04 Lec 4 Soil aeration - Soil as a habitat for...

Info iconThis preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Soil as a habitat for microorganisms Soil as a habitat for microorganisms 3) Soil aeration 3) Soil aeration Reading : Textbook from Sylvia et al., 2004. Chapter 2, pages 46-47 I. Composition of the soil air II. Diffusion of gas between soil and the atmosphere III. Factors affecting soil aeration IV. Spatial heterogeneity in soil aeration IV.1. Gradient with soil depth IV.2. Gradient within soil aggregates V. Oxygen classes of microorganisms VI. Soil aeration and soil color VII. Microbial culture and O 2 Air-filled porosity Soil porosity: 30-60% Soil porosity is filled with water and/or air Air filled porosity f a = = porosity - volumetric water content = ε - θ Higher for sandy soils > loamy soils > clayey soils Higher for aggregated soils > compacted soils Volume of air-filled pores Volume of soil
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Composition of soil atmosphere N 2 : 78.1% O 2 : 20.9% CO 2 : 0.035% ? Composition of soil atmosphere N 2 content similar in atmosphere and soil air O 2 in soil air generally than in atmosphere N 2 : 78.1% O 2 : 20.9% CO 2 : 0.035% N 2 : 78% O 2 : 17-21% CO 2 : 0.1-1.0%
Background image of page 2
Soil respiration CO 2 O 2 Soil surface Microorganisms Roots Atmosphere Soil Soil respiration CO 2 O 2 Soil surface Microorganisms Roots Atmosphere Soil 20-50% 50-80% Contribution to soil CO 2 flux
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
From Hanson et al., 2000. Separating root and soil microbial contributions to soil respiration: A
Background image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/02/2010 for the course ESPM 131 taught by Professor Pallud during the Spring '10 term at University of California, Berkeley.

Page1 / 14

04 Lec 4 Soil aeration - Soil as a habitat for...

This preview shows document pages 1 - 5. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online