Cyclic diarylheptanoids as potential signal compounds during actinorhizal symbiosis between Alnus sieboldiana and Frankia.

The nitrogen-fixing actinomycete Frankia coexists with actinorhizal plants via nodules and supplies nitrogen compounds to the plants. Although communication has been suggested to exist through chemical substances in this nodule symbiosis, the details underlying this mechanism remain elusive. The biphenyl-type diarylheptanoids (BP-CDHs), alnusonol, and alnusdione, previously isolated from the actinorhizal plant A. sieboldiana branch wood, are secondary metabolites that accumulate in a limited number of plant species. However, since relatively widely distributed in actinorhizal plants, we investigated whether adding A. sieboldiana root extracts and these BP-CDHs could affect plant seedlings inoculated with Frankia. The results showed that the addition of root extract or alnusonol significantly increased the number of nodules and lobes more than two times compared with that upon Frankia supplementation only. We also proved that the extracted components of this plant affected nodule symbiosis. Finally, we confirmed through LC-MS that the root extract component contained BP-CDH, alnusonol. The above-described results indicate that BP-CDHs, at leaset alnusonol, might function as signal compounds from the plant side of the actinorhizal symbiosis between A. sieboldiana and Frankia.

Effect of shading and nitrogen fertilization on nitrogen metabolism, essential oil content and antimicrobial activity of Achillea millefolium

The Achillea millefolium L. is a perennial herb with important antibacterial, antifungal, anti-inflammatory, antitumoral, and antioxidant properties. This research aimed to investigate the effect of shading (75%; black net) and nitrogen fertilization (0, 75 and 150 kg urea ha-1) on the nitrogen metabolism, essential oil yield and antimicrobial activity of A.millefolium at vegetative- and reproductive-stage. The evaluated parameters varied depending on the organ and the phenological stage of the plant considered. Overall, our findings indicated that shading decreased nitrogen assimilation. Decreased activities of nitrate reductase and glutamine synthetase were observed on shaded plants during reproductive and vegetative stages, respectively. Nitrate and total amino acid levels increased in shaded plants at the vegetative stage. Regarding nitrogen supply, the improved nitrogen metabolism and essential oil yield values were accompanied by intermediate concentrations of urea (75 kg ha-1). Plants fertilized with 75 kg urea ha-1 produced the highest amino acids concentration (vegetative stage), ammonium concentration (vegetative stage) and essential oil yield (reproductive stage). Shading or nitrogen supply did not influence the microbial activity of A. millefolium essential oil.However, the essential oil of leaves and flowers were highly effective against fungi and bacteria, especially gram-positive bacteria. In conclusion, the current study showed that full light and 75 kg urea ha-1 enhanced the nitrogen metabolism of A. millefolium in both vegetative and reproductive stages.

The utilisation of nitrogenous compounds by commercial non-Saccharomyces yeasts associated with wine.

Commercial wine fermentation is commonly conducted by inoculated strains of Saccharomyces cerevisiae. However, other non-Saccharomyces yeast species have recently become popular co-inoculants. Co-inoculated yeast species compete with each other for nutrients, and such competition may impact fermentation kinetics and aroma production. Understanding the specific nutrient requirements of non-Saccharomyces strains therefore is essential to better characterize the competitive potential of each strain, and to support rational decision making for nutrient supplementation during wine making. This study investigated the nitrogen source preference of commercial non-Saccharomyces yeasts by conducting pure culture and sequential culture fermentations in synthetic grape musts with adjusted nitrogen contents. Amino acid and ammonium uptake varied between yeast species. Lachancea thermotolerans and Torulaspora delbrueckii assimilated more nitrogen at a faster rate than Pichia kluyveri and Metschnikowia pulcherrima. Significant variation in amino acid preference between species was observed. Sequential fermentations confirmed the more competitive behaviour of L. thermotolerans and T. delbrueckii, with consequences for fermentation kinetics and aroma production. Furthermore, the data suggest that declining populations of non-Saccharomyces yeasts release nitrogen and supports the activity of S. cerevisiae. The data provide the most detailed assessment of nitrogen utilisation by the investigated yeast strains in a wine environment.

Effect of supplemental dietary slow-release urea on growth performance and physiological status of dairy heifers.

We examined the effect of supplemental dietary slow-release urea on the growth performance and physiological status of 16 dairy Holstein heifers (10 months of age, 322 ± 10 kg). The heifers were offered a formulated isocaloric and isonitrogenous 70:30 roughage : concentrate ration and were assigned randomly to one of four levels of slow-release urea supplementation (0% [U0 ], 1% [U1 ], 1.5% [U1.5 ] and 2% [U2 ] dry matter [DM]). The total study lasted 95 days, which included a 20 days adaptation period. Dry matter intake (DMI) of U2 was lower than the intakes of U0 and U1 (p < .05), while average daily gains (ADG) of U1 and U1.5 were higher than U0 and U2 (p < .05). Rumen volatile fatty acids concentration did not differ among the four treatments, while ammonia nitrogen concentration increased with an increase in urea level (p < .05). Serum blood urea nitrogen concentration was lower in U1.5 than in U0 and U2 while serum free fatty acids concentration in U2 was higher than in the other three treatments (p < .05). We concluded that the addition of urea at a level of 1.5 to 2.0% DM resulted in a reduction in DMI but the addition of 1.0%-1.5% urea resulted in the highest ADG, with no negative effects on rumen fermentation and health status of the calves.

Effects of supplementing corn silage with different nitrogen sources on ruminal fermentation and microbial populations in vitro.

Compared to grass silage (GS)-, corn silage (CS)-based diets appear to increase the efficiency of microbial protein synthesis (EMPS) in the rumen. Opposite results for the EMPS obtained in vitro have raised the question of whether an inadequate supply of amino N for microbes might explain the low EMPS. We examined the effects of supplementation with different N sources in CS on the EMPS and microbial populations in vitro. GS and CS were used as substrates for in vitro incubation. CS was non-supplemented or supplemented with urea, mixed amino acids (AA), peptone, or protein to adjust the N content to that of GS. Degradation of organic matter (OM) and crude protein (CP) revealed a positive effect of all N supplements, except protein. Additionally, N supplementation increased fiber degradation of CS. Peptone primarily stimulated hemicellulolytic activity and urea stimulated cellulolytic activity. The EMPS of CS was improved by all N supplements, with peptone and urea exhibiting the highest increase (57% and 54%, respectively), followed by AA mix (40%) and protein (11%) compared to that of CS alone (111 g microbial CP kg-1 fermented OM). However, the level of EMPS detected with GS (200 g microbial CP kg-1 fermented OM) was not achieved. Protozoal 18S rRNA gene copy numbers were negatively correlated with the EMPS, whereas no correlation was found between total bacteria and the EMPS. A stimulating effect of urea, AA mix, and peptone was detected for Ruminococcus albus and Prevotella bryantii, whereas Fibrobacter succinogenes was inhibited by N supplementation. This indicated that neither the amount of available N nor the N source was the only limiting factor in the low EMPS values of CS in vitro. Information is also provided on the stimulating effects of different N sources on several microbial species in mixed rumen culture.

Replacement of Tifton hay by spineless cactus in Girolando post-weaned heifers´ diets.

This study aims to evaluate the effect of the Tifton 85 hay (Cynodon dactylon L. Pers) replacement by Orelha de Elefante Mexicana spineless cactus (Opuntia stricta [Haw.] Haw) on the nutrient intake and digestibility, growth performance, microbial protein synthesis, and efficiency of dietary nitrogen compound utilization in the diets of Girolando heifers. Twenty-four (3.5 months and 100 kg ± 3.5 kg) Girolando heifers (5/8 Holstein x Gyr) were used and arranged in a completely randomized design. Dry matter, organic matter, crude protein, and neutral detergent fiber decreased linearly as a function of the levels of Tifton hay (TH) replacement by Orelha de Elefante Mexicana spineless cactus (OEM). The non-fiber carbohydrate intake and coefficient of dry matter digestibility increased, while the neutral detergent fiber (NDF) digestibility decreased linearly with the OEM inclusion. After evaluating the growth performance by observing weight gain and morphometric measurements, there were no significant alterations. The urinary volume, nitrogen balance as well as the efficiency of nitrogen retention had increased, while the urinary and plasma urea concentrations had decreased linearly with the OEM inclusion. The results obtained in this study show that Orelha de Elefante Mexicana spineless cactus should replace Tifton hay in post-weaned heifer diets.

GABA accumulation in response to different nitrogenous compounds in unicellular cyanobacterium Synechocystis sp. PCC 6803.

GABA accumulation and glutamate decarboxylase (GAD) activity, the principal enzyme involved in GABA formation, was investigated in cyanobacterium Synechocystis sp. PCC 6803 wild-type (WT) and gad knockout mutant strains grown in medium containing different nitrogenous compounds. Nitrate was the best nitrogen source for GAD activity and GABA accumulation followed by nitrite, ammonium, and urea. An increase in the accumulation of GABA was observed in WT and mutant cells grown for 24 h in medium supplemented with 0.5 mM putrescine or spermidine with a parallel increase in GAD activity. The mutant could not accumulate GABA at all the conditions tested except when supplemented with putrescine or spermidine, where high GABA levels were observed in both WT and mutant strains. Glutamate supplementation up to 10 mM for 24 h resulted in a significant increase in both GAD activity and GABA content. Overall results suggested that optimization of nitrogen source and nitrogenous compounds supplementation was effective for the enhancement of GABA accumulation in Synechocystis.

Preliminary investigation on the potential use of two C4 turfgrass species to reduce nutrient release in a Mediterranean drained peatland.

This study compared dry matter production, nutrient uptake and tissue nutrient concentration of two C4 turfgrass species (Cynodon dactylon × Cynodon transvaalensis Burtt Davy and Paspalum vaginatum Swartz) supplied with three different nutrient solutions in a sand and peat culture. The 8-week experiment was performed in mesocosms and simulated the conditions of an open-field phyto-treatment system located in a Mediterranean drained peatland (Tuscany, Italy). Peat was collected on the site, and one of the solutions mimicked drainage water flowing into it. Three hypotheses were tested: (i) the species chosen efficiently removed nutrients from both the solution and the substrate; (ii) peat contributed to the nutrient load; and (iii) the species chosen were suitable in the open-field system. Both species adapted well to the experimental conditions and demonstrated considerable ability to remove nutrients. P. vaginatum took up nitrogen more efficiently, mainly in conditions of high nutrient availability. We observed supplementary nutrient uptake by plants in the peat treatment. Performances of the two C4 turfgrasses extrapolated to the field scale seemed effective from a phyto-treatment perspective.

Enhancing crop yield with the use of N-based fertilizers co-applied with plant hormones or growth regulators.

Crop yield, vegetative or reproductive, depends on access to an adequate supply of essential mineral nutrients. At the same time, a crop plant's growth and development, and thus yield, also depend on in situ production of plant hormones. Thus optimizing mineral nutrition and providing supplemental hormones are two mechanisms for gaining appreciable yield increases. Optimizing the mineral nutrient supply is a common and accepted agricultural practice, but the co-application of nitrogen-based fertilizers with plant hormones or plant growth regulators is relatively uncommon. Our review discusses possible uses of plant hormones (gibberellins, auxins, cytokinins, abscisic acid and ethylene) and specific growth regulators (glycine betaine and polyamines) to enhance and optimize crop yield when co-applied with nitrogen-based fertilizers. We conclude that use of growth-active gibberellins, together with a nitrogen-based fertilizer, can result in appreciable and significant additive increases in shoot dry biomass of crops, including forage crops growing under low-temperature conditions. There may also be a potential for use of an auxin or cytokinin, together with a nitrogen-based fertilizer, for obtaining additive increases in dry shoot biomass and/or reproductive yield. Further research, though, is needed to determine the potential of co-application of nitrogen-based fertilizers with abscisic acid, ethylene and other growth regulators.

Effect of static magnetic field on electricity production and wastewater treatment in microbial fuel cells.

The effect of a magnetic field (MF) on electricity production and wastewater treatment in two-chamber microbial fuel cells (MFCs) has been investigated. Electricity production capacity could be improved by the application of a low-intensity static MF. When a MF of 50 mT was applied to MFCs, the maximum voltage, total phosphorus (TP) removal efficiency, and chemical oxygen demand (COD) removal efficiency increased from 523 ± 2 to 553 ± 2 mV, ∼93 to ∼96 %, and ∼80 to >90 %, respectively, while the start-up time and coulombic efficiency decreased from 16 to 10 days and ∼50 to ∼43 %, respectively. The MF effects were immediate, reversible, and not long lasting, and negative effects on electricity generation and COD removal seemed to occur after the MF was removed. The start-up and voltage output were less affected by the MF direction. Nitrogen compounds in magnetic MFCs were nitrified more thoroughly; furthermore, a higher proportion of electrochemically inactive microorganisms were found in magnetic systems. TP was effectively removed by the co-effects of microbe absorption and chemical precipitation. Chemical precipitates were analyzed by a scanning electron microscope capable of energy-dispersive spectroscopy (SEM-EDS) to be a mixture of phosphate, carbonate, and hydroxyl compounds.

Evaluating the main and side effects of high salinity on aerobic granular sludge.

Salinity can adversely affect the performance of most biological processes involved in wastewater treatment. The effect of salt on the main conversion processes in an aerobic granular sludge (AGS) process accomplishing simultaneous organic matter, nitrogen, and phosphate removal was evaluated in this work. Hereto, an AGS sequencing batch reactor was subjected to different salt concentrations (0.2 to 20 g Cl(-) l(-1)). Granular structure was stable throughout the whole experimental period, although granule size decreased and a significant effluent turbidity was observed at the highest salinity tested. A weaker gel structure at higher salt concentrations was hypothesised to be the cause of such turbidity. Ammonium oxidation was not affected at any of the salt concentrations applied. However, nitrite oxidation was severely affected, especially at 20 g Cl(-) l(-1), in which a complete inhibition was observed. Consequently, high nitrite accumulation occurred. Phosphate removal was also found to be inhibited at the highest salt concentration tested. Complementary experiments have shown that a cascade inhibition effect took place: first, the deterioration of nitrite oxidation resulted in high nitrite concentrations and this in turn resulted in a detrimental effect to polyphosphate-accumulating organisms. By preventing the occurrence of the nitrification process and therefore avoiding the nitrite accumulation, the effect of salt concentrations on the bio-P removal process was shown to be negligible up to 13 g Cl(-) l(-1). Salt concentrations equal to 20 g Cl(-) l(-1) or higher in absence of nitrite also significantly reduced phosphate removal efficiency in the system.

Non-Additive effects on decomposition from mixing litter of the invasive Mikania micrantha H.B.K. with native plants.

A common hypothesis to explain the effect of litter mixing is based on the difference in litter N content between mixed species. Although many studies have shown that litter of invasive non-native plants typically has higher N content than that of native plants in the communities they invade, there has been surprisingly little study of mixing effects during plant invasions. We address this question in south China where Mikania micrantha H.B.K., a non-native vine, with high litter N content, has invaded many forested ecosystems. We were specifically interested in whether this invader accelerated decomposition and how the strength of the litter mixing effect changes with the degree of invasion and over time during litter decomposition. Using litterbags, we evaluated the effect of mixing litter of M. micrantha with the litter of 7 native resident plants, at 3 ratios: M1 (1∶4, = exotic:native litter), M2 (1∶1) and M3 (4∶1, = exotic:native litter) over three incubation periods. We compared mixed litter with unmixed litter of the native species to identify if a non-additive effect of mixing litter existed. We found that there were positive significant non-additive effects of litter mixing on both mass loss and nutrient release. These effects changed with native species identity, mixture ratio and decay times. Overall the greatest accelerations of mixture decay and N release tended to be in the highest degree of invasion (mix ratio M3) and during the middle and final measured stages of decomposition. Contrary to expectations, the initial difference in litter N did not explain species differences in the effect of mixing but overall it appears that invasion by M. micrantha is accelerating the decomposition of native species litter. This effect on a fundamental ecosystem process could contribute to higher rates of nutrient turnover in invaded ecosystems.

Research on microbial lipid production from potato starch wastewater as culture medium by Lipomyces starkeyi.

In this paper, potato starch wastewater as culture medium was treated by the oleaginous yeast Lipomyces starkeyi to biosynthesize microbial lipid. The result indicated that carbon source types, carbon source concentration, nitrogen source types, nitrogen source concentration, inoculum size, and cultivation time all had a significant effect on cell growth and microbial lipid accumulation in batch cultures. A measure of 120 g/L of glucose concentration, 3.0 g/L of (NH4)2SO4 concentration, 10% inoculum size, and incubation time 96 h cultivated in a shaking flask at 30 °C were found to be the optimal conditions not only for cell growth but also for lipid synthesis. Under this condition, the cellular biomass and lipid content could reach 2.59 g/L and 8.88%, respectively. This work provides a new method for effective utilization of potato starch wastewater, which has particular social and economic benefits for yeast treatment technology.

Effects of Saccharomyces cerevisiae and monensin on digestion, ruminal parameters, and balance of nitrogenous compounds of beef cattle fed diets with different starch concentrations.

This study was carried out aiming to evaluate the effects of yeast or monensin supplementation on dry matter intake, nutrients digestibility, ruminal volatile fatty acids profile, ruminal pH and ammonia concentration, microbial protein synthesis, and the balance of nitrogen compounds of cattle fed high concentrate diet (80 % dry matter (DM) basis) with two different levels of starch. Eight crossbred beef steers fitted with rumen cannula were assigned to two simultaneous 4 × 4 Latin squares arranged in a 4 × 2 factorial design. Two different starch levels (23 and 38 % of DM) were assigned to each Latin square, independently. Within each Latin square, four treatments were randomly assigned to the experimental animals (control; monensin; 1-g yeast [1 g/100 kg body weight (BW)/day] treatment; and 2.5-g yeast [2.5 g/100 kg BW/day] treatment). Feed additives did not influence ruminal pH (P > 0.05). Total ruminal volatile fatty acids (VFA) concentration was greater (P<0.05) in the diet with the lowest starch level. Similarly, monensin and 1-g yeast treatments resulted in greater (P<0.05) VFA concentration in the rumen. Monensin inclusion in the diet with the highest starch level led to a decrease (P<0.05) in lactate concentration in the rumen. However, acetate levels were increased (P<0.05) by the inclusion of 1 g of yeast in the diet with lowest starch level. Ruminal concentrations of propionate and butyrate, and ammonia-N were not influenced (P>0.05) by none of the additives evaluated. However, propionate concentration was greater (P<0.05) in the low-starch diets. Low-starch diets resulted in lower ruminal ammonia-N concentration and greater neutral detergent fiber digestibility (P<0.05). The excretion of urinary nitrogenous compounds, purine derivatives, synthesis of microbial protein, microbial efficiency, and balance of nitrogenous compounds were not affected by treatments evaluated (P>0.05). Monensin or yeast inclusion in high concentrate beef cattle diets in tropical regions as in Brazil is not justified by do not alter nutrient digestibility, nitrogen balance, and main ruminal parameters.

Effect of oligochaete worm body fluids on biological phosphorus removal in a bench-scale EBPR system.

During waste sludge reduction by oligochaetes, phosphorus (P) concentrations in the effluent have been noticed to increase. In the current study, batch experiments were carried out in order to provide explanations for this phosphorus release. The results indicated that increase in effluent phosphorus concentration might not be directly linked to the phosphorus in worm body fluids, as the phosphorus concentration in the system at the start of each operational period did not change significantly. However, the phosphorus removal efficiency rapidly dropped from 93.9% +/- 1.9% to 62.2% +/- 1.3% with increasing addition ofoligochaete worm body fluids. Furthermore, an increase in worm body fluids induced a remarkable enhancement ofanaerobic phosphorus release rate as well as anaerobic storage of poly-beta-hydroxyalkanoate (PHA). At a worm density (wet weight) of 14.4 g/L, the anaerobic phosphorus release rate was elevated by 31.1% +/- 2.8% and 57.3% +/- 4.6% at 2.5% and 5.0% worm death rate, respectively, compared with the control. The contribution of worm body fluids to PHA production was 39.3-67.7 mg/g of dead worm (wet weight), which was mainly attributed to the extra synthesis of poly-beta-hydroxyvalerate (PHV). Unfortunately, in the concomitant aerobic stage, inhibition of 3-hydroxybutyric acid (PHB) oxidation and ammonia utilization was observed along with the increasing addition of worm body fluids. Meanwhile, nitrite elevation was found at the beginning of the aerobic stage, which might be negative to the aerobic metabolic processes performed by phosphate-accumulating organisms (PAOs), namely PHB oxidation, phosphate uptake and ammonia utilization for biomass growth.

Efficient 2,3-butanediol production from cassava powder by a crop-biomass-utilizer, Enterobacter cloacae subsp. dissolvens SDM.

BACKGROUND: 2,3-Butanediol (BD) is considered as one of the key platform chemicals used in a variety of industrial applications. It is crucial to find an efficient sugar-utilizing strain and feasible carbon source for the economical production of BD. METHODOLOGY/PRINCIPAL FINDINGS: Efficient BD production by a newly isolated Enterobacter cloacae subsp. dissolvens SDM was studied using crop-biomass cassava powder as substrate. The culture conditions and fermentation medium for BD production were optimized. Under the optimal conditions, 78.3 g l(-1) of BD was produced after 24 h in simultaneous saccharification and fermentation (SSF), with a yield of 0.42 g BD g(-1) cassava powder and a specific productivity of 3.3 g l(-1) h(-1). A higher BD concentration (93.9 g l(-1)) was produced after 47 h in fed-batch SSF. CONCLUSIONS/SIGNIFICANCE: The results suggest that strain SDM is a good candidate for the BD production, and cassava powder could be used as an alternative substrate for the efficient production of BD.

Supplementation of poultry feeds with dietary zinc and other minerals and compounds to mitigate nitrogen emissions--a review.

One of the environmental challenges that the poultry industry has been faced with is ammonia emission from manure. One way to reduce nitrogen excretion and emissions is supplementing dietary trace minerals to inhibit the activity of microbial uricase, a key enzyme converting nitrogen compounds in the manure into ammonia. Several dietary minerals are commercially available as economic alternatives for reducing ammonia emissions in poultry. In this review, we discuss different mineral elements including zinc as feed amendment minerals that could be used to reduce ammonia emission. Issues discussed include potential for inhibiting microbial uricase, dietary supplementation levels, growth performance, toxicity, their influence on manure nitrogen emission, and potential mineral accumulation in soil. In addition, we discuss other minerals and compounds that have the potential to reduce ammonia volatilization by inhibiting microbial uricase and growth of uric acid-utilizing microorganisms.

Observations of nitrogen and phosphorus biogeochemistry in a surface flow constructed wetland.

Free surface water constructed wetlands (CWs) provide a buffer between domestic wastewater treatment plants and natural waterways. Understanding the biogeochemical processes in CWs is crucial to improve their performance. In this study we measured a range of water and sediment parameters, and biogeochemical processes, in an effort to describe the processing of nutrients within two wetland cells in series. As a whole the studied CW effectively absorbed both nitrogen (N) and phosphorus (P) emanating from the waste treatment plant. However the two individual cells showed marked differences related to the availability of oxygen within the water column and the sediments. In one cell we speculated that the prevalence of surface plant species reduced its ability to function as a net nutrient sink. Here we observed a build-up of sediment organic matter, sediment anoxia, a decoupling of nitrification-denitrification, and a flux of N and P out of the sediments to the overlying water. The availability of DO in the surface sediments of the second studied cell led to improved coupling between nitrification-denitrification and a net uptake of both NH4+ and PO4(3-). We hypothesise that the dominance of deeply rooted macrophytes in the second cell was responsible for the improved sediment quality.

Efficacy and reliability of upgraded industrial treatment plant at Porto Marghera, near Venice, Italy, in removing nutrients and dangerous micropollutants from petrochemical wastewaters.

Chemical and petrochemical wastewaters contain a host of contaminants that require different treatment strategies. Regulation of macropollutants and micropollutants in the final discharge from industrial wastewater treatment plants (WWTPs) have become increasingly stringent in recent decades, requiring many WWTPs to be upgraded. This article presents an analysis of a WWTP treating petrochemicals in Porto Marghera, Italy, that recently was upgraded following legislative changes. Because of strict legal limits for macropollutants and micropollutants and a lack of space necessary for a full-scale WWTP overhaul, the existing activated sludge tank was converted into a membrane biological reactor. The paper presents experimental data collected during a five-month investigation showing the removal rates achieved by the upgraded plant for macropollutants (particularly nitrogen compounds) and micropollutants (heavy metals and organic and inorganic toxic compounds).

Effect of surface incorporation of broiler litter applied to no-till cotton on runoff quality.

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.