Alfalfa, a perennial with perfect flowers, is naturally crosspollinated by bees, tolerates comparatively little inbreeding, and can be vegetatively propagated by stem cuttings. The level of breeding alfalfa, identification of types generally adapted to a given region, is ecotype selection. The superiority of index selection as a breeding method increases with an increase in the number of traits under selection and decreases when the traits differ greatly in importance, or when selection intensity is increased. There have been numerous studies of the genetic segregation of qualitative trait differences among alfalfa clones. The development of genetic theory for cross-pollinated autotetraploid species, such as alfalfa, has been minimal in comparison with genetic theory developed for diploids. For all genetic model development, simplifying assumptions are necessary and the extrapolation of results as descriptions or predictions must be made on the basis of those assumptions.

Thorough characterization of litter within broiler houses provides end users with the information necessary to optimize litter utilization and their processes. Approximately 1100 samples were assessed within four commercial broiler houses in Mississippi. Results included litter temperature, moisture, and pH, and concentration of litter nutrients and minerals as well as in-situ estimation of NH3, N2O, and CO2 flux from the litter that had been reused for 8 to 30 flocks. Traditional statistics were employed to determine the effects of season, bird age, and half of house. Mean gas fluxes were 477 ± 427 mg NH3 m-2 h-1, 14.9 ± 14.1 mg N2O m-2 h-1, and 13900 ± 10700 mg CO2 m-2 h-1. Litter temperature was 28 ± 5 °C; moisture was 27.8 ± 8.4 %; pH was 8.3 ± 0.4. Overall N content was 2.76 ± 0.54 %. Most minerals had a greater concentration during summer growouts and in the brood half of the houses, There was a trend for decreased litter pH at the mid-flock age and the non-brood (fan) end of the house had greater litter pH overall. Gas flux increased with bird age. Ultimately, the user’s goal for the data will determine its utility. For growers, keeping litter dry is imperative to maintain lower NH3 emissions. For integrators, house structural remodeling and/or mid-flock litter treatment may be required to improve management strategies. For researchers, the data set provides a basis for modeling which is urgently needed to enhance emission estimates. For bulk litter users, the variability of litter characteristics is presented.

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.

Broiler litter use has largely been associated with land application as fertilizer. Reducing the NH3 released from litter enhances its fertilizer value (more N) and negates detrimental effects to the environment. A laboratory study was conducted to quantify the effect of airflow variation on litter NH3 volatilization. Increasing the airflow rate increased NH3 volatilization. The lower flows (8.4 and 16.9 L of air/h per L of litter) generated 59 and 86% of the NH3 generated, respectively, as compared with the highest flow (25.3 L of air/h per L of litter). By specifically studying flow rate per volume of litter, the results provide a basis for needed mitigation technologies to combine forced ventilation with other parameters known to increase NH3 generation (e.g., high temperature). Practical applications to reduce NH3 emissions on the farm may include covering litter stockpiles to reduce wind flow over them or using intense ventilation between flocks coupled with an NH3 scrubber.

Negative impacts on the environment, bird well-being, and farm worker health indicate the need for abatement strategies for poultry litter NH(3) generation. Type of bedding affects many parameters related to poultry production including NH(3) losses. In a randomized complete block design, 3 trials compared the cumulative NH(3) volatilization for laboratory-prepared litter (4 bedding types mixed with excreta) and commercial litter (sampled from a broiler house during the second flock on reused pine wood chips). Litters were assessed at the original moisture content and 2 higher moisture contents. Broiler excrement was mixed with pine wood shavings, rice hulls, sand, and vermiculite to create litter samples. Volumetrically uniform litter samples were placed in chambers receiving humidified air where the exhaust passed through H(3)BO(3) solution, trapping litter-emitted NH(3). At the original moisture content, sand and vermiculite litters generated the most NH(3) (5.3 and 9.1 mg of N, respectively) whereas wood shavings, commercial, and rice hull litters emitted the least NH(3) (0.9-2.6 mg of N). For reducing NH(3) emissions, the results support recommendations for using wood shavings and rice hulls, already popular bedding choices in the United States and worldwide. In this research, the organic bedding materials generated the least NH(3) at the original moisture content when compared with the inorganic materials. For each bedding type, incremental increases in litter moisture content increased NH(3) volatilization. However, the effects of bedding material on NH(3) volatilization at the increased moisture levels were not clearly differentiated across the treatments. Vermiculite generated the most NH(3) (26.3 mg of N) at the highest moisture content. Vermiculite was a novel bedding choice that has a high water absorption capacity, but because of high NH(3) generation, it is not recommended for further study as broiler bedding material. Controlling unnecessary moisture inputs to broiler litter is a key to controlling NH(3) emissions.

With global food demand expected to increase by 100% in the next 50 yr, urgency to combine comprehensive strategies for sustainable, efficacious, and environmentally sensible agronomic practices has never been greater. One effort for US meat bird management is to reduce NH(3) volatilization from litter to create a better growing environment for the birds, improve production efficiency, retain N in litter for fertilizer value, and negate the detrimental environmental impacts of NH(3) loss to the air. To derive the fundamental effects of temperature and moisture on litter NH(3) volatilization over the range of conditions found in commercial houses, experiments were conducted using commercial broiler litter that had moisture contents of approximately 20 to 55% while controlling temperatures ranging from 18.3 to 40.6°C. Litter samples (100 g) were placed in 1-L containers that received humidified air at approximately 113 mL/min. Volatilized NH(3) in exhaust air was captured in H(3)BO(3) traps. Ammonia loss (log(10) transformation) was modeled via an equation using linear coefficients for temperature and moisture, an interaction term for temperature × moisture, and a quadratic term for moisture. The surface responses resembled parabolic cylinders, indicating a critical moisture level at which NH(3) no longer increases but is diminished as moisture continues to increase. The critical moisture level lies between 37.4 and 51.1% litter moisture, depending on the temperature. An increase in temperature consistently increased NH(3) generation. When the temperature extremes were compared, the maximum NH(3) was up to 7 times greater at 40.6 vs. 18.3°C. The upper moisture limit at which NH(3) release is maximized and subsequently arrested as moisture continues to increase had not been defined previously for commercial broiler litter. The poultry industry and researchers can use these results as a decision tool to enable management strategies that limit NH(3) production.

Increasing interest of using broiler litter in the fall for row crops has implications for leaching losses of nutrients, particularly N. Any cultural practice that prevents nutrient losses could be agronomically beneficial and improve soil fertility. A field study was conducted in 2007 and 2008 on Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) soil to evaluate the impacts of a winter rye (Secale cereal L.) cover crop and broiler litter timing on cotton (Gossypium hirsutum L.) yield, yield components and leaching loss of NO3-N. Broiler litter was applied to the soil at the rates of 0, 4.5, 9, and 13.4 Mg ha(-1) in the fall and spring for both cover and no cover crop and incorporated immediately. Winter rye cover crop was planted following broiler litter application in the fall. Averaged across cropping system and broiler litter timing, cotton lint yield and yield components increased with increasing broiler litter application. Application of broiler litter at a rate >9 Mg ha(-1) was not advantageous and exceeded N need for optimum lint yield as evidenced by increasing postharvest NO3-N in the soil profile. In the absence of cover crop and averaged across litter rates, spring-applied broiler litter had the best agronomic response and increased lint yield by 19 and 18% compared with fall-applied litter in 2007 and 2008, respectively. Seeding a winter rye cover crop to fall-applied broiler litter did not benefit cotton lint yield and yield components but substantially reduced leaching loss of NO3-N.

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.

The effects of in ovo injection of different carbohydrate solutions on hatchability of fertilized eggs (HF), rate of hatch, BW, body moisture, yolk sac weight, and yolk sac moisture of Ross × 708 broiler chicks, hatched from eggs laid by a 34-wk-old breeder flock, were investigated. Eggs containing live embryos were injected, using an automated multiple-egg injector, in the amnion on d 18.5 of incubation with 0.1, 0.4, 0.7, or 1.0 mL of commercial diluent or a carbohydrate dissolved in diluent. The commercial diluent containing 0.25 g/mL of one of the following carbohydrates was injected into eggs: glucose, fructose, sucrose, maltose, or dextrin. The results showed that no carbohydrate type or solution volume affected rate of hatch. Absolute and proportional BW on day of hatch were positively related to injection volume (P < 0.001). However, HF was negatively related to injection volume (P < 0.001). To realize an HF of 90%, the injection volume could not exceed 0.4 mL for fructose or sucrose and could not exceed 0.7 mL for glucose, maltose, or dextrin. Yolk-free BW was negatively related to injection volume of fructose and sucrose (P < 0.004), but was not related to injection volume of diluent, glucose, maltose, and dextrin. Conversely, absolute and proportional yolk sac weights were positively related to injection volume of fructose, sucrose, and dextrin (P < 0.01), but were also not significantly related to injection volume of diluent, glucose, and maltose. Yolk sac moisture was positively related to injection volume for all injectables, including the diluent (P < 0.03). However, body moisture and yolk-free body moisture were not related to injection type or volume. In conclusion, the use of carbohydrates added to a commercial diluent for the in ovo injection of broiler hatching eggs requires the use of appropriate volumes to promote growth and nutrient utilization without adversely affecting HF.

Poultry litter is an effective N fertilizer for cotton. Litter contains substantial amounts of K and Mg also, but whether the K and Mg needs of cotton can be met by the commonly recommended litter rate has not been documented. The objectives of this research were to determine if cotton receives sufficient K from the application of the commonly recommended litter rate of 4.5 Mg ha(-1) and if Mg derived from the same litter rate improves cotton Mg nutrition. The research was conducted from 2002 to 2004 in Mississippi at Coffeeville and Cruger, which had contrasting soil K and Mg levels. The soil at Coffeeville had approximately five times less extractable K and approximately 22 times less extractable Mg than the soil at Cruger. Cotton at each location was fertilized with 2.2, 4.5, or 6.7 Mg ha(-1) broiler litter in an incomplete factorial combination with 0, 34, or 67 kg ha(-1) N as urea-ammonium nitrate solution (UAN). The results showed cotton received sufficient K from 4.5 Mg ha(-1) litter, a rate previously found to be insufficient in meeting the N requirement of cotton. Unlike K, Mg concentration in the plant did not respond to increased applied litter rate but showed a strong response to supplemental UAN-N rate, which suggests the external N supply might be more important to cotton Mg nutrition than the external Mg supply. The results showed that K nutrition of cotton depended on the rate of applied litter, whereas Mg nutrition is dependent on whether the cotton received sufficient N fertilization.

Estimates of litter value based on crop yield equivalency to inorganic fertilization may reflect the actual value of litter more accurately than estimates based on its N, P, and K content. The primary objective of this research was to identify a rate of broiler litter that results in cotton lint yield equivalent to inorganic N fertilization and to estimate litter value based on this yield equivalency. The research was conducted in northern Mississippi in 2002 to 2004 in a Loring silt loam upland soil. Cotton was fertilized with six broiler litter rates ranging between 2.2 and 13.4 Mg ha−1 or six NH4NO3–N rates ranging between 34 and 168 kg ha−1 or was not fertilized. Lint yield calculated based on fitted models peaked at 1033 kg ha−1 when cotton was fertilized with 94 kg ha−1 NH4NO3–N, which is similar to the 90 kg N ha−1 local recommendation. Lint yield of cotton fertilized with litter (8.7 Mg ha−1) peaked at 1156 kg ha−1, which is a 123 kg ha−1 lint yield increase over NH4NO3–N. The economic optimum NH4NO3–N rate was 72 kg ha−1, which produced 88 kg ha−1 less lint than the economic optimum litter rate of 5.2 Mg ha−1 Fertilization with 3.7 Mg ha−1 litter produced lint yield equivalent to the locally recommended 90 kg ha−1 NH4NO3–N. The N fertilizer replacement value of litter calculated based on this equivalency exceeded the value calculated using the traditional method by ≈27%. These results overall show that fertilizing cotton in this soil with litter increased lint yield above that possible with conventional inorganic fertilization by 12% and that broiler litter is substantially more valuable than can be estimated from its N, P, and K contents.

Effectiveness of surface-applied unincorporated broiler litter as a fertilizer relative to conventional inorganic fertilizers under no-till or conventional-till cotton (Gossypium hirsutum L.) production systems in the upland soils of the southern and southeastern USA is not well documented. The objectives of this research were to (1) test if broiler litter improves plant macronutrient (N, P, K, and Mg) nutrition of cotton above that of cotton fertilized with conventional inorganic fertilizers and (2) determine if lack of incorporating litter into the soil reduces macronutrient concentration in cotton plant parts in an upland soil considered marginal for cotton. Six treatments consisting of an unfertilized control, a fertilized standard (STD), two litter-only, and two litter plus inorganic N as urea–ammonium nitrate solution (UAN) were tested in two adjacent fields, one under no-till (NT) and the other under conventional-till (CT) systems. Litter alone, UAN, or a combination of litter plus UAN were applied to supply 101kgha−1 plant available N assuming nearly all of the UAN-N and 50% of the total litter N becomes plant available during the cotton growing season. Concentration of N, P, K, and Mg were measured in leaves, stems, and reproductive parts on three or four dates between early flowering and maturity. Cotton fertilized with the litter-only treatments always had less N concentration but greater P and K concentration in leaves, stems, and reproductive parts than cotton that received the STD treatment. Leaf and stem Mg concentration seems to depend on the N concentration in these plant parts. Lack of incorporating litter into the soil reduced N concentration in nearly all plant parts at all growth stages, suggesting some amount of the litter-derived N is lost due to lack of incorporation. Lack of incorporation also reduced leaf and stem Mg concentration, which seemed to be due to its reducing effect on N concentration. Unlike N and Mg, lack of incorporation did not consistently affect concentrations of P and K in all plant parts. Regardless of the incorporation treatment, fertilization with the litter-only treatments increased tissue P and K concentration and supported lint yield exceeding that of the STD without increasing tissue N concentration.

Poultry litter may benefit continuous cotton ( Gossypium hirsutum L.) production in the heavier Midsouth soils in the same way as crop rotation. The objective of this research was to determine the effectiveness of poultry litter in maintaining yield of continuous cotton compared with cotton‐corn ( Zea mays L.) rotation in the Black Belt Prairie clay soils of Mississippi. The research was conducted in a Catalpa silty clay loam soil in northern Mississippi. Three main plots with the sequence cotton‐cotton‐cotton, cotton‐corn‐cotton, and corn‐cotton‐cotton in 2003–2004–2005 were split into five subplots each of which received 0, 4.5, 9.0, 13.5 Mg litter ha −1 yr −1 , or 123 kg N ha −1 yr −1 as urea‐ammonium nitrate solution (32% N; UAN) (conventional inorganic fertilization, CIF). The CIF received 180 kg ha −1 UAN‐N when planted with corn. The results showed 3‐yr continuous cotton produced about the same lint yield as cotton that followed corn or 1 yr cotton. Unlike soils in other locations where ≤9.0 Mg ha −1 litter was adequate to produce yield equal to standard inorganic fertilization, cotton in this soil responded to litter up to 13.5 Mg ha −1 , which suggests lint yield in this clayey soil may be optimized with greater litter fertilization rate than in lighter soils. Cotton fertilized with 13.5 Mg ha −1 litter, regardless of the rotation, outyielded the CIF by up to 26%. Overall, the results show adequate fertilization with poultry litter may be more important to improving and maintaining lint yield in this soil than the perceived benefit of a short‐term rotation with corn.

Understanding the effects of management practices on soil properties is necessary because soil properties are directly related to the capacity of soil to function. Soil physical, chemical and biological properties were determined after 3 yr in three cropping sequences [continuous cotton (Gossypium hirsutum L.) (CCC), cotton‐corn (Zea mays L.)‐cotton (CMC), and corn‐cotton‐cotton (MCC) each at four broiler litter fertilization rates (0, 4.5, 9, and 13.4 Mg ha−1) to a soil depth of 15 cm on a Catalpa silty clay loam soil in Verona, MS. Inorganic N fertilizer was applied at the rate of 123 kg ha−1 yr−1 to cotton and 180 kg ha−1 yr−1 to corn. Averaged across crop sequences, broiler litter application significantly increased soil nutrient concentrations, microbial biomass C (MBC), total porosity, and aggregate stability (AS). The inclusion of corn into rotation with cotton increased soil MBC, AS, and reduced bulk density (Db). Application of broiler litter at rate greater than 9 Mg ha−1 to CCC resulted in increasing NO3–N concentration at the lower 30‐cm depth and P accumulation by fourfold at the 0‐ to 5‐cm depth. Rotating cotton with corn in this study improved soil quality parameters and decreased NO3–N and P accumulation at the soil surface by approximately 24 and 20%, respectively. Hence, corn is sown in rotation with cotton in Mississippi, the Mississippian cotton industry could potentially improve soil organic carbon, nutrient cycling, and soil quality if broiler litter is used as the nutrient source.

Greater understanding of the mechanisms affecting NH3 volatilization from reused broiler bedding is needed to determine path-ways for mitigating NH3 emissions. A chamber acid trap (CAT) system was developed to provide an improved laboratory method for determining NH3 volatilization from litter or cake samples and for assessing treatment technologies to decrease NH3 losses from Poultry litter. The CAT system offers precision control of air flow rate through sample chambers as well as straightforward, precise determination of the amount of N volatilized. This article outlines the basic Setup of the CAT system. The system can be utilized and modified for researching specific mechanisms involving physical. chemical, or biological treatments affecting NH3 volatilization from litter or cake.

The effectiveness of poultry litter as cotton ( Gossypium hirsutum L.) fertilizer is not well documented for upland soils in the southern and southeastern United States. The objective of this research was to measure cotton yield response to broiler litter fertilization in contrast to inorganic N fertilization and to quantify yield reduction due to lack of incorporation under no‐till and conventional‐till systems in an upland soil. Six treatments were tested in two unreplicated adjacent fields, one under no‐till (NT) and the other under conventional‐till (CT) management, from 2003 to 2006 near Pontotoc, MS. The treatments consisted of an unfertilized control (UTC), a standard fertilization (STD) with urea‐ammonium nitrate solution (UAN), fertilization with ∼5.2 Mg ha −1 incorporated or unincorporated broiler litter to supply 67% of the N need plus 34 kg ha −1 UAN‐N to supply 33% of the N need, and fertilization with ∼7.8 Mg ha −1 incorporated or unincorporated broiler litter. Lint yield results showed broiler litter was a more effective cotton fertilizer than inorganic fertilizers under both NT and CT systems. The UTC produced an average across years of 870 kg ha −1 lint under NT and 1105 kg ha −1 under CT. The STD treatment increased yield over the UTC by only 121 kg ha −1 (14%) under the NT and did not affect yield under the CT. Fertilization with litter‐only when incorporated, relative to the UTC, increased lint yield by 260 kg ha −1 (30%) under NT and by 137 kg ha −1 (12%) under CT. The yield of this incorporated litter‐only treatment exceeded the yield of the STD treatment by 139 kg ha −1 (14%) under NT and by 115 kg ha −1 (10%) under CT. Fertilization with litter also resulted in greater leaf area index but less chlorophyll index than the STD treatment. Lack of litter incorporation reduced yield by up to 84 kg ha −1 under NT but did not affect yield under CT. Overall, broiler litter appears to be a more effective cotton fertilizer than conventional inorganic N fertilizers for this upland soil, but the inherent inability to incorporate under no‐till may reduce this benefit.

Understanding how animal activities, management, and barn structure affect litter gases and nutrients is fundamental to developing accurate emission models for meat-bird facilities. This research characterized the temporal and spatial variability of litter ammonia (NH3) and nitrous oxide (N2O) flux via a chamber method, as well as determined litter nitrogen (N) compounds by intensive sampling in two commercial broiler houses on aged litter. Thirty-six grid samples were taken during a winter flock in Mississippi on days 2, 22, and 45. On day 45, eight additional samples were taken near the feeders and waterers (F/W). Geostatistical contour plots indicate NH3 flux on day 2 was elevated in the brood area of house one (H1) where litter and air temperatures were highest; a commercial litter treatment held the NH3 flux near zero for approximately 45% of the brood area in house two (H2). Day 45 NH3 fluxes were similar, averaging 694 mg m−2 h−1 in H1 vs. 644 mg m−2 h−1 in H2; both houses exhibited greater NH3 flux near the cooling pads. Ammonia flux, litter moisture and pH were diminished at the F/W locations. Heavy cake near the exhaust fans provided the lowest recorded litter pH, highest litter moisture and ammonium (NH4) with no NH3 flux at the flock's end. Trends in litter condition based on bird activity were evident, but individual differences persisted between the houses. The importance of cake formation over the litter surface and differences based on location, both related to bird activity and house structure, should be considered in NH3 mitigation strategies.

Knowledge of the magnitude of P extracted and removed by harvested crop is an important component of effectively managing poultry litter to minimize or prevent the buildup of P in soil. This knowledge does not exist or is not well documented in cotton fertilized with litter as the primary fertilizer. The objective of this research was to quantify the magnitude of P extracted by cotton when fertilized with broiler litter and to determine whether supplementing litter with inorganic N improves P extraction. The research was conducted from 2002 to 2004 on two commercial farms representing a conventional‐till at Cruger and a no‐till at Coffeeville, MS, USA. At each location, the treatments consisted of an unfertilized control; a farm standard (STD) fertilized with inorganic fertilizers; and broiler litter of 2.2, 4.5, and 6.7 Mg ha−1 in an incomplete factorial combination with 0, 34, or 67 kg ha−1 N as urea ammonium nitrate (UAN) solution. The unfertilized control extracted an average across years of 27.7 kg P ha−1 at Cruger and 26.0 kg P ha−1 at Coffeeville. Application of both litter and UAN‐N decreased tissue P concentration but increased extracted amount of P because of increases in dry weight. The largest end‐of‐season P extraction in this research, which included 53.9 kg P ha−1 in 2004 at Cruger and 49.3 kg P ha−1 in 2002 at Coffeeville, was recorded for the treatment that received the largest litter rate of 6.7 Mg ha−1 supplemented with 34 or 67 kg ha−1 UAN‐N. Applied P always exceeded extracted P in all 3 yr at both locations when the litter rate was 4.5 or 6.7 Mg ha−1. Extracted P equaled or exceeded applied P when 2.2 Mg ha−1 litter was applied. Increasing litter rate decreased phosphorus extraction efficiency (PEE) while supplemental UAN‐N increased PEE. An average of 53% of the total P extracted was partitioned to seed with an additional 2.4% partitioned to lint for a total of 55% that would be removed with harvested crop. Nitrogen fertilization appeared to shift P partitioning from vegetative to reproductive parts. Supplementing litter with inorganic N may be an effective strategy not only in extracting additional P from soils but also in increasing the fraction partitioned to seed so that more P is removed from the field.

Poultry litter is generated in large quantities in the same southeastern U.S. states where cotton (Gossypium hirsutum L.) is a dominant field crop, but is rarely used as a primary cotton fertilizer partly because of lack of adequate management recommendations. This research was conducted to determine adequate rates of broiler litter and whether supplementation with inorganic N would be necessary for optimum cotton lint yield and fiber quality. The research was conducted from 2002 to 2004 on two commercial farms representing conventional‐till (CT) and no‐till (NT) systems. The treatments consisted of an unfertilized control, a farm standard (STD) fertilized with inorganic fertilizers, and broiler litter of 2.2, 4.5, and 6.7 Mg ha−1 in an incomplete factorial combination with 0, 34, or 67 kg ha−1 N as urea–ammonium nitrate solution (UAN). Litter without supplemental UAN–N increased yield by 23 to 110 kg lint ha−1 for every 1.0 Mg ha−1 litter under both CT and NT. The often‐recommended litter rate of 4.5 Mg ha−1 was not adequate to increase yield to be equivalent to that of the STD that received 101 to 135 kg ha−1 as UAN. It was necessary to supplement this or the other litter rates with 34 or 67 kg ha−1. UAN–N to support yield equal to or greater than the yield of the STD. The most consistently well‐performing treatment under both tillage systems in all years was the 4.5 Mg ha−1 litter supplemented with 67 kg ha−1. UAN–N. Lint yield was highly correlated (r2 = 0.83–0.97) with applied total plant‐available N (NTPA) under both systems. Fiber quality, fiber length and micronaire in particular, also responded to NTPA, but the responses were smaller than lint yield. Litter when adequately supplemented with UAN–N did not adversely affect fiber quality. These results show broiler litter as much as 4.5 Mg ha−1 should be supplemented with inorganic N fertilizers when used as a primary cotton fertilizer and when the expected yield is ≈1700 kg ha−1 under CT and ≈1500 kg ha−1 under NT.