Impact of Manure Application on Soil Health and Crop Yield Under Corn-Soybean Rotation in South Dakota.

Improving Soil nutrients are essential for the sustainable agriculture and to get higher yields. Addition of manure to the soils can improve soil nutrients, soil health and crop yield. The objective of this research is to assess the impacts of manure on some of the soil health parameters that include soil organic matter, soil nutrients (N, P and K), and crop yield. This study was conducted in two different sites located at Beresford and Brookings, South Dakota. Two fertilizer and three rates of organic manure were applied in the field under a corn (Zea mays L.)-soybean (Glycine max L.) rotation. The soil test P from the P manure treatment was used to calculate the manure needed for that treatment. If the soil test P is high enough then no P recommendation were applied. The average crop P removal was used to calculate manure P rate. Similarly, the soil test nitrate-N from the N manure treatment was used to calculate the manure needed for that treatment.  Both the P and nitrate-N soil tests were used from the fertilizer treatments to make the P and N recommendations for the fertilizer treatment. Study treatments included: (i) recommended fertilizer (recommended fertilizer rate determined from soil test and yield goal), (ii) 175 kg manure, (iii) 379 kg manure, (iv) 780 kg manure, (v) double rate of fertilizer, and (vi) control. The manure was incorporated with a disc in one to three days after application. Treatments were followed randomized complete block design with four replications. Manure samples were taken to analyze the nutrient content in it. Soil samples with auger and intact core samples from 0-15 cm and 15-60 cm depths were collected to analyze different soil nutrients. Final grain yield was taken after the havens in the field. Preliminary Results from this study showed that addition of organic manure significantly improves the nutrient contents of the soil, and soil organic matter, and the crop yield.