Soil sulphate changes in the presence and absence of growing plants

1960 ◽  
Vol 11 (3) ◽  
pp. 339 ◽  
Author(s):  
JR Freney ◽  
K Spencer

To determine whether sulphate addition to sulphur-deficient soils affects mineralization of organic sulphur, an experiment was conducted in undrained pots with five soils of differing properties. Initial and final extractable soil sulphate (water-soluble and adsorbed), and sulphur taken up by Phalaris tuberosa L., were measured. Where plants were grown, mobilization of the organic sulphur occurred at the nil, 4 p.p.m., 12 p.p.m., and 36 p.p.m. levels of sulphate sulphur addition in four out of the five soils. In the fifth soil, a lateritic krasnozem, only at the nil and 4 p.p.m. levels was there any net release of sulphate. All five soils immobilized added sulphate at the 108 p.p.m. level. In the absence of plants, with one exception, no net mineralization of organic sulphur occurred following additions of sulphate. In the pots without added sulphate there was slight mineralization (less than under plants) in all soils but the lateritic krasnozem. The modifying effect of growing plants is obviously of great significance in the cycling of sulphur in soil. The relative intensity of immobilization and mineralization was affected by the presence of growing plants. This effect was probably due to the activities of rhizosphere microorganisms.

2021 ◽  
Vol 22 (1&2) ◽  
pp. 167-171
Author(s):  
Deepika Suri ◽  
V. K. Sharma ◽  
R. G. Upadhyay ◽  
Anjali K ◽  
Gazala Nazir ◽  
...  

The current investigation was conducted to study the fractions of sulphur in nine districts of low and mid hills of Himachal Pradesh. For this purpose 31 representative soil sampling sites were selected from nine districts and the soil samples were analyzed for physicochemical properties and different fractions of sulphur (water soluble sulphur, exchangeable sulphur, available sulphur, non-sulphate sulphur, organic sulphur and total sulphur). The results indicated that the total sulphur in soils varied from 98.2 to 470.1 mg kg-1 in surface soil (0-15 cm) and 67.2 to 370.7 mg kg-1 in sub-surface layer (15-60 cm). The organic sulphur varied from 80.5 to 401.1 mg kg-1 in surface and 44 to 306.1 mg kg-1 in sub-surface layer. The water soluble sulphur, exchangeable sulphur, available sulphur and non-sulphate sulphur varied from 1.7 to 9.2, 2.7 to 18.4, 4.5 to 27.6 and 10.2 to 58.9 mg kg-1 respectively in surface soil and 0.5 to 5.4, 1 to 17.7, 3.7 to 23.5 and 12.5 to 50.2 mg kg-1, respectively in sub-surface soil. It was observed during course of study that with increase in the soil depth the content of different fractions of sulphur decreased. These soils had the major part of their total sulphur content in organic form followed by non-sulphate sulphur, available sulphur, exchangeable sulphur and water soluble sulphur. It can be concluded that the soil texture and organic carbon content played a major role in determining the quantity of different fractions of sulphur in these soils.


2021 ◽  
Vol 901 (1) ◽  
pp. 012066
Author(s):  
A A Alferov ◽  
L S Chernova

Abstract The formation of spring wheat biomass on sod-podzolic soil is carried out mainly due to soil nitrogen, the share of which reaches 1/3 of the total removal of the element when using mineral fertilizers. Inoculation of spring wheat seeds with biologics of rhizosphere microorganisms increases the nitrogen content of fertilizers to 7.3%, increases its immobilization by 5.9-6.7% and reduces losses by 7.4-13.9%. The stability of the agroecosystem is characterized by nitrogen flows. During the growing season of spring wheat with a hydrothermal coefficient of 1.55-1.72, the amount of mineralized nitrogen (mineralization (M)), depending on fertilizers, reaches 9.4-11.1 g/m2, while the reimobilized nitrogen (reimobilization (RI)) – 2.2-3.1 g/m2, net-mineralized (net-mineralization (N-M)) – 6.8 - 8.0 g/m2. The use of nitrogen fertilizers and biological products leads the agroecosystem to the resistance mode (the maximum permissible level of exposure) (RI : M = 27-28%, N-M : RI = 2.5-2.7).


1971 ◽  
Vol 22 (3) ◽  
pp. 391 ◽  
Author(s):  
AR Till ◽  
PF May

Simultaneous measurements of sulphur content and specific radioactivity were made on soil fractions, two pasture species, and the fleece of grazing animals following the application of high specific radioactivity gypsum labelled with sulphur-35 (35S) to small randomly located sites in grazed pastures. The results show that the extractable soil sulphate was a precursor of plant sulphur and that the organic sulphur fractions in the soil were the source of replenishment of the extractable sulphate pool. Applied sulphur was shown to remain predominantly in the top 7.5 cm of the soil over a period of c. 600 days, and it was from this region that the plants drew their sulphur. The uptake of applied sulphur was initially different between plants of different species. These differences gradually decreased and finally disappeared as the applied sulphur became mixed into all soil sulphur fractions. A wide range of rates of mixing indicated that some fractions of the organic sulphur were recycling very slowly. Positive evidence of recycling of sulphur voided by the animals on the unlabelled areas of the pasture was found, and the rate of translocation of sulphur from the sites of its application to the remainder of the paddock was measured at two rates of stocking.


1959 ◽  
Vol 52 (2) ◽  
pp. 238-243 ◽  
Author(s):  
D. J. C. Jones

1. Three varieties of giant rape, two broad leaved Essex rapes, Hungry Gap Kale and Rape-Kale, were grown at two centres in mid-Wales. They were sampled in the early winter period and the samples divided into separate leaf and stem samples. These samples were used to calculate leaf to stem ratios on a green and dry-matter basis.2. The levels of the proximate constituents, silica, calcium, magnesium, phosphorus, sodium, potassium, chlorine, total sulphur, sulphate sulphur and ‘organic’ sulphur were determined in the dried samples. Whole plant values were calculated from the leaf and stem values with the appropriate leaf to stem ratios.3. The leaf values for ether extract, crude protein, silica-free ash, silica, calcium, phosphorus, magnesium, chlorine, total sulphur and ‘organic’ sulphur are higher than the corresponding stem values. For dry matter, crude fibre, nitrogen-free extractives and sodium the reverse is found, whilst for sulphate sulphur there is no definite distribution.4. There are no significant differences in composition between the main groups of varieties, and the rape-type kales are very similar to the other rapes in this respect.


1971 ◽  
Vol 22 (3) ◽  
pp. 443 ◽  
Author(s):  
PR Bird ◽  
ID Hume

In a 4 x 4 Latin square design experiment, sheep were fed on a basal ration which supplied 0.61 g sulphur per day, or the basal ration supplemented with 1.4 g inorganic sulphate sulphur, or 1.4 g cystine sulphur, or 1.4 g sulphate sulphur plus 1.4 g cystine sulphur per day. All forms of sulphur supplements increased the daily flow of protein sulphur from the rumen to the omasum (P < 0.05) above basal. Only the cystine treatments increased the flow of sulphide (P < 0.005), ester sulphate (P < 0.005), soluble organic sulphur (P < 0.05), and cystine (P < 0.05), and increased the ruminal sulphide concentrations above basal (P < 0.005). From 7.0 to 12.6% of the added cystine was not degraded in the rumen. In three animals less than 3 % of the added sulphate, alone or in combination with cystine, passed unchanged to the omasum. The fourth animal (67) differed from the others (P < 0.05): the added sulphate was poorly reduced in the rumen, and 62% reached the omasum unchanged. The sulphur composition of the digesta collected from the omasum was: protein sulphur, 55-70%; soluble organic sulphur, 13-22%; inorganic sulphate sulphur (excluding sheep 67), 2.2-2.6 %; ester sulphate sulphur, 1.8-3.4 %; and sulphide, 0.4-28%. Excluding sheep 67, 36% of the dietary sulphur was absorbed from the rumen when the sulphur was added as sodium sulphate or as cystine, and 50 % when added in both forms together. There was a net addition of 0.45 g sulphur per day to the rumen on the basal diet. The influence of the amount and the form of the dietary sulphur on the excretion of faecal and urinary sulphur fractions is discussed.


1989 ◽  
Vol 69 (3) ◽  
pp. 501-514 ◽  
Author(s):  
N. W. FOSTER

Net mineralization of sulfur (S) and nitrogen (N) and nitrification in an F(Oe) horizon were examined over a 16-wk period (May to September) with (a) buried bags, (b) lysimeters and (c) closed flasks at 10, 20 or 30 °C. The amount of [Formula: see text] plus [Formula: see text] extracted from soil held at 33 kPa tension over 16 wk, when extrapolated to the mass of soil in the field, was 30 kg ha−1 N and 9 kg ha−1[Formula: see text] at constant 20 °C in the flasks, and 33 kg ha−1 N and 4 kg ha−1[Formula: see text] in buried bags (mean daily temperature 15.2 °C). On the basis of lysimeter data there was a net release of only 8 kg ha−1 N and a net retention of 3 kg ha−1[Formula: see text] under field conditions, with fluctuating temperature and moisture and actively absorbing roots. Nitrate recovered from the three types of experiment was equivalent to 18, 36, and 4 kg ha−1 N, respectively. Mineralization appeared to be particularly sensitive to temporal changes in average daily temperatures in the field. The late-summer peak in mean daily forest-floor temperature triggered a shift from net mineralization to net immobilization of N. Key words: Soil temperature, forest floor, sulfate, ammonium, nitrate


2003 ◽  
Vol 39 (4) ◽  
pp. 395-407 ◽  
Author(s):  
M. W. WAIGWA ◽  
C. O. OTHIENO ◽  
J. R. OKALEBO

Most of the agricultural lands in the highlands of western Kenya are depleted of plant nutrients, particularly phosphorus. This depletion has resulted in a continued decline in crop production in the area. Recent experiments, in which direct application of indigenous phosphate rocks were evaluated, have yielded variable results, depending on the relative reactivity of the rock phosphate tested. The effectiveness of rock phosphate was generally low compared with fertilizers such as triple super phosphate. This is attributed to the relatively low solubility of the rocks as opposed to the readily water soluble phosphorus fertilizers. Phosphate rocks are available locally and are cheaper than triple super phosphate. If the solubility of these phosphate rocks could be improved, the resource-poor smallholder farmers in western Kenya would have an affordable source of phosphorus for their crops. Greenhouse and field experiments were conducted to evaluate the effects of combining different on-farm organic materials with the Minjingu rock phosphate (from Tanzania) on the availability of phosphorus to maize (Zea mays) in western Kenya. The greenhouse results indicated that there were significant positive linear relationships between rock phosphate application rates and (i) the Olsen-extractable soil phosphorus in the soil samples taken four weeks and nine weeks respectively after the application of the treatments; (ii) the dry matter yield, and (iii) phosphorus uptake. Results of the field experiments showed that rock phosphate combined with farmyard manure or crop residues (maize stover) generally increased the Olsen-extractable soil phosphorus, maize yields and phosphorus uptake, particularly in the first season when both the Minjingu rock phosphate and organic materials were applied, but the effectiveness of the materials and their combinations varied between the two sites. Combining Minjingu rock phosphate with the organic materials improved its relative agronomic effectiveness for maize.


1958 ◽  
Vol 9 (4) ◽  
pp. 483 ◽  
Author(s):  
CJ Williams ◽  
A Steinbergs

One hundred and fifty-five soils of differing soil types and collected from a wide range of parent materials, climatic conditions, and topography were examined for carbon, nitrogen, sulphur, and phosphorus. A close relationship between carbon, nitrogen, and non-sulphate sulphur was found, although alkaline soils contained a slightly higher relative proportion of non-sulphate sulphur than did acid soils. Water-soluble sulphate comprised only a small proportion of the total sulphur in the majority of the soils. Organic phosphorus, although correlated with carbon and nitrogen, showed much wider variation than did sulphur, and it seemed likely that part at least of the organic phosphorus was not closely associated with the carbon, nitrogen, and sulphur in the soil organic matter. The mean relative proportions of carbon, nitrogen, non-sulphate sulphur, and organic phosphorus were 150: 10: 1.26: 0.66.


Author(s):  
J. G. Robertson ◽  
D. F. Parsons

The extraction of lipids from tissues during fixation and embedding for electron microscopy is widely recognized as a source of possible artifact, especially at the membrane level of cell organization. Lipid extraction is also a major disadvantage in electron microscope autoradiography of radioactive lipids, as in studies of the uptake of radioactive fatty acids by intestinal slices. Retention of lipids by fixation with osmium tetroxide is generally limited to glycolipids, phospholipids and highly unsaturated neutral lipids. Saturated neutral lipids and sterols tend to be easily extracted by organic dehydrating reagents prior to embedding. Retention of the more saturated lipids in embedded tissue might be achieved by developing new cross-linking reagents, by the use of highly water soluble embedding materials or by working at very low temperatures.


Author(s):  
J. D. McLean ◽  
S. J. Singer

The successful application of ferritin labeled antibodies (F-A) to ultrathin sections of biological material has been hampered by two main difficulties. Firstly the normally used procedures for the preparation of material for thin sectioning often result in a loss of antigenicity. Secondly the polymers employed for embedding may non-specifically absorb the F-A. Our earlier use of cross-linked polyampholytes as embedding media partially overcame these problems. However the water-soluble monomers used for this method still extract many lipids from the material.


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