Rory Maguire

Influence of Poultry Litter Biochar on Soil Properties and Plant Growth

Abstract Biochar created from poultry litter is a way to produce a value-added soil amendment that is lighter and less expensive to transport out of manure nutrient excess areas, but effects on soil properties are unknown. Two studies were conducted with a Sandy loam and a Silt loam. First, lettuce seeds were germinated across biochar incorporation rates from 0% to 100% biochar, and second, a greenhouse trial was conducted in which peppers were grown in soils with up to 5% biochar by weight. Elemental analysis was completed on the biochar, and soils were analyzed for bulk density, water-holding capacity, pH, cation exchange capacity, and extractable nutrients. Biochar increased lettuce germination by almost 50% in the Sandy loam at low rates but became toxic at rates greater than 2.5% in both soils probably due to salt toxicity. Water-holding capacity increased linearly with biochar additions. For example, adding 15% biochar nearly doubled the water-holding capacity of the Sandy loam from 15% to 27%. The biochar had a pH of 9.3, and additions increased the pH of both soils. Total phosphorus (P) in the biochar was 43 g kg−1, and although almost none of this was water soluble in the pure biochar, the Mehlich 1 P and Olsen P were greatly increased in biochar amended soils. Biochar consistently increased the cation exchange capacity only at high rates. Biochar made from poultry litter showed several benefits as a soil amendment, but application rates would be limited by soil test P and pH.

Managing manure for sustainable livestock production in the Chesapeake Bay Watershed

Manure presents one of the greatest challenges to livestock (dairy and beef cattle, swine, poultry, equine, sheep, llamas, etc.) operations in the Chesapeake Bay Watershed, serving both as resource and liability. The Chesapeake Bay is threatened by excessive nutrient loadings, and, according to the US Environmental Protection Agency (USEPA), manure is the source of 18% of the nitrogen and 27% of the phosphorus entering the Chesapeake Bay annually (figure 1) (Chesapeake Bay Program 2010). Developing economical, practical, and effective manure management options for livestock producers will not only contribute to the restoration of the Chesapeake Bay, but will also provide a model for other areas where water quality and livestock production objectives must be balanced. The 166,000 km2 (64,000 mi2) Chesapeake Bay Watershed is home to 3.2 million animal units (animal unit = 454 kg [1,000 lbs] of livestock) generating roughly 36 million t (40 million tn) of livestock manure per year. In comparison, the 14 million humans who call the Chesapeake Bay Watershed home generate 3.6 million t (4 million tn) of waste annually (Brosch 2010; Blankenship 2005). The livestock manure contains approximately 259,000 t (285,000 tn) of nitrogen and 70,000 t (77,000 tn) of phosphorus. Most manure is…

Quantifying phytate in dairy digesta and feces: Alkaline extraction and high-performance ion chromatography1

Development of an analytical method with appropriate combination of extraction and quantification approaches for undigested phytate in ruminant feces and digesta will advance knowledge of phytate degradation in ruminants and help to reduce phosphorus excretion. Established quantification methods give satisfactory results for feedstuffs and nonruminant manure but recovery of phytate is incomplete for ruminant feces and digesta because of their complex sample matrix and low ratio of phytate to inorganic P. The objective was to develop a robust, accurate, sensitive, and inexpensive method to extract and quantify phytate in feeds, ruminant feces, and digesta. Diets varying in phytate content were fed to dairy heifers, dry cows, and lactating cows to generate digesta and fecal samples of varying composition to challenge extraction and quantification methods. Samples were extracted with 0.5 M HCl or 0.25 M NaOH + 0.05 M EDTA. Acid extracts were mixed with 20% NaCl, alkaline extracts were acidified to final pH < 2, and then both extracts were clarified with C₁₈ cartridges and 0.2-μm filters. High-performance ion chromatography (HPIC) was used to quantify phytate. In feed samples, the measured phytate was comparable in alkaline and acid extracts (2,965 vs. 3,085 μg/g of DM). In digesta and fecal samples, alkaline extraction yielded greater estimates of phytate content than did acid extraction (40.7 vs. 33.6 and 202.9 vs. 144.4 μg/g of DM for digesta and fecal samples, respectively). Analysis of alkaline extracts by HPIC is usually not possible because of sample matrix interferences; acidification and C(18)-cartridge elution of alkaline extracts prevented this interference. Pure phytate added to dry samples before extraction was almost completely recovered (88 to 105%), indicating high extraction efficiency, no adverse effect of extract clean-up procedures, and accurate quantification of phytate. The proposed method is rapid, inexpensive, robust, and combines the extraction power of NaOH-EDTA with the precision and sensitivity of HPIC quantification, allowing accurate quantification of phytate in feeds, ruminant digesta, and fecal samples.

Field Trials With Poultry Litter Biochar and Its Effect on Forages, Green Peppers, and Soil Properties

Abstract Pyrolysis offers a way to convert poultry litter into a carbon-rich soil amendment. This study was conducted to evaluate the effects of biochar made from poultry litter on soil chemical properties and plant production. The rates of 0, 4.5, and 9 Mg ha−1 were used at three field sites, and the rates were applied once a year in the early spring of 2009 and 2010. Biochar was surface applied on a tall fescue pasture (Lolium arundinaceum (Schreb.) Darbysh. (= Festuca arundinacea Schreb. subsp. arundinacea)) in the Shenandoah Valley and tilled in on two green pepper (Capsicum annuum L.) field sites in southwestern Virginia. The biochar had a carbon content of 25 ± 1%, and application increased soil carbon by 0.51% after 2 years of application of 9 Mg ha−1 at the forage site where it was surface applied and by an average of 0.38% at the two green pepper sites where it was tilled in. The biochar had a pH of 9.57 ± 0.01 and increased the pH of the soil where it was applied each year. Changes in soil cation exchange capacity showed no clear trends. Mehlich 1 P was increased by 57 mg kg−1 for each Mg ha−1 of biochar at the forage site and by an average of 39 mg kg−1 for each Mg ha−1 of biochar applied at the green pepper sites. The pH and Mehlich 1 P were increased above agronomic levels by the higher rates at all sites, suggesting these as limiting factors. Soluble salts numerically increased in the first year of application but were reduced at all sites through leaching when sampled in the early spring of 2011. No significant differences were found in yields at any of the three sites, but differences in forage quality were found at the tall fescue site probably because biochar increased the rate at which the forage matured.

Effects of Poultry Litter Injection on Ammonia Volatilization, Nitrogen Availability, and Nutrient Losses in Runoff

Abstract Poultry litter is a common organic amendment in agricultural production, but nutrient losses can reduce its effectiveness as a fertilizer. Three experiments were conducted to evaluate ammonia nitrogen (NH3-N) volatilization, N availability, and runoff losses of nutrients by conducting a closed chamber volatilization study, a soil incubation, and a rainfall simulation. In all studies, poultry litter was applied at a rate of 6.7 Mg · ha−1 either on the surface or injected and compared with an unamended control. In the volatilization and soil incubation studies, Braddock Loam and Bojac Sandy Loam surface soils were compared. Of the ammonium N added, cumulative loss of NH3-N by volatilization was 3% from injected and 121% from surface applied poultry litter after 7 days in the Loam. In the Sandy Loam, cumulative loss of NH3-N was 9% from injected and 153% from surface applied poultry litter after 7 days. After a 40-day soil incubation, injection increased total inorganic N by 52% and 99% for the Loam and Sandy Loam soils, respectively, when compared with surface application. Injection reduced total Kjeldahl N by 59%, total Kjeldahl P by 53%, dissolved reactive P, dissolved nitrate N by 73%, and dissolved NH3-N in runoff by 99%, compared with surface application. Injection reduced NH3-N volatilization and nutrients in runoff to levels of the control. These studies show that injection increases plant available N while decreasing losses through volatilization and runoff.

Using Synthetic Chelating Agents to Decrease Phosphorus Binding in Soils

Abstract Most acid soils have a high capacity to bind phosphorus (P) strongly on iron (Fe) and aluminum (Al) hydroxides, resulting in low P fertilizer use efficiency. Organic chelating agents form strong bonds with metals in soil and may reduce P binding with Fe and Al and increase fertilizer P use efficiency. Ethylenediamine tetraacetic acid (EDTA), hydroxyethyl ethylenediamine triacetic acid (HEEDTA), gluconic acid, and citric acid were tested to determine their influence on water-soluble P (WSP), Mehlich-1 P, and Mehlich-3 P in a loam and sand fertilized with P and incubated for 49 days. Soil P sorption capacity (PSC) was estimated from an oxalate extraction of Fe and Al, and chelates were applied at rates of 90% of the PSC. EDTA and HEEDTA were also applied at 0, 30, 60, 90, 120, and 150% PSC to produce a rate response curve for WSP in a second soil incubation. The EDTA, HEEDTA, and citric acid significantly (P < 0.05) reduced P sorption in the loam and sand when measured by WSP. In soils without P fertilizer added, EDTA and HEEDTA resulted in a significant increase in WSP concentrations, as well as increased concentrations of Mehlich-1 P and Mehlich-3 P. With increasing chelation rates of EDTA and HEEDTA, there was a linear increase in WSP for both soils, indicating higher rates were most effective at decreasing P sorption. The application of chelating agents, with and without P fertilizer, could potentially increase plant availability of P, therefore reducing P fertilizer.

Manure Injection Affects the Fate of Pirlimycin in Surface Runoff and Soil.

Antibiotics used in animal agriculture are of increasing environmental concern due to the potential for increased antibiotic resistance after land application of manure. Manure application technology may affect the environmental behavior of these antibiotics. Therefore, rainfall simulations were conducted on plots receiving three manure treatments (surface application, subsurface injection, and no manure control) to determine the fate and transport of pirlimycin, an antibiotic commonly used in dairy production. Rainfall simulations were conducted immediately and 7 d after application of dairy manure spiked with 128 ng g (wet weight) pirlimycin. Soil samples were collected from all plots at two depths (0-5 and 5-20 cm). For injection plots, soil was collected from injection slits and between slits. Pirlimycin concentrations were higher in soil within the injection slits compared with surface application plots at 0 and 7 d. Pirlimycin concentrations in the 0- to 5-cm depth decreased by 30, 55, and 87% in the injection slit, between injection slits, and surface application plots 7 d after application. Pirlimycin concentrations were 106 ng g in sediment and 4.67 ng mL in water from the surface application plots, which were 21 and 32 times that of the injection plots, respectively. After 7 d, pirlimycin levels in runoff sediment and water decreased 80 to 98%. Surface application resulted in six and three times higher pirlimycin concentrations in water and sediment than injection. These results indicate that pirlimycin is most susceptible to loss immediately after manure application. Thus, injection could be considered a best management practice to prevent loss of antibiotics in surface runoff.

Soil Nutrient and Fescue (Festuca spp.) Responses To Compost and Hydroseed on a Disturbed Roadside

Inadequate nutrients and poor soil quality pose challenges for turfgrass establishment on disturbed soils. Compost amendment has been shown to mitigate poor soil quality. This research was conducted to compare surface applications of compost to standard hydroseeding for improving soil chemical properties and turfgrass establishment. Plots established with either hydroseed or compost in spring 2007 were evaluated for soil pH, Mehlich-I extractable K, Mg, Zn, P, total N, organic C, and percent ground cover, fescue coverage and biomass production of tall (Festuca arundinacea Schreb.) and chewings fescue [Festuca rubra L. ssp. fallax (Thuill.) Nyman]. Two years after plot establishment, the compost treatment had significantly increased Mehlich-I extractable soil P, K and Zn. Phosphorus increased 566% in the compost soil but only 17% in the hydroseeded soil. Higher percentages of ground coverage were reported in the compost than the hydroseed treatments with coverage in treatments declining from 2008 to 2009. Although the surface additions of compost initially enhanced the establishment and growth of fescue, vegetation may be limited in the long run by soil conditions in the root zone and competing broadleaf weeds.

Compost Practices for Improving Soil Properties and Turfgrass Establishment and Quality on a Disturbed Urban Soil

ABSTRACT Urban land disturbance degrades physical, chemical, and biological soil properties by removing topsoil and compacting the remaining subsoil. Such practices create a soil environment that is unfavorable for vegetation establishment. A 3-year field study was conducted to compare the effects of various one-time compost application treatments on soil properties and re-vegetation of a disturbed soil. A disturbed urban soil received the following treatments: (1) inorganic fertilizer; (2) 2.5-cm-depth surface-applied compost; (3) 2.5-cm-depth incorporated compost; (4) 5.0-cm-depth incorporated compost; (5) inorganic fertilizer plus 0.6-cm compost blanket; and (6) inorganic fertilizer plus straw mat cover. The plots were seeded with a mixture of tall fescue Festuca arundinacea Shreb.: ‘Magellan,’ ‘Coronado Gold,’ ‘Regiment,’ and ‘Tomcat,’ perennial ryegrass Lolium perenne L. ‘Linn’, and Kentucky bluegrass Poa pratenis L. ‘Baron.’ Soil chemical and physical attributes and plant growth and quality parameters were measured during 840 days following study establishment. Soil C, N, P, K, Ca, and Mg, and turfgrass growth and quality were increased and soil bulk density was reduced by amending with composts. Incorporation of compost into soil improved soil and plant attributes more than unincorporated surface application, but the differences diminished with time. Compost benefits increased with time. One-time applications of compost can provide immediate and long-term benefits to soil and plant attributes, but there may be no need to incorporate the compost into soil, particularly if the soil has recently been loosened by tillage.

Multiple Applications of Sodium Bisulfate to Broiler Litter Affect Ammonia Release and Litter Properties.

Ammonia (NH) emissions from animal manures can cause air and water quality problems. Poultry litter treatment (PLT, sodium bisulfate; Jones-Hamilton Co.) is an acidic amendment that is applied to litter in poultry houses to decrease NH emissions, but currently it can only be applied once before birds are placed in the houses. This project analyzed the effect of multiple PLT applications on litter properties and NH release. Volatility chambers were used to compare multiple, single, and no application of PLT to poultry litter, all with and without fresh manure applications. A field component consisted of two commercial broiler houses: one had a single, preflock PLT application, while the other received PLT reapplications during the flock using an overhead application system. In the volatility chambers, single and reapplied PLT caused greater litter moisture and lower litter pH and , relative to no PLT. After 14 d, NH released from litter treated with reapplied PLT was significantly less than litter with both single and no applications. Furthermore, total N in litter was greatest in litter treated with reapplied PLT, increasing its fertilizer value. In the commercial poultry houses, PLT reapplication led to a temporary decrease in litter pH and , but these effects did not last because of continued bird excretion. Although one preflock PLT application is currently used as a successful strategy to control NH during early flock growth, repeat PLT application using the overhead reapplication system was not successful because of problems with the reapplication system and litter moisture concerns.