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.

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.

EXCHANGEABLE AND WATER-SOLUBLE POTASSIUM IN SOILS AND DEGREE OF SATURATION IN RELATION TO TOMATO YIELDS

1959 ◽  
Vol 39 (2) ◽  
pp. 129-135 ◽  
Author(s):  
R. L. Halstead ◽  
H. B. Heeney
Keyword(s):  
Sandy Loam ◽  
Clay Content ◽  
Field Trials ◽  
Water Soluble ◽  
Degree Of Saturation ◽  
Yield Response ◽  
Clay Loam ◽  
Exchangeable Potassium ◽  
Potassium Fertilizer ◽  
Prince Edward County

In 33 field trials on soils varying in texture from sandy loam to clay loam in Prince Edward County, Ontario, exchangeable potassium, per cent potassium saturation, and water-soluble potassium were significantly correlated with yield response of tomatoes to potassium fertilizer on the sandy loam soils, but there was no correlation within the loam and clay loam groups. The mean c1 value in the modified Mitscherlich equation relating exchangeable potassium to yield response within the sandy loam group was 0.00555 and the coefficient of variation was 19.8 per cent. The corresponding coefficients for c1 values based on per cent potassium saturation and water-soluble potassium were of greater magnitude. The amounts of potassium soluble in boiling 1 N HNO3 were not related to yield response.Exchangeable potassium and the non-exchangeable form soluble in boiling 1 N HNO3 increased, whereas water-soluble potassium decreased with increasing clay content of the samples. Water-soluble potassium was significantly correlated with per cent potassium saturation within the sandy loam and loam groups.

AVAILABLE SOIL POTASSIUM AND FERTILIZER POTASSIUM FOR BRUSSELS SPROUTS

1971 ◽  
Vol 51 (3) ◽  
pp. 197-200 ◽  
Author(s):  
D. C. MUNRO ◽  
J. A. CUTCLIFFE
Keyword(s):  
Brassica Oleracea ◽  
Prince Edward Island ◽  
Ammonium Acetate ◽  
Potassium Concentration ◽  
Soil Analysis ◽  
Leaf Tissue ◽  
Tissue Analysis ◽  
Potassium Fertilizer ◽  
Brussels Sprouts ◽  
Soil Potassium

Brussels sprouts (Brassica oleracea var. gemmifera DC., Jade Cross) require no potassium fertilizer on Prince Edward Island soils if exchangeable soil K as determined by neutral 1 N ammonium acetate exceeds 100 ppm. Below 75 ppm exchangeable soil K, 186 kg K/ha must be applied for maximum yields. Potassium treatments increased yields at only three of 12 locations studied. Leaf tissue potassium concentration was significantly increased at all locations by the fertilizer treatments. Neutral 1 N ammonium acetate for determining exchangeable K was the best soil analysis extract among those tested for measuring available potassium. Tissue analysis gave no information beyond soil analysis for predicting potassium fertilizer requirements on any soil studied.

The movement of potassium in irrigated and fertilized red sandy clay

1940 ◽  
Vol 30 (3) ◽  
pp. 499-502 ◽  
Author(s):  
D. Lachower
Keyword(s):  
Irrigation Water ◽  
Soil Profile ◽  
Fertilizer Application ◽  
Water Soluble ◽  
Exchangeable Potassium ◽  
Potassium Fertilizer ◽  
Soil Potassium ◽  
Sandy Clay

The present investigation was intended to furnish information concerning:(1) The movement of water-soluble and exchangeable potassium in the soil profile after successive fertilizer applications.(2) The form of potassium—exchangeable, soluble, or non-exchangeable—into which added potassium fertilizer is converted in the soil.(3) The effect of doubling the fertilizer ration on the absorption of potassium by the soil; and the effect of doubling the ration of irrigation water on the absorption and accumulation of potassium in the soil.(4) The effect of frequent successive summer irrigation following fertilizer application on the distribution of the three forms of soil potassium.(5) The effect of fertilization followed by irrigation on soil pH. value.

scholarly journals Effect of potassium fertilization on its available and fixed content in vineyard soil

2002 ◽  
Vol 47 (1) ◽  
pp. 37-44 ◽  
Author(s):  
V. Licina ◽  
N. Markovic
Keyword(s):  
Ammonium Acetate ◽  
Extraction Methods ◽  
Fertilizer Application ◽  
First Year ◽  
Potassium Fertilizer ◽  
Brown Forest Soil ◽  
Soil Layers ◽  
Soil Potassium ◽  
K Fertilizer

The experiment was conducted on brown forest soil in the vineyard with Sauvignon blanc variety on Kober 5BB rootstock. During a thre- year experiment (1994-1996), potassium fertilizer was added in a dose of 0 kg K2O/ha, 50 kg K2O/ha, 100 kg K2O/ha, 150 K2O/ha respectively. After the determination of soil potassium content (1870-1920 mg K2O/100 g), its available form was monitored by using two different extraction methods (AL method and 1N ammonium-acetate extraction). The amount of extracted available K was not significant between the used methods, while the effect of fertilization was visible only at 150 kg/ha potassium rate during the first year in soil layers (30-60 cm, 60-90 cm). Also, another examined soil K fraction (fixed K+) was not affected by K fertilizer application.

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).

scholarly journals Status Pemanfaatan Perikanan Tuna Madidihang (Thunnus albacares) Berdasarkan Model Biologi Schaefer

2018 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
Abgusta Fajri Wiranata ◽  
Budy - Wiryawan ◽  
Sugeng Hari Wisudo ◽  
Nimmi - Zulbainarni
Keyword(s):  
Linear Regression ◽  
Population Growth ◽  
Growth Function ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Quadratic Regression ◽  
Maximum Production ◽  
The Difference ◽  
Tuna Fishery

<p><em>There are two types of population growth function  of the basic formulation of Schaefer’s biology model, however in this study there is a difference in form and value of “r” as one of a biology parameter.   In addition  to the difference in the method by calculating the process of a and b coefficient. The calculating process of a and b coefficient in Schaefer’s biology model was conducted through linear regression which has not yet been exact.  This is  due to  the model itself which is quadratic. Therefore to provide the solution is through quadratic process. The linear regression shows the value of f<sub>msy</sub></em> and <em>Y<sub>msy </sub>1.40 and 1.34 times smaller than quadratic process respectively. Based on the two graphs from the calculating process of a and b coefficient, it can be concluded that the utilization of yellowfin tuna fishery was still not optimal. According to the result based on the linear and quadratic regression, the maximum production of yellowfin tuna  can be increased to 664,037 and 877,340 kg.</em></p><p class="TubuhTulisanAll"><strong><em>Keywords:</em></strong><strong><em> </em></strong><em>Population growth function, Schaefer’s Biology Model,</em><em> </em><em>Utilization status</em>, <em>Yellowfin tuna</em></p><p class="TubuhTulisanAll"><em><br /></em></p><p align="center"><strong>ABSTRAK</strong></p><p>Dua jenis fungsi pertumbuhan populasi menjadi dasar pembentukan model biologi Schaefer, namun dalam kajian ini terdapat perbedaan dalam bentuk dan nilai <em>r</em> sebagai parameter biologi ditambah juga berdasarkan perbedaan metode perhitungan koefisien <em>a</em> dan <em>b</em>. Metode perhitungan koefisien <em>a</em> dan <em>b</em> model biologi Schaefer melalui regresi linear masih kurang tepat, karena model biologi Schaefer berbentuk kuadratik, sehingga penyelesaiannya harus melalui proses kuadratik. Nilai <em>f<sub>msy</sub></em> dan <em>Y<sub>msy</sub></em> dari proses regresi linear memiliki nilai 1,40 dan 1,34 kali lebih rendah dari proses kuadratik. Berdasarkan kedua kurva dari kedua metode perhitungan koefisien <em>a</em> dan <em>b</em>, maka status pemanfaatan perikanan tuna madidihang diduga masih belum optimal. Sehingga berdasarkan proses regresi linear dan kuadratik, maka produksi maksimal tuna madidihang masih dapat ditingkatkan sampai dengan 664.037 dan 877.340 kg.</p><p><strong>Kata kunci:</strong>  Fungsi pertumbuhan populasi, Model biologi Schaefer, Status pemanfaatan Tuna madidihang</p>

scholarly journals Feasibility study of assessing the Preclinical Alzheimer Cognitive Composite (PACC) score via videoconferencing

2021 ◽  
Author(s):  
Giulia Seghezzo ◽  
Yvonne Van Hoecke ◽  
Laura James ◽  
Donna Davoren ◽  
Elizabeth Williamson ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Clinical Practice ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Pearson Correlation ◽  
Cognitive Tests ◽  
Strong Positive Correlation ◽  
Pearson Correlation Coefficient ◽  
Face To Face ◽  
The Difference

Abstract Background The Preclinical Alzheimer Cognitive Composite (PACC) is a composite score which can detect the first signs of cognitive impairment, which can be of importance for research and clinical practice. It is designed to be administered in person; however, in-person assessments are costly, and are difficult during the current COVID-19 pandemic. Objective To assess the feasibility of performing the PACC assessment with videoconferencing, and to compare the validity of this remote PACC with the in-person PACC obtained previously. Methods Participants from the HEalth and Ageing Data IN the Game of football (HEADING) Study who had already undergone an in-person assessment were re-contacted and re-assessed remotely. The correlation between the two PACC scores was estimated. The difference between the two PACC scores was calculated and used in multiple linear regression to assess which variables were associated with a difference in PACC scores. Findings Of the 43 participants who were invited to this external study, 28 were re-assessed. The median duration in days between the in-person and the remote assessments was 236.5 days (7.9 months) (IQR 62.5). There was a strong positive correlation between the two assessments for the PACC score, with a Pearson correlation coefficient of 0·82 (95% CI 0·66, 0·98). The multiple linear regression found that the only predictor of the PACC difference was the time between assessments. Interpretation This study provides evidence on the feasibility of performing cognitive tests online, with the PACC tests being successfully administered through videoconferencing. This is relevant, especially during times when face-to-face assessments cannot be performed.

Weed Control with Reduced Rates of Chlorimuron Plus Metribuzin and Imazethapyr in No-Till Narrow-Row Soybean (Glycine max)

1998 ◽  
Vol 12 (1) ◽  
pp. 32-36 ◽  
Author(s):  
William G. Johnson ◽  
Jeffrey S. Dilbeck ◽  
Michael S. Defelice ◽  
J. Andrew Kendig
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Field Studies ◽  
Weed Suppression ◽  
Crop Response ◽  
Soybean Production ◽  
No Till ◽  
Giant Foxtail ◽  
The Difference ◽  
Narrow Row

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to combinations of glyphosate, metolachlor, 0.5 X and 1 X label rates of chlorimuron plus metribuzin applied prior to planting (PP), and 0.5 X and 1 X label rates of imazethapyr applied early postemergence (EPOST) or postemergence (POST) in no-till narrow-row soybean production. Giant foxtail densities were reduced with sequential PP followed by (fb) EPOST or POST treatments. Large crabgrass was reduced equivalently with all herbicide combinations involving chlorimuron plus metribuzin PP fb imazethapyr. Common cocklebur control was variable but was usually greater with treatments that included imazethapyr. Ivyleaf morningglory densities were not reduced with any herbicide combinations. Sequential PP fb EPOST or POST treatments tended to provide slightly better weed suppression than PP-only treatments, but the difference was rarely significant. Soybean yields with treatments utilizing 0.5 X rates were usually equal to 1 X rates.

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