SOIL SURVEY INPUT IN EXPLORATORY MODELING OF SUSTAINABLE SOIL-MANAGEMENT PRACTICES

Soil survey information combined with exploratory simulation modeling was used to define indicators for sustainable land management. In one soil series in the Netherlands (the genoform), three different phenofo rms were formed as a result of different management practices. Locatio ns mere identified using a soil map and interviews with farmers. Organ ic matter, bulk densities, and porosities were significantly different for the three phenoforms: biodynamic management (Bio), conventional m anagement (Conv), and permanent grassland (Perm). By applying a dynami c simulation model for water movement, crop growth and N dynamics, the three phenoforms were analyzed in terms of sustainability indicators by defining four scenarios based on productivity and N leaching to the groundwater: (i) potential production, (ii) water-limited production, (iii) current management, and (iv) the environmental scenario. The la tter was divided into EnvA: never exceeding the N-leaching threshold o f 11.3 mg L-1; EnvB: exceedance occurring in one out of 30 yr; and Env C: exceedance occurring in three out of 30 yr. Biodynamic management o btained the lowest yield under current management, while yields fur Pe rm were highest. EnvA could not be reached for Perm as a result of hig h mineralization rates. Obtainable yields for scenarios EnvA, EnvB, an d EnvC differed substantially, illustrating the importance of selectin g ''acceptable'' risks in environmental regulation. The presented meth odology demonstrates the importance of pedological input in sustainabi lity studies.