A comparison of using poultry litter to using commercial fertilizer for the nutrient management requirements of a cotton crop found that cotton can be grown resulting in as good, if not better yields and as good, if not better returns. The owner of a poultry operation had a better opportunity to have better bottom lines than growers using litter brokers to gain access to poultry litter. Data from deep sampling to three foot revealed little or no differnce in leaching of nitrates and other nutrients of the two systems.
Cotton producers in Darlington County are dealing with high input costs and low revenues. One of the inputs that has really increased in the last 5 years is fertilizer costs. Since manure brokers have come into the county, farmers in an otherwise poultry deficit county, now has access to poultry litter from other locations.
The Objective of this project was to show cotton farmers in Darlington County that applying poultry litter in an environmentally friendly manner, could produce as good or better cotton yields and it could be obtained at equal or at lower costs to conventional fertilizer.
This was an onfarm research grant so three farms were selected that best described the situation across the county as far as cotton production is concerned. One farm bought poultry litter from a broker and used conservation practices such as strip till operations. The second farm had a broiler operation. The farm used its own litter to grow the cotton. This farm used conventional farming practices. The third farm bought its litter through a broker and used conventional farming practices.
On each farm comparisons were made using poultry litter as the fertilizer source versus using commercial fertilizer as the fertilizer source. To make it easier for the involved cooperators these comparisons were made in strips, but it was replicated three times across the field.
Sampling was done throughout the growing season. Soil samples were taken before the growing season and fertilizer or litter was applied according to soil sample results. After the crop was planted, both soil and tissue samples were taken to monitor and compare the crop’s growing conditions. Deep soil samples down to three feet were also taken during and after the growing season to monitor nitrates in the soil profile. Soil and nematode samples were taken on each farm after the crops was harvested.
On each farm, yields and input costs were compared to come up with a profit or loss for each situation/farm.
Of the three years that this project took place 2003 had the worst yields. However after going through a 5 year drought, even ’03 wasn’t so bad. For Farm 1 the fertilizer plots averaged 936 lbs/ac, while the litter plots averaged 946 lbs/ac. Farm 2 had yields not as good, but still respectable. The yields on the fertilizer plots were 724 lbs/ac, while the litter plots averaged 737 lbs/ac. Farm 3 drug up the rear with yields of 611 lbs/ac on the fertilizer plots while the litter for the only time in the entire project was outpaced with only a yield of 581 lbs/ac.
Yields were better in 2004 as we finally recovered from the drought at the turn of the millennium. For Farm 1 the fertilizer plots yielded a respectable 1156 lbs/ac while the litter plots came in with 1246 lbs/ac. At Farm 2 yields were recorded at 834 for the fertilizer plots and 847 lbs/ac for the litter plots. Farm 3 had better yields at 935lbs/ac for the fertilizer Plots and 994 lbs/ac for the litter plots.
Yields topped out in 2005, the final year of the project. The yields at Farm 1 were 1159 lbs/ac for the fertilizer plots and 1208 lbs/ac for the litter plots. Farm 2 came in with yields of 939 lbs/ac in the fertilizer plots and the 954 lbs/ac in the litter plots. Farm 3 had yields of 1261 lbs/ac and the litter plots came in with the highest yield of the entire project with a yield of 1405 lbs/ac.
Average Yields for the entire 3 year project ended up being better overall for the litter plots. At Farm 1 fertilizer plots averaged 1084 lbs/ac while the litter plots pulled in 1133 lbs/ac. Farm 2 averaged 832 lbs/ac in the fertilizer plots and the litter plots averaged 846lbs/ac. Farm 3 averaged 936 lbs/ac in the fertilizer plots, while the litter plots averaged 993 lbs/ac over the three years.
Soil nutrient levels could be built up over the three year period using poultry litter. Soil pH levels was maintained, while P and K levels in the soil were increased. The minor elements were also increased over the three year period in poultry litter plots. Another thing proven was that no additional plant regulators were needed in the manure plots. A good growing season allowed the plant to load up with fruit and cutout in both the fertilizer and litter plots. No problems were noted with regrowth after the cotton had been defoliated in all plots.
Educational & Outreach Activities
Outreach programs occurring during and after this project included presenting results of the project to Darlington County producers during the annual cotton production meeting after the 2003 and 2005 growing seasons. These results were also presented to Lee County cotton producers. A Field Day for both Darlington and Lee County Producers was held during the growing season where farmers were able to make side by side comparisons in the field in 2004. Powerpoint presentations were made to the South Carolina Agricultural Agents Annual Meeting and also to the National Association of Agricultural Agents Annual Meeting. As stated in the project proposal, results were also presented to the Beltwide Cotton Conference in San Antonio, Texas in 2006.
The biggest thing that this project has shown is that cotton producers have some options when planning their fertility program. With fertility costs soaring this project has shown that as good or even better yields can be obtained using poultry litter. This gives them confidence in that either program will work. Many producers have looked at the litter alternative and investigated the availability of using litter instead. Already and it will continue in the future, producers are looking to and investigating the possibility of getting into the poultry industry. This would enable them to utilize their own litter and not have to be at the mercy of a broker and not wonder whether or not the broker could get them enough litter to cover their entire crop. This is the case now for many producers at the mercy of the litter broker. Also more is known about what is in the different types of poultry litter used in Darlington and Lee Counties.
Another thing that was proven is that anytime a byproduct like litter could be used instead of commercial fertilizers, the environment as a whole was improved and the green fingerprint on these farms were improved.
The biggest thing economically that became evident over the course of this project was that the litter broker has a sharp pencil. Each year the price of his litter rose approximately the exact amount that commercial fertilizer went up. Of course the cost per acre was just under that of the fertilizer to make it enticing for the farmer to look at this alternative.
However, it was also evident a poultry producer had a distinct advantage in this aspect. The poultry producer could utilize his by product and use it to his advantage. It was much cheaper for this producer to have his litter custom spread on his land.
Fertility Costs for the three farms was diverse. On Farm 1 and Farm 3, farms that both used litter brokers, the cost difference was from about a $.80 loss per acre for Farm 1 using litter to a cost savings of $5.14 per acre advantage using litter. However, Farm 2 who used his own litter could save over $60.00 per acre on his fertility costs and this information really made an impression with growers.
In Darlington County alone, over 15 farms have adopted production methods using poultry litter in the fertility program of their cotton crop. In Lee County more farms adopted these practices and others who were already using litter had a better idea of the levels of litter needed to produce a productive cotton crop. This project has reached numerous producers in a two county area in the largest cotton region of South Carolina. From this two county region, over 100 producers have seen and heard results of this project, through production meetings and a field day. In addition to this, another 75 extension agents were given results of this project at state and national association meetings. Finally, at the Beltwide Cotton Conference, over 110 cotton producers, cotton specialists, and other Extension Professionals were able to hear and learn of this project.
Areas needing additional study
One thing that was not compared was fiber quality. Would litter have an effect on cotton fiber quality?