The Effect of Dairy Manure and Inorganic Nitrogen on Soil Fertility, Nutrient Uptake and Yield in Corn.

The use of manure has often been related to improved soil properties such as cation exchange capacity, and higher levels of soil Phosphorus (P) and Potassium (K) in comparison to inorganic fertilizers. In a field study, the effect of manure and inorganic fertilizer on soil fertility, nutrient uptake, and corn yield will be evaluated.  The objectives of this study are 1) to compare the effects of dairy manure and inorganic nitrogen (N) fertilizer on soil pH, cation exchange capacity (CEC), soil N, P, and K and 2) to compare the effect of dairy manure and inorganic N on N uptake and Yield in corn. The study will be conducted at the University of Wisconsin River Falls Laboratory Farm and will be laid out in a randomized complete block design. Treatments will include a control (no fertilizer/manure), one treatment with 30 tons per acre (688lbs per plot) of dairy cattle manure added, and one treatment with 60 tons per acre (1376lbs per plot) of dairy manure added, and one treatment with 150lbs N per acre added. Each treatment will be replicated 3 times.  The inorganic source of N used in this study will be urea (46-0-0). To monitor the difference in plant growth and development between treatments, plant height and biomass will be measured at different growth stages. Optical sensors will be used to measure biomass at V5, V8, and V10. In addition, soil samples will be collected before planting and after harvest. Results will show that manure application will increase CEC and soil N, P, and K and give comparable yields in comparison to inorganic N.