Hog Manure Research Articles

Influence of the time and rate of liquid-manure application on yield and nitrogen utilization of silage corn in south coastal British Columbia

Manure-N availability must be known in order to design application practices that maximize the nutrient value of the manure while minimizing adverse environmental impacts. This study determined the effect of time and rate of liquid manure application on silage corn yield and N utilization, and residual soil nitrate at harvest, in south coastal British Columbia. Liquid dairy or liquid hog manure was applied at target rates of 0, 175, 350 or 525 kg N ha−1, with or without addition of 100 kg N ha−1 as inorganic fertilizer, at two sites in each of 2 yr. Time of liquid-dairy-manure application was also tested at two sites in each of 2 yr with N-application treatments of: 600 kg N ha−1 as manure applied in spring; 600 kg N ha−1 as manure applied in fall; 300 kg N ha−1 as manure applied in each of spring and fall; 200 kg N ha−1 applied as inorganic fertilizer in spring; 300 kg N ha−1 as manure plus 100 kg N ha−1 as inorganic fertilizer applied in spring; and a control that received no applied N. Fall-applied manure did not increase corn yield or N uptake in the following growing season. At all sites, maximum yield was attained using manure only. Selection of proper spring application rates for manure and inorganic fertilizer were found to be equally important in minimizing residual soil nitrate at harvest. Apparent recovery of applied N in the crop ranged from 0 to 33% for manure and from 18 to 93% for inorganic fertilizer. Key words: N recovery, manure management

Phytotoxicity of fatty acids present in dairy and hog manure

Abstract The application of animal waste on farm land is currently considered as a safe method to dispose the excreta from farm animals because it provides an easy outlet to alleviate envaronmental danger associated with animal excreta. In most published studies, animal waste is viewed as a good source of nitrogen, phosphorus and potassium (NPK). Little attention has been given to minor chemical compounds present in the contents of animal wastes. Some classes of compounds which are suspected to be phytotoxic have been reported to be present in animal waste. Identification and mode of action of such compounds present in animal waste is important because agricultural practices which are considered as environmentally safe today may become a hazard to agricultural crops in the future. Fatty acids are known for germination inhibiting activity. The objectives of this study were to identify fatty acids present in dairy and hog manures and to investigate their biological effects on germination of sorghum seeds. S...

Water Contamination by Ammonium Nitrogen Following the Spreading of Hog Manure and Mineral Fertilizers

AbstractInappropriate fertilization practices in regions where livestock manure exceeds crop requirements may cause pollution by NH+4‐N) during snowmelt. Annual and seasonal NH+4‐N losses were evaluated for three consecutive years from 45 m2 corn (Zea mays L.) and timothy (Phleum pratense L.) and red and white clover (Trifolium repens L.) erosion plots that had annually received the recommended chemical fertilizer rates of 180 and 55 kg N ha−1, respectively, plus hog manure at twice those rates. Total N applications for corn and forage were 540 and 165 kg ha−1 except for a check plot receiving only fertilizer. The hog manure was surface‐applied in three different ways: all in the fall, all in the spring, and in a split application with about one‐half in each season. Corn plots receiving fall‐applied manure were immediately rototilled while plots receiving spring‐applied manure were ratotilled prior to planting. Each plot was equipped to collect runoff and drainage water separately throughout the whole year. Total NH+4‐N losses in both runoff and drainage water from autumn application were greater than for the two other application methods for corn and the forages. Plots receiving chemical fertilizer plus hog manure had a significant increase in NH+4‐N losses as compared with the plots receiving fertilizer only. Due to the fall manure effect, NH+4‐N loads increased by three‐fold after the first year (1.11–3.43 kg ha−1), by 1.46 times between the first and the second year, and by 1.14 times between the second and the third year for corn when compared with the fertilizer only treatment and exceeded the standard of 0.5 mg L−1 for raw water. Similar trends were measured for the forages. Most NH+4‐N was lost during the autumn and winter periods for corn. For both crops, there was an increase in loss from fall to winter and a decrease both from winter to spring and from spring to summer.

Simulating corn yields over 16 years on three soils under inorganic fertilizer and hog manure fertility regimes

Abstract Corn yields (Zea mays L.) on control treatments with inorganic fertilizer and on copper‐enriched hog manure treatments with annual rates up to 168 mt/ha from a 16‐year study were modelled with the Erosion Productivity Impact Calculator (EPIC) simulation model. The field research study was conducted on three diverse soils, a Guemsey silt loam, a Bertie fine sandy loam, and a Starr‐Dyke clay loam. Results indicated that EPIC simulated the manure and fertilizer treatments equally well. EPIC produced simulated yield means that were not different from measured yield means for all treatments (p ≤ 0.05). Goodness of fit tests indicate that simulated yields did not differ from measured yields for all simulation models except the Bertie manure treatment (p ≤ 0.05). For control and manure treatments, simulated yields explained 78% and 89% of variation in measured yields for the Guernsey soil, 55% and 42% for the Bertie soil, and 76% and 70% for the Starr‐Dyke soil, respectively. Overall, these are reasonab...

Comparing crop-hog-fish agroecosystems with conventional fish culturing in China

This research conducted in subtropical hilly Jiangsu Province, China, was aimed at developing intensive fish farming systems for better use of local resources while achieving ecological and economic benefits. A semi-intensive system with moderate inputs (crop-hog-fish agroecosystem) was found to be more profitable than extensive or intensive fish culture systems and yielded twice as much as cropping alone. The techniques for fish culture in the crop-hog-fish system consisted of a polyculture of fish, pond water management, green forage supply and food supplements. Targeting gross weight output of 6 t/ha or a net output of 5 t/ha, the crop-hog-fish system consists of a 1-ha fish pond, 0.5 ha cultivated grassland to support the herbivorous fishers, 0.5 ha cropland to provide fish food, and 2.5 heads of hog. The hog manure is used to fertilize the pond water. The external energy subsidies include 1000 kg fish fry, 400 days of labor, certain chemicals and electricity. The total energy input is 193.5 GJ/ha, while the energy output is 34.3 GJ/ha, yielding a transfer rate of 0.177. The output value is 2.57 times the production costs. The authors believe the recommended model is adaptive and viable to small farms with appropriate resources, especially in subtropical and temperate areas.

Ammonia Volatilization from Liquid Hog Manure: Influence of Aeration and Trapping Systems

AbstractMeasurements of N loss from manures may reflect differences in the types of manures and methodologies used. This study's objective was to test the suitability of 0.32 M H3BO3 and 0.9 M H2SO4 for trapping NH3 volatilized from liquid hog manure (LHM) under various experimental conditions. Samples of LHM were incubated for 15 d in containers with aeration outlets positioned above, at the middle, or at the bottom of the LHM. Lowering the position of the aeration outlet increased both the pH of the LHM and the amount of NH3 volatilized. More NH3 was trapped in H2SO4 than H3BO3, and the difference in trapping efficiency of the two acids increased with their NH3 concentrations. Neither the amount of NH3 trapped nor the exponential relationship between the NH+4 concentrations of two H3BO3 traps in series was influenced by changing the bubble path length through the acid. Regression analysis indicated that >95% trapping efficiency was obtained only when the NH3 concentration of H3BO3 was below 0.42 mg N mL−1, much lower than the 0.9 mg N mL−1 reported to be the limit for using H3BO3 in the Kjeldahl method. Even when using two traps in series, H3BO3 appeared to trap less NH3 than H2SO4. Amending LHM with sucrose lowered the pH of H3BO3 used to trap volatilized NH3, thereby interfering with NH3 determination and rendering H3BO3 unsuitable for determining NH3 volatilization. Investigators who use H3BO3 to measure NH3 volatilization in other systems must ensure that similar interferences do not occur and that NH3 concentrations do not exceed 0.42 mg N mL−1.

Influence of incubating monocalcium phosphate with liquid hog manure on inorganic phosphorus, organic phosphorus and phosphorus availability in two Quebec soils

The effects of incubating monocalcium phosphate monohydrate (MCPM) with liquid hog manure (LHM) on P availability and uptake by Italian ryegrass (Lolium multiflorum Lam.) were evaluated in a 99-d growth chamber experiment. Liquid hog manure with (0.738 g P kg−1 fresh LHM) or without MCPM was aerated for a 21-d period at 24 °C. The soils used in this experiment were an Ormstown silty clay loam (Orthic Humic Podzol), and a Ste. Rosalie clay loam (Humic Podzol). Five treatments were applied to each soil: (i) control with no LHM or MCPM additions, (ii) MCPM, (iii) LHM incubated without MCPM, (iv) LHM incubated with MCPM, and (v) the separate applications of MCPM and LHM incubated without MCPM. Rates of MCPM and LHM applications were 513 kg P2O5 ha−1 and 32 t ha−1, respectively. Incubating LHM with MCPM resulted in a loss of 6% of the total manure-N during the 3-wk incubation period, compared with a 67% loss from the unamended LHM. Additions of both MCPM and LHM had the same effect on shoot-P contents and soil P fractions regardless of whether the materials had been incubated together or added to the soil separately. When compared with adding MCPM only, LHM-MCPM mixtures resulted in greater ryegrass shoot-P contents for plants growing on the Ste. Rosalie soil. However, this increase was approximately equal to the response to LHM additions, and thus presumably not due to improved MCPM P availability. Additions of both LHM and MCPM did not affect soil inorganic P forms compared with the lone addition of MCPM, but sodium hydroxide extractable organic P and sodium bicarbonate extractable organic P tended to be higher when just MCPM was added. Key words: P fractionation, liquid hog manure, manure-fertilizer mixtures, monocalcium phosphate, P uptake

Organic and Inorganic Amendments to Reduce Ammonia Losses from Liquid Hog Manure

AbstractLiquid hog manure (Sus scrofa domesticus) is in common use as a fertilizer or a soil conditioner in agricultural production. Liquid hog manure (LHM) suffers from N loss through volatilization of ammonia (NH3), however. Reduction of NH3 loss from 4% total solids LHM was studied using added Sphagnum peat moss (Sphagnum fuscum peat), sulfuric acid, phosphoric acid, monocalcium phosphate monohydrate (MCPM), elemental S, and calcium carbonate. Cumulative losses of NH3‐N ranged between 0 and 711 mg N kg−1 LHM applied. Elemental Sulfur and calcium carbonate (CaCO3) treatments induced greater NH3 losses compared with the nonamended LHM, whereas acidic treatments including Sphagnum peat moss (SM) reduced NH3 losses by at least 74.6%. Volatilization of NH3 from LHM increased as the pH of amended LHM treatment increased. The relationships between cumulative (15 d) NH3 volatilized and initial pH of amended LHM varied, depending on the amendment. The nutrient values of amended LHM stored for 25 d under continuous aeration were assessed on two soils mapped as Chicot (fine loamy, mixed, nonacid, mesic Typic Hapludoll) and Uplands (coarse loamy, mixed, nonacid, Typic Haplorthod) from eastern Canada. Treatment of LHM with SM at greater than 1% (w/w) reduced NH3 volatilization. Added CaCO3 increased NH3 loss. In general, amendments did not reduce effectiveness of LHM‐N for barley (Hordeum vulgare L.) growth. An exception was the 1% SM + 2% CaCO3 amendment that reduced plant growth.

Odor Control in Liquid Hog Manure by Added Amendments and Aeration

AbstractA reduction in the emission of malodorous gases from liquid hog manure (LHM) would represent an advantage for LHM use in agricultural systems. Procedures for the reduction of disagreeable odors during storage of LHM (Sus scrofa domesticus) were studied in the laboratory. Sphagnum peat moss (Sphagnum moss species), 1.5 M H2SO4, 1.7 M H3PO4, monocalcium phosphate monohydrate (MCPM), elemental S, CaCO3, and CaO were used to reduce odors. Amended and nonamended LHM was incubated with and without aeration for periods ranging from 2 to 720 h at 23 ± 0.4°C. Odor measurements of emitted air were carried out using a sensory panel. Gas chromatography‐mass spectrometry (GC‐MS) was used to identify specific odor‐producing compounds. The GC‐MS analysis revealed that added Sphagnum moss (SM) prevented the release of 1,2‐ethanediamine, N‐methyl methanamine, 3‐methyl 2‐butanamine, methyl hydrazine, ethanethioic acid, and methanethiol from LHM. Aeration as a treatment, in general, resulted in a greater reduction of odor presence and offensiveness than nonaeration. In nonaerated LHM treatments, SM at levels of 4 or 8% (w/w) or a combined treatment of 2% CaCO3 plus 1% SM resulted in a significant reduction in odor presence and offensiveness. Little odor reduction was observed with H2SO4, H3PO4, MCPM, and CaO, and no odor reduction was found with elemental S.

Copper availability in two soils amended with eleven annual applications of copper‐enriched hog manure

Abstract Relatively high amounts of Cu are found in manure of hogs (Sus scrofa domesticus) maintained on diets containing growth‐stimulating levels of Cu. While disposal of Cu‐enriched hog manure through repeated long‐term application to agricultural land is commonly practiced, concern exists regarding Cu availability in these soils. Field studies were conducted on a Bertie fine sandy loam (Aquic Hapludults) and a Starr‐Dyke clay loam (Fluventic Dystochrepts‐Typic Rhodudults), located in the Coastal Plain and Piedmont regions of Virginia. The objective was to examine the effects of long‐term Cu application on corn (Zea mays L.) growth and to ascertain the Cu sorption capacity of these soils. Field plots were treated with Cu‐enriched hog manure or CUSO4 (on an equivalent Cu basis) annually. Manure amendments totaled about 240 t ha‐1 (dry weight) over an 11 yr period (1978 through 1989). The manure averaged 1300 mg Cu kg‐1 (dry weight) over this time period totaling 340 kg Cu ha‐1. Sorption isotherms were d...

Psychological disorders in rheumatoid arthritis: a growing consensus?

Previous reviews of psychological factors in arthritis have emphasised the methodological weaknesses of many studies, especially those attempting to measure personality after years of disabling disease. To make sense of the published reports three factors need to be considered separately: previous personality, social stresses, and current mental state. Each can now be measured reliably and independently of symptoms which might be directly attributable to the arthritis. There is a growing consensus that the normal range of personality is represented among patients with early arthritis, that the prevalence of depression is similar to that of patients with other medical conditions, and that social stress is more closely related to depression than activity and the disabling effect of arthritis. Longitudinal studies are now required to examine which social stresses can be attributed to the disabling effect of arthritis. Depression and social stress often manifest themselves to the rheumatologist as excessive complaints of pain and frequent clinic attendances so appropriate psychosocial treatments may reduce this behaviour.

EFFECT OF ADDED MONOCALCIUM PHOSPHATE MONOHYDRATE AND AERATION ON NITROGEN RETENTION BY LIQUID HOG MANURE

Retention of nitrogen in manure to be used for crop production and to reduce environmental pollution is an essential management component. The effects of monocalcium phosphate monohydrate (MCPM) and aeration on N retention in liquid hog (Sus scrofa domesticus) manure (LHM) were investigated under laboratory conditions. The manure received 0, 20 or 40 g of MCPM kg−1 of LHM (0, 250 or 500 g MCPM kg−1 manure solids) and was incubated over a 15-d period with and without aeration. Manure pH decreased with added MCPM and then remained constant, but pH increased with time when MCPM was not added. Losses of NH3 from hog manure were significantly reduced by added MCPM, but increased significantly with aeration where MCPM was not added to the manure. The NH4-N content of LHM was higher where MCPM was added to the manure. Conversely, the NH4-N content tended to decrease with aeration in the absence of MCPM. Total N content of LHM was significantly decreased where MCPM was not added to the manure. Aeration had no significant effect on total N. It was concluded that addition of MCPM can increase the NH4-N content of LHM by decreasing NH3-N losses through acidification of the manure. Key words: Aeration, Ca(H2PO4)2∙H2O, hog manure, pH reduction, NH3 loss

Urea and Manure Effects on Soil Nitrogen and Corn Dry Matter Yields

AbstractFresh (FC) and composted (CC) cow (Bos taurus) manures, liquid hog (Sus scrofa domesticus) manure (HM), and urea (U) were applied as N sources for silage corn (Zea mays L., hybrid W844) production on a Chicot (Hapludalfs) and a St. Benoit soil (Eutrochrepts) at rates of 0 to 240 N ha−1. Soil NO3‐N levels were significantly increased while soil NH4‐N levels were only temporary increased by N additions. Highest NO3‐N levels were noted 30 and 60 d (June and July) after N applications for the St. Benoit and the Chicot soils respectively. Hog manure resulted in more NO3‐N compared with FC and CC manures. One to 5 kg manure‐N was found to be equivalent to 1 kg of urea‐N in terms of increasing soil NO3‐N levels at the end of growing season. Differences between surface spreading or incorporating of manures on corn dry matter yields (DMY) and N uptake were not significant. Nitrogen uptake increased with increases in N application rates and was higher with HM than with CC or FC manures. Regression between DMY or N uptake and N application rates showed linear relationships with manure‐N and quadratic relationships with urea‐N. In 1984, 1 to 4 kg manure‐N resulted in similar corn DMY as 1 kg urea‐N. Cumulative effects of treatments on yields and on nutrient uptake observed in second and third years were greater on the St. Benoit soil than on the Chicot soil.

Evaluation of the protein quality of solids recovered from hog manure slurry

The purpose of this study was to explore the possibility of utilizing portions of hog manure for animal feed, based on proximal chemical, microbiological, protein quality and cooper toxicity testing. Solids recovered from hog manure (RS) were mixed in levels of substitutions of 15, 30, 45 and 60% with commercial cattle feed (CF). The protein content of the mixtures varied little. The in vitro digestibility of the protein decreased as the RS content was increased, and was 87·8% for a substitution level of 0% RS and 66% for a 60% substitution. The quality of the protein was evaluated by the Protein Efficiency Ratio (PER) and Net Protein Utilization (NOU) assigning maximum values of 1·24 and 24·12, respectively, to a 30% SR and 70% CF (commercial feed).mixture. This mixture showed an adequate amino acid profile. The microbiological analysis of the RS showed negative results for the pathogenic microorganisms studied. Total counts of microorganisms, fungi, yeast and most probable number of organisms were similar to those of commercial cattle feed. The copper content of the RS was 170·35 ppm.

The effect of surface applied soil amendments on barley root growth in an acid subsoil

Abstract The root growth of an Al sensitive barley (Hordeum vulgare L.) was used to evaluate the influence of surface applied amendments on the properties of an acid subsoil. Soil columns were packed with 10 cm of A horizon over 45 cm of an acidic Bt horizon from a Gilpin silt loam. Prior to planting of the barley the columns received surface treatments of dolomitic lime (8.4 Mg.ha‐1), hog manure (44.8 Mg.ha‐1) with and without lime, cow manure (44.8 Mg.ha‐1) with and without lime, gypsum (14.6 Mg.ha‐1), and EDTA (5.1 Mg.ha‐1) with lime. The columns were leached twice weekly over a 6 week period with 5 cm additions of water. Lime alone did not significantly increase subsoil pH or reduce exchangeable Al at depths below 15 cm. The EDTA plus lime treatment caused significant increases in soil pH and reductions in exchangeable Al throughout the column. Gypsum treatments also reduced exchangeable Al but neither gypsum nor EDTA plus lime treatments resulted in Improved barley root growth or rooting depth in the...

Characteristics of Hog Raising Farmers in the Kasumiaura Region, Ibaraki Prefecture

Most of the farmers in Hokota-machi, a part of the Kasumigaura hog raising zone, were engaged in small scale hog raising for the purposes of breeding and getting manure. The hog raising played an important role as a subsidiary part of producing such crops as rice, wheat, barley, sweet potato and peanut until 1964. After that, the number of the petty and subsidiary hog raising farmers decreased gradually due to the fluctuations in hog price, so-called pig cycle, and increasing use of chemical fertilizer instead of hog manure. Furthermore, the hog raising farmers have been diversified into three managemental types; 1) hog fattening management, 2) hog breeding and fattening management, 3) swine breeding management. The specialized hog raising farmers have been mainly engaged in the first two managemental types. In this paper the author attempts to elucidate the diversifying processes of the hog raising farmers in the Minamino-area, Hokota-machi.The Minamino-area is located on a part of the Kashima diluvial upland. Most of the Minamino-area is utilized as upland fields, which were cleared forest land and wasteland during the Meiji era. The pioneer farmers combined producing upland crops with keeping livestocks in order to fertilize upland field with manure. As one manner of fertilizing, they started to raise swine. These managemental bases of the swine raising, however, were weak and unstable, and those scales were very small. Therefore, the swine raising in farming management was a subsidiary position. After 1965, the hog raising farmers have been diversified into three types. In the first type, the position of hog raising in the farms has developed from the subsidiary one to the main one and to the specialized one. In the second type, the position of hog raising in the farms has remained the subsidiary one. In the third type, the farmers have stopped the subsidiary hog raising management and changed to the full-time or the part-time farmers producing only field crops. These diversification is related with the differences among the farmers in the existence of farming successor, skill and managemental abilities of hog raising, and the accumulation of capital.Eventualy, the development of the hog raising in the Minamino-area has been supported with the farmers who are dispersed on the upland and held the large scale of upland field possible to be changed to the manure lots, and the hog raising farmers maintainning the relationships with the specialized field crops farmers through hog manure.

EFFECTS OF LIQUID HOG MANURE APPLICATION RATES ON SILAGE CORN YIELD AND NUTRIENT UPTAKE

The objective of this work was to determine the response of corn to liquid hog manure surface applied at rates of 28, 56 and 112 tonnes/ha. In greenhouse trials, yield of corn grown for 4 wk on St. Jude loamy sand was not affected by manure application. On Kamouraska silty clay, only manure applied at a rate of 112 tonnes/ha increased corn yield, as compared to the non-treated control. Corn response on Janvier sandy clay loam improved with increasing rate of manure application up to 56 tonnes/ha. Application of 112 tonnes/ha (325 kg N/ha) manure increased N content of corn and had a significant residual effect as noted by the high yield obtained at the second harvest. In a 2-yr field experiment on Kamouraska soil, corn yield was significantly higher at 112 tonnes/ha (avg 432 kg N/ha) than chemical fertilizer application at 150 kg N/ha, and manure-treated soil contained more P, Ca and Mg after the first year. Nutrient uptake by corn increased with amount of manure applied. However, corn whole plant composition was not affected by rate of manure application. N recovery was higher from manure at 28 or 56 tonnes/ha than from a chemical fertilizer (150 kg N/ha, 65.5 kg P/ha and 125 kg K/ha). At the rates applied, the liquid hog manure did not result in reduced corn yield.Key words: Corn yield, hog manure, nutrient uptake, silage corn

Microbial Pathogens and Human Parasites in an Animal Waste Polyculture System

Abstract Four species of carp and the Malaysian prawn grown in aquaculture ponds receiving swine manure were sampled throughout the growing season to determine levels of potentially pathogenic bacteria and human parasites. Water, swine manure, and sediments were also sampled routinely. The swine were fed antibiotic-free rations. Although the swine parasites Ascaris and Trichuris were present in hog manure, pond water, and sediments, no human parasites were found in the digestive tracts or tissues of necropsied fish or prawns. Several pathogenic and indicator bacteria present in swine manure were cultured using enrichment techniques, but these bacteria were cultured only rarely from water, sediments, or fish samples. Ponds enriched with swine manure generally supported more pathogenic bacteria, as well as more total bacteria. Aeromonas hydrophila, Pseudomonas sp., Corynebacterium sp., and several Enterobacteriaceae were isolated in relatively low numbers from scales of fish grown in swine manures. Since re...

The Effects of Application of Hog Manure Composted with Sawdust and Mulching on the Soil Microflora

The Effects of Application of Hog Manure Composted with Sawdust and Mulching on the Soil Microflora

Copper Availability, Form, and Mobility in Soils from Three Annual Copper‐Enriched Hog Manure Applications

AbstractRelatively high Cu concentrations occur in manure from hogs fed growth‐stimulating Cu levels. Concern exists that detrimental effects may occur in crop production from incorporation of the Cu‐enriched hog manure into agricultural soils. This research was conducted during three growth seasons to evaluate effects of Cu‐enriched hog manure applications on Cu availability, form, and mobility in one Alfisol and two Ultisols. Five field treatments applied to the three soils annually for 3 years were 33.6 and 67.2 metric tons/ha of wet manure from hogs on high‐Cu diets, Cu levels as CuSO4 equivalent to that in the manure, and a control. Copper concentrations in the hog feed ranged from 178 to 261 ppm during the 3 years. Amounts of Cu in manure used in the field experiments varied with Cu concentrations in the feed and ranged from 899 to 1,398 ppm. From 55.6 to 65.6 kg/ha Cu were incorporated into the soils over the 3‐years at the 67.2‐metric ton/ha manure rate. Application of these levels of Cu as either CuSO4 or Cu‐enriched hog manure did not decrease corn (Zea mays L.) grain yields on the three soils. In some cases, the Cu applications caused relatively small increases in Cu concentrations in corn ear leaves and grain. Diethylenetriaminepentaacetic acid (DTPA)‐extractable Cu data indicated that downward movement of Cu from Cu‐enriched hog manure application occurred in only one of the three soils. This soil contained relatively low amounts of clay and free Fe and Mn. Sequential Cu extraction data indicated that the applied Cu increased the potentially plant‐available soil Cu fractions and that a portion of the applied Cu reverted to relatively plant‐unavailable soil Cu forms.