scholarly journals Variability of topsoil properties at the southern coast of Finland and the number of  soil samples needed for the estimation of soil properties

1983 ◽  
Vol 55 (2) ◽  
pp. 109-117
Author(s):  
Raili Jokinen
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Carbon Content ◽  
Field Experiments ◽  
Available P ◽  
Organic Carbon Content ◽  
Plant Available P ◽  
Bray 1 ◽  
Extractable Al

A total of 430 topsoil samples were collected from ten fields of the Viikki Experimental Farm, University of Helsinki. Particle size distribution, organic carbon content, pH(CaCl2), exchangeable Ca, Mg, K contents, plant available P (Bray 1), 1 M KCI extractable (Al+H) content and effective cation exhange capacity of the soils were determined. The coefficient of variation was used as indicator of the variability of soil properties with in each field. The lowest coefficients of variation were observed for pH(CaCl2) and the highest for exchangeable Mg 1 M KCI extractable (Al+H) and effective cation exchange capasity. The results indicate that from 1 (pH(CaCl2)) to 33 (exchangeable Mg) samples per hectare are needed from individual fields for strict level of accuracy in estimation of the soil properties. For determination of soil type (according to clay content) and organic carbon content on average 8 samples, and for the plant available P (Bray 1) and exchangeable Mg and K contents 10 to 16 samples per hectare appear sufficient. Four samples suffice for a less stringent, lax accurate determination of all properties. The variability of soil properties is discussed from the viewpoint of agricultural advisory work and field experiments for agricultural research.

scholarly journals Assessing the Effect of Rubber (Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.) Leaf Chemical Composition on Some Soil Properties of Differently Aged Rubber Tree Plantations

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1871 ◽  
Author(s):  
Porntip Puttaso ◽  
Weravart Namanusart ◽  
Kanjana Thumanu ◽  
Bhanudacha Kamolmanit ◽  
Alain Brauman ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Properties ◽  
Carbon Content ◽  
Hevea Brasiliensis ◽  
Organic Chemical ◽  
Organic Carbon Content ◽  
Old Trees ◽  
The Impact

Leaf litter plays a major role in carbon and nutrient cycling, as well as in fueling food webs. The chemical composition of a leaf may directly and indirectly influence decomposition rates by influencing rates of biological reactions and by influencing the accumulation of soil organic carbon content, respectively. This study aimed to assess the impact of the chemical composition of rubber (Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.) leaves on various soil properties of different ages of rubber (4–5, 11–12, and 22–23 year-old). Synchrotron-based Fourier transform infrared microspectroscopy (Sr-FTIR) was utilized for analyzing the chemical composition of plant leaves. The Sr-FTIR bands illustrated that the epidermis of rubber leaves from 4–5-year-old trees was found to contain a high quantity of polysaccharides while mesophyll from 22–23-year-old trees had a large number of polysaccharides. The change in soil properties in the older rubber plantation could be attributed to its chemical composition. The change in soil properties across all tree ages, i.e., increased litter and organic carbon content, was a relatively strong driver of soil biota evolution. The aliphatic of C-H in the leaves showed high correlation with soil organic carbon (SOC) and permanganate-oxidizable C (POXC) from 22–23 year-old trees. This study shows the differences in the organic chemical composition of leaves that are consequential to soil organic carbon.

scholarly journals Determination of soil specific surface area by water vapor adsorption: I Drying of soil samples

1987 ◽  
Vol 59 (2) ◽  
pp. 63-65
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Mineral Soil ◽  
Clay Content ◽  
Fine Sand ◽  
Water Vapor Adsorption ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Clay Sample

Drying of three mineral soil samples (clay content 4—58 %, organic carbon content 1—5 %) equilibrated at 75.5 % relative humidity was studied. The soils were dried in an oven at +50°C, +70°C and + 105°C for 4 and 8 hours and in a desiccator over pure concentrated H2SO4 and P2O5. Drying over desiccants for 8 hours removed less water than drying at + 50°C. Drying over desiccants for 3—7 days was as efficient as drying at +70°C, for 14—24 days as efficient as 4 hours of drying at + 105°C. Eight hours of drying at + 105°C seemed to be too drastic, because it caused a greater weight loss in the clay sample of 5 % organic carbon content than did prolonged desiccant-drying. Drying at + 70°Cremoved as much water from fine sand which contained 4 % clay as prolonged desiccant-drying.

Sign in / Sign up

Export Citation Format

Share Document