Nutrient Sufficiency Ranges for Corn at the Early Growth Stage: Implications for Nutrient Management.

Growers rely on nutrient sufficiency ranges (NSRs) after plant tissue analysis to inform timely nutrient management decisions. The NSRs are typically established from survey studies across multiple locations, which could be confounded by several abiotic and biotic factors. We conducted field studies in 2020, 2021, and 2022 to validate the lower thresholds of the NSRs for corn () at the early growth stage as reported in the Southern Cooperative Series Bulletin #394.

Molecular Hallmarks, Agronomic Performances and Seed Nutraceutical Properties to Exploit Neglected Genetic Resources of Common Beans Grown by Organic Farming in Two Contrasting Environments.

Common bean ( L.) is an essential source of food proteins and an important component of sustainable agriculture systems around the world. Thus, conserving and exploiting the genetic materials of this crop species play an important role in achieving global food safety and security through the preservation of functional and serependic opportunities afforded by plant species diversity.

Spatial Distribution of Inorganic Nitrogen in Pastures as Affected by Management, Landscape, and Cattle Locus.

Uneven spatial distribution of soil N in conventionally managed pastures is a function of various biotic and abiotic factors and results in poor land use efficiency. In this study, we measured soil inorganic N (at depths of 0-5, 5-10, and 10-20 cm) in a 50-m grid and specific areas of interest from eight conventionally managed beef pastures (∼17 ha each), four near Eatonton and four near Watkinsville in the southern Piedmont of Georgia, USA, to assess the effects of management, landscape, and cattle locus in spatial distribution of soil inorganic N. Significant spatial autocorrelation was observed in the soil inorganic N indicating that the regions of high inorganic N deposition were near (within 91 m of) one or more pasture equipage (hay, shade, and water).

Metals in Soil and Runoff from a Piedmont Hay Field Amended with Broiler Litter and Flue Gas Desulfurization Gypsum.

Flue gas desulfurization gypsum (FGDG) from coal-fired power plants is readily available for agricultural use in many US regions. Broiler litter (BL) provides plant available N, P, and K but can be a source of unwanted As, Cu, and Zn. As a source of Ca and S, FGDG can reduce losses of P and other elements in runoff from BL-amended areas.

Ammonia Oxidizers in a Grazing Land with a History of Poultry Litter Application.

Poultry litter (PL) is widely applied on grazing lands in Georgia. However, it is not clear how its long-term use affects soil microorganisms and their function. We examined changes in activity and community structure of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in a grazing land with a history of PL application and compared it to treatment with urea ammonium nitrate (UAN).

Rainfall-induced release of microbes from manure: model development, parameter estimation, and uncertainty evaluation on small plots.

A series of simulated rainfall-runoff experiments with applications of different manure types (cattle solid pats, poultry dry litter, swine slurry) was conducted across four seasons on a field containing 36 plots (0.75 × 2 m each), resulting in 144 rainfall-runoff events. Simulating time-varying release of Escherichia coli, enterococci, and fecal coliforms from manures applied at typical agronomic rates evaluated the efficacy of the Bradford-Schijven model modified by adding terms for release efficiency and transportation loss.

Alum and Rainfall Effects on Ionophores in Runoff from Surface-Applied Broiler Litter.

Polyether ionophores, monensin, and salinomycin are commonly used as antiparasitic drugs in broiler production and may be present in broiler litter (bird excreta plus bedding material). Long-term application of broiler litter to pastures may lead to ionophore contamination of surface waters. Because polyether ionophores break down at low pH, we hypothesized that decreasing litter pH with an acidic material such as aluminum sulfate (alum) would reduce ionophore losses to runoff (i.

Flue gas desulfurization gypsum: implication for runoff and nutrient losses associated with broiler litter use on pastures on ultisols.

Gypsum has been shown to reduce runoff on soils prone to crust formation in the southeastern United States. Increased infiltration from gypsum applications could therefore help reduce runoff P and other nutrient losses from application of broiler litter (BL), a nutrient-rich fertilizer. In rainfall simulation experiments in June 2009 and May 2011, runoff and nutrient (N, P, Ca, Mg) losses in runoff were compared among treatments consisting of 0, 2.

Rainfall and tillage effects on transport of fecal bacteria and sex hormones 17beta-estradiol and testosterone from broiler litter applications to a Georgia Piedmont Ultisol.

Poultry litter provides nutrients for crop and pasture production; however, it also contains fecal bacteria, sex hormones (17beta-estradiol and testosterone) and antibiotic residues that may contaminate surface waters. Our objective was to quantify transport of fecal bacteria, estradiol, testosterone and antibiotic residues from a Cecil sandy loam managed since 1991 under no-till (NT) and conventional tillage (CT) to which either poultry litter (PL) or conventional fertilizer (CF) was applied based on the nitrogen needs of corn (Zea mays L) in the Southern Piedmont of NE Georgia. Simulated rainfall was applied for 60 min to 2 by 3-m field plots at a constant rate in 2004 and variable rate in 2005.

Evaluating aeration techniques for decreasing phosphorus export from grasslands receiving manure.

Because surface-applied manures can contribute to phosphorus (P) in runoff, we examined mechanical aeration of grasslands for reducing P transport by increasing infiltration of rainfall and binding of P with soil minerals. The effects of three aeration treatments and a control (aeration with cores, continuous-furrow "no-till" disk aeration perpendicular to the slope, slit aeration with tines, and no aeration treatment) on the export of total suspended solids, total Kjeldahl P (TKP), total dissolved P (TDP), dissolved reactive P (DRP), and bioavailable P (BAP) in runoff from grasslands with three manure treatments (broiler litter, dairy slurry, and no manure) were examined before and after simulated compaction by cattle. Plots (0.

Ground cover impacts on nitrogen export from manured riparian pasture.

Maintaining ground cover of forages may reduce the export of nitrogen (N) from pastures. The objective of this work was to determine the effect of ground cover on N export from pastured riparian areas receiving simulated rainfall. Plots were established on two adjacent sites in the North Carolina Piedmont: one of 10% slope with Appling sandy loam soils and a second of 20% slope with Wedowee sandy loam soils.

Ground cover impacts on sediment and phosphorus export from manured riparian pasture.

Maintaining pasture ground cover is important in preventing environmental degradation of grasslands and associated riparian areas. The objective of this work was to determine the effect of ground cover on sediment and P export from pastured riparian areas under simulated rainfall events. Plots were established on two sites in the North Carolina Piedmont: a 10% slope with Appling sandy loam soils (fine, kaolinitic, thermic Typic Kanhapludults) and a 20% slope with Wedowee sandy loam soils (fine, kaolinitic, thermic Typic Kanhapludults), both with mixed tall fescue (Festuca arundinacea Schreb.

Combined effects of constant versus variable intensity simulated rainfall and reduced tillage management on cotton preemergence herbicide runoff.

Pesticide runoff research relies heavily on rainfall simulation experiments. Most are conducted at a constant intensity, i.e.