Barry M. Olson

Nitrogen dynamics in soil amended with composted cattle manure

The amount and pattern of plant-available nitrogen (N) release from composts are variable and not well-defined. We used a 425-d canola (Brassica napus L.) bioassay to follow the release of N from eight composted cattle manures applied to soil at 20 g kg-1. Two stockpiled manures, one inorganic fertilizer and an unamended control were also included for comparison. Eight consecutive 30-d growth cycles were conducted in a controlled environment chamber (20°C) and plant N uptake was measured. Total N uptake was greatest from the N fertilizer and least from the wood-chip bedded manure. Addition of compost increased N uptake by 27–99% compared with that in the control. Nitrogen uptake from compost was directly proportional to its inorganic N content (r2 = 0.98; P < 0.0001) showing that the initial inorganic N content of compost, analyzed prior to its application can be used to predict plant available N. In seven of the eight composts studied, less than 5% of organic N was mineralized over 425 d, suggesting that...

Nitrate leaching in two irrigated soils with different rates of cattle manure.

Manure applied to irrigated land may potentially contaminate groundwater with NO3-N. An 8-yr field experiment was conducted in southern Alberta, Canada, to determine the effects of different rates of manure on NO3-N accumulation in two irrigated soil types and NO3-N leaching to shallow groundwater. An annual cereal silage was grown at each site and irrigation was based on soil moisture depletion. Treatments included a control, nitrogen fertilizer (NF) at 180 kg N ha(-1) yr(-1), and four rates of cattle (Bos taurus) manure (20, 40, 60, and 120 Mg ha(-1) yr(-1), wet-weight basis). Annual manure applications for 8 yr resulted in NO3-N accumulation in the soil profile at both sites. For every megagram of total N added from manure, NO3-N in the 0- to 1.5-m layer increased by about 50 kg ha(-1) at the coarse-textured (CT) site and by about 100 kg ha(-1) at the medium-textured (MT) site. Silage yield for all of the manure treatments was similar to yield for the NF treatment after the first 3 to 4 yr of annual manure applications. The greatest manure rate and NF treatments significantly increased NO3-N concentrations in groundwater at the CT site. Groundwater NO3-N concentrations were not adversely affected by manure or NF applications at the MT site. An annual cattle manure application rate of 20 Mg ha(-1) provided sufficient N for irrigated cereal silage production and minimized NO3-N leaching in a medium-textured soil.

Soil quality and productivity responses to simulated erosion and restorative amendments

There is little quantitative information on the interrelatedness of soil erosion, soil quality and soil productivity. A simulated erosion approach was used to quantify erosion and amendment effects on soil quality and subsequent productivity at four southern Alberta sites. Zero, 5, 10, 15 and 20 cm of topsoil were removed (cuts) at each site and subplots were amended with N + P fertilizer, 5 cm topsoil, 70 Mg ha−1 cattle manure or left unamended. Wheat (Triticum aestivum L.) yields in the 2-yr study on the non-amended check plots showed significant correlations with organic C at three of the four sites, and extractable P and inorganic C at all four sites. While manure was the best amendment for enhancing soil productivity, the magnitude of its effect depended on the organic C content of the recipient soil. At an organic C content of 8 g kg−1 on the Lethbridge Dryland site, manure addition increased crop yield by 1.75 Mg ha−1, compared with only 0.27 Mg ha−1 at an organic C content of 15 g kg−1. Our result...

Soil salinity and sodicity after application of fresh and composted manure with straw or wood-chips

Limited information exists on the effect of fresh versus composted beef cattle manure containing straw or wood chips on salinity (EC), soluble salts (Ca, Mg, Na, K, Cl, SO4), sodicity (sodium adsorption ratio, SAR), and potassium adsorption ratio (PAR) status of soil in the Great Plains region of North America. A site on a clay loam soil under irrigated barley (Hordeum vulgare) in southern Alberta was used for this study. The treatments were three rates (13, 39, 77 Mg ha-1 dry material) of fresh manure (FM) or composted manure (CM) containing either straw (ST) or wood-chip (WD) bedding, one inorganic (IN) fertilizer treatment, and a control (CON) treatment. All treatments were applied in the fall of 1998, 1999, and 2000. Soil sampling was conducted in the fall of 1998, 1999, 2000, and 2001 prior to manure and fertilizer application. Our results indicated that applying CM to irrigated barley for 3 yr at rates up to 77 Mg ha-1 should not cause an increase in any of the salinity variables compared with FM. C...

Phosphorus accumulation and leaching in two irrigated soils with incremental rates of cattle manure

The risk of P leaching increases on land that receives manure at rates sufficient to meet crop N requirements, but calcareous subsoils may minimize P loss due to P adsorption. An 8-yr field experiment was conducted to determine the effects of different rates of manure on the accumulation and leaching of soil P in a coarse-textured (CT) soil and a medium-textured (MT) soil under typical irrigation management in southern Alberta. Treatments included a non-manured control and four rates of cattle (Bos taurus) manure (20, 40, 60, and 120 Mg ha-1 yr-1, wet-weight basis). In manured treatments, P addition ranged from about 80 to 450 kg P ha-1 yr-1, while P removal by annual cereal silage crops ranged from 15 to 22 kg P ha-1 yr-1. High soil test P (STP) concentrations occurred to a depth of 0.6 m at the CT site and 0.3 m at the MT site. Increase in STP concentration to 0.6 m was equivalent to 43% of net P input, and increase in total soil P was equivalent to 78% of net P input. Non-recovery of net P input sugges...

Phosphorus and nitrogen in runoff after phosphorus- or nitrogen-based manure applications.

Application of beef cattle () manure based on nitrogen (N) requirements of crops has resulted in elevated concentrations of soil test phosphorus (P) in surface soils, and runoff from this cropland can contribute to eutrophication of surface waters. We conducted a 3-yr field study (2005-2007) on a Lethbridge loam soil cropped to dryland barley () in southern Alberta, Canada to evaluate the effect of annual and triennial P-based and annual N-based feedlot manure on P and N in runoff. The manure was spring applied and incorporated. There was one unamended control plot. A portable rainfall simulator was used to generate runoff in the spring of each year after recent manure incorporation, and the runoff was analyzed for total P, total dissolved P, total particulate P, dissolved reactive P, total N, total dissolved N, total particulate N, NO-N, and NH-N. Annual or triennial P-based application resulted in significantly ( ≤ 0.05) lower (by 50 to 94%) concentrations or loads of mainly dissolved P fractions in runoff for some years compared with annual N-based application, and this was related to lower rates of annual manure P applied. For example, mean dissolved reactive P concentrations in 2006 and 2007 were significantly lower for the annual P-based (0.12-0.20 mg L) than for the annual N-based application (0.24-0.48 mg L), and mean values were significantly lower for the triennial P-based (0.06-0.13 mg L) than for the annual N-based application. In contrast, other P fractions in runoff were unaffected by annual P-based application. Our findings suggested no environmental benefit of annual P-based application over triennial P-based application with respect to P and N in runoff. Similar concentrations and loads of N fractions in runoff for the P- and N-based applications indicated that shifting to a P-based application would not significantly influence N in runoff.

Physical and chemical properties of feedlot pen surfaces located on moderately coarse- and moderately fine-textured soils in southern Alberta.

Southern Alberta has the highest density of feedlot cattle in Canada, and there is a concern that leaching of water and contaminants may be greater for feedlots located on coarser-textured than finer-textured soils. Our objective was to determine if infiltration and leaching were greater for a 4-yr-old feedlot located on a moderately coarse-textured (MC) soil compared with two feedlots located on moderately fine-textured (MF) soils (5- and 52-yr-old pens). Various soil physical properties of feedlot pen surfaces were measured, including field-saturated hydraulic conductivity (K(fs)) and near-saturated hydraulic conductivity at -0.9 and -3.9 cm water potential. Selected chemical properties of feedlot soil layers were measured, as well as the chloride content of the soil profile (0-100 cm). Mean K(fs), K(-0.9), and K(-3.9) values were not significantly (P > 0.10) greater at the MC site than the two MF sites, indicating no evidence of greater infiltration on coarser-textured soils. In addition, mean K(fs), K(-0.9), and K(-3.9) values of soils within feedlot pens at all three sites were significantly (P < or = 0.10) reduced by 46 to 78% compared with soil outside the pens. Depth of chloride accumulation was greatest at the 52-yr-old feedlot on MF soil (60-70 cm), followed by 4-yr-old feedlot on MC soil (40-50 cm) and 5-yr-old feedlot on MF soil (30-40 cm). Visual inspection determined that the black interface layer formed within 2 mo of cattle stocking at all three sites.

Short-Term Nitrogen Leaching Potential Of Fresh and Composted Beef Cattle Manure Applied to Disturbed Soil Cores

Although fresh beef cattle (Bos taurus) manure has traditionally been applied to cropland in southern Alberta, there has been a recent increase in application of composted manure to cropland in this region. Nitrogen leaching from fresh manure (FM) versus composted (CM) beef cattle manure application has not been investigated in this region. Our objective was to compare short-term (# 23 d) N leaching potential of NO3 -N and NH4 -N under increasing rates (0, 13, 39, 77 Mg ha−1 dry wt.) of FM and CM applied to a clay loam soil under uniform soil and simulated environmental conditions. Amendments were applied and incorporated into repacked 15-cm soil (surface Ah horizon) cores, incubated for 15 d, and then leached under constant-head and saturated conditions in the laboratory. An unamended control (CON) was also used. Leaching potential of NO3-N and NH4-N depended on how the N leaching variable was expressed: peak concentration vs flow-weighted mean concentration (FWMC) vs mass loss vs recovery in leachate. Peak concentrations of NO3-N were at least 90% greater for CM (125.8 mg L−1) than FM (66.3 mg L−1) and the CON (60.5 mg L−1) treatments. The FWMC of NO3-N was significantly (P # 0.05) greater for CM (21.0 mg L1) than FM (16.3 mg L−1). Recovery of NO3-N in leachate as a percentage of total N applied was significantly greater for CM (4.7%) than FM (0.8%). Peak concentrations of NH4-N, FWMC of NH4-N, mass loss of NO3 and NH4, and recovery of NH4, were similar between FM and CM. These results suggest that short-term N leaching potential of CM was greater than FM for peak concentration, FWMC, and recovery of NO3-N.

Soil chemical changes following manure application on irrigated alfalfa and rainfed timothy in southern Alberta

In areas within Alberta where suitable cultivated land is not available, or for convenience, the use of forage land is an alternative for manure application. However, there is limited research on the effects of manure on forage land in the province. The objective of this 5-yr study was to determine the effects of manure on soil chemical properties of forage land. Cattle (Bos taurus L.) and hog (Sus scrofa L.) manures were applied at five rates on irrigated alfalfa ( Medicago sativa L.) and on rainfed timothy(Phleum pratense L.) sites. Treatments were replicated four times and arranged in a randomized complete block design. Soil samples (0 to 15, 15 to 30, 30 to 60, 60 to 90, 90 to 120, and 120 to 150 cm) were collected each spring prior to manure application. Manure application on forage land significantly affected soil chemical properties such as increases in NO3-N, PO4-P, K, Na, and electrical conductivity. There was also evidence of accumulation and some downward movement of NO3-N, Na, and K below 15 c...

Soil quality attributes, soil resilience, and legacy effects following topsoil removal and one-time amendments

Abstract: Inter-relationships among soil erosion, soil quality, soil resilience, and legacy effects of organic amendments have not been adequately quantified. Topsoil was mechanically removed (cuts) to simulate erosion in semiarid southern Alberta in 1990. Three cuts (0, 10, and 20 cm) superimposed with three one-time (1990 only) amendment treatments (check, N + P fertilizer, and manure) were chosen for this study. In the absence of amendments, light fraction C (CLF) and mineralizable C (Cmin) recovered sufficiently by 2004 to render the cut effect nonsignificant. Organic C (Corg) responded more slowly with the 10-cm cut recovering to the 0-cm cut concentration by 2004, and the 20-cm cut (13.9 g kg-1) remaining significantly lower than the 0-cm cut concentration (16.3 g kg-1) through to 2012. Nitrogen fractions behaved similarly. Among cuts and years (2004 and 2012), C fraction values were 19-27% greater on the manure versus check treatment (17.5 vs. 14.7 g kg-1 for Corg, 1.38 vs. 1.09 g kg-1 for CLF, and 650 vs. 531 mg kg-1 for Cmin) demonstrating a strong legacy effect of manure. Water-stable aggregation exhibited a 22-yr legacy effect of manure. Our findings help quantify soil resilience following major disturbance and legacy effects of one-time manure application under semiarid conditions.