Conventional commercial broiler production involves the rearing of more than 20,000 broilers in a single confined space for approximately 6.5 wk. This environment is known for harboring pathogens and antibiotic-resistant bacteria, but studies have focused on previously established houses with mature litter microbial populations. In the current study, a set of three naive houses were followed from inception through 11 broiler flocks and monitored for ambient climatic conditions, bacterial pathogens, and antibiotic resistance. Within the first 3 wk of the first flock cycle, 100% of litter samples were positive for and , whereas was cultivation negative but PCR positive. Antibiotic resistance genes were ubiquitously distributed throughout the litter within the first flock, approaching 10 to 10 genomic units g. Preflock litter levels were approximately 10 CFU g for heterotrophic plate count bacteria, whereas midflock levels were >10 colony forming units (CFU) g; other indicators demonstrated similar increases. The influence of intrahouse sample location was minor. In all likelihood, given that preflock levels were negative for pathogens and antibiotic resistance genes and 4 to 5 Log lower than flock levels for indicators, incoming birds most likely provided the colonizing microbiome, although other sources were not ruled out. Most bacterial groups experienced a cyclical pattern of litter contamination seen in other studies, whereas microbial stabilization required approximately four flocks. This study represents a first-of-its-kind view into the time required for bacterial pathogens and antibiotic resistance to colonize and establish in naive broiler houses.

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The implementation of nutrient management plans for confined animal feeding operations requires recording N and P loads from land-applied manure, including nutrients applied in irrigation water from manure treatment lagoons. By regulation, lagoon irrigation water nutrient records in Mississippi must be based on at least one lagoon water nutrient analysis annually. Research in Mississippi has shown that N and P levels in lagoon water, and the N:P ratio, vary significantly through the year. Nutrient estimates based on one annual analysis do not account for this variability and may overestimate or underestimate N and P loads. The present study reports an improved method to more precisely estimate N and P loads in irrigation water from swine manure lagoons. The method is based on predictable annual cycles of N and P levels in lagoon water and employs simple curve-fitting of lagoon-specific formulas derived by analyses of historical data. Similarity of curves from analyses of Mississippi lagoons and other lagoon studies suggests that the method can be applied using the often limited nutrient data for a lagoon to more precisely estimate seasonal shifts of N and P and to improve the precision of estimates for N and P in irrigation water. Although the present study focused on swine manure lagoons in the southern US, recognition that the annual N cycle in lagoon water is temperature driven, suggests that additional research incorporating temperature into future models could extend these models to other types of waste treatment lagoons and climates.

In-house litter composting has been reintroduced to the industry and shown to reduce bacteria by as much as 2 orders of magnitude. Other industries have demonstrated that pathogens can recolonize a waste-residual when microbial competition has been reduced or inhibited following composting. Poultry growers, in the process of shifting to in-house composting for pathogen control, should be aware of this potential problem. A laboratory microcosm study investigated pathogenic bacteria recolonization into composted and noncomposted broiler litter over a simulated broiler grow-out cycle. Objectives were to: 1) determine colonization potential for zoonotic and poultry bacterial pathogens, 2) identify beneficial bacteria which reduce pathogen recolonization, and 3) identify the effects of ammonia on pathogen recolonization. Composted broiler litter allowedListeria andCampylobacter to colonize within the first 2 wk of the grow-out period while noncomposted litter resisted colonization. Colonization was nearly identical by the end of the grow-out period, and showed that bacterial pathogens had essentially been overtaken by commensal or normal bacteria. 16S rRNA libraries demonstrated reductions in Proteobacteria associated with composted litter (48 vs. 16%), which may indicate that this phylum occupies a niche which zoonotic pathogens prefer to occupy. Ammonia generation neither inhibited nor promoted bacterial colonization, as levels were high for both litter treatments. This study neither suggests nor condemns the continued use of this cost-effective, litter-treatment process; findings suggest that while the beneficial microbial population was initially reduced, it quickly recovered and pathogen colonization was neither enhanced nor inhibited because of this. This study demonstrates that the recently adopted in-house composting process may continue to be used, provided poultry health gains continue to be seen.

Disposition of mortalities challenges confined animal feeding operations (CAFOs), especially sow (farrowing) farms, which experience mortalities daily. Regulations and transportation costs may preclude incineration, land-fill burial, and rendering; therefore, swine CAFOs in Mississippi in the Mid-South U.S. often compost mortalities. In this study, a farm-standard composting mix of sawdust (S) and water (W) was compared with mixes where N was supplied by broiler litter (L) and water was replaced with swine lagoon effluent (E). The objective was to assess the effects of these manure byproducts: 1) on nutrients and bacteria in composts destined for land application; and 2) on emissions of ammonia and greenhouse gases. Three replications of four mixes (SW, SLW, SE, SLE) were compared in microcosms comprising modified plastic recycling bins. The experiment was repeated three times in different seasons in one year. Mixes were compared for differences in temperature, water content, nutrients (C, N, P, K, Ca, Mg, Na, Mn, Fe, Cu, Zn), bacteria (Gram-, Gram+, Clostridium perfringens, Salmonella, Listeria, Escherichia coli), and emissions (NH3, CO2, CH4, N2O). Litter addition increased composting temperatures initially and after aerations; increased nutrient concentrations, except C, in start mixes and all except C and N, in finish mixes; increased Gram+ bacteria, Salmonella, and E. coli in start mixes, but only Gram+s in finish mixes; and increased emissions. Effluent addition increased early composting temperatures; had no effect on nutrients or bacteria, except increased C. perfringens in start, but not finish mixes; and had no effect on emissions. Nutrients in finish composts did not differ among mixes for N (average 3.3%), but litter composts had more P and K, and lower N:P than composts without litter. Improving mortality composting is of global importance as increasing livestock populations and intensive animal production systems require practical, safe, environmentally sound disposal of carcasses.

A 3-year study was conducted on a Prentiss sandy loam near Pheba, Mississippi to determine optimum berseem clover (Trifolium alexandrinum L.) seeding rate (SR) for dry-matter (DM) yield and nutrient uptake in an annual clover-perennial bermudagrass [Cynodon dactylon L. (Pers.)] sward, fertilized in April to October with swine effluent. Seed of annual berseem clover (cv. 'Bigbee') was drill-seeded in October at 4, 8, 12, 16, 20 and 24 kg ha(-1) and harvested either twice in April and May (spring) or once in May. Yield of clover harvested twice was less than that harvested once (5410 vs. 7566 kg ha(-1)), but N and P uptake were greater in the double-harvest regime. Annual clover responses to SR were described by quadratic trends. Pooled across years and harvest regimes, the optimum SR for DM yield was 165 kg ha(-1) and for P, Cu and Zn uptake, it was 157, 148 and 160 kg ha(-1), respectively. Bermudagrass DM yield decreased linearly as SR increased by approximately 6.3 and 66.7 kg DM kg seed(-1) in double- and single-harvest regimes, respectively. For clover-bermudagrass, the optimum SR for DM yield was 140 kg ha(-1), and for P, Cu, and Zn uptake, it was 151, 146 and 153 kg ha(-1), respectively. A SR of 14.0-14.9 kg ha(-1) and a first harvest of clover in April appeared to optimize hay yields and uptake of nutrients in clover-bermudagrass. Because bermudagrass N requirement is usually met by swine effluent irrigations, overseeding annual clover would chiefly satisfy producer needs for early forage production.

A sampler was needed for a spatial and temporal study of microbial and chemical stratification in a large swine manure lagoon that was known to contain zoonotic bacteria. Conventional samplers were limited to collections of surface water samples near the bank or required a manned boat. A new sampler was developed to allow simultaneous collection of multiple samples at different depths, up to 2.3 m, without a manned boat. The sampler was tethered for stability, used remote control (RC) for sample collection, and accommodated rapid replacement of sterile tubing modules and sample containers. The sampler comprised a PVC pontoon with acrylic deck and watertight enclosures, for a 12 VDC gearmotor, to operate the collection module, and vacuum system, to draw samples into reusable autoclavable tubing and 250-mL bottles. Although designed primarily for water samples, the sampler was easily modified to collect sludge. The sampler held a stable position during deployment, created minimal disturbance in the water column, and was readily cleaned and sanitized for transport. The sampler was field tested initially in a shallow fresh water lake and subsequently in a swine manure treatment lagoon. Analyses of water samples from the lagoon tests showed that chemical and bacterial levels, pH, and EC did not differ between 0.04, 0.47, and 1.0 m depths, but some chemical and bacterial levels differed between winter and spring collections. These results demonstrated the utility of the sampler and suggested that future manure lagoon studies employ fewer or different depths and more sampling dates.

Ammonia (NH3) volatilized from broiler litter diminishes indoor air quality, which can potentially decrease bird productivity. Emissions of NH3 exhausted from broiler houses pose environmental concerns for ecosystem biodiversity, aquatic nutrient enrichment, and particulate formation in the atmosphere. Research was conducted sampling litter (rice hull base) in 3 tunnel-ventilated commercial broiler houses during wk 3 (mid-growout) of 6 flocks. The purpose was to assess NH3 generated near the sidewalls, waterers, and feeders. Litter samples (100 g) were placed in chambers receiving constant air flow. Boric acid (H3BO3) titration each 24 h for 4 d was used to determine NH3 volatilized from the samples. Litter located near waterers emitted the most cumulative NH3 (approximately 12.3 mg of N•kg of litter(-1)•h(-1)) with less NH3 associated with feeders and sidewalls (2.9 to 7.6 mg of N•kg of litter(-1)•h(-1)). Moisture content of litter samples was greatest at waterers (45%) followed by sidewalls (26%) and feeders (20%). In addition, litter pH at the sidewalls and feeders could be predicted by linear equations associated with the number of flocks on the litter. At the waterers, litter pH was differentiated based on the half of house where higher litter pH existed in the nonbrood half (8.55 vs. 8.13). The results indicate that controlling NH3 near watering lines to a level consistent with feeding lines and near the house wall could reduce NH3 generated by 38 to 77%. These findings support efforts for NH3 control at mid-growout, especially considering zone litter treatments near waterers and appropriate attention to waterer management.

The main objectives of this study were to discern intrahouse spatial and temporal effects on foodborne and nuisance pathogen bacterial levels in actively used commercial broiler litter. The purpose of the study was to provide critical information regarding microbial hot spots, which may be targeted for site-specific litter treatments. A single broiler-concentrated animal feeding operation was monitored throughout 3 consecutive flocks. Salmonella enterica, Listeria monocytogenes, Staphylococcus spp., Enterococcus spp., Clostridium perfringens, and Campylobacter spp. were monitored at specific locations. Additionally, antibiotic resistance characteristics were quantified from bacterial isolates. Clostridium perfringens, Staphylococcus spp., and Enterococcus spp. were consistently present at levels of 7 log(10), 12 log(10), and 8 log(10) cfu/kg of litter, respectively; whereas S. enterica, Campylobacter spp., and L. monocytogenes were not present or present at low levels compared with other bacteria investigated. Temporally, S. enterica was found early in the flock, whereas C. perfringens, Staphylococcus spp., and Enterococcus spp. levels were greater later in the flock. The effect of flock cycle was noted for S. enterica and L. monocytogenes, which were found at greater frequency with the first flock (summer). Salmonella enterica was more commonly associated with the end walls, but overall it appeared that pathogen levels were difficult to predict.

Surface broadcast of broiler litter to no-till row crops exposes the litter and its nutrients to risks of loss in runoff water and volatilization and may limit the potential benefit of litter to the crops. Subsurface banding of litter could alleviate these risks. A field study was conducted in 2008 and 2009 on an upland Falkner silt loam soil to determine the effect of broiler litter placement on runoff nutrient losses from no-till cotton ( L.). Treatments included surface broadcast broiler litter applied manually, subsurface-banded litter applied by tractor-drawn equipment, and no broiler litter, all in combination with or without winter wheat ( L.) cover crop residue. Broiler litter rate was 5.6 Mg ha. The experimental design was a randomized complete block with a split-plot arrangement of treatments replicated three times. In 2008, simulated rainfall was used to generate runoff 27 d after litter application. Subsurface-banded litter reduced runoff total C, N, P, NH, NO, Cu, Zn and water-soluble P (WP) concentrations by 72, 64, 51, 49, 70, 36, 65, and 77%, respectively, compared with surface broadcast. The reductions were greater in 2009 where runoff occurred 1 d after litter application. Bacterial runoff was decreased by one log with subsurface-banded litter compared to surface broadcast. Except for C, NH, N, and WP, the presence of winter cover crop residue did not affect the load or runoff nutrient concentrations in either year. The results indicate that subsurface banding litter to no-till cotton substantially reduces nutrient and bacterial losses in runoff compared with surface broadcasting.

Increasing costs associated with inorganic fertilizer have led to widespread use of broiler litter. Proper land application, typically limiting nutrient loss, is essential to protect surface water. This study was designed to evaluate litter-borne microbial runoff (heterotrophic plate count bacteria, staphylococci, Escherichia coli, enterococci, and Clostridium perfringens) while applying typical nutrient-control methods. Field studies were conducted in which plots with high and low litter rates, inorganic fertilizer, AlCl(3)-treated litter, and controls were rained on five times using a rain generator. Overall, microbial runoff from poultry litter applied plots was consistently greater (2-5 log(10) plot(-1)) than controls. No appreciable effect on microbial runoff was noted from variable litter application rate or AlCl(3) treatments, though rain event, not time, significantly affected runoff load. C. perfringens and staphylococci runoff were consistently associated with poultry litter application, during early rain events, while other indicators were unreliable. Large microbial runoff pulses were observed, ranging from 10(2) to 10(10) CFU plot(-1); however, only a small fraction of litter-borne microbes were recoverable in runoff. This study indicated that microbial runoff from litter-applied plots can be substantial, and that methods intended to reduce nutrient losses do not necessarily reduce microbial runoff.

Overseeded winter annuals in bermudagrass [Cynodon dactylon (L.) Pers.] improve annual dry-matter (DM) yield and capture nutrients in fields receiving manure application. This study determined the DM and nutrient uptake responses of annual ryegrass (Lolium multiflorum L.), cereal rye (Secale cereale), berseem clover (Trifolium alexandrinum L.) and bermudagrass-winter fallow to 0, 50, 100 and 150 kg N ha(-1) applied approximately 2 months before a single spring harvest, and in addition to swine-effluent N (258 and 533 kg ha(-1) in summer 2000 and 2001, respectively). Under drought conditions in 2000, DM yield at the spring harvest was highest in ryegrass, and summer DM yield of bermudagrass was greater at 100 and 150 kg N ha(-1) than 50 kg N ha(-1) (P < 0.05). The concentration and uptake of N at the spring harvest increased linearly across N rates in both years (P < 0.05). Cover crops differed in N uptake in 2000 (P < 0.01) and values ranged from approximately 141 kg N ha(-1) in berseem clover to 86 kg N ha(-1) in rye. Per unit of N applied, uptake of N increased by approximately 0 409 kg ha(-1) in 2000 and 0 267 kg ha(-1) in 2001; uptake of P increased by 0.029 and 0.014 kg ha(-1) respectively. In 2000, uptake of P was responsive to N rate and this relationship was significant (P < 0.01) in winter fallow (slope = 0.032) and ryegrass (slope = 0.057). Increased uptake of N and P at the single spring harvest was due mainly to higher concentrations in herbage and not higher DM yield.

Surface application of broiler litter to no-till cotton could lead to degradation of water quality. Incorporation of broiler litter into the top surface soil (0.05 m) could alleviate this risk. A 2-yr field study was conducted on a silt loam upland soil to determine the effect of incorporation of broiler litter into the soil surface on nutrient and bacterial transport in runoff. The experimental design was a randomized complete block with four treatments and three replications. Treatments were (i) unfertilized control; (ii) surface-appliedbroiler litter at 7.8 Mg ha(-1) without incorporation; (iii) surface-applied broiler litter at 7.8 Mg ha(-1) with immediate incorporation; and (iv) inorganic fertilizer N (urea ammonium nitrate, 32% N) and inorganic fertilizer P (triple superphosphate) at the recommended rate. Phosphorus was surface appliedat 25 kg ha(-1) and N was injected at 101 kg ha(-1) into the soil using a commercial liquid fertilizer applicator. Runoff was collected from small runoff plots (2.4 m by 1.6 m) established at the bottom side of main plots (13.7 m by 6.0 m). Incorporation of broiler litter reduced total N (TN), NO3-N, water soluble P (WSP), and total P (TP) concentrations in runoffby 35, 25, 61, and 64%, respectively, and litter-associated bacteria by two to three orders of magnitude compared with unincorporated treatment. No significant difference in total suspended solids (TSS) in runoffwas obtained between incorporated and unincorporated treatments. Incorporation of broiler litter into the surface soil in the no-till system immediately after application minimized the potential risk for surface nutrient losses and bacteria transport in runoff.

Poultry are known to harbor antibiotic resistant and pathogenic bacteria, and as such poultry litter and poultry house air can be contaminated with these bacteria. However, the presence of antibiotic resistant bacteria in biological aerosols and litter is largely not understood. The purpose of this study was to determine the amount of aerosolized bacteria and endotoxin, particularly fecal indicators, staphylococci, and enterococci, associated with poultry house and outdoor air. Aerosol samples were collected at multiple locations on the farm and in the house. Antibiotic resistance was investigated using the Kirby Bauer method on selected isolates using twelve different antibiotics spanning both narrow to broad spectrums of effectiveness. Overall there was a cyclical increase in bacterial concentrations as flocks progressed from pre-flock to late-flock, with >2 orders magnitude lower concentration during pre-flock periods (no chickens), in both the litter and aerosol samples. The house environment provided for significantly concentrated bacterial and endotoxin levels. It was estimated that Staphylococcus bacteria accounted for at least 90% of cultured aerobic bacteria and culture-independent 16S rRNA analyses demonstrated that significant population changes occurred from pre- to late-flock. Rarely was an isolate resistant to more than 4 antibiotic classes; however there was a trend upwards in overall resistance of enterococci as the flock cycle progressed. It appears that although levels of antibiotic resistant bacteria were highly concentrated within the house, levels were much lower outside of the house, and very little house escape occurred.

Although land application of swine (Sus scrofa) manure lagoon effluent is a common and effective method of disposal, the presence of antibiotic-resistant bacteria, both pathogenic and commensal can complicate already understood issues associated with its safe disposal. The aim of this study was to assess antibiotic resistance in swine lagoon bacteria from sow, nursery, and finisher farms in the southeastern United States. Effluents from 37 lagoons were assayed for the presence of Escherichia coli, Campylobacter, Listeria, and Salmonella. Antibiotic resistance profiles were determined by the Kirby-Bauer swab method for 12 antibiotics comprising eight classes. Statistical analyses indicated that farm type influenced the amount and type of resistance, with nurseries and sow farms ranking as most influential, perhaps due to use of more antibiotic treatments. Finisher farms tended to have the least amount of antibiotic class resistance, signaling an overall healthier market pig, and less therapeutic or prophylactic antibiotic use. Many bacterial isolates were resistant to penicillin, cephalosporin, and tetracycline class antibiotics, while nearly all were susceptible to quinolone antibiotics. It appeared that swine farm type had a significant association with the amount of resistance associated with bacterial genera sampled from the lagoons; nurseries contributed the largest amount of bacterial resistance.

Many contract swine producers are located in the southeastern U.S. In this region almost all of the swine effluent from swine production is applied to warm-season perennial species such as bermudagrass [Cynodon dactylon (L.) Pers.] which is widely grown for summer grazing and hay production. A 3-yr study was conducted to investigate the impact of forage double-cropping on nutrient accumulation and leaching in Mantachie fine loam soil fertilized with swine (Sus scrofa domesticus) lagoon effluent as the source of plant nutrients. Plots of previously established Tifton 44 bermudagrass were overseeded in the fall with one of four winter annuals: berseem clover (Trifolium alexandrinum L.); crimson clover (T. incarnatum L.); ryegrass (Lolium multiflorum L.); or wheat (Triticum aestivum L.). Four plots of bermudagrass were not overseeded and considered as control. Plots were harvested in spring for cool-season annual hay and in summer for bermudagrass hay. Swine effluent was applied during spring and summer on a need base. Suction lysimeters were installed in selected plots at two depths to monitor nutrient leaching. Surface soil samples were taken to determine baseline nutrient contents, followed by three other sampling dates during the study. Bermudagrass dry matter production(3-yr average = 9.8 Mg ha−1) was not adversely affected by the overseeding treatments. Greatest dry matter production was achieved with bermudagrass overseeded with ryegrass (3-yr average  = 11.3 Mg ha−1). Soil pH decreased by almost one unit by the end of the study. While total P (TP) did not change much, Mehlich-3 P (M3-P), K, Cu, and Zn increased significantly, Mg and Mn concentrations decreased by 2002 compared to the baseline levels. Soil P, Mg, K, Fe, Mn, and Zn accumulation were greater under bermudagrass/wheat combination. In general, the influence of double cropping on soil nutrient accumulation was not conclusive, however, this practice provides the year-round green forage for grazing and haying. Nutrient concentrations in soil and lysimeter leachate were directly related to the quantity of effluent applied. Results also demonstrated that effluent application must be coordinated with the nutrient requirements of the growing forages in order to minimize accumulation and leaching.

Bacteriophages (phages) associated with Salmonella were collected from nine swine manure lagoons in Mississippi. Phages were isolated by an enrichment protocol or directly from effluent. For enrichment, chloroform-treated samples were filtered (0.22 mum) and selectively enriched by adding a cocktail of Salmonella strains in trypticase soy broth. After overnight incubation at 35 degrees C, chloroform was added and samples stored at 5 degrees C. Enriched samples were tested by double agar layer (DAL) plaque assay against individual Salmonella isolates. Phage titers of 2.9 x 10(8) to 2.1 x 10(9) plaque forming units (pfu) per mL were produced, but estimation of phage titers in lagoons was not possible. For direct isolation, effluent was clarified by centrifugation, filtered (0.22 microm), and used in DAL plaque assays to select single-plaque isolates for 15 Salmonella strains. Plaque counts varied among Salmonella strains and lagoons. The most sensitive strain for direct phage recovery was ATCC 13311. Phage titers estimated by direct isolation with ATCC 13311 ranged among lagoons from 12 to 148 pfu per mL. In limited host range tests, 66 isolates recovered by the enrichment protocol produced plaques only on Enteritidis and Typhimurium strains of Salmonella and none produced plaques on lagoon isolates of Citrobacter, Escherichia, Proteus, Providencia, or Serratia. Electron microscopy (EM) showed purified enrichment isolates had Podoviridae morphology (tailless 50-nm icosahedral heads with tail spikes). Electron microscopy of clarified concentrated effluent showed 5.5:1 tailless to tailed phages. The isolated phages have potential as typing reagents, specific indicators, and biocontrol agents of Salmonella.

A 3-year study was conducted to investigate the major nutrient dynamics in soil receiving swine effluent as the sole source of plant nutrients for warm-season perennial bermudagrass and cool-season annuals. Berseem and crimson clovers, ryegrass, and wheat were seeded in common bermudagrass for a year-round nutrient uptake and spring through Summer haying. Bermudagrass dry matter of 9.0 mg ha(-1) (3-yr average) was not impacted by the overseeding treatments. Most of the Soil nutrient element concentrations increased during the study, particularly phosphorus in top 5 cm of the soil Surface. The increase of Fe and NO3-N concentration at the 0-5 cm depth was high. Double cropping can be a better practice than growing bermudagrass alone, but, the effluent nutrient application must be coordinated with the nutrient requirements of the growing forages in order to minimize the build up of any nutrient in the soil.

Use of Tifton 44 bermudagrass [Cynodon dactylon (L.) Pers.] in manure nutrient management is limited to summer haying. This study was done to determine how hay yield and nutrient uptake in a manure‐fertilized Tifton 44 field were affected by fall overseeding and spring haying with berseem clover (Trifolium alexandrinum L.), crimson clover (T. incarnatum L.), annual ryegrass (Lolium multiflorum L.), and wheat (Triticum aestivum L.). Overseeding treatments were compared with a nonoverseeded control on Mantachie loam (fine, siliceous, acid, thermic Aeric Fluvaquents) receiving 168 kg P ha−1 in swine (Sus scrofa domesticus) effluent. Spring hay was cut April–June and summer hay July–October 2000–2002. Dry matter (DM) (4.4–5.5 Mg ha−1 yr−1) and P uptake (12.2–17.1 kg ha−1 yr−1) of spring berseem clover hay were higher than the control in 2 of 3 yr and higher than other treatments in 2002. Total DM and P uptake with berseem clover overseeding were 10% higher than the control. Final Mehlich‐3 P soil levels (0–5 cm) tended to be lower in the berseem clover treatment than the control (65 vs. 81 mg kg−1, respectively). Spring berseem clover hay was higher in N (94–122 kg ha−1 yr−1) than the control each year and higher than other treatments in 2 of 3 yr. Summer Tifton 44 hay in the berseem clover treatment had more DM in 2002 and higher N uptake in 2001 and 2002 than other treatments. No treatment reduced Tifton 44 yield or nutrient uptake. Overseeding increased hay yield and nutrient uptake, and berseem clover was as good as or better than other treatments.

Haying common bermudagrass [Cynodon dactylon (L.) Pers.] is commonly used to manage field‐applied manure P in the southeastern USA but is limited to summer. This 3‐yr study was done to examine effects of extending the haying season by spring haying of fall‐overseeded annuals. Berseem clover (Trifolium alexandrinum L.), crimson clover (T. incarnatum L.), annual ryegrass (Lolium multiflorum L.), and wheat (Triticum aestivum L.) were compared with a nonoverseeded control. Dry matter (DM) yield and N and P uptake were measured in spring and summer hay on a Prentiss sandy loam (coarse‐loamy, siliceous, thermic Glossic Fragiudults, Ultisols) with high soil P following 6 yr of swine (Sus scrofa domesticus) effluent fertilization. Fall‐seeded plots were cut twice for spring hay and three times for summer hay. Spring hay of annual ryegrass (3.8–5.3 Mg ha−1 yr−1) yielded more DM than crimson clover (2.6–3.4 Mg ha−1 yr−1), wheat (2.5–3.3 Mg ha−1 yr−1), and the control (2.8–3.4 Mg ha−1 yr−1) every year but did not differ from berseem clover (3.1–4.6 Mg ha−1 yr−1) in 2 of 3 yr. Phosphorus uptake in spring hay of annual ryegrass and berseem clover (10–16 kg ha−1) was higher than crimson clover (8–12 kg ha−1), wheat (7–12 kg ha−1), and the control (6–11 kg ha−1). Nitrogen uptake in spring hay was higher in berseem clover (71–128 kg ha−1) than other treatments (43–80 kg ha−1), which did not differ. No differences occurred in summer hay (DM = 3.9–7.6 Mg ha−1, N = 72–191 kg ha−1, P = 13–21 kg ha−1). Overseeding common bermudagrass with berseem clover or annual ryegrass can improve hay yield and P removal.