ECOPICS_MX Monolith soil chemical analysis

   ECOPICS Project : Monolith Soil Data 

In the field, after the extraction of the monolith  and root and fauna collection , a composite soil sample ( ±500 g) was collected.  Beside the monolith a soil cylinder (98.17 cm3) was extracted at a depth of 0.10 m, dried at 105 ° C and weighed to determine the bulk density (g /cm3).

There were  in total 83 samples. From each of these samples 100g were frozen (for nitrate and ammonium analysis), the rest were air dried and sieved at 2 mm for the rest of physicochemical analysis (% carbon,% hydrogen,% nitrogen and real density) the texture and the other chemical analysis described below were analyzed with the fresh sample.

Ca, Mg, K, Na and cation exchange capacity (CEC, cmol / kg1) were determined by 1N ammonium acetate, pH7. 

Nitrate and ammonium were measured by extraction with potassium chloride solution and then by steam distillation with magnesium oxide and Dervada alliance. (Bremner, J. M., 1965)

Available P was measured by Bray-Kurtz 1. Total P (mg / Kg) by wet digestion with nitric acid: perchloric acid 1: 2 and then quantified with sodium metavanadate. % P retained was measured by the Blackmore technique.

Soil texture was measured using the pipette (Pleijsier, 1986). Soil particles were classified into size fractions: clay (0.002 m), silt (0.02mm), silt (0.05 mm), sand (<0.25 mm), sand (> 0.25 <0.05mm) and sand (> 0.5mm).

The electrical conductivity in distilled water, a 1:5 ratio, is mixed and after 24 h it is measured with a Corning brand conductivity meter. 

The pH in water was in a 1:2 ratio.

Humidity was determined using the oven technique at 105 ° C.

The field capacity was determined in a pressure cooker at 0.33 Bar and then dried at 105 ° C.

Organic matter and % organic C was determined by the Walker-Black technique.

% C,% H and% N were determined by combustion (Dumas method) by the Perkin Elmer CHN 2400 analyzer.