COBALT STATUS IN QUEBEC SOILS

1967 ◽  
Vol 47 (2) ◽  
pp. 83-88 ◽  
Author(s):  
S. K. Rana ◽  
G. J. Ouellette

Studies on thirty mineral soil series and five organic soils from the broad cultivated areas of Quebec indicated that total cobalt, extracted with 70% perchloric acid digestion, ranged from 1.1 to 21.6 ppm and 2.5% acetic acid-extractable cobalt from 0.3 to 0.83 ppm. Extractable cobalt in the surface soils was significantly correlated with total cobalt, which in turn was highly dependent on the clay content of the soil. The soil pH or the organic matter content did not seem to have any influence on the cobalt content in the cultivated soils. Light-textured and podzolized soils are likely to be low m cobalt, while soils with richer clay content are higher. Organic soils, in general, were found to be lower in cobalt content than mineral soils. Nineteen out of the thirty mineral soils studied and all the organic soils contained less than 0.25 ppm of extractable cobalt and may be considered as critical or deficient because forage grown on such soils is likely to cause cobalt deficiency in livestock.

1964 ◽  
Vol 44 (1) ◽  
pp. 137-144 ◽  
Author(s):  
R. L. Halstead

In laboratory incubation experiments liming with Ca(OH)2, CaCO3, or MgCO3 inhibited the phosphatase enzyme activity as measured by determination of phenol or phosphorus released from disodium phenyl phosphate. Chloride and sulphate salts of calcium and magnesium had no appreciable effect on the measured activity. Incubation for 9 months reduced the activity in a group of acid soils but not in a group of nearly neutral soils. Addition of phosphate prior to incubation had no effect on activity in either group.In buffer systems with the pH controlled over the range pH 2.0 to 11.0, activity in samples of an acid mineral soil increased gradually from pH 2.0 to a maximum at about pH 7.0, and then declined rapidly. The occurrence of peaks of optimum activity at pH 5.0 and 9.5 indicated the presence of both acid and alkaline phosphatases in an organic soil.Although there was no significant relationship between phosphatase activity and pH, clay content, nitrogen, and total carbon content of 10 mineral soils, there was a higher activity associated with higher organic matter content in three groups of soils with 3.2, 24.8, and 80.2% organic matter. Initial phosphatase activity of a group of mineral soils was not related to the degree of mineralization of organic soil phosphorus found to occur during an incubation period.


2019 ◽  
Vol 34 (3) ◽  
pp. 362-370
Author(s):  
Jose V. Fernandez ◽  
D. Calvin Odero ◽  
Gregory E. MacDonald ◽  
Jason A. Ferrell ◽  
Brent A. Sellers ◽  
...  

AbstractDissipation of S-metolachlor, a soil-applied herbicide, on organic and mineral soils used for sugarcane production in Florida was evaluated using field studies in 2013 to 2016. S-metolachlor was applied PRE at 2,270 g ha−1 on organic and mineral soils with 75% and 1.6% organic matter, respectively. The rate of dissipation of S-metolachlor was rapid on mineral soils compared with organic soils. Dissipation of S-metolachlor on organic soils followed a negative linear trend resulting in half-lives (DT50) ranging from 50 to 126 d. S-metolachlor loss on organic soils was more rapid under high soil-moisture conditions than in corresponding low soil-moisture conditions. On mineral soils, dissipation of S-metolachlor followed an exponential decline. The DT50 of S-metolachlor on mineral soils ranged from 12 to 24 d. The short persistence of S-metolachlor on mineral soils was likely attributed to low organic matter content with limited adsorptive capability. The results indicate that organic matter content and soil moisture are important for persistence of S-metolachlor on organic and mineral soils used for sugarcane production in Florida.


2021 ◽  
Vol 22 (1) ◽  
pp. 74-83
Author(s):  
Nabeel Rizwan

Potassium (K) availability to plants varies with the adsorption characteristics of soil, to evaluate the adsorption capacity, five soil series of different characteristics were used. K adsorption isotherms were performed by equilibrating 2.5 g soil samples with 10 levels of K (30-300 mg kg-1) as KCl in 0.01 CaCl2 solutions and shaken for 24 h at 25oC. The amount of K adsorbed ranged from 33.2 to 94.9% of added K. Freundlich model explained K adsorption behavior better than the other two equations. Higher coefficient of regression values 0.99, 0.97 and 0.96 were recorded in Sultanpur (Silt loam), Naivela (Fine sandy loam) and Bhutesar (Clay loam), respectively. The highest 1/n value 1.54 kg mg-1 and kf value 31.47 mg kg-1 of Freundlich isotherm were observed in Sultanpur (silt loam) due to high pH, high OM and high clay contents, lowest values of constants were observed in Wajan (loamy sand) with 1/n value 0.44 kg mg-1 and kf value 0.28 mg kg-1 might be due to high EC, high CaCO3 and sand contents. The K adsorption of soil varied with physico – chemical characteristics of soil, especially clay content, alkaline pH and organic matter content.


2017 ◽  
Vol 13 (2) ◽  
pp. 74-77
Author(s):  
Imelda J Lawalatta ◽  
Francina Matulessy ◽  
Meitty L Hehanussa

Chili (Capsicum annum L.) often experience the highest price fluctuations in Indonesia. This is caused by the production that is often disrupted in certain months, especially in the months in the rainy season due to flowers and fruits that fall before the harvest. Since agricultural land has changed its function for infrastructure development, marginal land (Ultisol) is used. The ultisol problem is: high acidity, low organic matter content, nutrient deficiency important for plants (eg N, P, Ca, Mg and Mo) and high solubility of Al, Fe and Mn. The provision of organic materials such as manure and marine mud will overcome the problem of acid-rich mineral soil and play an important role in improving, increased and maintaining sustainable land productivity. Research results for chili flower significantly. the highest number of flowers found in the treatment of L0P3, L1P2, L1P3 and L2P3 that is > 60 flower/plant. There was a single factor effect for the amount of fruit, mostly found in L3 treatment (600 ton/ha marine mud) that is 22.36 fruit/plant. The treatment of manure significantly influenced the formation of the most fruit set in the treatment of P0 and P2 (without manure and manure 20 ton/ha) that is 77.60% and 70.,45%. Keywords: Ultisol, Marine mud, Manure, Flowers and Fruit sets   ABSTRAK Tanaman cabai besar (Capsicum annum L.) sering mengalami fluktuasi harga paling tinggi di Indonesia. Hal tersebut disebabkan oleh produksi yang sering terganggu pada bulan tertentu terutama pada bulan-bulan di musim penghujan dikarenakan bunga dan buah yang rontok sebelum panen. Karena lahan pertanian banyak beralih fungsinya untuk pembangunan infrastuktur, maka digunakan lahan marginal (Ultisol). Masalah ultisol ialah: kemasaman tinggi, kadar bahan organik yang rendah, kekurangan unsur hara penting bagi tanaman (contoh: N, P, Ca, Mg dan Mo) serta tingginya kelarutan Al, Fe dan Mn. Pemberian bahan organik seperti pupuk kandang dan Lumpur laut akan mengatasi persoalan tanah mineral masam berkadar Al tinggi dan berperan penting dalam memperbaiki, meningkatkan serta mempertahankan produktifitas lahan secara berkelanjutan Hasil Penelitian untuk jumlah bunga cabai berpengaruh signifikan. jumlah bunga terbanyak terdapat pada perlakuan L0P3, L1P2, L1P3 dan L2P3 yaitu > 60 bunga/tanaman. Terjadi pengaruh faktor tunggal untuk jumlah buah, terbanyak terdapat pada perlakuan L3 ( 600 ton/ha lumpur laut) yaitu 22,36 buah/tanaman. Perlakuan pupuk kandang berpengaruh signifikan Pembentukan fruit set terbanyak pada perlakuan P0 dan P2 (tanpa pupuk kandang dan pupuk kandang 20 ton/ha) yaitu 77,60% dan 70,45%. Kata kunci: Ultisol, Lumpur Laut, Pupuk Kandang, Bunga dan Fruit set


1998 ◽  
Vol 37 (6-7) ◽  
pp. 181-188 ◽  
Author(s):  
Diane F. Malley

The potential for improvement in the rapidity, cost-effectiveness, and efficiency of sediment analysis by the application of near-infrared reflectance spectroscopy (NIRS) is recognized. The rapid (<2 min), non-chemical, non-destructive analytical technique of near-infrared (700–2500 nm) spectroscopy combines applied spectroscopy and complex statistics. It has been used for the experimental analysis of various constituents and functions of soils since the 1960s, and applications for the analysis of sediments are currently being explored. For application of NIRS, sediment samples require little preparation, other than drying, and the samples are not subject to the manipulations of conventional analytical techniques. The spectral information recorded in a 2 min scan can be used to predict numerous constituents and parameters on the samples once appropriate calibration equations have been prepared from sets of samples analyzed by both NIRS and conventional analytical techniques. Constituents and properties of soil and/or sediment analyzed by NIRS technology include moisture, organic matter content, organic C, CO3=, N, P, S, K, Ca, Mg, clay content, humic acids, lignin, cellulose, metal oxides, heavy metals, aggregate size, and inferred past pH of lakes. Several areas are identified where further research is needed to prepare for the application of NIRS to the routine analysis of sediments.


2001 ◽  
Vol 1 ◽  
pp. 122-129 ◽  
Author(s):  
Alan Olness ◽  
Dian Lopez ◽  
David Archer ◽  
Jason Cordes ◽  
Colin Sweeney ◽  
...  

Mineralization of soil organic matter is governed by predictable factors with nitrate-N as the end product. Crop production interrupts the natural balance, accelerates mineralization of N, and elevates levels of nitrate-N in soil. Six factors determine nitrate-N levels in soils: soil clay content, bulk density, organic matter content, pH, temperature, and rainfall. Maximal rates of N mineralization require an optimal level of air-filled pore space. Optimal air-filled pore space depends on soil clay content, soil organic matter content, soil bulk density, and rainfall. Pore space is partitioned into water- and air-filled space. A maximal rate of nitrate formation occurs at a pH of 6.7 and rather modest mineralization rates occur at pH 5.0 and 8.0. Predictions of the soil nitrate-N concentrations with a relative precision of 1 to 4 μg N g–1of soil were obtained with a computerized N fertilizer decision aid. Grain yields obtained using the N fertilizer decision aid were not measurably different from those using adjacent farmer practices, but N fertilizer use was reduced by >10%. Predicting mineralization in this manner allows optimal N applications to be determined for site-specific soil and weather conditions.


1987 ◽  
Vol 35 (3) ◽  
pp. 407-415 ◽  
Author(s):  
A. Kamphorst

A small rainfall simulator is described, which can be used in the field as well as in the laboratory for the determination of infiltration and erosion characterisitcs of soils. It is particularly suitable for soil conservation surveys, as it is light to carry and easy to handle in the field. A description is given of a standard procedure for the determination of topsoil erodibilities in the field and some results are presented. The method appears to be highly sensitive to soil properties influencing soil erodibility, such as clay content, organic matter content and soil pH. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1969 ◽  
Vol 36 (2) ◽  
pp. 122-133
Author(s):  
M. A. Lugo López

Very accurate estimations of the permanent wilting percentage can be obtained for soils of all regions of Puerto Rico by use of regression equations based on the hygroscopic coefficient. Reliable estimates can also be obtained for humid-region soils by using the clay content as a basis. Attempts to correlate permanent wilting-percentage values with moisture equivalents and organic-matter content did not give such satisfactory results. The 15-atmosphere percentage as determined by using pressure plates gives an accurate approximation of permanent wilting-percentage values. It is time-saving, but initial expense in laboratory equipment is rather high. This approach is to be preferred whenever feasible. A regression equation is given relating pressure-plate values to the permanent wilting percentage. Whenever less precise estimates are acceptable and time is not a factor, advantage should be taken of the established correlation between the hygroscopic coefficient and the permanent wilting percentage.


Weed Science ◽  
1976 ◽  
Vol 24 (6) ◽  
pp. 549-552 ◽  
Author(s):  
J. D. Gaynor ◽  
V. V. Volk

The effects of soil organic matter, clay, extractable Al, cation exchange capacity, and pH on the adsorption of picloram (4-amino-3,5,6-trichloropicolinic acid) from aqueous and surfactant solutions were investigated. Linear adsorption isotherms for the soils were obtained with the Freundlich equation. Of the five soil properties investigated, Freundlich K values correlated with extractable Al and clay content. Picloram adsorption from aqueous solutions and from the non-ionic and anionic surfactant solutions was greater on the soils at pH 5 than at pH 7. The anionic surfactant competed with picloram for adsorption sites on the soils at pH 5. Picloram adsorption from solutions containing 0.1 and 1% cationic surfactant was greater than that from aqeuous and anionic and nonionic surfactant solutions. Picloram adsorption from the 10% cationic surfactant solution was similar on soils with pH 5 and 7 and increased with decreased organic matter content.


2008 ◽  
Vol 53 (No. 5) ◽  
pp. 225-238 ◽  
Author(s):  
N. Finžgar ◽  
P. Tlustoš ◽  
D. Leštan

Sequential extractions, metal uptake by <i>Taraxacum officinale</i>, Ruby&rsquo;s physiologically based extraction test (PBET) and toxicity characteristic leaching procedure (TCLP), were used to assess the risk of Pb and Zn in contaminated soils, and to determine relationships among soil characteristics, heavy metals soil fractionation, bioavailability and leachability. Regression analysis using linear and 2nd order polynomial models indicated relationships between Pb and Zn contamination and soil properties, although of small significance (<i>P</i> < 0.05). Statistically highly significant correlations (<i>P</i> < 0.001) were obtained using multiple regression analysis. A correlation between soil cation exchange capacity (CEC) and soil organic matter and clay content was expected. The proportion of Pb in the PBET intestinal phase correlated with total soil Pb and Pb bound to soil oxides and the organic matter fraction. The leachable Pb, extracted with TCLP, correlated with the Pb bound to carbonates and soil organic matter content (<i>R</i><sup>2</sup> = 69%). No highly significant correlations (<i>P</i> < 0.001) for Zn with soil properties or Zn fractionation were obtained using multiple regression.


Sign in / Sign up

Export Citation Format

Share Document