, basalt and sedimentary rocks near Goulburn, New South Wales. Decreases in the pH of yellow duplex soils formed on granite, sedimentary rocks and basalt had occurred to depths of 60, 40 and 30 cm, respectively. The smaller depth of acidification in the latter two soils is considered to be due to their shallower A horizons over well buffered, clay B horizons. Under the oldest pastures (55 years) the decreases exceeded one pH unit throughout the entire sampled depth (60 cm). In some soils, under old improved pastures, calcium chloride-extractable manganese had increased to more than 20 ppm throughout the 60 cm profile and to greater than 50 ppm in the surface 10 cm. These levels are considered toxic to sensitive plant species and the highest levels may be toxic to subterranean clover. The amounts of extractable manganese in soils appear to be determined by both pH and the amounts of reactive manganese. In general, the amounts of total and reactive manganese were appreciably higher in the soils of basaltic origin. Substantial increases in extractable and exchangeable aluminium had also accompanied the decrease in pH and, in the surface 10 cm, were greatest in the soils formed on sedimentary parent materials. In many of the soils under old improved pastures, exchangeable aluminium, as a percentage of the effective cation exchange capacity, now exceeds 12%, especially in the 5-10 cm layer, and is probably harmful to sensitive species. Increases in exchangeable aluminium also occurred below the surface 10 cm and, in the granitic soils under the oldest pastures, exchangeable aluminium accounted for 30-50% of the effective cation exchange capacity throughout the 5-50 cm soil depth. The adverse changes in pH, manganese and aluminium observed in this study can be expected to continue under many improved pastures and to generate soil conditions unsuitable for many agricultural plants. The use of lime to arrest or reverse these changes seems inevitable.


2018 ◽  
Vol 19 (1) ◽  
Author(s):  
M Mofizul Islam ◽  
Ian S. McRae ◽  
Soumya Mazumdar ◽  
Paul Simpson ◽  
Dennis Wollersheim ◽  
...  

2021 ◽  
Author(s):  
Jin Jin ◽  
Luoqi Wang ◽  
Karin Muller ◽  
Jiasen Wu ◽  
Hailong Wang ◽  
...  

Abstract Long-term monitoring shows intensive management can significantly change soil properties and cause soil degradation. Knowledge related to the spatio-temporal variation of soil properties and their influencing factors are important for nutrient management of economic forest plantation. Here, we conducted an intensive field investigation in Chinese hickory plantation to clarify the spatial and temporal variation of soil properties and its influencing factors, and to evaluate the change of soil fertility. The results showed that the soil pH and soil organic carbon (SOC) significantly increased from 2008 to 2018, while available N significantly decreased from 2008 to 2018. The semi-variance revealed that except available P, the spatial dependencies of soil properties increased from 2008 to 2018. An increasing south-north gradient was found for soil available N, available P, available K and SOC and a decreasing south-north gradient was found for soil pH. One-way ANOVA analysis showed that the change of soil properties from 2008 to 2018 was mainly influenced by anthropogenic factors. The average soil fertility in the whole area was at a medium level from 2008 to 2018. These change of soil properties can provide a reference basis for monitoring the effects of intensive management on soil environment.


2014 ◽  
Vol 281 (1783) ◽  
pp. 20132438 ◽  
Author(s):  
Micaela Martinez-Bakker ◽  
Kevin M. Bakker ◽  
Aaron A. King ◽  
Pejman Rohani

More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on childhood disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.


2002 ◽  
Vol 42 (7) ◽  
pp. 909 ◽  
Author(s):  
J. D. Croft ◽  
P. J. S. Fleming ◽  
R. van de Ven

Although there have been a number of studies that have examined the effects of rabbits on pasture, the relationship between rabbit density and pasture degradation caused by rabbits has never been quantified. An experiment was conducted at Cowra, New South Wales, from October 1984 to October 1987, to determine the impact various densities of rabbits have on pasture composition, indices of pasture biomass and ground cover. Using plots set stocked with the equivalent of 8 sheep/ha (the district average) and 4 densities of rabbits as treatments, 0,�24, 48 and 72 rabbits/ha, the consequences of rabbit grazing were investigated.Pasture composition changed with season, year and rabbit density. Cumulative effects were also evident. Rabbits severely depleted improved pastures of legumes (subterranean clover particularly), with grass cover increasing proportionate to rabbit density. In the final year of the experiment, the rabbit-free treatment had 31% legumes and 25.2% grasses, whereas the highest rabbit density treatment had 6.2% legumes and 47.4% grasses. Indices of pasture biomass were highest in the zero rabbits/ha treatment and lowest in the 72 rabbits/ha treatment. More bare soil was exposed in the highest rabbit density treatment. Once seasonal and year effects were accounted for, the relationship between rabbit density and percentage damage was positive.


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