EVALUATING THE LONG TERM EFFECTS OF CONTINUOUS BROILER LITTER APPLICATIONS ON RESIDUAL SOIL FERTILITY AND YIELDS OF CORN AND SOYBEAN CROPS, AND A SIDE EXPERIMENT STUDYING THE RESIDUAL COPPER FERTILIZATION EFFECTS ON THESE CROPS
The increasing cost of commercial fertilizers and the availability of animal waste that has high nutrient content have led to producers utilizing animal waste such as poultry litter in their fertility programs. This increased use has raised concerns as to what are the optimum rates to apply to meet crop needs and how will long term use at high rates of litter effect soil test levels of nutrients such as phosphorus and potassium. The objective of this study was to address these concerns. This study has been ongoing since 1997 with treatments of zero to seven tons of litter being applied in years where corn was planted and then in years where soybeans were planted the residual fertility from the previous years of applications were observed. In 2005, 2006, and 2009; 230 lbs/A of commercial phosphorus (P2O5) and 250 lbs/A of commercial potassium (K2O) were applied to the plots treated with the historical rates of one and two tons per acre of broiler litter. This study looked at the effects residual fertility from past broiler litter applications had on soil nutrient levels and plant nutrient uptake during the 2013 soybean growing season, as well as, the effect on soybean yield in 2012 and 2013. In 2014 the study was returned to corn and the zero through seven tons per acre broiler litter treatments were again applied. Data reported from 2014 included soil test results, R1 corn ear leaf tissue analysis, and yield. In 2007 a positive correlation between soybean uptake of copper and yield was observed. In 2009 a second study to compliment the broiler litter study was started where the effects of pre plant soil applied rates of 0, 10, and 20 lbs/A of copper on soil test copper levels, plant uptake of copper, and yield were evaluated. This study was continued with only yield data being reported for the 2012 growing season and soil test results, plant tissue analysis, and yield data being reported for the soybeans in 2013 and the corn in 2014. Mean soil test values for pH, organic matter, and total nitrogen, though not always significant, tended to be higher in plots treated with the higher rates of broiler litter. Plots treated with the higher rates of broiler litter and those treated with the past rates of one and two tons per acre rates of broiler litter, which also received high rates of commercial phosphorus (P2O5) and potassium (K2O) fertilizers three years of the study, tended to have higher soil test phosphorus and potassium values. No statistical difference in mean soil test calcium values were observed among the one through seven tons per acre rates of broiler litter treatments in either year. Mean soil test magnesium values were highest in plots treated with the four through seven tons per acre rates of broiler litter. In both 2013 and 2014 mean soil test values for zinc and copper were highest in the plots treated with the seven tons per acre rate of broiler litter, then soil test values declined steadily as the rate of litter applied was reduced. Mean soil test values for boron were only collected in 2013, but followed a similar pattern as zinc and copper. Mean values for manganese did not seem to follow a pattern based on fertility, as in both years the highest values came from the no litter treatment, but were not significantly different from other treatments of moderate to high rates of broiler litter. Though not always significantly different, in both years, mean soil test values for iron tended to be lowest in the no litter and three tons per acre rates of broiler litter treatments. No statistical differences from R5 soybean leaf tissue analysis or R1 corn ear leaf analysis were observed for plant uptake of nitrogen, magnesium, calcium, sulfur, zinc, manganese, or iron. Tissue analysis from both years showed that plant uptake of phosphorus was significantly lower in the plots treated with no litter, than in plots receiving any rate of litter. No statistical difference in plant uptake of potassium was observed from soybean tissue samples in 2013, but R1 corn ear leaf analysis in 2014 revealed that plant uptake of potassium was statistically lower in plots that received no litter, compared to plots that received any rate of broiler litter. Boron and copper uptake were statistically lower in soybeans treated with the seven tons per acre rate of broiler litter than the zero through five tons per acre treatments in 2013, but no statistical difference in boron or copper uptake by corn was observed in 2014. No statistical difference in soybean yield was observed among broiler litter treatments in 2012 due to extended dry periods during the growing season. In 2013 the soybeans treated with past applications of seven tons per acre of broiler litter had statistically higher yields than all other treatments except the one ton per acre treatment, which was not significantly different. In 2014, corn that received the five through seven tons per acre rates of broiler litter tended to have higher yields, due in part to the amount of nitrogen supplied by the litter. In both 2013 and 2014 mean soil test values for copper were significantly higher in the plots receiving the 2009 application of 20 lbs/A of copper and the soil test values declined steadily as the rate applied was reduced. Despite the significant differences in soil test copper values, no statistical differences in plant uptake of copper were observed from R5 leaf tissue analysis in 2013 or R1 corn ear leaf analysis in 2014. Although no statistical differences in yield were observed among the treatments from 2012 to 2014, a strong trend was observed where the plots treated with the 10 lbs/A application of copper in 2009, yielded highest among treatments.
Key Words: Broiler litter, Copper, Soybeans, Corn, Fertilization
Year manuscript completed
Year degree awarded
Broiler Litter, Copper, Soybeans, Corn, Fertilization
Master of Science
Hutson School of Agriculture
Dr. David Ferguson
Dr. David Ferguson
Dr. Alyx Shultz
Dr. Iin Handayani
Dr. John Mikulcik
Gray, Jesse Lee Mr., "EVALUATING THE LONG TERM EFFECTS OF CONTINUOUS BROILER LITTER APPLICATIONS ON RESIDUAL SOIL FERTILITY AND YIELDS OF CORN AND SOYBEAN CROPS, AND A SIDE EXPERIMENT STUDYING THE RESIDUAL COPPER FERTILIZATION EFFECTS ON THESE CROPS" (2017). Murray State Theses and Dissertations. 43.