Impact of Poultry Litter and N Fertilizer On Microbial Diversity in Soybean Fields in Central Missouri.

Efficient nitrogen fertilizer management is necessary to achieve higher soybean yields. A field experiment was established at the Bradford Research and Extension Center in Columbia, MO to compare the effect of different nitrogen sources on soil and microbial properties. The field consisted of a Mexico silt loam (Fine, smectitic, mesic Aeric Vertic Epiaqualfs) and the experimental design consisted of two treatments (high and low) each for mineral fertilizer and poultry litter with four replications. Soil sampling was done at the end of the growing season in 2010.

Results from the soil chemical analysis reveal that the soil pH was significantly lower in mineral fertilizer treatments compared to poultry litter. Soil Ca, Mg, K, CEC, OM were all comparable between the treatments. DGGE profiles created from the 16s rDNA fragments were mostly similar between treatments with minor differences. DGGE bands were cut and sequenced in order to ascertain the identity of dominant bacterial communities. The sequence data revealed the presense of genera such as Acidobacteria, Actinobacteria, Bradyrhizobia, Cytophaga along with several uncultured bacterial species common in agricultural landscapes.