Forms of potassium in the profiles of two long-term experiments in relation to K nutrition of crops

1985 ◽  
Vol 105 (1) ◽  
pp. 209-212
Author(s):  
A. N. Ganeshamurthy ◽  
C. R. Biswas ◽  
Bhajan Singh
Keyword(s):  
Relative Rate ◽  
Water Soluble ◽  
Continuous Cropping ◽  
Potassium Fertilizer ◽  
Leaching Losses ◽  
Soil Potassium ◽  
Image Position ◽  
Discernible Difference ◽  
Exchangeable Form

Potassium occurs in soils in four different forms, namely water-soluble, exchangeable, nonexchangeable and mineral (Reitemeir, 1951; Munson & Nelson, 1963). Water-soluble and exchangeable forms are considered to be directly available to plants. Under continuous cropping one may therefore expect depletion of these two forms, but in fact not much discernible difference in the amounts of available K was observed even after a few crops had been grown. Hence several people have stated that there exists an equilibrium among the following forms of KThis equilibrium implies that a change in magnitude of a form is compensated by the movement from, to and among other forms (Reitemeir, 1951; Garman, 1957; Munson & Nelson, 1963; Chevalier, 1971). If water-soluble and exchangeable forms of K are removed by crops more potassium would become exchangeable from non-exchangeable forms (Maurya & Ghosh, 1972). Whether soils when cropped can maintain the level of exchangeable K depends upon the type of soil, nature and intensity of cropping, the relative rate of removal and release from non-exchangeable form. Continuous cropping therefore alters the existing equilibrium of soil potassium in the profile as crop roots penetrate as deep as 2 m. Since all the potassium fertilizer for a crop is applied at sowing, the temporary overloading of the system may cause leaching losses of K in light soils. This may result in the enrichment of deeper layers.

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.

scholarly journals Potassium status of sod-podzolic loamy soils

2021 ◽  
Vol 2(26) ◽  
pp. 233-243
Author(s):  
V.G. Sychev ◽  
◽  
L.V. Nikitina ◽  
Keyword(s):  
Field Experiments ◽  
Soil Samples ◽  
Exchangeable Potassium ◽  
Soil Potassium ◽  
Experimental Station ◽  
Organic Mineral ◽  
Term Field ◽  
Exchangeable Form

Potassium is one of the essential plant nutrients. Despite numerous surveys, some issues related to the transformation of potassium in soils require additional study. The purpose of the research was to study the potassium transformation in sod-podzolic loamy soils and its entry into plants influenced by various farming methods in long-term field experiments of different duration. Field experiments were conducted at the experimental station of the FSBSI “Pryanishnikov Institute of Agrochemistry” located in the Moscow region, Domodedovo district, village of Barybino. To study the potassium status, an archive of soil samples created in the Geographical Network of Experiments with Fertilizers was used. Soil samples were collected in long-term field experiments after their closure (experiment SH-8, year of laying – 1971–1973, duration – 14 years) or modification (experiment SH-5, year of laying – 1964-1966, duration – 28 years). The experimental schemes included the systematic introduction of various fertilizing systems (organic, mineral, organo-mineral) and the determination of their impact on crop rotation productivity and soil fertility. Previous studies have shown that the formation of the crop yield in the context of long-term potassium deficiency burdened by the absence of fertilization was chiefly due to the consumption of non-exchangeable potassium by plants. For the 14–year period, the annual use of non-exchangeable potassium in the control and NP variants was 62.0-63.0 kg K2O/ha. As potassium reserves in the soil of the control variant become depleted (longer experiment), its assimilation from the non-exchangeable form decreased by 1.6 times and amounted to 39.5 kg K2O/ha. The use of a mineral fertilizing system (potassium dose < 90 kg/ha for 14 years) increased the annual mobilization of the non-exchangeable form of the element (over 100 kg/ha of K2O). The transformation of soil potassium forms that differed in the degree of their availability for plants was determined by the fertilizing systems, the doses of potassium fertilizers in the systems, as well as the duration of the experiments.

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.

Effect of long-term potassium application on irrigated soil potassium and on the yield and nutrient of crops

2010 ◽  
Vol 17 (4) ◽  
pp. 625-629 ◽  
Author(s):  
De-Shui TAN ◽  
Ji-Yun JIN ◽  
Shao-Wen HUANG ◽  
Zhao-Hui LIU ◽  
Li-Hua JIANG
Keyword(s):  
Soil Potassium ◽  
Potassium Application

scholarly journals Selection Response in Finite Populations

Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1961-1974 ◽  
Author(s):  
Ming Wei ◽  
Armando Caballero ◽  
William G Hill
Keyword(s):  
Linkage Disequilibrium ◽  
Inbreeding Depression ◽  
Genetic Variance ◽  
Relative Rate ◽  
Selection Response ◽  
Rate Of Change ◽  
Effective Population ◽  
Short Term ◽  
Model Account

Formulae were derived to predict genetic response under various selection schemes assuming an infinitesimal model. Account was taken of genetic drift, gametic (linkage) disequilibrium (Bulmer effect), inbreeding depression, common environmental variance, and both initial segregating variance within families (σAW02) and mutational (σM2) variance. The cumulative response to selection until generation t(CRt) can be approximated asCRt≈R0[t−β(1−σAW∞2σAW02)t24Ne]−Dt2Ne,where Ne is the effective population size, σAW∞2=NeσM2 is the genetic variance within families at the steady state (or one-half the genic variance, which is unaffected by selection), and D is the inbreeding depression per unit of inbreeding. R  0 is the selection response at generation 0 assuming preselection so that the linkage disequilibrium effect has stabilized. β is the derivative of the logarithm of the asymptotic response with respect to the logarithm of the within-family genetic variance, i.e., their relative rate of change. R  0 is the major determinant of the short term selection response, but σM2, Ne and β are also important for the long term. A selection method of high accuracy using family information gives a small Ne and will lead to a larger response in the short term and a smaller response in the long term, utilizing mutation less efficiently.

scholarly journals Effects of Sugar Cane Molasses Addition on the Fermentation Quality, Microbial Community, and Tastes of Alfalfa Silage

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 355
Author(s):  
Runbo Luo ◽  
Yangdong Zhang ◽  
Fengen Wang ◽  
Kaizhen Liu ◽  
Guoxin Huang ◽  
...  
Keyword(s):  
Sugar Cane ◽  
Ph Value ◽  
Electronic Tongue ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Cane Molasses ◽  
Fermentation Quality ◽  
Alfalfa Silage ◽  
Additive Control

The objective was to study the effects of sugar cane molasses addition on the fermentation quality and tastes of alfalfa silage. Fresh alfalfa was ensiled with no additive (Control), 1% molasses (M1), 2% molasses (M2), and 3% molasses (M3) for 206 days. The chemical composition and fermentation characteristics of the alfalfa silages were determined, the microbial communities were described by 16S rRNA sequencing, and the tastes were evaluated using an electronic tongue sensing system. With the amount of added molasses (M), most nutrition (dry matter and crude protein) was preserved and water-soluble carbohydrates (WSC) were sufficiently used to promote the fermentation, resulting in a pH reduction from 5.16 to 4.48. The lactic acid (LA) content and LA/acetic acid (AA) significantly increased, indicating that the fermentation had turned to homofermentation. After ensiling, Enterococcus and Lactobacillus were the dominant genus in all treatments and the undesirable microbes were inhibited, resulting in lower propionic acid (PA), butyric acid (BA), and NH3-N production. In addition, bitterness, astringency, and sourness reflected tastes of alfalfa silage, while umami and sourness changed with the amount of added molasses. Therefore, molasses additive had improved the fermentation quality and tastes of alfalfa silage, and the M3 group obtained the ideal pH value (below 4.5) and the best condition for long-term preservation.

Research into water-soluble salts in efflorescent pottery during long-term storage in a museum

2014 ◽  
Vol 89 ◽  
pp. 268-274 ◽  
Author(s):  
Pujun Jin ◽  
Weiqiang Zhang ◽  
Quanjun Wang ◽  
Xiaogang Yang ◽  
Sheng Sun ◽  
...  
Keyword(s):  
Water Soluble ◽  
Soluble Salts ◽  
Long Term Storage ◽  
Term Storage

scholarly journals Adsorption of heavy metals by road deposited solids

2013 ◽  
Vol 67 (11) ◽  
pp. 2622-2629 ◽  
Author(s):  
Chandima Gunawardana ◽  
Ashantha Goonetilleke ◽  
Prasanna Egodawatta
Keyword(s):  
Heavy Metals ◽  
Kinetic Studies ◽  
Field Studies ◽  
Water Soluble ◽  
Trivalent Cation ◽  
Urban Road ◽  
High Charge Density ◽  
Road Surfaces ◽  
Adsorption Desorption ◽  
Exchangeable Form

The research study discussed in the paper investigated the adsorption/desorption behaviour of heavy metals commonly deposited on urban road surfaces, namely, Zn, Cu, Cr and Pb, for different particle size ranges of solids. The study outcomes, based on field studies and batch experiments, confirmed that road deposited solids particles contain a significantly high amount of vacant charge sites with the potential to adsorb additional heavy metals. Kinetic studies and adsorption experiments indicated that Cr is the most preferred metal element to associate with solids due to the relatively high electronegativity and high charge density of trivalent cation (Cr3+). However, the relatively low availability of Cr in the urban road environment could influence this behaviour. Comparing total adsorbed metals present in solids particles, it was found that Zn has the highest capacity for adsorption to solids. Desorption experiments confirmed that a low concentration of Cu, Cr and Pb in solids was present in water-soluble and exchangeable form, whilst a significant fraction of adsorbed Zn has a high likelihood of being released back into solution. Among heavy metals, Zn is considered to be the most commonly available metal among road surface pollutants.

From one ritual to another: the long-term sequence of the Bury gallery grave (northern France, fourth–second millennia BC)

Antiquity ◽  
2017 ◽  
Vol 91 (355) ◽  
pp. 57-73
Author(s):  
Laure Salanova ◽  
Philippe Chambon ◽  
Jean-Gabriel Pariat ◽  
Anne-Sophie Marçais ◽  
Frédérique Valentin
Keyword(s):  
Northern France ◽  
Image Position

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