K. R. Sistani

Characterization of broiler cake and broiler litter, the by-products of two management practices

The application of broiler manure and bedding (litter) on land has been a long-used disposal method that benefits plant and soil. For proper manure management, factors such as nutrient content, house cleaning management, application methods, and many land, crop, and climatic factors must be considered. A study was undertaken to characterize broiler cake and broiler litter as the by-products of two management systems in Mississippi. Broiler cake and litter productions were quantified and analyzed for four flocks during 1999 and 2000. The overall means for broiler cake production were 12.50, 13.90, and 10.30 kg m(-2) for producers 1, 2, and 3, respectively. Significantly greater quantities of litter, 27.50, 29.0, and 28.30 kg m(-2) than cake were determined for the same producers. The cake and litter moisture averaged 455 and 277 g kg(-1), respectively. No significant differences were observed between cake and litter total N, NH4-N, total C, total P, and water-soluble P (WP). However, cake had significantly greater Ca, Mg, K, Cu, Fe, Mn, and Zn than litter. Approximately 16.8% of the broiler cake and 15.2% of the broiler litter total P were in the form of water-soluble P. The NH4-N content of the cake and the litter were 12.5% and 11.5% of the cake and litter total nitrogen, respectively. The results also showed the advantage of the decaking practice with respect to the quantity of the manure generated for land application. Approximately 57% of the litter remains in the poultry house with decaking practice after each growth cycle compared to the 0% for total cleanout practice.

Bermudagrass Cultivar Response to Swine Effluent Application

Bermudagrass is the predominant forage grass grown in the region (Burton and Hanna, 1995), and hybrid Bermudagrass [Cynodon dactylon (L.) Pers.] has great potential bermudagrass responds readily to increasing N rates to recover nutrients due to its pronounced yield response to N. Our from either inorganic or organic sources (Overman et objective was to determine differences in forage dry matter (DM) al., 1993). When swine effluent was applied to Russell yield, nutrient concentration, and nutrient uptake among diverse berhybrid bermudagrass to provide 560, 1120, and 2240 kg mudagrass cultivars fertilized with swine effluent. ‘Alicia’, ‘Brazos’, N ha 1 yr 1, a yield response similar to that for inorganic ‘Coastal’, ‘Russell’, ‘Tifton 44’, and ‘Tifton 85’ hybrid bermudagrass N was observed, but efficiency of N and P recovery and common bermudagrass were grown on a Brooksville silty clay loam (fine, smectitic, thermic Aquic Hapludert) and fertilized with declined quickly with increasing effluent rate (Liu et effluent to provide 370 and 61 kg ha 1 yr 1 N and P, respectively al., 1997). Applying effluent at the two higher rates (mean of 3 yr), and on an Atwood silt loam (fine-silty, mixed, thermic resulted in large additions of N and P to the soil that Typic Paleudalf) and fertilized to provide 200 and 38 kg ha 1 yr 1 N were not recovered in the forage and were potential and P, respectively. Annual DM yields of Brazos, Coastal, Russell, contributors to ground and surface water pollution. In and Tifton 85 were similar on Brooksville (23.3–24.2 Mg ha 1) and North Carolina, Burns et al. (1985) reported that Atwood (12.3–14.1 Mg ha 1) soils. Annual N and P uptake ranged Coastal hybrid bermudagrass receiving 670 kg N ha 1 from 422 to 467 kg N ha 1 and 50 to 58 kg P ha 1 on the Brooksville and 153 kg P ha 1 from swine effluent removed an soil and from 181 to 230 kg N ha 1 and 32 to 40 kg P ha 1 on the average of 382 and 43 kg ha 1 yr 1 N and P, respectively. Atwood soil. Common bermudagrass uptake of N and P was similar Nutrient uptake by unimproved common bermudagrass, to or greater than all hybrids except Russell on Atwood soil due to prevalent throughout much of the southeastern USA, greater herbage N and P concentration. Hybrids generally recovered has not been compared with that of the hybrids when more K, Cu, and Zn than common bermudagrass. Relatively small manure served as the fertilizer source. differences in nutrient uptake among the bermudagrass cultivars sugBecause forage nutrient concentration tends to fluctugest that forage quality, winter hardiness, and establishment cost be ate little, nutrient removal is primarily a function of given equal consideration when choosing a cultivar. herbage yield (Robinson, 1996), which, among many factors, is strongly influenced by cultivar. Since the release of Coastal hybrid bermudagrass in 1943, several S production has traditionally been concenhybrid cultivars have become available to producers in trated in the Midwest (Hatfield et al., 1998), and the southeastern USA. Routine application of swine the manure has been applied primarily to soils that effluent to bermudagrass requires additional informaproduce row crops (Schmidt et al., 2001). The rapid tion about potential cultivar-dependent responses. Our growth of confined, contract swine production in the objective was to determine differences in forage DM southeastern USA (Welsh and Hubbell, 1999) has reyield and nutrient concentration and uptake among disulted in widespread application of swine effluent to verse bermudagrass varieties grown on contrasting soil forage crops. Forage crop uptake of nutrients applied types fertilized with swine effluent. with manure is often less than the quantity applied because the manure is applied at rates necessary to meet MATERIALS AND METHODS the N requirements of the forage (Sims, 1995) and the The study was conducted for 3 yr on two different confinedN/P ratio of manure does not match that of the crop feeding swine farms at Crawford, MS (33 17 N, 88 35 W), (Edwards, 1996). In addition, hay production may not on a Brooksville silty clay loam and at Houston, MS (34 0 prevent nutrient accumulation in the soil due to continN, 89 0 W), on an Atwood silt loam. At both locations, excreta ued manure application (Kingery et al., 1993). Hay prois washed from pits located below the barn floor into open duction, however, represents an important component lagoons and applied as effluent to adjacent fields using a center-pivot irrigation system (Crawford) or traveling spray gun of nutrient management. By exporting nutrients in the (Houston). Effluent had been applied to the soil at both locaform of hay from land receiving manure and by reducing tions at rates ranging from 10 to 15 cm ha 1 yr 1 (unknown runoff and soil loss, the rate of nutrient accumulation mineral concentration) for 2 to 5 yr before the experiment in the soil and the potential for ground and surface water started. Before forage yield measurements were made the first impairment may be reduced (Sims and Wolf, 1994). year, 20 soil samples were collected in the plot area at 0to 5-, 5to 15-, and 15to 30-cm depth and composited by depth. Selected soil chemical characteristics were determined using USDA-ARS, Waste Manage. and Forage Res. Unit, P.O. Box 5367, Mehlich-3 extractant (Mehlich, 1984; Table 1). Total soil N Mississippi State, MS 39762. G.E. Brink, current address: USDAconcentration was determined by the Dumas method (BremARS, U.S. Dairy Forage Res. Cent., 1925 Linden Drive West, Madiner, 1996). son, WI 53706-1108. Mississippi Agric. and Forestry Exp. Stn. Journal Alicia, Brazos, Coastal, Russell, Tifton 44, and Tifton 85 Article no. J10019. Received 7 Feb. 2002. *Corresponding author hybrid bermudagrass and common bermudagrass were estab(gebrink@wisc.edu). Abbreviations: DM, dry matter. Published in Agron. J. 95:597–601 (2003).

Protocols for Nationally Coordinated Laboratory and Field Research on Manure Nitrogen Mineralization

Abstract The National Program structure of USDA‐ARS provides an opportunity to coordinate research on problems of national and global significance. A team of USDA‐ARS scientists is conducting nationally coordinated research to develop predictions of manure N availability to protect water quality and improve farm solvency. Experimental design and research protocols were developed and used in common across all participating locations. Laboratory incubations are conducted at each location with a minimum of three soils, three temperatures, two wetting/drying regimes, and two manure treatments. A soil from the central United States (Catlin silt loam, fine‐silty, mixed, superactive, mesic Oxyaquic Argiudoll) is used as an internal reference across all locations. Incubation data are compiled across locations to develop generalized predictions of manure nitrogen mineralization (Nmin). Field validation data are then obtained by monitoring nitrogen (N) transformations in manure‐amended soil cores equipped with anion exchange resin to capture leached nitrate. This field data will be used to compare laboratory‐based predictions with field observations of Nmin in each soil, climatic zone, and manure type represented. A Decision Support System will then be developed for predicting manure N mineralization across ranges in soil, climate, and manure composition. Protocols used by this research team are provided to 1) document the procedures used and 2) offer others detailed information for conducting research on nutrient transformation processes involving collaboration across locations or complementary research between laboratory and field environments.

Phosphorus Dynamics in Broiler Litter‐Amended Soils

Abstract Because land application of broiler litter is commonly made in the spring before cropping season and in the fall, it is essential to understand how environmental variations, such as temperature, affect the phosphorus (P) dynamics. A laboratory incubation study was conducted at Waste Management and Forage Research Unit, USDA‐ARS with the objective of determining the effects of temperature and soil properties on water‐soluble P (WSP), Mehlich 3 P, and P fractions in broiler litter‐amended soils. Broiler litter was mixed with three soils (Leeper silty clay, Grenada silt loam, and Ruston sandy loam) at the rate of 10 Mg ha−1. The mixtures were incubated at 18°C, 25°C, and 32°C for up to 90 days and repeated three times. Soil samples were taken at eight time intervals (2, 5, 10, 15, 30, 60, and 90 days) and analyzed for water‐soluble P and Mehlich 3‐extractable P (MEP). Phosphorus also was fractionated chemically into inorganic and organic components by sequential extraction for soil samples taken at the end of incubation period (90 days). Water‐soluble P decreased rapidly after a 15‐day incubation in all soils for all temperatures and followed to a steady state to the end of incubation period. Averaged across temperatures, broiler litter application resulted in a significant increase in all fractions compared with controls. However, the increase was greater for inorganic than for organic fractions. The concentration of calcium (Ca)‐P fraction was highest in calcareous Grenada soil, which suggests that the presence of carbonates influence the fate of P from applied broiler litter. The coarse textured Ruston contained a greater concentration of water‐soluble P (WSP) than the other soils. At 32°C, the concentration of plant‐available P fractions [bicarbonate inorganic P (IP) and hydroxide IP] significantly increased and WSP decreased. It is likely that the higher temperature (32°C) promotes higher biological activity and lower water‐soluble P than lower temperature. Contribution of the Mississippi Agricultural and Forestry Experiment Station, journal paper no. J10120.

Nutrient Uptake by Ryegrass Cultivars and Crabgrass from a Highly Phosphorus‐Enriched Soil

Abstract Long‐term poultry litter application to crop and pasture lands may result in the buildup of nutrients, particularly phosphorus (P) in the soil. Poultry producers use poultry litter in place of chemical fertilizers to grow crops or forages for grazing and hay production. Cool‐season annual ryegrass (Lolium multiflorum) and warm‐season crabgrass (Digitaria ciliaris) are annual forages commonly grown in the southeastern region of USA. The combination of two forages gives year‐round pasture for a forage‐livestock system. A study was initiated to evaluate the P uptake efficiency of five ryegrass cultivars (Marshall, Rio, Jackson, TAM 90, and Gulf) grown during the winter and spring followed by the annual crabgrass variety Red River during summer. The experiment was conducted during the 2000 and 2001 growing seasons in Mize Mississippi on a highly P enriched Ruston silt loam soil. The ryegrass was grazed during winter then harvested once in early June. Cultivar Rio produced the greatest dry matter (DM) in both growing seasons. In 2001, due to optimum soil moisture conditions, cultivars Gulf and TAM 90 produced more DM than 2000, an extremely dry year. In 2001 crabgrass planted after TAM 90 produced significantly greater DM (7565 kg ha−1) than crabgrass following the other ryegrass cultivars. Cultivar Marshall was the most effective in removing P from soil in 2000 (7.38 kg ha−1), while Rio was superior in 2001 (8.73 kg ha−1). In general, crabgrass was more effective in P removal than ryegrass cultivars tested. Therefore, the combination of ryegrass followed by crabgrass may provide an effective forage‐livestock management system in the southeastern states.

Impact of drying method, dietary phosphorus levels, and methodology on phosphorus chemistry of broiler manure

Areas of intensive poultry production are prone to high phosphorus (P) losses due to excessive manure application. Historically, manure application rate has been calculated based on nitrogen (N) needs of the crops and N content of the manure with no attention to the quantity of phosphorus (P) loading. In many instances, a gradual buildup of P in soil has resulted from long-term manure application. Therefore, P input from animal manure via runoff is acknowledged as the primary factor for the eutrophication of surface water bodies. This study was conducted to evaluate (i), the impact of dietary P concentration on the broiler manure P content and the pre-analysis drying methods on the broiler manure nutrient composition with emphasis on phosphorus and (ii), to compare the use of Ion Chromatography and the Murphy–Riley method for the determination of inorganic phosphorus in the broiler manure water extract. Four drying methods were used to dry the fresh broiler manure as follows: air drying (AD), freeze drying (FD), oven drying at 65°C (OD65), and oven drying at 105°C (OD105). The results were compared with analysis of the fresh broiler manure with no drying (ND). The diet P concentration did not affect the broiler manure total N content. However, a significant decrease in total N occurred at all P levels due to drying when compared with fresh manure analysis. The diet P level had significant effect on total P and water-extractable P. Freeze drying followed by OD105 caused the most reduction in manure total P content. Drying also had a significant effect on the metal nutrient content of the broiler manure. However, the effect was inconsistent.