Soil Sampling If You Are Not Measuring Bulk Density If you are using the Surface Sample Method 1. Dig three large samples from the soil surface. Avoid. - презентация

1 Soil Sampling If You Are Not Measuring Bulk Density If you are using the Surface Sample Method 1. Dig three large samples from the soil surface. Avoid the area of the soil face that was tested for carbonates and avoid touching the soil samples so that you pH measurements will not be contaminated. 2. Place each sample in a bag or other soil container. 3. Label each bag with the site name and top and bottom depths. 4. Bring these samples in from the field. 5. Spread the samples on separate plastic plates or sheets of newspaper to dry in the air.

2 Field Analysis Conclusion When You Are Finished Sampling: 1. Photograph the face of the pit, or the soil profile you have removed and placed on the ground with the auger. F Place a tape measure along the profile (in the pit or next to the auger sample profile you created) so that 0 cm is at the top of the profile to record horizon depths for the picture. F Take another photograph of the landscape outside the pit or around the auger hole. F Send these photographs to: the GLOBE Student Data Archive at the address given in the Teachers Guide, or if they were taken with a digital camera, submit them to the GLOBE Student Data Archive electronically.

3 Soil Sampling 1. Auger to a depth of 1 or 2 cm past the top of the horizon to be sampled. If the horizon is thinner than the length of the auger head, partially turn the auger so that the whole sample will be from one horizon. * If you are using the Auger Technique 2. Place the sample in a labeled bag or other soil conainer. Avoid touching the sample and contaminating it. 3. Repeat steps one and two for each horizon of three profiles. 4. Bring these samples in from the field, and spread them on separate plastic plates or sheets of newspaper to dry in the air. * Use the depths from the first soil profile you withdrew with the auger as a guide.

4 Soil Profile Description Litter (undecomposed) Organic layer, fermented Organic layer, humified Mineral layer with organic carbon and leached minerals Mineral layer with precipitation of oxides/hydroxides and/or carbon Unaltered parent substrate

5 Soil Horizons O Mostly organic materials, decomposing leaves, and twigs. Often dark brown color. Mineral and organic materials, light black to brown. Leaching of clay, Fe and Ca. Light colored materials due to leaching of clay, Ca, Mg, and Fe to lower horizons. Horizons A and E make up the Zone of Leaching. Enriched in clay, Fe oxides, Silica, carbonate and other material leached from above. This is the Zone of Accumulation. Partially altered (weathered) parent material, which is either rock or loose sediment. Unweathered (unaltered) parent material = rock. S. Hughes, 2003 A E B C R

6 Water in Soils Moisture Content of soil is calculated as follows: W = weight, so that: [(W wet - )/W dry ] x 100 = H 2 O content (%) W drу Moisture content affects the engineering properties and stability of soils. A soil that is stable in dry conditions may become unable to support the structures built on it when saturated with water. Be sure to read the sections of your text describing the engineering properties of soil.

7 Формы воды в почве Saturation, field capacity, wilting point, and hygroscopic water Field capacity: The percentage of water compared to the dry weight of soil that is held in the soil after drainage of the excess water, at 1 atmosphere of pressure. Wilting point: The amount of water held in the soil at 15 atmospheres of pressure. (This is a standard that depicts a point at which many borad- leaved plants wilt.) Available water: The difference between the Field Capacity and the Wilting Point. Field CapacityW.iling Cceffitient Hygroscopic water: The water held at 30 atmospheres of pressure. This is representative of the amount of water that is tightly held to the soil particles, and which is not available to the plants.

8 Common soil physical properties analyzed in the laboratory Soil moisture Soil particle size - texture Bulk density Color % organic matter Soil water retention properties –Field capacity - 1/3 atm –Wilting point - 15 atm –Hygroscopic water - 30 atm –Available water = field capacity - wilting point

9 Common soil chemical properties analyzed in the laboratory pH Cation exchange capacity - total amount of cations (including H+) that can be displaced Base saturation - the percent of the cation exchange complex occupied by exchangeable bases (mostly plant nutrients such as Ca, Mg, Na, K, etc.) Nutrients - amounts of macronutrients and micronutrients

10 Определение гранулометрического состава почв

11 Гранулометрический состав отдельных почв ПесокПыль крупная и средняя Пыль мелкаяИл ДП ДК ДПЗб Дзб

12 Типы структуры почв

13 Атлас цветов Манселла

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15 Работа с атласом Манселла Quantification of color using the Munsell notation: Hue, value, chroma Hue (page in Munsell color book): The dominant color, (e.g. 10 R is red; 2.5YR has some yellow, 7.5YR are tans and browns, 2.5 Y is yellow, G is green). As soils age they oxidize and change from yellow to brown to red (e.g., 2.5Y to 10YR to 7.5YR to 5 YR to 10R). Value (rows on each page): The relative darkness or lightness of the hue from 1 (dark) to 8 (light). The value is often a function of the amount of humic organic material in the soil. Darker soils have more organic material. Very black horizons may be buried charcoal or accumulations of MnO2. Whiter horizons may be the result of leaching as in an E horizon, or the accumulation of carbonate or gypsum. Chroma (columns on each page): The strength or intensity of the color from 0 (least with none of the hue) to 8 (most vivid). This is indicative of the amount pigmenting material present, but it is strongly influenced by the texture of the soil. Example: a soil with color 10YR5/6 is 10YR hue, 5 value, and 6 chroma, a yellowish brown in the U.S. system of color names.

16 Clay crystal with adsorbed cations

17 Relationship between soil pH, cation exchange capacity, and base saturation

18 Relationship between pH and selected plant nutrients and the activity of soil fungi and bacteria

19 <* Automated Soil pH Mapping Systems I Automated Soil pH Mapping Systems Soil Sampling Mechanism *f Soil pH Mapping Soil pH Maps of a Nebraska Field + / Tes Data were collected by Veris Technologies (Salina, KS) Soil pH Mapping Field Test (Soil pH Mapping) 2

20 Extraction of the monolith Working in fine textured soil Extraction of the monolith Continuous kneeling of the lysimeter casing 4

21 JOANNEUM RESEARCH Institute of Water Resources Management Hydrogeology and Geophysics Umweltanalytische Messsysteme GmbH measure to know Extraction of the monolith Using the pressure of an excavator 5

22 Final assembly of weighable field lysimeter 11