Macherey-Nagel Visocolor Manual

Macherey-Nagel Visocolor Manual Manual pdf 27 page image

Manual VISOCOLOR® reagent case for soil analysis27Manual VISOCOLOR® reagent case for soil analysis 03.14MN2. Soil analysis procedure2.1 SamplingTake several samples from various locations of the area to beexamined and mix them. Do not take samples after prolongedor strong rainfall. Soil from arable land should be taken after theharvest and prior to fertilizing. Grassland can be analyzed inspring and winter or after each cut. The sampling depth is 10 cmfor lawns and grassland, 15–30 cm for arable land and 30 cm forvegetable beds and shrub areas.The samples can be taken with a spade; soil drills are requiredfor examining the deeper layers of soil at depths of 30–60 cm and60–90 cm.Prior to the analysis, remove all untypical parts such as stones,parts of plants and other items (glass, metal, pieces of plastic,etc.).The sample is then weighed and dried, and the moisture contentand density of the soil are determined (see 2.2, page 27, see2.4, page 27).2.2 Weighing and determination of moisture content1. Set up balance (1)2. Place plastic beaker (17) on the balance pan3. Tare to ZERO4. Weigh the required quantity of soil with the aid of the plasticscoop (18)Determination of moisture content:Weigh 200 g of the soil sample and spread evenly over one ofthe cardboard sheets (210 x 297 mm). Crush any large clumpsof soil and dry in a well-ventilated room at room temperature for16–24 hours.After drying, pour the soil sample back into the tared measuringbeaker and establish its weight.Calculation of the moisture content of the soil.Weight of moist soil [g] – Weight of dry soil [g]Weight of moist soil [g] x 100 = % soilmoisture210 x 279 mm50100150200250250 mlppCMAXpp135MAXAPPROXIMATE VOLUMES17 1812.3 Sieving the soil samplePrior to the preparation of the soil extracts and the determinationthe soil density and soil structure (sedimentation) of the sampleis screened. The mesh width is 2 mm. This means that all par-ticles larger than 2 mm are removed from the sample. Analyticalvalues from screened samples provide improved comparability,as the accuracy and precision of the individual examination areincreased.Place the air-dry sample on the sieve (2) in portions, carefullycrushing large clumps of earth beforehand. Screen the soil ontoa clean cardboard sheet 210 x 297 mm. Discard the material re-tained by the sieve. The material obtained in this manner is usedto prepare the soil extracts.210 x 297 mm22.4 Determination of the soil densitySoils consist of grains of varying sizes and shapes. The specificweights of the constituent parts, and the pore volume result in thesoil density (kg/dm 3 ). We determine the soil density on the basisof the air-dry, screened soils.Procedure:Insert the 100 mL measuring cylinder (8) into the green plasticbase (9). Place the cylinder onto the balance (1) and write downits weight. Take the cylinder off the balance and fill with sievedsoil using the plastic shovel (18). Compact the soil by gentlytapping the cylinder on a solid surface until the 100 mL mark isreached, or read the respective volume. If necessary, level thesurface without exerting any pressure (in case the soil quantity isnot sufficient, write down the respective volume). Place measur-ing cylinder on the balance and read weight.ml 1009080706050403020108 9 118Calculation:D [ kg ] = A [g]dm3 V [mL]A = Soil weight D = Soil density V = Volume