Amended Soil Columns Research Articles

Development of Rice Straw-derived Biochar-Bentonite Composite and its Application for in situ Sequestration of Ammonium and Phosphate Ions in the Degraded Mine Soil.

Nutrient pollution has a diverse impact on the environment and human health. The presence of nutrients, such as ammonium and phosphate, is ubiquitous in the environment due to their extensive use in agricultural land and leaching through non-point sources. In this context, biochar-based composites could play an essential role in improving the soil's nutrient retention capacity. The present study aims to develop bentonite-biochar composites (BNT@BC 400 and 600) and utilize them as an ameliorating material in the coal mine degraded soil to reduce the leaching of ammonium and phosphate ions. The bentonite-biochar composite (BNT@BC 400 and 600) was synthesized using the pristine rice straw-derived biochar using the solvothermal method. The biochar was produced at two different pyrolytic temperatures, 400 °C and 600 °C, and denoted as BC 400 and 600, respectively. Hence, the bentonite-biochar composite was denoted as BNT@BC 400 and 600. The BNT@BC 400 and 600 were characterized using the elemental, proximate, SEM, XRD, and FTIR analysis. Subsequently, the BNT@BC composites were evaluated for the adsorptive removal of NH4+ and PO43- ions using batch adsorption and column leaching studies. In the soil columns, the BNT@BC 400 and 600 were mixed with the soil at two different application rates, viz. 1 and 2.5% (w/w). The leaching characteristics data were fitted using three different fixed-bed models to predict the maximum adsorption capacity of the amended soil columns and the dominant mechanism of adsorption. Results indicated that the BNT@BC 600 showed the maximum adsorption capacity of 33.77 and 64.23 mg g-1 for the adsorption of NH4+ and PO43- ions, respectively. The dominant adsorption mechanisms in the aqueous solution were the electrostatic attraction, complexation, ion exchange, and precipitation processes. In the soil columns, the sorption of NH4+ and PO43- ions was governed by diffusive mass transfer and electrostatic interaction. Findings of the study indicated that incorporating the BNT@BC composite in the soil can significantly reduce the leaching of the NH4+ and PO43- ions and increase the overall soil fertility.

Assessing Nitrogen Cycling in Corncob Biochar Amended Soil Columns for Application in Agricultural Treatment Systems

Biochar soil amendment to agricultural systems can reduce nitrogen (N) leaching; however, application to agricultural nitrogen treatment systems has not been extensively explored. The objective of this study was to assess the impact on N leaching in soils receiving repeated N applications which may be observed in agricultural treatment systems. In this study, 400 °C, 700 °C, and oxidized 700 °C corncob biochar was amended to sandy loam soil columns at 5% (wt/wt) to assess the impacts to N cycling following repeated synthetic N applications. Columns received weekly applications of either organic N (ORG-N), ammonium (NH4+-N), or nitrate (NO3−-N) and the N effluent, gaseous emissions, and soil N retention was measured. Biochar produced at 400 °C significantly reduced N leaching compared to control columns by 19% and 15% for ORG-N and NH4+-N, respectively, with application concentrations similar to silage bunker runoff. For NO3−-N applications, 700 °C biochar significantly reduced leaching by 25% compared to the controls. The primary mechanism reducing N effluent for biochar amended columns was enhanced soil retention of ORG-N and NO3−-N. Biochar surface chemistry analysis measured an increase in oxygenated functional groups and cationic minerals on the biochar surface, which likely enhanced retention through cationic bridging or the development of an organomineral layer on the biochar surface. Results indicated biochar amendment to agricultural treatment systems receiving N runoff may reduce the risk of N leaching.

Measuring and simulating effect of organic residues on the transport of cadmium, nickel, and zinc in a calcareous soil

Knowledge of heavy metal movement from organically-rich soils is important for assessing heavy metal mobility and developing methods for predicting such losses. Laboratory soil column study and sequential extraction analysis were conducted to evaluate the effect of eight organic residues (sewage sludge, municipal solid waste compost (MSWC), poultry manure, sheep manure, mushroom compost, and residues of wheat, potato, and rape) on retention and leaching of cadmium (Cd), nickel (Ni), and zinc (Zn) in a sandy loam soil. Cadmium, Ni, and Zn were monitored in the leachate of soil column by passing a mixture of 50mgL−1 CdCl2, 50mgL−1 NiCl2, and 50mgL−1 ZnCl2 solutions through the soil column. The addition of all amendments to the soil caused to an increase in leachate pH in the initial stage of leaching. Movement of Cd, Ni, and Zn ions in control soil was retarded due to adsorption. The retardation factor (Rf) decreased due to the addition of organic residues, enhancing heavy metal movement. Soil treated with wheat residue, MSWC, and mushroom compost had the highest Rf for heavy metals, followed by sheep manure, rape residue, sewage sludge, potato residue and poultry manure. Potato residues and poultry manure enhanced heavy metals transport to the greatest degree. For most organic residues studied, Rf showed the trend Ni>Zn>Cd, indicating the rate of heavy metals transport in this calcareous soil was: Cd>Zn>Ni. The above trend was confirmed by sequential extractions of soil columns, indicating 44% (average of all amended soil columns) of total Cd was in the exchangeable form (EXCH), while EXCH fraction was 26% and 19% for Zn and Ni, respectively. The risk of groundwater contamination will increase after applying organic resides and it needed to be used very carefully. An integrated modeling approach employing a surface complexation and an ion exchange model has been developed in PHREEQC. The similarity between measured and simulated data indicated that the model was successful to predict Cd, Ni, and Zn movement in control and organically-amended soils.

Winery vermicomposts to control the leaching of diuron, imidacloprid and their metabolites: Role of dissolved organic carbon content

Soil organic amendment addition is an effective practice in Mediterranean areas due to its associated high agricultural benefits and its potential to reduce the pesticide impact on water resources. However, their metabolites have received scarce attention, even when they may pose more risk than their parent compounds. Two winery vermicomposts obtained from spent grape marc (V1) and the mixture vine shoot-biosolid vinasses (V2) have been investigated as low cost organic amendments to minimize the leaching of diuron, imidacloprid and their metabolites in columns packed with a sandy loam (S1) and a silty-clay loam soil (S2) under steady state flow conditions. In the unamended soil columns, leached amounts of diuron were 75% and 53% in S1 and S2, respectively. Its metabolites (3-(3,4-dichlorophenyl)-1-methylurea, DPMU; and 3,4-dichlorophenylurea, DPU) percolated less than 35% of the total applied amount. The amount of the metabolite 3,4-dichloroaniline (DCA) was 2% and 30% for S1 and S2, respectively. Leaching of imidacloprid was 79% and 96% for S1 and S2, respectively, while its metabolite 6-chloronicotinic acid (CNA) was entirely leached. In the vermicompost-amended columns, the leaching of diuron was reduced 2 to 3-fold. DPMU and DPU were also significantly reduced (more than 6-fold). DCA did not appear in any of the leachates of the amended soil columns. Imidacloprid leaching was reduced 1 to 2-folds in the amended columns. The amendments did not affect the transport of CNA. The dissolved organic carbon (DOC) from the vermicomposts did not enhance pesticide transport throughout the soil in any case. This qualitative study presents these vermicomposts as an effective potential low-cost tool in reducing pesticide and metabolite leaching. The next step would be to test them under more realistic conditions.

Batch and column experiments on nutrient leaching in soils amended with Italian natural zeolitites

This paper describes the application of the Italian chabazite-rich tuff of Sorano (Grosseto) as a soil conditioner and slow nutrient fertilizer to a silty-clay soil and a sandy soil. The study was developed by means of batch and column experiments. The objectives of the study were: (1) to evaluate and compare the physical and hydraulic properties of mixtures of soil and natural zeolitite (95:5% v/v) with those of unamended soils, (2) to determine the effects of applying NH4+-enriched zeolitites on soils and (3) to model water and solutes movement in two different scenarios, with and without amendment incorporation. Results of column experiments were then modelled to obtain the physical–chemical and hydraulic parameters representative of the soils amended with the NH4+-enriched zeolitites. Using synthetic rainwater as eluent, NH4+ was never detected in the water phase of batches and columns; NO3− and PO43− were both present at high concentrations in batch tests and were leached in column elution tests. NO3− displayed very high concentrations at the beginning of the elution whereas PO43− showed low concentrations and retarded peaks in both amended soil columns. The rationale of the study lies in the belief that inorganic amendments, which improve the physical and hydraulic properties of soils, can lead to minimized leaching of nutrients.

Mobility of spiromesifen in packed soil columns under laboratory conditions.

On percolating water equivalent to 1,156mm of rainfall, spiromesifen formulation did not leach out of 25-cm long columns, and 62.7% of this was recovered in 5-10-cm soil depth. In columns treated with the analytical grade, 52.40% of the recovered spiromesifen was confined to 0-5-cm soil depth, with 0.04% in leachate fraction, suggesting high adsorption in soil. Results revealed that percolating 400mL of water, residues of enol metabolite of spiromesifen was detected up to 20-25-cm soil layer, with 23.50% residues of spiromesifen in this layer and 1.73% in the leachate fraction indicating that metabolite is more mobile as compared to the parent compound. Results suggested a significant reduction in leaching losses of enol metabolite in amended soil columns with 5% nano clay, farmyard manure (FYM), and vermicompost. No enol spiromesifen was recovered in the leachate in columns amended with nano clay, vermicompost, and FYM; however, 85.30, 70.5, and 65.40%, respectively, was recovered from 0-5cm-soil depth of column after percolating water equivalent to 1,156mm of rainfall. Spiromesifen formulation is less mobile in sandy loam soil than analytical grade spiromesifen. The metabolite, enol spiromesifen, is relatively more mobile than the parent compound and may leach into groundwater. The study suggested that amendments were very effective in reducing the downward mobility of enol metabolite in soil column. Further, it resulted in greater retention of enol metabolite in the amendment application zone.

Aerobic biotransformation of N-nitrosodimethylamine and N-nitrodimethylamine in methane and benzene amended soil columns

Aerobic biotransformation of N-nitrosodimethylamine (NDMA), an emerging contaminant of concern, and its structural analog N-nitrodimethylamine (DMN), was evaluated in benzene and methane amended groundwater passed through laboratory scale soil columns. Competitive inhibition models were used to model the kinetics for NDMA and DMN cometabolism accounting for the concurrent degradation of the growth and cometabolic substrates. Transformation capacities for NDMA and DMN with benzene (13 and 23μg (mgcells)(-1)) and methane (0.14 and 8.4μg (mgcells)(-1)) grown cultures, respectively are comparable to those presented in the literature, as were first order endogenous decay rates estimated to be 2.1×10(-2)±1.7×10(-3)d(-1) and 6.5×10(-1)±7.1×10(-1)d(-1) for the methane and benzene amended cultures, respectively. These studies highlight possible attenuation mechanisms and rates for NDMA and DMN biotransformation in aerobic aquifers undergoing active remediation, natural attenuation or managed aquifer recharge with treated wastewater (i.e., reclaimed water).

Effects of sewage sludge amendments on pesticide sorption and leaching through undisturbed Mediterranean soils

The Gharb region in Morocco is an important agricultural zone where soils receive pesticide treatments and organic amendments to increase yields. The groundwater aquifer in the Gharb region is relatively shallow and thus vulnerable. The objective of this work was to study the influence of organic amendments on diuron, cyhalofop-butyl and procymidone leaching through undisturbed soil columns. Two soils were sampled from the Gharb region, a Dehs (sandy soil) and a R’mel (loamy clay soil). Following elution (124.5 mm), the amount of pesticide residues in the leachates of the sandy soil (0.06–0.21 %) was lower than in those of the loamy clay soil (0.20–0.36 %), which was probably due to preferential flow through the loamy clay soil. The amount of procymidone leached through the amended soil columns was greater than the control for the sandy soil only. The organic amendments did not significantly influence diuron and cyhalofop-butyl leaching in either of the soils. The application of organic amendments affected the amounts of dissolved organic matter (DOM) eluted and thus pesticide leaching as a function of soil-type. Nevertheless, in some case, the formation of pesticide-DOM complexes appeared to promote pesticide leaching, thus increasing groundwater contamination risks.

Immobilization of Copper, Lead, and Tungsten in Mixed Munitions Firing Range–Contaminated Soils by Various Amendments

Batch and column leaching tests were conducted to assess the simultaneous stabilization of copper (Cu), lead (Pb), and tungsten (W) in eight representative contaminated firing range soils in the United States using various amendments. The amendments included granulated ferric oxide (GFO), granulated titanium dioxide (GTD), Pahokee peat soil (PPS), Gascoyne leonardite soil (GLS), Elliot silty loam soil (ESLS), calcium phosphate monobasic (CPM), and apatite II. The metal oxides and the organic soil amendments were applied at a dosage of 10%, and phosphates were applied at phosphorus to lead (P/Pb) molar ratio of 1.8. The experimental results indicated that GFO was superior to all materials tested for simultaneously stabilizing Cu, Pb, and W during the batch leaching tests. Flow-through column tests were conducted for one of the soil samples to test the effectiveness of GFO to immobilize Cu, Pb, and W. The concentrations of Cu, Pb, and W were significantly reduced in the effluent of the amended soil columns ...

Direct and residual effects on diuron behaviour and persistence following two-phase olive mill waste addition to soil: Field and laboratory experiments

Two-phase olive mill waste (TPOMW) is a by-product of olive oil extraction, contains up to 90% organic matter, and may be used as a soil amendment. In order to investigate the impact of TPOMW amendments to soil on the sorption-desorption, degradation, leaching, and persistence of the herbicide diuron, field and laboratory experiments were conducted on a representative olive grove soil. The soil was amended in the laboratory with TPOMW at the rates of 5% and 10%, and in the field with 30 and 60 Mg ha − 1 of TPOMW for seven years. Direct and residual effects were evaluated in the last year and two years after the last TPOMW field application (2005 and 2007, respectively). Significant increases in diuron sorption were observed with the greater amount of TPOMW in the laboratory and field-amended soils, mainly promoted by an increase in humic acid content, this process being more reversible in the laboratory than in the field amended soils. The TPOMW soil application only significantly increased the half-life of diuron in the laboratory amended soils, ranging from 8.5 days for the original soil to 32 days at the greater application rate. The TPOMW amendments significantly reduced the downward mobility of diuron, and reduced the amount of herbicide leached in the laboratory and field-amended soils, with a major residual decrease two years after the last waste addition since no herbicide leached through these amended-soil columns. In the field persistence study, TPOMW addition increased diuron retention mainly in the upper 30 cm of the soils, decreasing the herbicide's vertical movement through the amended soils. The residence time of diuron increased with increasing TPOMW rate, especially in the direct year (2005). The results revealed major changes in diuron's behaviour due to the different TPOMW loading rates and the transformation of the amendment during two years of biodegradation in the soil. This study has shown the usefulness of TPOMW for reducing groundwater contamination by pesticides for at least 24 months following its application.

Influence of organic amendments on diuron leaching through an acidic and a calcareous vineyard soil using undisturbed lysimeters

The influence of different organic amendments on diuron leaching was studied through undisturbed vineyard soil columns. Two composts (A and D), the second at two stages of maturity, and two soils (VR and Bj) were sampled. After 1 year, the amount of residues (diuron + metabolites) in the leachates of the VR soil (0.19–0.71%) was lower than in the Bj soil (4.27–8.23%), which could be explained by stronger diuron adsorption on VR. An increase in the amount of diuron leached through the amended soil columns, compared to the blank, was observed for the Bj soil only. This result may be explained by the formation of mobile complexes between diuron and water-extractable organic matter (WEOM) through the Bj soil, or by competition between diuron and WEOM for the adsorption sites in the soil. For both soils, the nature of the composts and their degree of maturity did not significantly influence diuron leaching.

Biogeochemical behaviour of anionic radionuclides in soil: Evidence for biotic interactions

Tc and 79 Se, two long-lived radionuclides, are supposed to be highly mobile in soils, because of their anionic forms. Their behaviours in the soil are often considered only from a physico-chemical point of view, although the microorganisms can affect either directly or indirectly their speciation. This study demonstrates the role of the microbial compartment in the retention of Se and Tc in soil by comparing experiments with soils constrained to different microbiological status (sterile / raw / amended). Kd coefficients for Se and Tc were determined in batch experiments, whereas transport of Se and Tc was investigated through column leaching experiments. Kd for Se was enhanced for the raw soil without amendment compared to the value obtained for the sterilised soil. The retention of Se was higher again in the amended soil. Besides, a biofilm, which can directly retain Se, was obtained at the entrance of the amended soil column. This effect was less obvious for Tc in batch experiments, but was revealed by leaching experiments where a high quantity of Tc was retained in the amended soil columns. These results give strong evidence that microorganisms are responsible for a greater retention of Se and Tc in soil.

Ozone treatment of soil contaminated with aniline and trifluralin

Column studies were conducted to determine the ability of ozone to degrade aniline and trifluralin in soil. Ozone rapidly degraded aniline from soil under moist soil conditions, 5% (wt). Removal of 77–98% of [UL- 14C]-aniline was observed from soil columns (15 ml, i.d.=2.5 cm), exposed to 0.6% O 3 (wt) at 200 ml/min after 4 min. Initial ozonation products included nitrosobenzene and nitrobenzene, while further oxidation led to CO 2. Ring-labeled-[UL- 14C]-trifluralin removal rates were slower, requiring 30 min to achieve removals of 70–97%. Oxidation and cleavage of the N-propyl groups of trifluralin was observed, affording 2,6-dinitro-4-(trifluoromethyl)-aniline, 2,6-dinitro- N-propyl-4-(trifluoromethyl)-benzamine, and 2,6-dinitro- N-propyl- N-acetonyl-4-(trifluoromethyl)-benzamine. Base solutions revealed that trifluralin was similarly oxidized to CO 2, where 72–83% of the activity recovered comprised 14CO 2. Use of ozone-rich water improved contaminant removal in trifluralin-amended soil columns, but did not improve removal in aniline, pentachloroaniline, hexachlorobenzene amended soil columns, suggesting that ozonated water may improve contaminant removal for reactive contaminants of low solubility.

The Suitability of an Iron Oxide‐Rich Gypsum By‐Product as a Soil Amendment

AbstractAn industrial titanium dioxide process produces a gypsum by‐product rich in iron oxides (red gypsum). Dissolution of red gypsum when applied to soil may be affected by the presence of the oxides due to adsorption of sulfate. This may affect red gypsum's suitability as a sulfur source for crops compared with other forms of gypsum. In addition, the oxides could act as a sink for metal cations, again by adsorption. Adsorption behavior depends on the properties of the material. Characterization showed that the gypsum and iron oxide were present as discrete particles, and that these components had very large surface areas. The iron oxides were a mixture of crystalline and amorphous hydrated forms. They had a point of zero net charge (PZNC) of 6.5. The affinity of anions for adsorption on the iron oxide material was in the order: phosphate > sulfate > nitrate > chloride. Metal cation adsorption revealed an affinity order of Pb > Cu > Ni > Zn > Cd for the iron oxide material and Pb > Zn > Cd > Cu > Ni for red gypsum. In a soil column dissolution experiment, retention of SO2−4 by adsorption on the soil was not evident. Only a pelleted form of the red gypsum appeared to be effective at providing sulfate at a controlled rate. In contrast to sulfate, phosphate was strongly retained in the amended soil columns, while there was little retention of nitrate. Metal cation adsorption on the red gypsum suggested that it could be beneficial as an amendment in soils that have potentially toxic metals present.

Leaching of mecoprop and dichlorprop in calcareous soil. Effect of the exogen organic matter addition in this process

Leaching studies of mecorprop (R,S)‐2‐(4‐chloro‐2‐methylphenoxy)propanoic acid, and dichlorprop, (R,S)‐2‐(4‐chloro‐2,4‐dichlorophenoxy) propanoic acid, under saturated conditions were conducted in unamended and amended soil columns. The purpose of the study was to investigate the leaching of these herbicides in three type of soils and the exogen organic matter effect on this process. The leaching patterns could be related to variation in the soil texture and diffusion processes of the herbicides into micropores within the walls of conducting pore. The leaching rate in the amended soil columns decreased with the addition of organic matter. The breakthrough curves (BTC) of these herbicides in the leachates of the amended soil columns were wider and more diffused than the BTC obtained for the corresponding unamended soil. The theoretical BTC overestimated the pore volume required for the displacement of these pesticides from the soil column. This may be due to the differences in the adsorption process between the bacth and soil columns methods

Decomposition of seawater-irrigated halophytes : implications for potential carbon storage

Seawater-irrigated halophytes are a non-traditional crop that may serve to offset anthropogenic carbon dioxide emissions through long-term carbon storage. To assess the feasibility of storing carbon as cultivated halophyte residues in coastal desert soils, the decay rate, microbial activity and microbial decomposer abundance of post-harvest residues were investigated for three potential halophyte crops. Decay rates were determined by measuring weight loss from residues in litterbags in both the field and laboratory. The effect of incorporating residues into the soil was examined by locating litterbags both on and below the soil surface. Microbial decomposition activity was measured as the CO2 efflux from residue amended soil columns in the greenhouse. The abundance of bacteria, fungi, and nematodes was assessed in decomposing residues using litterbags in the field. The three halophytes decomposed at rates similar to those of conventional, non-saline residues (0.20–0.30% d-1) whether placed on the surface or buried at 30 cm. Residue type affected microbial activity in soil columns during the first 21 days, but decomposition was similar for the three halophytes thereafter. Residue type affected the abundance of nematodes, but not of bacterial and fungal decomposers. Because the rate of halophyte residue decay and the number of microbial decomposers associated with the residues are similar to those of fresh water systems, there appears to be no advantage in storing carbon as plant residue in this saline agricultural system.

NITROGEN RECOVERY FROM CONTROLLED-RELEASE FERTILIZERS UNDER INTERMITTENT LEACHING AND DRY CYCLES1

The efficiency of nitrogen (N) use by crop plants depends, in part, on the leaching losses below the rooting depth in soils. A leaching column study was conducted to evaluate N transformation and leaching from three urea- based Controlled Release Fertilizers (CRF) and uncoated urea applied to a sandy soil. Each leaching was followed by 6 days of incubation at 33-35°c. After 18 leaching and dry cycles (3960 mL of water leached, equivalent to 90-cm rainfall), recovery of total N (sum of all forms in the leachate, residual soil N, and residual fertilizer N) accounted for 89, 85, 84, and 45% of the total N applied as Poly-S, Meister, Osmocote, and Urea, respectively. Cumulative N forms in 3960 mL leachate accounted for 59, 44, 33, and 28% oftotal N applied as Poly-S, Urea, Osmocote, and Meister, respectively. Leachate N accounted for 98% of total N recovery from uncoated urea, and 60% of leachate N was in Urea-N form. Cumulative NO 3 - -N in 3960 mL leachate accounted for 80, 98, 97, and 24% of the total N leached from Poly-S, Meister, Osmocote, and Urea amended soil columns, respectively. Soil residual N, (sum of NH 4 + -N and NO 3 - -N) after completion of 18 leaching and dry cycles, accounted for 11, 9, 3 and 0.9% oftotal N applied as Meister, Poly-S, Osmocote, and Urea, respectively. No fertilizer residue was recovered in the urea treatment. In the case ofthe CRF sources, the residual fertilizer N accounted for 48, 45, and 22% of total N applied: as Osmocote, Meister, and Poly-S, respectively. Among the CRF products, longevity of release was significantly greater for the Meister and Osmocote compared with Poly-S.

Leaching of Nitrate, Ammonium, and Phosphate From Compost Amended Soil Columns

Compost amendment to agricultural soils has been reported to reduce disease incidence, conserve soil moisture, control weeds, or improve soil fertility. Application rate and placement of compost largely depends on the proposed beneficial effects and the rate may vary from 25 to 250 Mg ha−1 (N content up to 4 percent). Application of high rates of compost with high N or P levels may result in excessive leaching of nitrate, ammonium, and phosphate into the groundwater. Leaching could be a serious concern on the east coast of Florida with its inherent high annual rainfall, sandy soils and shallow water table. In this study, five composts (sugarcane filtercake, biosolids, and mixtures of municipal solid wastes and biosolids) were applied on the surface of an Oldsmar sand soil (in 7.5 cm diameter leaching columns) at 100 Mg ha−1 rate and leached with deionized water (300 ml day−1, for five days; equivalent to 34 cm rainfall). The concentrations of NO3-N, NH4-N, and PO4-P in leachate reached as high as 246, 29, and 7 mg L−1, respectively. The amount of N and P leached accounted for 3.3-15.8 percent of total N and 0.2-2.8 percent of total P in the compost. The leaching peaks of NO3-N occurred following the application of only 300-400 ml water (equivalent to 6.8-9.1 cm rainfall).

Leaching of Nitrate, Ammonium, and Phosphate from Compost Amended Soil Columns

Compost amendment to agricultural soils has been shown to either reduce disease incidence, conserve soil moisture, control weeds or improve soil fertility. Application of compost can range from 5 to 250 Mt·ha–1 (N content up to 4%). Large application of compost with high N and P levels may result in excessive leaching of nitrate, ammonium, and phosphate into groundwater. It could be a serious concern on the east coast of Florida with its high annual rainfall and shallow water table. In this study, five composts (sugarcane filtercake, biosolids, and mixtures of municipal solid wastes and biosolids) were collected from different facilities throughout Florida. Composts were applied on a surface of 15-cm sandy soil columns at the rate of 100 Mt·ha–1 on the surface basis and leached with deionized water by 300 ml·d–1 for 5 days (equivalent to 34 cm rainfall). The concentrations of NO3-N, NH4-N, and PO4-P in leachates reached as high as 246, 29, and 142 mg·L–1, respectively. The amount of N and P leached following 5-day leaching events accounted for 3.3% to 15.8% of total N and 0.2% to 2.8% of total P as inorganic forms.