  In this paper is developed a simple mathematical model of transient heat
transfer under soil with plastic mulch in order to determine with numerical
studies the influence of different plastic mulches on the soil temperature and
the evolutions of temperatures at different depths with time. The governing
differential equations are solved by a Galerkin Finite Element Model, taking
into account the nonlinearities due to radiative heat exchange between the soil
surface, the plastic mulch and the atmosphere. The model was validated
experimentally giving good approximation of the model to the measured data.
Simulations were run with the validated model in order to determine the optimal
combination of mulch optical properties to maximize the soil temperature with a
Taguchi's analysis, proving that the material most used nowadays in Colombia is
not the optimal and giving quantitative results of the properties the optimal
mulch must possess.
