Aquatox assumes a fixed mass of pesticide applied in its 10-acre watershed, without regard to where in the watershed it is applied. Each pesticide is used on a limited number of crop types. Because of the patchwork of farmland and forest land upstate, only a limited portion of a watershed above a minimum size will be treated with a given chemical. On Long Island, near-monoculture of potatoes and the universal popularity of insecticides and nematicides like aldicarb and carbofuran exaggeraged the ground water residue problems created in the 1970's. Upstate there are very few areas with such extensive areas of the same crop grown consistently from year to year.
Dairy farms intersperse and rotate grass and corn crops.
Horticultural farms typically grow a variety of crops which differ between adjacent farms. Time Patterns Real routine field use of pesticides has a distinct seasonal pattern driven by crop type, weather conditions, user preferences, and legal constraints. A field will receive pesticides on one to a few days around or within the growing season. The time pattern for a given field consists of very short application periods separated by long periods when no new pesticide is applied. Farmers growing the same crop within a small watershed will have similar application timings, because of similar cropping seasons driven by similar weather and soil.