Assessing the availability of potassium in soils

1981 ◽  
Vol 21 (112) ◽  
pp. 543 ◽  
Author(s):  
AM Graley
Keyword(s):  
Nitric Acid ◽  
Root System ◽  
Perennial Ryegrass ◽  
Podzolic Soil ◽  
Subterranean Clover ◽  
Root Systems ◽  
Exchangeable Potassium ◽  
Soil Potassium ◽  
Whole Plant ◽  
Total Potassium

Two forms of depletion cropping were examined. Perennial ryegrass was continuously cropped on two contrasting soils in pots. Simultaneously, repeated crops of ryegrass, subterranean clover, and marrow-stem kale were grown by a modified system of depletion cropping in which the whole plant was harvested and the soil sampled before being repotted for further crops. Fractions of soil potassium determined by chemical extractions were compared with the results from depletion cropping. Although the modified system needed added attention, particularly between crops, the available potassium was well exploited because of the thorough mixing of the soil. A further benefit was that the depletion of potassium in soils and plants could be followed progressively. Different root systems of the plant species greatly influenced the total potassium uptake. Reserves of initially non-exchangeable potassium contributed much to the uptake while decrease in soil potassium measured by repeated nitric acid extractions ranged from 63 to 80% of the uptake. Ryegrass with its dense root system was able to take up more non-exchangeable potassium from a yellow podzolic soil than clover and kale.

The build-up of available potassium under subterranean clover pastures on a podzolic soil

1960 ◽  
Vol 11 (4) ◽  
pp. 473 ◽  
Author(s):  
CH Williams ◽  
J Lipsett
Keyword(s):  
Laboratory Experiments ◽  
Podzolic Soil ◽  
New South ◽  
Subterranean Clover ◽  
Exchangeable Potassium ◽  
Podzolic Soils ◽  
Soil Potassium ◽  
South Wales ◽  
Pasture Plants ◽  
Pot Culture

A group of podzolic soils from the Crookwell district of New South Wales was examined for potassium status by field, pot culture, and laboratory experiments. Close relationships were found between the exchangeable potassium and the potassium content of the plant material and uptake of potassium both in the field and in pot culture. However, the measured decreases in exchangeable potassium in soil during plant growth were insufficient to account for the total uptake, indicating that other sources of soil potassium were also available. It is probable that the pasture plants themselves contribute to the conversion of non-exchangeable potassium to exchangeable forms. The results suggest that the range 0.25–0.30 m-equiv. exchangeable potassium per 100 g may be critical for these soils. Exchangeable potassium built up under the subterranean clover pastures plays an important part in eliminating a potential potassium deficiency. Removal of hay from these pastures would seriously deplete this available potassium reserve.

THE EFFECTS OF AMMONIUM NITRATE AND UREA ON THE RELEASE OF NON-EXCHANGEABLE POTASSIUM BY EIGHT EASTERN PRAIRIE SOILS DURING CONTINUOUS CROPPING IN THE GREENHOUSE

1974 ◽  
Vol 54 (3) ◽  
pp. 255-263 ◽  
Author(s):  
L. D. BAILEY
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Content ◽  
Plant Material ◽  
Total Yield ◽  
Continuous Cropping ◽  
Exchangeable Potassium ◽  
Total N ◽  
Prairie Soils ◽  
Soil Potassium ◽  
Total Potassium

Continuous cropping of eight Manitoba soils to alfalfa in the greenhouse decreased the exchangeable potassium of the soils to low equilibrium levels. Non-exchangeable potassium was removed from the soils by the alfalfa. The rate of decrease of exchangeable potassium and the quantity of non-exchangeable potassium mobilized was significantly influenced by the addition of ammonium nitrate or urea to the soils. However, there were no significant differences between the soils treated with ammonium nitrate and those treated with urea. There was considerable variation among soils in the rate of decrease of exchangeable potassium and the quantity of non-exchangeable potassium mobilized. The total yield of soil potassium was related to the initial exchangeable potassium levels of the soils. Addition of NH4NO3 increased the percentage of total N in the plant material harvested prior to the eighth harvest. After this eighth harvest the added nitrogen had no effect on the nitrogen content of the harvested material. In general, fine-textured soils yielded more plant material and total potassium, and maintained a higher level of exchangeable potassium than coarse-textured soils.

The availability of potassium in some Tasmanian soils. I. The variability of soil potassium in the field and its fractionation

1960 ◽  
Vol 11 (5) ◽  
pp. 750
Author(s):  
AM Graley ◽  
KD Nicholls ◽  
CS Piper
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Soil Type ◽  
Field Experiments ◽  
Sandy Loam ◽  
Water Soluble ◽  
Soluble Form ◽  
Exchangeable Potassium ◽  
Exchangeable Fraction ◽  
Total Potassium

The potassium status of Frodsley sandy loam and some associated soils from the Fingal district, north-eastern Tasmania, has been investigated. Regularly spaced sampling of surface soils on a rectilinear grid pattern disclosed a variability of exchangeable potassium values in the field much greater than recorded for soils elsewhere; even for 3-ft spacings there was a sevenfold range. The need for adequate sampling of experimental areas is stressed. The median value for exchangeable potassium in the A1 horizon of Frodsley sandy loam was 0.31 m-equiv./100 g for "developed" areas and 0.35 m-equiv./100 g for "undeveloped" areas. Values for the A2 horizon were closely correlated with those for the corresponding surface horizon, but only about one-third as high. The amounts in the B horizon tended to approximate to those in the A1 horizon except for soils with high values in the surface. The potassium-supplying capacity of the soils was assessed by fractionation of the potassium into water-soluble, exchangeable, difficultly exchangeable, hydrochloric acid-soluble, and total potassium. In Frodsley sandy loam approximately 35 per cent. of the exchangeable potassium appeared in the water-soluble form, which suggested that there may be moderate losses from this soil by leaching. Ten minutes' boiling with normal nitric acid released only about 90 per cent. more potassium than was present in the exchangeable fraction. Boiling normal nitric acid extracted much less potassium from some samples of this soil type than did cold normal ammonium chloride from others, because of the great variability of exchangeable potassium. Concentrated hydrochloric acid dissolved a further 0.60.7 m-equiv./100 g on the average. These low values for the two latter fractions are taken to indicate the poverty of this soil type in reserves of potassium and, with the relatively low values for the exchangeable fraction, explain the widespread responses to potassium reported in field experiments. Examination of the minerals of the clay fraction of Frodsley sandy loam supported the chemical data in regard to the poor potassium status of these soils. Separation of sand, silt, and clay from the B horizons of two profiles showed that much of the total potassium was present in the coarser fractions of the soil. Type A, a soil associated with Frodsley sandy loam on river terraces, had a similar potassium status. Soils formed on dolerite were significantly higher in all categories of potassium.

The use of chemical extractions and continuous cropping to measure the potassium status of soils

1978 ◽  
Vol 29 (6) ◽  
pp. 1247 ◽  
Author(s):  
AM Graley
Keyword(s):  
Nitric Acid ◽  
Critical Level ◽  
Potassium Uptake ◽  
Continuous Cropping ◽  
Exchangeable Potassium ◽  
Soil Potassium ◽  
Chemical Extractions ◽  
Plant Yields ◽  
Yield Responses ◽  
Soil Groups

Soil potassium, measured by simple chemical extractions, was compared with potassium availability assessed during continuous cropping of perennial ryegrass in pots, on 12 surface soils representing four Tasmanian soil groups. For three soil groups with mainly kaolinitic clay, potassium uptake by the plant (the main measure of potassium availability) was related to a decrease in the potassium extracted from the soil by boiling lM nitric acid during the experiment. The decrease in soil potassium extracted by repeated nitric acid digestions averaged 95% of the total potassium uptake. However, a large and rapid uptake from the illitic yellow podzolics was only partly assessable by chemical extractions. For all soils, much of the large amount of potassium taken up early was stored in the plant roots and transferred to the tops much later. Plant yields were related to exchangeable potassium only within soil groups; over most soils they were related to nitric acid-soluble potassium. Yield responses to added potassium usually occurred when exchangeable potassium became depleted to a critical level of 0.2–0.25 m-equiv./100 g or nitric acid-soluble potassium to 0.4–0.7 m-equiv./100 g. The critical level of potassium in ryegrass tops was 0.5–0.8%. On average nearly two-thirds of the potassium released from soils came from exchangeable sources. Potassium initially non-exchangeable was differentiated into quickly released 'intermediate' potassium and slowly released 'constant rate' potassium. Release of intermediate potassium predominated from the yellow podzolics and from one non-calcic brown soil with much randomly interstratified material in its clay.

Premières données sur l'architecture comparée des systèmes racinaires et caulinaires

1994 ◽  
Vol 72 (7) ◽  
pp. 963-975 ◽  
Author(s):  
Claire Atger ◽  
Claude Edelin
Keyword(s):  
Key Words ◽  
Root System ◽  
Woody Plants ◽  
Functional Organization ◽  
Root Systems ◽  
Architectural Analysis ◽  
Tree Crowns ◽  
Tree Root System ◽  
Whole Plant ◽  
Architectural Patterns

Since 1970, the architectural analysis of woody plants has given much information about structural and functional organization of tree crowns, their development, and reiteration patterns. In this study, we have extended this method to tree root systems. We describe the whole architecture of three species and we compare their root system and crown architectural patterns. Key words: architecture, tree, root system, crown, whole plant.

scholarly journals POTASSIUM FORMS STATUS IN SOME DESERT TORRIFLUVENTS SOIL AND EFFECT OF CULTIVATION ON IT

2017 ◽  
Vol 48 (2) ◽  
Author(s):  
R. A. Al-Tamimi
Keyword(s):  
Nitric Acid ◽  
Sulphuric Acid ◽  
Potassium Concentration ◽  
Soil Samples ◽  
Arid Soils ◽  
Exchangeable Potassium ◽  
Surface Soils ◽  
Total Potassium ◽  
Semi Arid

This research was conducted to study potassium status and forms in some desert Torrifluvents soil, from south of Libya and to clarify the effect of cultivation on its forms. Composite soil samples were collected from surface soils (0-30 cm) of some cultivated fields and from larva regions besides these fields. Various forms of potassium were determined i.e. soluble-K, NH4OAC extractable-K, reserve-K, sulphuric acid-K, boiling nitric acid-K to determine primary step-K and total step-K, and total K. Results indicated that all soils have high content of soluble and exchangeable potassium, and within the range of arid and semi–arid soils. Reserve-K was ranged between 0.359– 3.422 cmol kg-1 with an average of 1.702 and 2.637 cmol kg-1 in cultivated and virgin soils respectively. All soils had low content of primary step which ranged between 0.214-1.294 cmol kg-1 with an average of 0.522 and 0.926 cmol kg-1 in cultivated and virgin soils respectively. Total step potassium was ranged between 0.982–5.995 cmol kg-1 with average of 2.480 and 3.765 cmol kg-1 for cultivated and larva soils respectively. Total potassium concentration was between 15.16–36.71 and 23.53-30.06 cmol kg-1 with average of 24.52 and 26.38 in cultivated and virgin soils respectively. All forms of potassium were decreased as a result of cultivation. Apart from K-HCl and total K, the rest forms of potassium were significantly correlated with each other's.

Studies on soil potassium. II. The Q/I relation and other parameters compared with plant uptake of potassium

Soil Research ◽  
1972 ◽  
Vol 10 (1) ◽  
pp. 95 ◽  
Author(s):  
IF Fergus ◽  
AE Martin ◽  
IP Little ◽  
KP Haydock
Keyword(s):  
Exchange Resin ◽  
Clay Fraction ◽  
Cation Exchange Resin ◽  
Mean Value ◽  
Potassium Uptake ◽  
Exchangeable Potassium ◽  
Soil Potassium ◽  
Setaria Sphacelata ◽  
Total Potassium ◽  
Equilibrium Activity

Setaria (Setaria sphacelata cv. Nandi) was grown in 10 surface soils, of contrasting properties, in pots until (after repeated harvesting of tops) plant growth virtually ceased. Uptake of potassium by tops and roots was correlated with change in exchangeable potassium during cropping, initial exchangeable potassium, and with quantities of potassium predicted from the immediate Q/I relations of the soils. Some initially non-exchangeable potassium was absorbed from seven of the soils by the plants, such that these soil quantity parameters (which were statistically equivalent) predicted two-thirds of the total potassium uptake averaged over all soils. Potassium uptake was also correlated with soil potassium soluble in constant-boiling hydrochloric acid, and with potassium extracted by a cation exchange resin (both of which predicted about twice the plant absorption). For six of the soils, uptake of initially non-exchangeable potassium was correlated with the quantity of total potassium present in each pot in the 1 0 . 1 pm clay fraction. The intensity of soil potassium (measured in dilute calcium chloride solution from the immediate Q/I relation) was reduced on all soils by exhaustive cropping to a mean value for the equilibrium activity ratio (AR0) of 4.7 10-4 mole1/2 L.-1/2 (�G = -4500 cal equiv.-1); it was suggested that the observed variations in this value were unlikely to prohibit its use for practical soil testing, except for the prediction of the quantity parameter for those soils for which the form of the isotherm is altered by cropping. A tentative value for the potential of soil potassium at which setaria has an adequate average potassium concentration in its tops was - 3600 cal equiv.-1 (AR0 2.1 x 10-4 mole1/2 L.-1/2).

Biochemical Composition and Phosphorus Use Efficiency in Some Mixtures

2016 ◽  
Vol 5 (07) ◽  
pp. 4694 ◽  
Author(s):  
Viliana Vasileva ◽  
Anna Ilieva
Keyword(s):  
Perennial Ryegrass ◽  
Biochemical Composition ◽  
Plant Biomass ◽  
Soluble Sugars ◽  
Subterranean Clover ◽  
Water Soluble ◽  
Birdsfoot Trefoil ◽  
Phosphorus Use Efficiency ◽  
Forage Crops ◽  
Use Efficiency

In pot trial the biochemical composition and phosphorus use efficiency of birdsfoot trefoil, sainfoin and subterranean clover grown pure and in mixtures with perennial ryegrass in the next ratios were studied in the Institute of Forage Crops, Pleven, Bulgaria: birdsfoot trefoil + perennial ryegrass (50:50%); sainfoin + perennial ryegrass (50:50%); subterranean clover + perennial ryegrass (50:50%); birdsfoot trefoil + subterranean clover + perennial ryegrass (33:33:33%); sainfoin + subterranean clover + perennial ryegrass (33:33:33%). The highest crude protein content was found in the aboveground mass of birdsfoot trefoil (19.17%) and sainfoin (19.30%). The water soluble sugars contents in mixtures was found higher compared to the pure grown legumes. Birdsfoot trefoil showed the highest phosphorus use efficiency for plant biomass accumulation and nodules formation. In mixtures the phosphorus use efficiency was found be higher as compared to the same in pure grown legumes.

scholarly journals Clifford Spinors and Root System Induction: $$H_4$$ and the Grand Antiprism

2021 ◽  
Vol 31 (3) ◽  
Author(s):  
Pierre-Philippe Dechant
Keyword(s):  
Root System ◽  
Root Systems ◽  
Invariant Sets ◽  
Simple Construction ◽  
Reflection Groups ◽  
Computational Work ◽  
Algebraic Framework ◽  
Underlying Geometry ◽  
Coxeter Plane ◽  
Insight Into

AbstractRecent work has shown that every 3D root system allows the construction of a corresponding 4D root system via an ‘induction theorem’. In this paper, we look at the icosahedral case of $$H_3\rightarrow H_4$$ H 3 → H 4 in detail and perform the calculations explicitly. Clifford algebra is used to perform group theoretic calculations based on the versor theorem and the Cartan–Dieudonné theorem, giving a simple construction of the $${\mathrm {Pin}}$$ Pin and $${\mathrm {Spin}}$$ Spin covers. Using this connection with $$H_3$$ H 3 via the induction theorem sheds light on geometric aspects of the $$H_4$$ H 4 root system (the 600-cell) as well as other related polytopes and their symmetries, such as the famous Grand Antiprism and the snub 24-cell. The uniform construction of root systems from 3D and the uniform procedure of splitting root systems with respect to subrootsystems into separate invariant sets allows further systematic insight into the underlying geometry. All calculations are performed in the even subalgebra of $${\mathrm {Cl}}(3)$$ Cl ( 3 ) , including the construction of the Coxeter plane, which is used for visualising the complementary pairs of invariant polytopes, and are shared as supplementary computational work sheets. This approach therefore constitutes a more systematic and general way of performing calculations concerning groups, in particular reflection groups and root systems, in a Clifford algebraic framework.

Sign in / Sign up

Export Citation Format

Share Document