**DESCRIPTION OF COURSES**

**AP 613 ADVANCE SOIL PHYSICS II (2L+1P) I**

*(Pre-requisite: AP 110 & AP 104)*

**Objective**

To study the use of advanced mathematical tools in understanding the soil physical processes related to transport of soil heat and soil air.

**Theory**

UNIT I

Variability in soil physical properties: classical measures of variability, spatial variability of soil physical properties: spatial dependence, autocorrelation function and spatial structure studies : empirical semivariogram, semivariogram models, classical and geostatistical interpolation: IDW, spline , global polynomial, Kriging – stationarity, trend ,solving kriging equations, type of kriging, GIS for geospatial analysis, Kriging for precision farming

UNIT II

Mathematical tools: Fourier series, Bessel functions, Infinite series of orthogonal functions, Numerical approximations: finite elements and finite difference model of applicability of numerical approximations, numerical simulations.

UNIT III

Soil heat flow: equation of heat transport by conduction and its sine wave solution, measurement and estimation of soil thermal properties- single and dual probe, heat flux plates, Jackson and Kirkham’s method, numerical simulation technique.

UNIT IV

Sediment transport by runoff: equations of sediment transport for rill and interrill erosion, measurement of inter-rill and rill erodibility, computation of sediment detachment , transport and deposition rates.

UNIT V

Movement and exchange of gases in soils: Darcy’s law for advective transport (nonisobaric system) of gas, deviation from Darcy’s law, gas transport by diffusion in isobaric system (Fick’s law). Multi component gas transport- Dusty Gas model, Stefan Maxwell equation. Gas permeability: laboratory and field measurement of gas permeability.

UNIT VI

Soil quality: definitions, selection of minimum data set of physical, chemical and biological characteristics for quality assessment, indices of soil quality-nonquantitative and quantitative systems, least limiting water range(LLWR) for assessment of soil physical health, soil conditioner: water soluble conditioners and soil hydrogels, their effects on soil structure, water and nutrient retention and other soil hydraulic properties

**Practicals**

Empirical semivariogram and fitting appropriate semivariogram model, Preparation of prediction map of a soil property by kriging, Computation of sediment detachment rate, sediment transport rate, interrill and rill erodibility, Computation of LLWR under different soil management practices, Computation of thermal properties using finite difference method

**Suggested Readings**

- Advanced Soil Physics by Daniel Hillel
- Advanced soil physics by Kirkham and Powers
- Mathematical Physics by B.D.Gupta
- Soil Physics Companion by A.W.Warrick