Evaluation of sensitivity and setting of the MACRO 5.2. model on direct lysimeter studies of leachate

The water assembly of the MACRO model, making allowance regarding the double porosity of soils, was parameterized according to experimental laboratory data and tested according to the results of studying the water regime of sod-podzolic middle loamy soils of large lysimeters of MSU. Testing of pesticide migration models is necessary to improve forecast accuracy and justify their use. The analysis of the sensitivity, estimated from the data on the lysimetric runoff at the lower point (1.5 m) of the soil, showed that the WRC parameters are the main physical support of the models, which sets the forecast accuracy. These are the parameters that must be used to customize the model. The MACRO model has showed itself better at describing lysimetric runoff during the growing season by taking into account the fast flows along macropores and fissures that occur during periods of intense precipitation in the model than the models previously used.