Yes, QPS works excellently in the ground and with various soils. However, due to the wide range of soil types, determining the exact nutrient strength required is not as straightforward. Soil is a non-neutral growing medium, containing various elements found in the nutrient formula at different levels. Due to this variability, we recommend using a half-strength dose with regular water or a full-strength dose on every third watering cycle when dealing with soil. This approach has been adopted by many successful farms using QPS, and the results are comparable to those of hydroponic growers.