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.

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.

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.

Rates of growth, potassium uptake, and changes in the potassium properties of four Queensland soils during intensive cropping by buffel grass, Cenchrus ciliaris

Soil Research ◽  
1975 ◽  
Vol 13 (2) ◽  
pp. 217 ◽  
Author(s):  
DC MacKay ◽  
JS Russell
Keyword(s):  
Potassium Deficiency ◽  
Potassium Uptake ◽  
Controlled Environment ◽  
Exchangeable Potassium ◽  
Cenchrus Ciliaris ◽  
Buffel Grass ◽  
Soil Potassium ◽  
Matter Production ◽  
Intensive Cropping ◽  
Rates Of Growth

Four Queensland soils were intensively cropped by buffel grass, Cenchrus ciliaris, in controlled environment growth rooms at three temperatures. Rates of growth (dry matter production) of tops and roots, of potassium uptake, and of changes in soil potassium properties were examined. With adequate potassium applied, growth rates for 31 weeks were nearly constant at 2.7, 2.6, 2.0, and 2.0 t/ha/week on a brigalow, grey clay, podzolic, and solodic soil, respectively. Without potassium, exchangeable potassium decreased quickly to a nearly common level on all soils, corresponding decreases occurred in the potassium content of tops and roots, and severe deficiencies with restricted yields soon resulted. Without applied potassium, moderate release of non-exchangeable potassium occurred on all soils during the first 4 weeks of cropping (0.10-0.18 m-equiv./100 g). Apparent fixation of potassium resulted in the succeeding 6-9 weeks, and, on the fine-textured soils (brigalow and grey clay) only, further slow release took place during the period of potassium deficiency when growth was slow. The overall release of non-exchangeable potassium by all four soils was small (0.02-0.16 m-equiv.1 100 g). Higher temperatures significantly increased yields of tops and roots, decreased the potassium concentration in the plants, increased the rate of depletion of exchangeable potassium, and had no effect on the release of non-exchangeable potassium. It is concluded that on these soils, particularly the solodic and podzolic, potassium deficiency will occur under intensive cropping.

RELEASE OF POTASSIUM BY 18 ONTARIO SOILS DURING CONTINUOUS CROPPING IN THE GREENHOUSE

1957 ◽  
Vol 37 (1) ◽  
pp. 1-10 ◽  
Author(s):  
J. A. Smith ◽  
B. C. Matthews
Keyword(s):  
Potassium Content ◽  
Continuous Cropping ◽  
Exchangeable Potassium ◽  
Luxury Consumption ◽  
Soil Potassium ◽  
Total Uptake ◽  
Close Relationship ◽  
Highly Correlated

Eighteen Ontario soils were ranked according to their capacity to supply potassium from non-exchangeable forms to eight successive crops of alfalfa. This capacity was found to be closely related to the percentage of clay in the soils. Potassium content of the alfalfa and total uptake of potassium were highly correlated with both exchangeable soil potassium and release of potassium from non-exchangeable forms. Exchangeable potassium levels below 100 lb. per acre gave low yields and potassium content of the crop. Excessively high exchangeable potassium levels resulted in luxury consumption of potassium by the crop or in fixation by the soil. In soils at or near their equilibrium exchangeable potassium levels, i.e., not heavily fertilized, there was a close relationship between potassium-supplying power and the exchangeable potassium content measured either before cropping commenced or at the end of the cropping period.

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).

The critical concentration of manganese in field-grown wheat

1985 ◽  
Vol 36 (2) ◽  
pp. 145 ◽  
Author(s):  
RD Graham ◽  
WJ Davies ◽  
JS Ascher
Keyword(s):  
Field Experiments ◽  
Critical Level ◽  
Critical Concentration ◽  
Optimal Growth ◽  
Mn Deficiency ◽  
Unreliable Method ◽  
Chlorophyll A Fluorescence Transients ◽  
Yield Responses ◽  
Fluorescence Transients ◽  
Wheat Tissues

The critical concentration of manganese (Mn) in wheat tissues for optimal growth was determined from field experiments. In the youngest emerged blade showing a ligule (YEB), the critical concentration was 11 � 1 8g g-1 (DW). The critical concentrations for older blades and whole tops were: next leaf below YEB, 13 � 1 8g g-1 DW; older leaves, 16 � 1 8g g-1 DW; whole tops, 12 � 1 8g g-1 DW. The older blades were less sensitive determinants of the growth response and are not recommended tissues for analysis. Diagnosis using whole tops was less sensitive than with YEB, but analysis of whole tops may give an integrated picture of Mn deficiency where availability varies rapidly with time. The critical concentration of 11 � 1 8g g-1 in the YEB for growth is also the critical level for the appearance in that leaf of normal chlorophyll a fluorescence transients. The Fo/Fv ratio, a parameter of the leaf fluorescence transients, correlated well with the Mn concentration in the leaf and may prove suitable for the diagnosis of Mn deficiency in field-grown wheat. The critical level of Mn was the same for two genotypes differing in their ability to tolerate Mn deficiency in the soil. Grain yield responses and other relevant data collected over three years are presented. Analysis of grain was shown to be an unreliable method of diagnosing an earlier Mn deficiency in the crop.

scholarly journals Predicting Response of Southeast Texas Loblolly Pine to Fertilization

2001 ◽  
Vol 25 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Gregoire Ngono ◽  
R.F. Fisher
Keyword(s):  
Loblolly Pine ◽  
Critical Level ◽  
Nutrient Status ◽  
Integrated System ◽  
Vector Analysis ◽  
Diagnostic Tools ◽  
Southeast Texas ◽  
Pinus Taeda L ◽  
The Cost ◽  
Soil Groups

Abstract The Diagnosis and Recommendation Integrated System (DRIS), vector analysis, and critical level approaches are diagnostic tools commonly used for assessing nutrient status of trees by foliar analysis. This study evaluated the relative merits of the three approaches for identifying N and P deficiencies in stands of loblolly pine (Pinus taeda L.) in southeast Texas. Only 25% of the time did all three approaches select the same stands as N deficient, and only once did they agree that a stand was N sufficient. The three approaches agreed 25% of the time that stands were P deficient and 13% of the time that stands were P sufficient. No method was universally accurate in predicting response across soil groups. The critical level approach proved best for identifying all responsive sites, and it would be useful if the cost of fertilization was deemed low in comparison with the cost of lost growth when responsive sites are not fertilized. The DRIS approach failed to identify some responsive sites, but a high proportion of the sites it predicted would respond, did respond. It would be useful if the cost of fertilization were deemed high in comparison with the cost of lost growth when responsive sites are not fertilized. The vector analysis approach proved most useful because of its ability to predict response to N and P when added together. Soil group alone was a reasonable predictor of response to fertilization. South. J. Appl. For. 25(2):84–87.

scholarly journals Forms and Dynamics of Soil Potassium in Acid Soil in the Wolaita Zone of Southern Ethiopia

2021 ◽  
Author(s):  
Mesfin Kassa ◽  
Wassie Haile ◽  
fassile kebede
Keyword(s):  
Land Use ◽  
Ammonium Acetate ◽  
Water Soluble ◽  
Land Use Type ◽  
Exchangeable Potassium ◽  
Management Options ◽  
Grazing Land ◽  
Soil Potassium ◽  
Crop Land ◽  
Land Use Types

Quantity-intensity characteristics are among conventional approaches for studying potassium dynamics and its availability; this was assessed to determine availability in four districts: namely, Sodo Zuria, Damot Gale, Damot Sore, and Boloso Sore at three different land use type viz., enset-coffee, crop land, and grazing land. There was water soluble, ammonium acetate, nitric acid extractable potassium, exchangeable potassium, and non-exchangeable potassium studied in soil samples, which were collected from 0-20 cm depth of each land type. The study revealed that water soluble and ammonium acetate extractable potassium concentrations ranged from 0.04 to 0.42 cmolKg-1 soils enset-coffee and grazing land use types, respectively. The study showed that exchangeable potassium constituted the highest proportion of available potassium, while the proportion of water soluble potassium was found to be the lowest. In this study, non-exchangeable potassium concentrations varied from 0.10 to 0.04cmolKg-1soils for enset-coffee, and crop and grazing land use type. Furthermore, available potassium and exchangeable potassium concentrations were positively correlated with OC(r=0.95***), cation exchange capacity, and sand and clay(r=0.98***). In addition, the K dynamics as impacted by land use types found that the highest change in exchangeable potassium (0.31cmolkg-1soils) and potential buffering capacity (1.79cmolkg-1soils) were noted in crop land use types, whereas the lowest change(1.26cmolkg-1 soils) was observed in the enset-coffee system, The varying properties, potassium status, dynamic and land use type of soils identified in the study areas provided adequate information to design soil potassium management options and further research about the soil in each site. Therefore, application of site specific soil fertility management practices and research can improve soil potassium status and quantity intensity parameters to sustain crop productive soils.

RELEASE OF NON-EXCHANGEABLE SOIL POTASSIUM BY RESIN-EQUILIBRATION AND ITS SIGNIFICANCE FOR CROP GROWTH

1962 ◽  
Vol 42 (2) ◽  
pp. 266-272 ◽  
Author(s):  
T. E. Barber ◽  
B. C. Matthews
Keyword(s):  
Linear Regression ◽  
Ammonium Acetate ◽  
Cation Exchange Resin ◽  
Yield Response ◽  
Exchangeable Potassium ◽  
Quadratic Regression ◽  
Potassium Fertilizer ◽  
Crop Response ◽  
Soil Potassium ◽  
The Difference

The non-exchangeable potassium released by soil after equilibration with cation-exchange resin was determined by extraction of the mixture with neutral ammonium acetate at room temperature and compared with a similar extraction in the absence of resin. The difference obtained following a 2-day equilibration period was called moderately-available potassium.Simple linear regression of yield on exchangeable potassium or exchangeable plus moderately-available potassium accounted for only 16 and 27 per cent respectively of the variability in yield response of corn, wheat, oats and potatoes to potassium fertilizer in the field. Multiple linear regression of yield on exchangeable and moderately-available potassium accounted for an average of 37 per cent of the variation in crop response; but a multiple quadratic regression of Log (100-per cent yield) on exchangeable and moderately-available potassium accounted for an average of 56 per cent of the variability in Log (100-per cent yield). Multiple quadratic regression of absolute yield or per cent yield on exchangeable and moderately-available potassium accounted for 46 and 50 per cent, respectively, of the variability in crop response to potassium fertilizer.

POTASSIUM-SUPPLYING POWER OF SOME CANADIAN SOILS

1961 ◽  
Vol 41 (2) ◽  
pp. 196-206 ◽  
Author(s):  
A. J. MacLean
Keyword(s):  
Exchange Resin ◽  
Initial Level ◽  
Water Soluble ◽  
Exchangeable Potassium ◽  
K Uptake ◽  
Soil Potassium ◽  
Surface Samples ◽  
Canadian Soils ◽  
Different Levels ◽  
Exchangeable Form

The amounts of exchangeable potassium in surface samples of 11 Canadian soils were significantly correlated with uptake of potassium by plants in the greenhouse. Per cent K-saturation and water-soluble potassium were indicative of the percentage of K-uptake that was derived from soil potassium in exchangeable form at the time of seeding.Amounts of non-exchangeable potassium extracted from the soils by repeated boiling in 1 N HNO3, by H-saturated exchange resin, and by continuous leaching with 0.01 N HCl were significantly correlated with each other and with the amounts of this form of potassium removed by plants.Following cropping, release of non-exchangeable potassium to exchangeable form during moist incubation of the samples for 112 days was slight. When samples containing different levels of exchangeable potassium were incubated moist for 13 months and then wetted and dried five times, potassium tended to be released to exchangeable form or converted to non-exchangeable form depending on initial level established. The degree of K-saturation at which potassium in six Ontario soils would be expected to be at equilibrium was estimated by regression to be 1.21 per cent. There was evidence that the degree of K-saturation for equilibrium in a Brown soil from Saskatchewan was at least 4.5 per cent.

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