Technical Abstract: No-tillage and contour strip cropping are two conservation practices recommended by the Natural Resources Conservation Service (NRCS). Our objective was to quantify the effects of those practices after imposing them on deep loess soils in two field-scale watersheds in western Iowa. Hydrology, soil fertility, and crop yield response were evaluated for a nine-year period after converting both watersheds from conventional tillage, continuous corn (Zea mays L.) to a no-till corn – soybean [Glycine max (L.) Merr.] or no-till contour strip-cropping with a six-year corn, soybean, and alfalfa (Medicago sativa L.) rotation. Despite having three of the most intense rainfall events recorded for this site, no-till plus contour strip-cropping reduced runoff 20% for rainfall amounts of 35 to 80 mm d-1. No-tillage alone, however, resulted in increased runoff. After a four-year transition period, the diversified six-year rotation reduced nitrogen(N) fertilizer requirements for corn by approximately 75% compared to the long-term average (178 kg N ha-1) for continuous corn. Coupling the conservation practices with good agronomic management increased corn yield by 2 Mg ha-1 compared to the long-term average. Average soybean (3.6 Mg ha-1) and 1st, 2nd, and 3rd year alfalfa yields (4.2, 7.5, and 7.5 Mg ha-1, respectively) were also good. Economic comparisons demonstrate the impact of market price and stress the importance of good agronomic management. We conclude that implementing conservation practices that include diversified crop rotations plus very reduced or no-till operations can be profitable for land owners/operators and more environmentally sustainable for taxpayers supporting conservation for clean water and healthy soils.