General Management

Management operations that control the plant growth cycle, the timing of fertilizer and pesticide and the removal of plant biomass are explained in this chapter. Water management and the simulation of urban areas are summarized in subsequent chapters.

A new operations input file was added that allows user to schedule management by Julian day and calendar year without considering cropping rotations and without using heat unit scheduling. Operations have been added for contouring, terracing, subsurface drains, filter strips, fire, and grass waterways.

Previous versions of SWAT+ only allowed the growth of one plant species at a time to be simulated. Algorithms from the ALMANAC model (Kiniry et al., 1992, Johnson et al., 2009) have been added to simulate multiple plant species growing and competing within a plant community. Plant communities that have been simulated include: crops and weeds, trees and grasses, different tree species in a boreal forest, and grasses and shrubs in rangeland communities. A data file is developed prior to simulation that describes the various plants within each community.