Duh! again!(Duh means "No shit sherlock" and/or "Thank you captain obvious")
Dairy Manure Goes Urban: Organic Compost Improves Soil, Enhances Ornamental Plants in Residential Landscapes
ScienceDaily (June 23, 2011) — When natural ecosystems are replaced by roads, homes, and commercial structures, soil is negatively impacted. Studies have shown that, among other issues, distressed urban soils are often significantly compacted, may have alkaline pH, and may contain low amounts of essential organic matter and nutrients. This altered soil is typically not conducive to healthy plant root growth and establishment, leading to challenges for urban landscapes and home gardens.
. . .
The scientists applied composted dairy manure solids as an organic soil amendment at a depth of 5 cm in combination with two mechanical soil treatments (tillage to 15 cm and plug aeration), then assessed soil physical and chemical properties, plant growth and quality, and plant tissue nutrient concentrations to determine the effects of the different treatments.
The data showed that applications of compost significantly reduced soil density and pH and increased soil organic matter, electrical conductivity, and concentrations of phosphorus and potassium.