C. Ray et al., SIMULATION OF THE IMPACT OF AGRICULTURAL MANAGEMENT-PRACTICES ON CHEMICAL-TRANSPORT IN MACROPOROUS SOILS, Transactions of the ASAE, 39(5), 1996, pp. 1697-1707
A simulation model capable of describing preferential movement of wate
r and pesticides in macroporous soils has been developed. The model as
sumes a bi-continuum, with flow and transport in and between each of t
wo coexisting pore domains (matrix and macropore). In each pore domain
, water pow is assumed to obey Richards' equation and chemical movemen
t is assumed to obey the convection-dispersion equation. Interdomain t
ransfer of water and chemicals occurs under pressure and concentration
gradients. The model incorporates features such as root water extract
ion, rate limited sorption and desorption, and first-order decay. The
macropore volume fractions are allowed to vary with space to accommoda
te variabilities in soil propel-ties. The model can represent two-dime
nsions, to simulate the impact of agricultural management practices, s
uch as tillage, irrigation, cropping practice, and organic addition, o
n pow and transport.