Location: Soil Dynamics Research2011 Annual Report
1a. Objectives (from AD-416)
Develop and evaluate animal waste management strategies for reducing greenhouse gas emissions in conservation tillage systems in the Tennessee Valley region of North Alabama.
1b. Approach (from AD-416)
Data collection and soil sampling will be imposed on an ongoing field plot experiment at the Winfred Thomas Agricultural Experiment Station, Hazel Green, Alabama. The Winfred Thomas Agricultural Experiment Station is owned and operated by the Department of Natural Resources and Environmental Sciences at Alabama A&M University. A total of 14 treatments are being used in the study consisting of two tillage systems: conventional and no-tillage; three fertilizer treatments: 0 kg N ha-1 (control), 100 kg N ha-1 in the form of poultry litter and 100 kg N ha-1 in the form of inorganic N fertilizer; and three fertilizer application methods: surface application, soil incorporation, and subsurface band application. In addition, an undisturbed grass fallow treatment to determine baseline or background soil properties will be studied. Soil CO2 emissions will be measured, Plants will be measured for yield and plant nutrient uptake ,and soil samples will be collected and analyzed for nutrient enrichment. The information generated from this study will be used to advance knowledge on environmental aspects of animal waste management in conservation tillage systems. The results from this study will provide science-based information to assess the impact of animal waste management strategies on soil C dynamics (emissions vs storage) and C sequestration in conservation tillage crop production systems in the Tennessee Valley region of North Alabama.
3. Progress Report
A study to investigate nitrogen uptake pattern by cotton (Gossypium hirsutum L.) at different growth stages in response to long-term poultry litter (PL) application in no-till system (NT) was carried out at the Tennessee Valley Research and Extension Center at Belle Mina, AL. The study was done in plots which were established in 1996 on a Decatur silt loam soil. Treatments included incomplete factorial combinations of three tillage systems [conventional till (CT), mulch-till (MT), and no-till (NT)], two cropping systems [cotton- fallow and cotton-winter rye (Secale cereale L.)], and two nitrogen sources and rates [100 kg Nitrogen (N) ha 1 from ammonium nitrate (AN), and 100 and 200 kg N ha 1 from PL]. Results showed that NT and CT systems supplied similar quantities of N at all cotton growth stages. We also found that NT system recorded similar cotton growth, yield, and total nitrogen uptake compared to CT system. Application of PL at 100 kg N ha 1 resulted in significantly better plant growth compared to AN at the early growth stage, but the differences disappeared later in later growth stages of the crop. Similar yields and N uptake were observed with application of PL or AN at 100 kg N ha 1. Application of a double rate of PL (200 kg N ha 1) resulted in significantly higher nitrogen uptake compared to that of PL or AN at 100 kg N ha 1, but a significant yield advantage was not observed with this higher rate. Of the total nitrogen extracted by cotton at maturity, 50% uptake was completed by early flowering stage and 97% was completed by boll development stage. At maturity, the majority of nitrogen (52%) was partitioned into seeds, while the rest was distributed into leaves (16%), stems (18%) and reproductive parts (14%). Nitrogen uptake by cotton was not influenced by winter rye cover crop. In an effort to continue Alabama A&M’s collaborative research partnership with the USDA/ARS Soil Dynamics Laboratory at Auburn AL, a new research project entitled “Animal Waste Management Strategies for Reducing Greenhouse Gas Emissions in Conservation Tillage Cropping Systems in the Tennessee Valley Region of North Alabama” was developed and submitted to USDA/ARS. The goal of the collaborative study is to investigate soil CO2 emissions to assess soil C sequestration in conservation tillage corn production systems following two seasons of poultry litter application using surface, band, and soil incorporation application methods. Continuation of this project, initially targeted to run up to 2015, will be based on availability of funding. The ADODR has monitored activities via email and telephone correspondence, collaborator meetings, and site visits.