Solid Cattle Manure Research Articles

Giardia duodenalis cyst survival in cattle slurry

Giardia duodenalis is a protozoan parasite known to infect animals and humans. Zoonotic transmission of G. duodenalis can occur by the consumption of drinking water produced from surface water that is contaminated by runoff from manure-laden fields or pastures. Although it was previously reported that storing solid cattle manure decreases G. duodenalis cyst viability, no data are available on cyst survival in slurry waste from cattle. In this study the number and the viability of G. duodenalis cysts was determined in cattle slurry for up to 90 days. G. duodenalis cysts were counted in 30 slurry samples with a quantitative direct immunofluorescence assay. The geometric mean number of cysts was reduced by 77% after 90 days (P<0.0014), although there was substantial variability between samples. A fluorogenic dye staining using 4′,6′-di-amino-2-phenylindole and propidium iodide showed a decreased viability from 45 days onwards, and after 90 days incubation, only 3% of the cysts were viable. Gerbils and lambs were artificially infected with 50 day-old and 90 day-old cysts and faecal excretion of G. duodenalis was monitored between 5 and 7 days after infection. Seven days after infection the gerbils were euthanized for Giardia trophozoite counts. Although one cyst was found in the faeces of one of the gerbils after infection with 50 day-old cysts, no trophozoites were recovered from the intestines of any gerbil (n=8). Experimental infection of lambs with 10550 day-old and 90 day-old slurry cysts caused low cyst excretion in one out of two and one out of three lambs, respectively. Together, these data show that storage of cattle slurry for 90 days greatly reduces the number and viability of G. duodenalis cysts.

Soil test phosphorus changes and phosphorus runoff losses in incubated soils treated with livestock manures and synthetic fertilizer

Kumaragamage, D., Flaten, D., Akinremi, O. O., Sawka, C. and Zvomuya, F. 2011. Soil test phosphorus changes and phosphorus runoff losses in incubated soils treated with livestock manures and synthetic fertilizer. Can. J. Soil Sci. 91: 375–384. Source of phosphorus (P) and soil properties influence changes in soil test P (STP) concentrations and P runoff losses in manured and fertilized soils. We compared STP changes and P runoff losses in two soils, a clay loam and a sand, that were either unamended (control), or amended with liquid swine manure (LSM), solid cattle manure (SCM), or monoammonium phosphate (MAP) and incubated for 6 wk. Soil subsamples after incubation were analyzed for STP using Olsen (OP), Modified Kelowna (KP), Mehlich 3 (M3P) and water extraction (WEP) methods. We collected runoff from incubated soils for 60 min under a rainfall simulator, and analyzed for dissolved reactive P (DRP). Magnitude of STP increase in amended soils was greater in sand (19–48%) than in clay loam (7–37%). Increases in STP and DRP runoff concentrations in amended soils generally followed the order; MAP&gt;LSM&gt;SCM. Olsen P, KP and M3P were more accurate than WEP for predicting runoff DRP concentrations and loads, accounting for 43–49% of the variation in P concentrations for the first 30 min of runoff. Olsen P, the currently used STP method for environmental P regulation in Manitoba is sufficiently robust to predict runoff P losses from manure and fertilizer amended soils.

THE EFFECTS OF SOME ORGANIC AND CHEMICAL FERTILIZER APPLICATIONS ON YIELD, MORPHOLOGY, QUALITY AND MINERAL CONTENT OF COMMON VETCH (Vicia sativa L.)

A field experiment was conducted to evaluate the effects of some organic and chemical fertilizers on morphological, yield and quality properties and mineral contents of common vetch (Vicia sativa L.) between 2007 and 2008 in Gumushane, Turkey. Treatments were control (no fertilizer), liquid manure (LM = 51-52 L ha -1 N ), chemical fertilizer (CF = 30 kg N ha -1 + 80-100 kg P2O5 ha -1 ), three leonardite doses (L1= 2.8; L2= 5.6 and L3= 8.4 kg N ha -1 ), three zeolite doses (Z1= 0.4; Z2= 0.8 and Z3= 1.2 N kg ha -1 ) and three solid cattle manure doses (SM1= 34-35 kg N ha -1 , SM2= 68-70 kg N ha -1 , SM3= 102-105 kg N ha -1 ). Dry hay yield (DHY), leaf weight, stem weight, plant height, leaf number, crude protein content (CP), crude protein yield (CPY), acid detergent fiber (ADF), neutral detergent fiber (NDF), Ca, Fe, K, Mg, B, Cu, Mn, Na, Ni, P, Pb, S and Zn contents were determined. Organic and chemical fertilizer applications had significant effect (P<0.01) on DHY, leaf weight, stem weight, CP, CPY and mineral contents except leaf number, ADF and NDF in the both years. The plant height were significantly (P<0.05) affected by the treatments in the first year. The SM2 application in the first year and control and LM applications in the second year resulted to obtain improved yield components and crude protein yield. Z2 and Z3 applications also loomed large in terms of mineral contents.

The Effects of Solid, Liquid and Combined Cattle Manure Applications on the Yield, Quality and Mineral Contents of Common Vetch and Barley Intercropping Mixture

A field experiment was conducted to evaluate the effects of solid, liquid and the combination of solid and liquid cattle manure applications on the yield, quality and mineral content of common vetch (Vicia sativa L.) + barley (Hordeum vulgare L.) intercropping mixture in 2006-2007 at Gumuþhane, Turkey. The treatments were control (no manure), two liquid (L 1 = 10 000 L ha-1 liquid cattle manure and L 2 = 20 000 L ha-1 liquid cattle manure), two solid (S1 = 20 ton ha-1 solid cattle manure, S2= 40 ton ha-1 solid cattle manure) and four different combinations of liquid and solid cattle manure applications (S1L1 = 20 ton ha -1 solid cattle manure + 10 000 L ha-1 liquid cattle manure, S 1 L 2 = 20 ton ha-1 solid cattle manure + 20 000 L ha-1 liquid cattle manure, S2L1 = 40 ton ha-1 solid cattle manure + 10 000 L ha-1 liquid cattle manure, and S2L2 = 40 ton ha -1 solid cattle manure + 20 000 L ha -1 liquid cattle manure). Total forage dry matter yield (TFDMY), crude protein content (CP), crude protein yield (CPY), acid detergent fiber (ADF), neutral detergent fiber (NDF), dry matter intake (DMI), dry digestible matter (DDM), relative feed value (RFV) and mineral contents (Mg, Ca, K, P, Na, Mn, Zn, Fe and Cu) were determined to evaluate the effects of different cattle manure applications on intercropping mixtures. Solid, liquid and the combined cattle manure treatments had no effect on the TFDMY, CPY, ADF, NDF, DMI, DDM, RFV, Mg, Ca, K, Mn and Zn of the intercropping mixture except CP (p<0.01), P (p<0.01), Na (p<0.05), Fe (p<0.05) and Cu (p<0.05) in the first year. The treatments had significant effects on TFDMY (p<0.01), CP (p<0.01), ADF (p<0.05), NDF (p<0.01), DMI (p<0.01), DDM (p<0.05), RFV (p<0.01) and Zn (p<0.01) values of the intercropping mixture except CPY, Mg, Ca, K, P, Na, Mn, Fe and Cu in the second year. The results of the study revealed that the common vetch and barley intercropping mixture can be fertilized with 40 ton ha-1 solid cattle manure to improve the yield and quality. But if mineral content of forage is more important than yield and quality for the farmer, then it may be fertilized with 20 ton ha-1 solid cattle

The survival of eggs and infective larvae of Ostertagia ostertagi and Cooperia oncophora in solid cattle manure and urine.

The survival of eggs and infective larvae of Ostertagia ostertagi and Cooperia oncophora in solid cattle manure and urine.

Effects of Sample Processing on Ash Content Determination in Solid Cattle Manure with Visible/Near-Infrared Spectroscopy

Visible and near-infrared (VisNIR, 350-2500 nm) diffuse reflectance spectroscopy (DRS) may be a useful tool for determining crude ash content of solid cattle manure. However, the effect of sample preprocessing protocols on the predictive ability of the VisNIR-DRS models is unknown. In this study we explored the effects of drying and milling on the prediction of crude ash in feedyard manure using VisNIR-DRS. Samples (n = 120) of beef manure from open lots were evaluated for ash content by dry oxidation and then subjected to four preprocessing treatment protocols: oven-dried and milled, air-dried and milled, oven-dried and not milled, and air-dried and not milled. Each treatment protocol was used to calibrate partial least squares regression models for prediction of ash content by VisNIR-DRS. Two thirds of the samples were randomly selected to build calibration models, and the remaining third was used for validation. The root mean squared deviation (RMSD) and the ratio of the standard deviation over the RMSD (RPD) for each treatment were assessed to determine the best pretreatment protocol for ash determination of manure. The first derivative of the reflectance from air-dried, unmilled samples consistently generated the best predictive models with an RMSD of 5% crude ash (d.b.), an RPD of 2, and a bias of 0% crude ash (d.b.).

Relationship between N-cycling communities and ecosystem functioning in a 50-year-old fertilization experiment

The relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-year fertilizer trial and the treatments comprised unfertilized bare fallow, unfertilized with crop, and plots with crop fertilized with calcium nitrate, ammonium sulfate, solid cattle manure or sewage sludge. The size of the functional guilds and the total bacterial community were greatly affected by the fertilization regimes, especially by the sewage sludge and ammonium sulfate treatments. The community size results were combined with previously published data on the composition of the corresponding communities, potential ammonia oxidation, denitrification, basal and substrate-induced respiration rates, in addition to crop yield for an integrated analysis. It was found that differences in size, rather than composition, correlated with differences in process rates for the denitrifier and ammonia-oxidizing archaeal and total bacterial communities, whereas neither differences in size nor composition was correlated with differences in process rates for the ammonia-oxidizing bacterial community. In contrast, the composition of nitrate-reducing, denitrifying and total bacterial communities co-varied with primary production and both were strongly linked to soil properties.

Determination of Ash Content in Solid Cattle Manure with Visible Near-Infrared Diffuse Reflectance Spectroscopy

Visible and near-infrared (VisNIR, 350-2500 nm) diffuse reflectance spectroscopy (DRS) is increasingly being used to quantify constituents of organic matter both in the lab and in situ. However, it is unknown if DRS can be utilized as a tool for determining crude ash content of solid cattle manure. Ash content is a significant contributor to the suitability and value of manure for use both as a biofuel and soil fertilizer, but conventional ash analysis is time-consuming and labor-intensive. In this study, we explored the feasibility of VisNIR-DRS for the rapid prediction of ash content in solid manure from beef feedyards in the southern High Plains. Proportionally mixed samples of soil and manure (n = 201) were evaluated for ash content by conventional analysis and then used to calibrate a statistical model for prediction of ash content by VisNIR-DRS based on multivariate partial-least squares regression and random test-set validation. Two thirds of the samples were randomly selected to build a calibration model, and the remaining third was used for validation. The coefficient of determination (r2), root mean squared deviation (RMSD), and ratio of prediction to standard deviation (RPD) were calculated to assess the prediction model. The prediction model had an r2 of 0.94, an RMSD of 5% ash (d.b.), and an RPD of 4. The VisNIR-DRS model successfully predicted crude ash content within 5% of the observed ash content (d.b.) as determined by dry oxidation using the accepted ASTM standard E1755-01.

Evaluating phosphorus loading from repeated manure applications to two Saskatchewansoils

An understanding of the impact of repeated manure additions on soil phosphorus (P) is needed to determine appropriate manure application rates for prairie soils and manure sources. The objective of this study was to assess the loading of manure-derived phosphorus using P budgets and soil P measurement techniques applied to two Saskatchewan soils with known histories of manure application. Liquid hog manure (LHM) and solid cattle manure (SCM) treatments were applied annually over 8 yr to Black Chernozemic soils (Dixon site), and LHM was applied to Dark Brown Chernozemic soils (Plenty site) over 6 yr. Soil samples were collected in the spring of 2003 and 2004 and analyzed for labile P (Modified Kelowna extractable, Olsen extractable, water extractable, and Plant Root Simulator exchange resin methods) and total P. The P budgets were in good agreement with the observed patterns in labile soil P at the two sites. The annual application of LHM (37000 L ha-1 yr-1) at agronomic nitrogen (N) rates with no additional P fertilizer (Dixon only) did not significantly elevate soil labile P compared with the unfertilized controls at both Dixon and Plenty. The annual application of SCM (7.6 Mg ha-1 yr-1) at agronomic N rates did not significantly elevate soil labile P compared with the unfertilized control at Dixon; whereas of SCM at higher rates (15.2 Mg ha-1 yr-1 and 30.4 Mg ha-1 yr-1) showed some elevation in labile soil P. Measures of labile P were sensitive to P surpluses or deficits predicted by P balances, and all methods of measuring labile soil P were strongly correlated with one another at both sites (r ≥ 0.803 at P ≤ 0.01). Key words: Manure, cattle manure, nitrogen, phosphorus, soil test phosphorus

Spring thaw and growing season N2O emissions from a field planted with edible peas and a cover crop

Nitrous oxide emissions are highly episodic and to accurately quantify them annually, continuous measurements are required. A tower-based micrometeorological measuring system was used on a commercial cattle farm near Cô teau-du-Lac, (QC, Canada) during 2003 and 2004 to quantify N2O emissions associated with the production of edible peas. It was equipped with an ultrasonic anemometer and a fast-response closed-path tunable diode laser. Continuous measurements of N2O fluxes were made during the spring thaw following corn cultivation in summer 2002, then during an edible pea growing season, followed by cattle manure application, cover crop planting and through until after the next spring ploughing. The cumulative N2O emissions of 0.7 kg N2O-N ha-1 during the initial snowmelt period following corn harvest were lower than expected. Sustained and small N2O emissions totalling 1.7 kg N2O-N ha-1 were observed during the growing season of the pea crop. Solid cattle manure applied after the pea harvest generated the largest N2O emissions (1.9 kg N2O-N ha-1 over 10 d) observed during the entire sampling period. N2O emissions associated with the cover crop in the fall were mostly influenced by manure application and totalled 0.8 kg N2O-N ha-1. For the subsequent spring thaw period, N2O emissions were 0.8 kg N2O-N ha-1. This represents approximately 15% of the annual emissions for the edible pea-cover crop system, which totalled 5.6 kg N2O-N ha-1 over the measuring periods. There was little difference in spring thaw N2O emissions between the two growing seasons of corn and edible pea-cover crop. Key words: Nitrous oxide emissions, legumes, snowmelt, dairy manure, tunable diode laser, flux tower

Copper, zinc, and cadmium accumulation in two prairie soils and crops as influenced by repeated applications of manure

AbstractA study was conducted to determine the effect of repeated (5–7 y) annual application of liquid swine or solid cattle manure on the plant availability of copper (Cu), zinc (Zn), and cadmium (Cd) at two field sites in the W‐central and E‐central agricultural regions of Saskatchewan, Canada. Soil samples, plant‐straw and grain samples from the 2003 growing season were collected and analyzed for total Cu, Zn, and Cd concentrations using nitric acid microwave digestion followed by atomic‐absorption spectroscopy. An ammonium bicarbonate diethylenetriaminepentaacetic acid (AB‐DTPA) extraction was performed on the soil samples as a measure of the plant‐available fraction. Crop plants that were tested included wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). The results of this study indicated that long‐term repeated applications of manure fertilizer sometimes resulted in increased plant availability of Cu, Zn, and Cd, as reflected in increased concentrations of the plant‐available metal observed both in the soil and plant tissue. In the case of Cu and Zn, these increases were related to the rate of application, as the manure is a source of Cu and Zn. Changes in soil conditions from repeated manure application, including a decrease in pH and stimulated plant‐root growth can explain the effect that both manure and urea‐fertilizer application had on increasing the Cd concentration in the plant. Overall, there does not appear to be any concern about soil metal loading and plant accumulation in these soils after 5–7 y of manure application, as soil and plant concentrations were well below the allowable limits.

Nitrogen balance and accumulation pattern in three contrasting prairie soils receiving repeated applications of liquid swine and solid cattle manure

The expansion of intensive livestock operations in western Canada has increased concerns about overloading of nutrients in manured lands. The magnitude of nutrient accumulation and its distribution in the soil profile varies with soil-climatic conditions. The objective of this study was to determine loading and distribution of manure-derived nitrogen (N) in the soil profile as influenced by repeated manure applications. Four field experiments were conducted at three sites (Dixon, Melfort and Plenty) in Saskatchewan under longer-term manure management. The four field experiments provide contrasts in soil type, climatic conditions, manure type, application and cropping history to enable the effect of these factors to be evaluated. Liquid hog manure (LHM—Experiment 1) and solid cattle manure (SCM—Experiment 2) treatments were applied annually over 8 years at Dixon (Black Chernozemic loam soil—Udic Boroll in sub-humid climate), while only LHM was applied at Plenty (Dark Brown Chernozemic heavy clay soil—Typic Boroll in semi-arid climate) over 6 years (Experiment 3), and at Melfort (Dark Gray Luvisol silty clay loam soil—Mollic Cryoboralf in humid climate) over 5 years (Experiment 4). Soil samples were collected in the spring and autumn of 2003 and 2004, and were analyzed for organic N, ammonium-N (NH 4 + -N) and nitrate-N (NO 3 − -N) concentrations. Plant samples were collected to determine the impact of manure application rate on plant N uptake and crop N removal. The annual application of LHM (37,000 L ha−1 yr−1) and SCM (7.6 Mg ha−1 yr−1) at agronomic rates at Dixon (added N balances crop demand for that year), or larger rates of LHM (111,000 L ha−1) applied once every 3 years (Melfort) did not significantly elevate NO 3 − -N in soil compared to the unfertilized control. Lower crop removal and reduced leaching of NO 3 − -N due to drier conditions as occurred at the Plenty site contributed to greater accumulation of nitrate in the top 60 cm at equivalent rates compared to the other two sites. At large manure rates, excess N from the balance estimates could not be accounted for in soil organic N and was assumed to be lost from the soil-plant system. At the Dixon LHM site, deep leaching of NO 3 − -N was observed at the excessive rate (148,000 L ha−1 yr−1) up to the 150 cm depth, compared to the control. At Dixon, the large annual application rate of SCM (30.4 Mg ha−1 yr−1) did not significantly increase NO 3 − -N in the 0–60 cm soil compared to the control, which was attributed to lower mineralization of organic N from the SCM. Over the short and medium term, LHM application at large rates every year poses a greater risk for loading and deep migration of NO 3 − -N in soil than large rates of SCM. Larger single applications made once every 3 years were not associated with accumulation or deep leaching. To prevent loading, rates of applied manure nitrogen should be reduced when crop N removal potential is diminished by high frequency of drought.

Solid and Liquid Cattle Manure Application in a Subarctic Soil: Bromegrass and Oat Production and Soil Properties

An experiment was conducted in subarctic Alaska from 1999 to 2001 to determine the effect of liquid and solid cattle (Bos taurus) manure application rates on smooth bromegrass (Bromus inermis Leyss.) and oat (Avena sativa L.) biomass production, nutrient uptake, and soil properties. One‐time manure application of 100 and 200 kg N ha−1 was made in May 1999 in comparison with annual fertilizer application of 50, 100, and 200 kg N ha−1. In the first year, liquid manure at 100 and 200 kg N ha−1 generated 3036 and 4292 kg ha−1 smooth bromegrass biomass, respectively, statistically (p ≥ 0.05) similar to that of fertilizer application (3654 kg ha−1) at 200 kg N ha−1 but greater (p ≤ 0.05) than control (1572 kg ha−1). Similar results were found with oat. The 200 kg N ha−1 liquid manure application continued to benefit crop growth in the second and third years. Solid manure did not influence biomass production of either crop in most crop/year combinations. Cumulatively, in 3 yr, smooth bromegrass recovered 59% of nitrogen from liquid manure, compared with 37% by oat. Soil Mehlich 3–P accumulation was found in some liquid and solid manure treatments for both crops. High soil exchangeable K was found in 1999 after liquid manure application but declined over time. Our results suggest that 100 kg N ha−1 liquid manure can replace nitrogen fertilizer at a similar rate. Liquid cattle manure was better than solid cattle manure in promoting bromegrass and oat production.

Effect of Inoculum Addition Modes and Leachate Recirculation on Anaerobic Digestion of Solid Cattle Manure in an Accumulation System

The effect of both leachate recirculation (at 40 and 50 °C) and the mode of inoculum addition (at 50 °C) on the performance of a non-mixed accumulation (i.e. fed batch) system treating solid cattle wastes was investigated, using laboratory scale reactors at a filling time of 60 days. A relatively high methane production rate (MPR) and low stratification of intermediates occur with leachate recirculation. The leachate recirculation volume flow and methane production rate are smaller at 40 °C than at 50 °C: 0·31 and 0·7 l [CH4] l−1 [reactor] day−1, respectively. The increased MPR at higher temperature is at one hand caused by the increase of microbial activity, at the other hand by the lower viscosity causing the increased leachate recirculation volume. Dividing the inoculum in equal doses and distributing them with the feed positively affects the system behaviour as compared to adding the same inoculum amount at the reactor bottom at the start only. Without addition of inoculum a very poor system performance was observed. The average MPR was 0·2, 0·4 and 0·5 l [CH4] l−1 [reactor] day−1 for the reactor without inoculum, inoculum addition at the reactor bottom and inoculum addition in different equal doses, respectively.

Grain 15N of crops applied with organic and chemical fertilizers in a four-year rotation

Variations in crop grain and soil N isotope composition (δ15N) in relation to liquid hog manure (δ15N of total N was +5.1‰), solid cattle manure (+7.9‰) and chemical fertilizer (+0.7‰ for urea and −1.9‰ for ammonium phosphate) applications, and control (no fertilizer application) were examined through a 4-year crop rotation under field conditions. Canola (Brassica napus), hull-less barley (Hordeum vulgare), wheat (Triticum aestivum), and canola were grown sequentially from 2000 (year 1) to 2003 (year 4). From year 2, hog manure or chemical fertilizers, but not cattle manure, treatments increased grain N concentrations over the control. Grain δ15N (+0.3 to +2.5‰) of crops applied with chemical fertilizers was lower than those in the other treatments, reflecting the effects of the N source with a lower δ15N, while the manure treatments tended to increase grain δ15N. The higher grain δ15N of crops applied with hog manure (+5.6 to +8.4‰) than those applied with cattle manure (+2.2 to +4.1‰) reflected the higher N availability of liquid hog manure (up to 70% as NH 4 + ) than solid cattle manure (99% organic N) and higher potentials for ammonia volatilization loss in hog manure rather than differences in manure δ15N signatures. Soil total- and extractable-N concentrations and δ15N tended to vary with the application of N sources with different N isotope composition and availability. Our study expanded the application of the δ15N technique for detecting N source (organic vs chemical) effects on N isotopic composition to field conditions and across a 4-year rotation, and revealed that N availability played a greater role than the δ15N signature of N sources in determining crop δ15N under the studied conditions.

Effect of repeated manure application on potassium, calcium and magnesium in soil and cereal crops in Saskatchewan

Increasing use of animal manures in Saskatchewan requires information on the effect of manure addition on the availability of soil K, Ca and Mg and their concentrations in plant tissue. To address these issues, we examined the effects of repeated application of liquid swine and solid cattle manure at low and high rates on extractable K, Ca and Mg in soils from three different long-term field trials in Saskatchewan, and on plant K, Ca and Mg concentrations in cereal straw grown on the soils. After 5 to 7 yr of manure application, extractable potassium in the soils was significantly increased, while extractable Ca and Mg tended to remain similar, or was decreased with swine manure addition. In the cereal straw, concentrations of K, Ca, and Mg were all increased by repeated swine manure application, such that there was no significant increase in the K/(Ca + Mg) ratio. However, the K/(Ca + Mg) ratio in the cereal straw grown on soil amended with the high rate of cattle manure was increased. These findings suggest that increased risk of tetany potential from manure application would mainly be associated with excessive application rates of cattle manure in these soils, but should be monitored in feeds grown on all manured soils.Key words:Soil extractable K, Ca, Mg and Na; cereal K, Ca and Mg concentrations, K/(Ca + Mg) ratio, tetany potential, urea, swine manure, cattle manure

Nitrogen Source and Rate Effects on the Production of Buffalograss Forage Grown with Irrigation

Application of livestock manure to crop lands is one method of recycling nutrients. An experiment was conducted to determine the effect of applying solid cattle (Bos spp.) manure (SCM), liquid swine (Sus spp.) effluent (LSE), or commercial fertilizer (CF; urea) at three application rates (0, 120, or 240 kg N ha−1) on the yield, plant canopy height, and nutritive value (crude protein, CP; and in vitro organic matter digestibility, IVOMD) of buffalograss [Buchloë dactyloides (Nutt.) Engelm.] forage grown with irrigation during a 4‐yr period. Two forage harvests were made in each of four growing seasons, and canopy height was measured before each harvest. For all N sources, seasonal dry matter yield (DMY), canopy height, and CP increased as N rate increased during each of the 3 yr following establishment. However, as the buffalograss stand aged, the yield, canopy height, and nutritive value of forage declined. Given the availability of livestock manure in the High Plains region of the USA and the need to recycle this by‐product from confined animal feeding operations, the application of livestock manure to buffalograss grown with irrigation for hay or pasture could be a viable and sustainable production system. Future work should address the long‐term effects of applying livestock manure to soils in relation to nutrient loading and water quality.

Relation of yield of corn (Zea mays L.) to nitrogen in shoot and soil during the early-season following manure application to field plots

We investigated corn grain yield responses to early-season soil mineral N and plant N content following application of a variety of manures in Eastern Canada. Liquid cattle, liquid swine, straw-bedded poultry, wood-bedded poultry, and solid cattle manures were each applied at 100, 200, and 300 kg N ha-1 prior to planting corn in a field experiment repeated 3 consecutive years. Additional treatments were urea applied at 50, 100, and 150 kg N ha-1, and liquid cattle and solid cattle manures at 200 kg N ha-1 with bedding amendments added to the field before manure spreading. Control plots received no manure, no urea, and no bedding amendment. Part of the ammonium-N applied in manures and a portion of that added as urea was volatilized or immobilized shortly after application and was not recovered as soil mineral N at planting. Across all treatments, soil mineral N in the top 30 cm on Jun. 10 in each year gave a better relationship to corn grain yield than soil mineral N measured at planting or on Jul. 10. Inclusion of data for plant N content on Jun. 10 or Jul. 10 did not improve the regressions. With remarkable consistency across all manure types, across manure rates, and over the three years, similar values for soil mineral N on Jun. 10 in plots given manure at planting had yields typically 0.5-1.0 t ha-1 greater than those in plots given urea at planting. This result indicates that mineralization of N from manure after the time of sidedress N and undetected as soil mineral N on Jun. 10 can contribute to yield increases of corn. Recent manure history should be considered when using soil tests for mineral N that are taken 3-4 wk after planting to calculate sidedress N fertilization. Key words: Sidedress, soil test, slurry, solid, cattle, swine, poultry

Phosphorus amounts and distribution in a Saskatchewan soil after five years of swine and cattle manure application

Repeated application of animal manures to Saskatchewan soils has led to interest in the fate and distribution of residual manure P in the soil. The concentrations of soil phosphorus in various inorganic and organic fractions were investigated in soils sampled from long-term field research plots (Dixon, SK) with a 5-yr history of annual application of liquid swine manure or solid cattle manure at low, medium and high rates. The soil type at the research site is a loamy textured Black Chernozem (Cudworth Association). Annual rates of manure application over the 5 yr were based on the N contents in the manures and were equivalent to 0 (control), and approximately 100 (low), 200 (medium) and 400 (high) kg total N ha-1 yr-1 as manure. For comparison, urea alone was also applied at rates of 50, 100 and 200 kg N ha-1 yr-1. The total P concentration in the surface soil (0&amp;ndash15 cm) was significantly increased only by the addition of cattle manure and only in the medium and high rate treatments compared to the control. The most labile P fractions (Resin-P and NaHCO3-P) were also significantly increased with increasing rate of cattle manure addition. No significant increases in either soil total P or labile P fractions were observed in liquid swine manure treatments, which is attributed to the lower amount of P added with the swine manure treatment than the cattle manure treatment. Added P in the swine manure treatment more closely matched P removal in crop harvest compared to cattle manure treatment, which had more P added than was removed by the crop. Key words: Phosphorus fractions, labile P fraction, sequential P extraction, urea, swine manure, cattle manure

Evaluation of metal concentrations in edible vegetables grown in compost amended soil

Agricultural uses of compost usually have a positive effect on the yield of vegetable crops for human consumption. However, compost that contains heavy metals can transfer these components to soils and plants. To evaluate the contamination levels of metals in soil, compost, and edible vegetables, the Mn, Zn, Pb, Cd, Cu, and Ni total contents were measured. Metal availability in soils, as well as other variables – the pH, CEC (cation exchange capacity), total nitrogen, organic carbon, particle size distribution and mineralogy of the clay fraction – were examined in the soil samples. The analysed compost samples were produced from urban solid waste, cattle manure, and edible vegetable and tree pruning residues. The values of pH, CEC, total nitrogen, organic matter, exchangeable hydrogen and carboxylic groups were measured in the compost samples. Of the six metals examined in the soils, in general, Mn and Zn attained the highest concentrations, followed by Cu. Relatively high Mn, Zn, Cu, Cd and Pb concentrations were found in the soils. Metal concentrations extracted with DTPA were below the critical levels in soils, i.e. the levels above which toxicity is likely. In general, Zn, Pb, Cd, Cu and Ni concentrations in compost were lower than those reported by other workers, while Mn levels were within the range for this metal in compost. The results showed that there was an effect of the vegetable type (p < 0.01) for all the parameters examined. High Pb concentrations were found in lettuce and chive as compared with the tolerance limit for this metal in fresh vegetables in Brazil. Cadmium concentrations were also enhanced in the fresh vegetables compared with the typical concentrations of metals in plants. Zinc, Cu, Cd, and Ni concentrations were lower than the tolerance limits established for foods by the Brazilian legislation.