Soil antibiotic resistance genes accumulate at different rates over four decades of manure application.

Manure can be a source of antibiotic resistance genes (ARGs) that enter the soil. However, previous studies assessing ARG persistence in soil have generally lacked continuity over sampling times, consistency of location, and assessing the impact of discontinuing manure application. We evaluated both short- and long-term ARG accumulation dynamics in soil with a 40-year known history of manure use.

Organic carbon and nitrogen accumulation in orchard soil with organic fertilization and cover crop management: A global meta-analysis.

In orchard systems, organic amendments and cover crops may enhance soil organic carbon (SOC) and total nitrogen (STN) stocks, but on a global scale a comprehensive understanding of these practices is needed. This study reports a worldwide meta-analysis of 131 peer-reviewed publications, to quantify potential SOC and STN accumulation in orchard soils induced by organic fertilization and cover cropping. Annual gains of 3.

Modelling soil salinity effects on salt water uptake and crop growth using a modified denitrification-decomposition model: A phytoremediation approach.

Soil salinization is a widespread problem affecting global food production. Phytoremediation is emerging as a viable and cost-effective technology to reclaim salt-affected soil. However, its efficiency is not clear due to the uncertainty of plant responses in saline soils.

Effects of 3-nitrooxypropanol manure fertilizer on soil health and hydraulic properties.

Supplementing beef cattle with 3-nitrooxypropanol (3-NOP) decreases enteric methane production, but it is unknown if fertilizing soil with 3-NOP manure influences soil health. We measured soil health indicators 2 yr after manure application to a bromegrass (Bromus L.) and alfalfa (Medicago sativa L.

Modeling the effect of salt-affected soil on water balance fluxes and nitrous oxide emission using modified DNDC.

Soil salinity restricts plant growth, affects soil water balance and nitrous oxide (NO) fluxes and can contaminate surface and groundwater. In this study, the Denitrification Decomposition (DNDC) model was modified to couple salt and water balance equations (SALT-DNDC) to investigate the effect of salinity on water balance and NO fluxes. The model was examined against four growing seasons (2008-11) of observed data from Lethbridge, Alberta, Canada.

Greenhouse gas and ammonia emissions from stored manure from beef cattle supplemented 3-nitrooxypropanol and monensin to reduce enteric methane emissions.

The investigative material 3-nitrooxypropanol (3-NOP) can reduce enteric methane emissions from beef cattle. North American beef cattle are often supplemented the drug monensin to improve feed digestibility. Residual and confounding effects of these additives on manure greenhouse gas (GHG) emissions are unknown.

Modeling nitrous oxide emissions from rough fescue grassland soils subjected to long-term grazing of different intensities using the Soil and Water Assessment Tool (SWAT).

Given the rising nitrous oxide (NO) concentration in the atmosphere, it has become increasingly important to identify hot spots and hot moments of NO emissions. With field measurements often failing to capture the spatiotemporal dynamics of NO emissions, estimating them with modeling tools has become an attractive alternative. Therefore, we incorporated several semi-empirical equations to estimate NO emissions with the Soil and Water Assessment Tool from nitrification and denitrification processes in soil.

Are distinct nitrous oxide emission factors required for cattle urine and dung deposited on pasture in western Canada?

While some countries disaggregate NO emission factors for urine and dung deposited onto pastures, in Canada, distinct NO emission factors for beef cattle urine and dung have not been defined. To help address this knowledge gap, we conducted a 1-year study to quantify NO fluxes from beef cattle urine and dung patches on a semiarid tame pasture in western Canada, as well as to quantify the NO emission factors (EF3) for urine and dung as the percentage of applied N emitted as NO-N. Urine and dung were deposited when soil water-filled pore space was nearly 60%, a wet soil condition for the grazing season in the semiarid study region, which led to a burst of NO from urine in the first 14 days of the study (42% of total N emitted).

Nitrous Oxide Emitted from Soil Receiving Anaerobically Digested Solid Cattle Manure.

Limited information is available about soil nitrous oxide (NO) fluxes, NO emission factors (EFs), and yield-scaled NO emissions for biogas residues used to fertilize crops in semiarid regions. To address this knowledge gap, a 4-yr field experiment was conducted in a semiarid climate to determine growing season NO fluxes from soil receiving (i) anaerobically digested solid beef cattle manure (digestate), (ii) separated solids from the digestate (separated solids), and (iii) undigested solid beef cattle manure (cattle manure) applied to target one and two times the recommended rates (200 and 400 kg total N ha) for barley ( L.) forage, assuming 50% of N was annually plant available.

Fertilization Shapes Bacterial Community Structure by Alteration of Soil pH.

Application of chemical fertilizer or manure can affect soil microorganisms directly by supplying nutrients and indirectly by altering soil pH. However, it remains uncertain which effect mostly shapes microbial community structure. We determined soil bacterial diversity and community structure by 454 pyrosequencing the V1-V3 regions of 16S rRNA genes after 7-years (2007-2014) of applying chemical nitrogen, phosphorus and potassium (NPK) fertilizers, composted manure or their combination to acidic (pH 5.