Poultry Litter Application Research Articles

Response of the Bacterial Communities Associated With Maize Rhizosphere to Poultry Litter as an Organomineral Fertilizer

Maize is an important food source worldwide and is of considerable industrial importance. Low maize yields are mostly due to low soil fertility, so expensive mineral fertilizers are often used to offset the lack of nutrients. Poultry litter (PL) is one of the most valuable and phosphorous-rich animal wastes. However, PL usually contains veterinary antibiotic residues, particularly fluoroquinolones (FQs), which may alter soil microorganism diversity and resistance patterns. In this study, we aimed to understand the impact of applying mineral (triple superphosphate - STP) or organomineral (STP with PL and reactive Bayovar phosphate with PL) fertilizers (130 or 260 kg/ha of total P2O5) on the structure and composition of the soil bacteriome and on phosphate-mineralizing bacteria associated with the maize rhizosphere. Maize plants were sampled at 60 and 90 days after sowing and a clear rhizosphere effect was observed in all samples. No specific groups of bacterial genera predominated (>3% relative abundance) according to the different fertilizer treatments and most of the genera were shared among samples. Multivariate analyses of 16S rRNA sequences revealed clear clustering based on sampling time and distinct separation from bulk soil samples. Abundances of phosphate-mineralizing bacteria varied depending on the sampling time. We observed a positive effect on phytase activity under the 260 kg STP with PL treatment. Although the FQ enrofloxacin and its main metabolite ciprofloxacin were detected in PL, their concentrations in fertilized soils were below quantification thresholds. Quinolone resistance genes were not detected in the maize rhizosphere or bulk soil. Together, these results suggest that the rhizosphere effect, plant age and applied amounts of fertilizer are more influential on bacterial communities than the type of fertilizer used. Thus, application of PL as an organomineral fertilizer does not appear to have extensive impacts on the bacterial diversity of maize rhizosphere, so it could be an excellent option for enhancing maize production.

Soil carbon and physical-mechanical properties after successive applications of swine and poultry organic waste

ABSTRACT In agricultural crops, the use of swine and poultry waste as organic fertilizers results in gains in the productivity and reduction of production costs, but it may also change the physical properties and mechanical behavior of the soil, either increasing or reducing its quality. This study aimed to investigate the influence of applying increasing doses of liquid swine manure (160 m³ ha-1 year-1, 320 m³ ha-1 year-1 and 480 m³ ha-1 year-1) and poultry litter (6 Mg ha-1 year-1, 12 Mg ha-1 year-1 and 18 Mg ha-1 year-1), along four years, on the physical-mechanical properties and organic carbon content of a very clayey Rhodic Eutrudox. The application of liquid swine manure and poultry litter increased the surface soil organic carbon contents. The soil density decreased, whereas the total porosity and macroporosity increased, with the addition of liquid swine manure and poultry litter. There were no significant changes in the soil susceptibility to compaction.

Leaching of the different forms of nitrogen by the application of poultry litter, swine waste, and mineral nitrogen on corn cultures (Zea mays L.)

Leaching of the different forms of nitrogen by the application of poultry litter, swine waste, and mineral nitrogen on corn cultures (<i>Zea mays</i> L.)

Fertilizer Recommendations for Switchgrass: Quantifying Economic Effects on Quality and Yield

Fertilizer recommendations for switchgrass depend on its price and fertilizer cost. Different fertilizer rates affect yield and hay quality for first and second cuts. Substituting poultry litter for fertilizer affects breakeven, yield, and quality. Switchgrass hay can compete with traditional hay in cattle rations. Switchgrass (Panicum virgatum L.) is a native, perennial warm‐season grass suited for biomass production for renewable fuels and also fodder on marginal soils. To develop fertilizer recommendations, yield responses to and nutrient removal in harvest biomass associated with five levels of macronutrients of N, P, and K on Leadvale silt loam (fine‐silty, siliceous, semiactive, thermic Typic Fragiudults) with a fragipan at 14 to 97 cm at a mid‐southern US location were examined. Feed quality was assessed using crude protein (CP) and total digestible nutrient (TDN) concentration to assess feasibility in beef cow (Bos taurus) rations. Nitrogen affected economic performance to a larger extent than P and K. Profit‐maximizing K use rivaled that of N use, whereas P use was low and thereby limited sustainable poultry litter application. Hay ranged between 7 and 9% CP and 51% ± 0.5% TDN in response to harvest time and nutrient application rate. Cattle producers would find such hay suitable for maintaining dry cows without need for supplemental feed. Profitability of hay production and fertilizer recommendations varied largely with changes in switchgrass price and fertilizer cost. As such, a supplemental spreadsheet tool was developed for research outreach purposes to provide output price‐ and input cost‐specific fertilizer recommendations for switchgrass hay with attendant quality impacts. Overall, breakeven prices were lower using inexpensive litter in comparison with synthetic fertilizers and ranged from approximately US$40 to US$60 Mg−1 in this study. Therefore, switchgrass hay compared favorably in cost to traditional hay averaging US$126 Mg−1 over the study period.

Soil physical indicators of management systems in traditional agricultural areas under manure application

ABSTRACT Studies of the successive application of manure as fertilizer and its combined effect with long-term soil management systems are important to the identification of the interdependence of physical attributes. The aim of this study was to evaluate changes in the physical properties of a Rhodic Kandiudox under management systems employing successive applications of pig slurry and poultry litter, and select physical indicators that distinguish these systems using canonical discriminant analysis (CDA). The systems consisting of treatments including land use, management and the application time of organic fertilizers are described as follows: silage maize under no-tillage (NT-M7 years); silage maize under conventional tillage (CT-M20 years); annual pasture with chisel plowing (CP-P3 years); annual pasture with chisel plowing (CP-P15 years); perennial pasture without tillage (NT-PP20 years); and no-tillage yerba mate (NT-YM20 years) and were compared with native forest (NF) and native pasture (NP). Soil samples were collected from the layers at the following depths: 0.0-0.05, 0.05-0.10, and 0.10-0.20 m, and were analyzed for bulk density, porosity, aggregation, flocculation, penetration resistance, water availability and total clay content. Canonical discriminant analysis was an important tool in the study of physical indicators of soil quality. Organic fertilization, along with soil management, influences soil structure and its porosity. Total porosity was the most important physical property in the distinction of areas with management systems and application times of manure for the 0.0-0.05 and 0.10-0.20 m layers. Soil aeration and micropores differentiated areas in the 0.05-0.10 m layer. Animal trampling and machinery traffic were the main factors inducing compaction of this clayey soil.

Changes in Arsenic, Copper, Iron, Manganese, and Zinc Levels Resulting from the Application of Poultry Litter to Agricultural Soils.

Twelve applications of poultry litter were made to a 2.1-ha field located in the Shenandoah Valley of Virginia, United States (USA), between March 1999 and August 2014. The field was planted with bermudagrass (Cynodon dactylon) and used as a pasture on an active farm. Copper, iron, manganese, zinc, and arsenic concentrations in the poultry litter were measured, and the application rates of these metals were calculated. The median application rates were: Cu, 1.32 kg/ha, Fe, 5.57 kg/ha, Mn, 1.80 kg/ha, Zn, 1.39 kg/ha, and As, 0.011 kg/ha. Twelve surface and subsurface soil samples were taken from the treated field in February 2016. Twelve samples were also taken from a comparison site. The comparison site was directly adjacent to the study site, consisted of the same soil type, and had been maintained as an undisturbed forest. Extractable Cu, Fe, Mn, Zn, and As concentrations in the soil samples were determined by atomic absorption spectroscopy, and the results of the chemical analysis were analyzed by ANOVA. Fe and Mn were depleted from the soil in the treated field, while Cu and Zn levels increased over the 12 years of treatment and grazing, and arsenic levels were unchanged in both the surface and subsurface soils between the comparison and the study site. The changes observed for Cu, Fe, Mn, and Zn are within the critical deficiency level and critical toxicity level for these metals, and no arsenic remains in the soil from roxarsone feed supplements, which were added to the poultry feed when the litter was applied to the study site.

Effects of Subsurface Banding and Broadcast of Poultry Litter and Cover Crop on Soil Microbial Populations.

Agronomic management is aimed at managing the crop environment to maximize crop yield, but soil biology is often ignored. This study aimed to compare the application of poultry litter via broadcast and subsurface banding versus standard inorganic fertilizer to cotton ( L.) and their effects on soil bacterial populations and fecal indicator bacteria. The study comprised a randomized complete block design, with fertilizer and time of application as treatment effects and cover crop as a main effect. Soil cores were collected and analyzed from 2008 to 2014. Fecal indicator bacteria were at detection limits for all treatments, where the integron 1 gene was significantly elevated in litter plots. There were few differences between litter application approaches, but both significantly increased key biogeochemical genes over control plots, whereas a cover crop only increased soil moisture and urease C. Data suggested a positive residual effect of litter application with 16S, phosphatase A, and urease C genes elevated over controls, but similar to standard fertilizer plots. High-throughput 16S ribosomal RNA analysis suggested increased diversity and enrichment indices in litter and standard fertilizer over untreated control plots. Litter and standard fertilizer effects persisted 4 and 2 yr after application, respectively, as evidenced by residual library community structures. This study demonstrated the positive effects of litter application on the soil bacterial community when compared with untreated control plots. Some differences between standard fertilization and litter practices were noted and suggest that there is a positive residual effect on soil microbial populations associated with both practices.

Phosphorus Leaching from Soil Cores from a Twenty-Year Study Evaluating Alum Treatment of Poultry Litter.

Adding alum to poultry litter is a best management practice used to stabilize P in less soluble forms, reducing nonpoint-source P runoff. However, little research has been conducted on how alum additions to litter affect subsequent leaching of P from soil. The objective of this study was to evaluate the effects of alum-treated versus untreated poultry litter on P leaching from soil cores receiving long-term poultry litter applications. Two intact soil cores were taken from each of 52 plots in a long-term study with 13 treatments: a control, four rates each of untreated and alum-treated litter (2.24, 4.49, 6.72, and 8.96 Mg ha), and four rates of ammonium nitrate (65, 130, 195, and 260 kg N ha). One core from each plot received the same fertilizer as for the previous 20 yr, whereas the other was unfertilized in the study year, resulting in a total of 25 treatments. Cores were exposed to natural rainfall, and P leaching was measured for 1 yr. The average soluble reactive P concentrations in the leachate varied from 0.16 to 0.44 mg P L in fertilized alum-treated cores, whereas leachate from cores fertilized with untreated litter ranged from 0.40 to 2.64 mg P L. At the highest litter rate (8.96 Mg ha), alum reduced total dissolved P and total P concentrations in leachate by 83 and 80%, respectively, compared with untreated litter. These results indicate that alum additions to poultry litter significantly reduced soluble and total P fractions in leachate.

Influence of Poultry Litter on Crop Productivity under Different Field Conditions: A Meta‐Analysis

Core Ideas Meta‐analysis showed that poultry litter’s influence on crop productivity is comparable to that of inorganic fertilizer.Poultry litter’s effectiveness on crop yield is influenced by soil properties, tillage, application practice, and crop species.More positive effects were found in acidic soil compared with neutral or alkaline, in loam soil compared with sand or clay, under conservation tillage compared with conventional, by subsurface banded poultry litter compared with broadcast or incorporation through tillage.The full benefits of using poultry litter was achieved from long‐term studies, with litter improving crop yield compared with inorganic fertilizer. Research has shown that poultry litter (PL) can be used as a nutrient source for crop production. However, yield responses often varied when compared with inorganic fertilizer (IF) depending on soil type, management conditions, and PL application practices. Therefore, we reviewed the literature and conducted a meta‐analytic assessment to summarize the effects of PL vs. IF on yield response under different agricultural practices. A total of 866 observations from 90 studies were evaluated to determine how soil properties, tillage, application practices, crop species, and repeated applications influenced yield. Poultry litter significantly increased yield in loam, sandy loam, and silty‐clay loam soils, whereas yields were significantly greater with IF in sand and silty‐clay soils; no differences were observed between PL and IF with clay loams or silt loams. Under conventional tillage, IF’s effect on yield was positive, albeit not significant, whereas PL had a significant positive effect under strip‐till or no‐till. Poultry litter produced slightly lower yield when surface incorporated, but higher yield with subsurface band application when compared with IF. Poultry litter had significantly higher yield with cotton (Gossypium hirsutum L.), corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and peanut (Arachis hypogaea L.), significantly lower with bermudagrass [Cynodon dactylon (L.) Pers] than IF, and no effects on tall fescue (Festuca arundinacea Schreb.), corn silage, rice (Oryza sativa L.), and wheat (Triticum aestivum L.). Overall, PL was comparable to IF. However, the greatest benefits of PL on yield when compared to IF tended to occur following repeated (three or more) annual applications.

Long-term effects of alum-treated litter, untreated litter and NH4NO3 application on phosphorus speciation, distribution and reactivity in soils using K-edge XANES and chemical fractionation

Whereas soil test information on the fertility and chemistry of soils has been important to elaborate safe and sound agricultural practices, micro-scale information can give a whole extra dimension to understand the chemical processes occurring in soils. The objective of this study was to evaluate the effects that the consecutive application of untreated poultry litter, alum-treated litter or ammonium nitrate (NH4NO3) had on P solubility in soils over 20 years. For this, we used soil test data, sequential chemical fractionation (SCF) of P, and P K-edge XANES and μ-fluorescence spectroscopies. Water extractable P data indicated that application of alum to poultry litter was a very effective treatment for reducing P solubility. On the basis of our SCF of P data, P was primarily found within the 0.1 M NaOH pool across the applied rates and regardless of the treatment, where application of alum-treated litter accounted for as much as 59 ± 2% of the total, followed by NH4NO3, 49 ± 4%, and untreated litter, 40 ± 2%. It was also shown that in soils where alum-treated litter was applied, the Resin pool accounted for 10 ± 1% of the total, followed by NH4NO3, 13 ± 4%, and untreated litter, 18 ± 2%, indicating that P was less readily available in soils where alum-treated litter was applied. Phosphorus XANES indicated that P was predominantly associated to Fe > Al > Ca > organic molecules, regardless of the treatment or applied rates, though the formation of PoAl complexes was only found in soils that received application of alum-treated litter and was positively related to the applied rates. The combination of P-XANES with SCF or μ-fluorescence data was shown to provide valuable information about P reactivity and distribution in soils and should thus be used to address the fate of applied P amendments in soils.

Crop yield responses to surface and subsoil applications of poultry litter and inorganic fertiliser in south-eastern Australia

In the high-rainfall zone of south-eastern Australia, deep incorporation of organic matter has previously been reported to increase crop yields by improving access to subsoil water and nutrients, resulting from the amelioration of subsoil constraints. However, previous experiments did not separate the yield response resulting from nutrients contained in the amendment from yield response due to amelioration of subsoil constraints. In order to separate these effects, eight field experiments were conducted on a range of soil types across the medium- and high-rainfall zones of south-eastern Australia between 2014 and 2016. Grain yield and quality responses of a range of annual crops (canola, wheat, barley and lentil) to surface and deep placement of poultry litter and inorganic fertilisers with matched nutrition were assessed. Over 15 site × year combinations, there was no consistent, significant positive interaction between amendment and incorporation treatments necessary to demonstrate that deep placement of amendment (i.e. subsoil manuring) had advantages over surface application of the same amendment. Differences in crop yield in these experiments are attributed to nutrients (particularly nitrogen) supplied by the amendment, and not to the amelioration of subsoil constraints. Future research, including analysis of subsoil physicochemical properties and plant nutrient concentrations after treatment, is necessary to confirm the role of nitrogen and other nutrients in the crop response to subsoil manuring.

English

The high generation of organic residues from the intensive farming of chickens has induced their use as fertilizer for forage crop production. This aimed to evaluate the effect of poultry litter application on agronomic traits and quality of silage of elephant grass. The experiment was conducted in the experimental field of Boa Vista Farm, in district of Cachoeira de Santa Cruz, Vicosa, State of Minas Gerais, in sandy argisol. The experimental period was from November 2014 to February 2015 and the treatments consisted of four levels of fermented poultry litter (0, 4, 8 and 12 ton.ha-1) with five repetitions. Evaluations consisted of measurements of plant height, stem diameter, number of plants.ha-1 and green mass yield. In relation to silage, measurements of gas losses, effluents and total losses were performed using the four treatments cited and four repetitions. There was a positive linear effect (P 0.05) on the stem diameter, green mass yield and silage quality. Key words: Organic waste, Pennisetum purpureum Schum, poultry litter, productivity, qualitative parameters.

Nutrient Sources and Harvest Frequencies Impact Water Stable Soil Macro-Aggregates

ABSTRACTWe evaluated the effects of nutrient sources [cattle manure, poultry litter, urea, chemical fertilizers [nitrogen (N), phosphorus (P) and potassium (K)], inter-seeded crimson clover (Trifolium incarnatum L.), and a control], and harvest frequency (single and twice) on water stable soil macro-aggregates through wet sieving. The experiment was performed in a split-plot design with four replications. In most cases, single harvest resulted in more water stable soil aggregates than twice harvest. This could be due to less soil disturbance and uninterrupted root exudate supplies for soil microbes. Application of cattle manure and poultry litter significantly increased the percent of water stable soil macro-aggregates to the extent of 47% compared with chemical (NPK) fertilizer application. These results demonstrated that vigilant recycling of these animal wastes could improve soil aggregate formation. However, long-term monitoring of this practice is needed to evaluate system sustainability and profitability.

Within-House Spatial Distribution of Fecal Indicator Bacteria in Poultry Litter.

Land application of poultry litter is often considered to be a major source of water pollutants in poultry-producing regions. However, reported levels of fecal indicator microorganisms in litter vary widely, with considerable variation possible within houses and across farms, depending on management practices. Therefore, a study was conducted to determine the levels and distribution of indicator microorganisms within 12 broiler farms representing three companies. Within each house, litter samples were collected from around the feed line, water line, north wall, cool pad end, middle, and fan end. Litter moisture content was significantly different within the houses, with the litter being driest around the feed line (19.8%) and wettest around the water line (40.7%). Mean levels of total coliforms, , enterococci, and were 3.7, 3.3, 6.4, and 4.0 log colony-forming units g dry litter, respectively. Levels of total coliforms, , and were positively correlated with litter moisture content, but enterococci levels were not. Consequently, levels of total coliforms, , and , as well as enterococci, were highest around the water line and lowest around the feed line. These results indicate that areas with higher litter water content are more likely to contain higher levels of most fecal indicator microorganisms. Approaches to reduce litter water content in these areas would not only benefit the microbial quality of litter for land application but would also likely improve in-house disease control.

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

Poultry litter (PL) is widely applied on grazing lands in Georgia. However, it is not clear how its long-term use affects soil microorganisms and their function. We examined changes in activity and community structure of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in a grazing land with a history of PL application and compared it to treatment with urea ammonium nitrate (UAN). Soil samples (0-15 cm) were collected in 2009 (after 15 yr of PL application) and in 2013 (after 2 yr of no application). The abundance and community composition of ammonia oxidizers (AO) were determined with molecular techniques that targeted Nitrification potential (NP) was used for measuring their activity. Abundance of AO was significantly higher in PL (7.41 and 7.10 log copies g soil for AOB and AOA, respectively) than in UAN plots (6.82 and 6.50 log copies g soil for AOB and AOA, respectively) in 2009. This is consistent with NP, which was higher in PL (0.78 mg NO -N kg h) than in UAN (0.50 mg NO-N kg h) plots in 2009. The abundance of AO and NP decreased in 2013. There was no treatment effect on the composition of AO. Correlation analysis suggested that AOB were functionally more important than AOA, indicating the need to target AOB for efficient management of N in PL-receiving soils. Overall, the difference in nitrification between PL and UAN was mainly caused by the change in AO abundance rather than composition, and AO were not negatively affected by an increase in PL-derived trace metal concentrations.

Natural degradation of roxarsone in contrasting soils: Degradation kinetics and transformation products

Roxarsone (ROX) is transformed to more toxic arsenicals after land application of ROX-containing poultry litter to agricultural soils. To date, no reports have compared ROX degradation in soils with contrasting properties. In this study, the impact of different incubation conditions on ROX degradation was investigated in red (C-Soil) and yellow-brown (H-Soil) soils. The degradation half-lives of extractable ROX in C-Soil and H-Soil were found to be 130–394d and 4–94d, respectively, indicating that the extractable ROX degraded faster in H-Soil. This result stems from the higher organic matter content, more abundant soil microbes, and lower ROX sorption capacity of H-Soil compared to C-Soil. Degradation of extractable ROX in both C-Soil and H-Soil was significantly promoted by soil moisture and exogenous glucose. Exogenous P(V) facilitated degradation of extractable ROX in C-Soil, but limited effects were observed for H-Soil. HPLC-ICP-MS analysis confirmed that ROX and dimethylarsinic acid were the predominant As species in soil extracts from 119-day incubated C-Soil and H-Soil, respectively. Ultimately, minimal transformation of extractable ROX was observed in C-Soil, but the majority of extractable ROX in H-Soil was biologically transformed. The differences in degradation of extractable ROX in C-Soil and H-Soil highlight the key roles of soil properties on the environmental fate of ROX and associated arsenicals. Results from this study inform the need for comprehensive evaluation of the ecological risks in organoarsenical-contaminated soils.

Influence of Poultry Litter and Poultry Litter Biochar on Soil Microbial Respiration and Nitrifying Bacteria Activity

The application of organic materials, such as poultry litter or poultry litter biochar, may lead to major changes in the structural and functional diversity of microbial populations. The understanding of the relationship between microorganisms and environment is crucial to assess the effect of organic materials on soil. Therefore, the objective was to evaluate the influence of the addition of poultry litter (5 t DM ha−1) and poultry litter biochar in doses of 2.25 t and 5 t DM ha−1 on soil respiration activity, microbial biomass, and nitrifying bacteria activity. In soils with poultry litter biochar added in 2.25 t and 5 t DM ha−1 doses, microbial biomass was significantly higher than in treatment with mineral fertilisation applied (MF), by 59 and 77%, respectively. The significantly highest basal respiration value was determined in soil with 5 t DM ha−1 biochar. The application of poultry litter had significant effect on nitrifying bacteria activity (increase by 50%). Poultry litter biochar added to the soil in both doses contributed to an increase in nitrifying bacteria activity by 36 and 34%, respectively compared to MF treatment. Biochar had more adverse effect on soil microbial biomass and nitrifying bacteria activity than non-converted poultry litter, but it had significant effect on soil respiration activity.Graphical

Adsorption and Degradation of Metolachlor in Alluvial Soils: Effect of Poultry Litter

Soils in the Southern Mississippi Valley Alluvium (MLRA 131) have low organic matter content (&lt; 20 g kg-1) and application of poultry (Gallus gallus domesticus) litter to these soils may improve their quality. However, after litter application, chemical weed control practice such as herbicide application for row crop production remains the same. In soils where soybean [Glycine max (L.) Merr.] is grown, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl] acetamide] is applied as a pre-emergent herbicide to control broadleaf and annual grasses. There is an opportunity for metolachlor to leach to the groundwater during and after rainfall events. We hypothesize that metolachlor applied to these alluvial soils amended with poultry litter may degrade rapidly when compared to unamended (control) soils. Soil samples were collected from the top 10 cm of Commerce silt loam (Aeric Fluvaquents) and Sharkey clay (Vertic Haplaquepts). The samples were air dried and amended with poultry litter to increase the organic matter content to 20 g kg-1. Control samples received no poultry litter but were subjected to similar protocols as the amended samples. Batch experiments indicated significant increase in metolachlor adsorption for the amended soils, although adsorption was higher in Sharkey clay. Kinetics experiments showed that equilibrium was established 2 h for Commerce silt loam and 24 h for Sharkey clay. Metolachlor degradation was 6 times faster in the amended Commerce soil and 2.5 times faster in the amended Sharkey soil. Degradation rate in the amended Commerce soil was 2.3 times faster than the amended Sharkey clay. We conclude that adding poultry litter to these alluvial soils will increase metolachlor adsorption and further increase rates of degradation. However, appropriate amounts of poultry litter when applied, are promising for enhancing remediation of metolachlor.

Using column experiments to examine transport of As and other trace elements released from poultry litter: Implications for trace element mobility in agricultural watersheds

Trace elements are added to poultry feed to control infection and improve weight gain. However, the fate of these trace elements in poultry litter is poorly understood. Because poultry litter is applied as fertilizer in many agricultural regions, evaluation of the environmental processes that influence the mobility of litter-derived trace elements is critical for predicting if trace elements are retained in soil or released to water. This study examined the effect of dissolved organic carbon (DOC) in poultry litter leachate on the fate and transport of litter-derived elements (As, Cu, P and Zn) using laboratory column experiments with soil collected from the Delmarva Peninsula (Mid-Atlantic, USA), a region of intense poultry production. Results of the experiments showed that DOC enhanced the mobility of all of the studied elements. However, despite the increased mobility, 60–70% of Zn, As and P mass was retained within the soil. In contrast, almost all of the Cu was mobilized in the litter leachate experiments, with very little retention in soil. Overall, our results demonstrate that the mobility of As, Cu, Zn and P in soils which receive poultry litter application is strongly influenced by both litter leachate composition, specifically organic acids, and adsorption to soil. Results have implications for understanding fate and transport of trace elements released from litter application to soil water and groundwater, which can affect both human health and the environment.

Effects of Organic and Inorganic Fertilizers on the Yield Components of NH-Ae 47-4 Variety of Okra

The experiment was carried out to evaluate the effects of organic and inorganic fertilizers on the yield components of okra (variety NH-Ae 47-4). Organic fertilizers (cow dung and poultry droppings) and inorganic (NPK 15:15:15 and Urea 64:0) fertilizers were used for the experiment. The fertilizers were weighed and applied at 5g, 10g and 15g and were replicated three times and each having a control. The fertilizers were mixed three days prior to sowing the seeds. Yield components taken include; fresh pod weight (g), dry pod weight (g), length of pod (cm), number of grooves on the pod, length of stalk (cm) and pod girth (cm). Application of cow dung, poultry litter, and urea and NPK fertilizer had significant effects on all the parameters accessed with Urea fertilizer having least effect. The application of cow dung resulted in significant increase in the yield components. The results obtained from the experiment also showed that the effect of the treatments were significantly difference from the controlKeywords: evaluate, cow-dung, poultry-droppings, okra, yield