Alfalfa Silage

Alfalfa Silage
Author: Ollie Ezekiel Reed
Publisher:
Total Pages: 28
Release: 1917
Genre: Alfalfa silage
ISBN:

A National Ecological Framework for Canada

A National Ecological Framework for Canada
Author: Ecological Stratification Working Group (Canada)
Publisher: Centre for Land and Biological Resources Research ; Hull, Quebec : State of the Environment Directorate
Total Pages: 140
Release: 1996
Genre: Nature
ISBN:

[An] expanded attribute database [that] includes attribute data for the ecoprovince level of generalization.

Denitrification in Soil and Sediment

Denitrification in Soil and Sediment
Author: Niels Peter Revsbech
Publisher: Springer Science & Business Media
Total Pages: 352
Release: 2013-11-11
Genre: Science
ISBN: 1475799691

The formation of atmospheric nitrogen gas by denitrifying bacteria may represent a significant nutrient sink in natural ecosystems. The rate of denitrification has often been difficult to measure in situ, however, and new methodologies should stimulate research on distribution of activity in space and time. The load of fertilizer nitrogen in modem agriculture has led to increasing nutrient reservoirs in recipient subsoils, aquifers, inland waters and coastal seas. By its conversion of nitrate to atmospheric nitrogen, bacterial denitrification is the only biological process to potentially reduce the impact of increasing nutrient loadings by fertilizer nitrogen in the environment. As part of a scientific program set up by the Danish Ministry of Environment to study environment cycling of nitrogen, phosphorous and organic matter (NPO program) in the light of agricultural, domestic and industrial activities, a symposium on DENITRIFICATION IN SOIL AND SEDIMENT was held at the University of Aarhus, Denmark from 6-9 June 19i\9. On the basis of lectures given at the symposium, this book contains a number of invited contributions on the regulation of denitrification activity (control of enzyme synthesis and activity) and measurement of in situ rates of denitrification in terrestrial and aquatic environments (control factors, diel and seasonal variations, etc). Emphasis has been placed on including the recent improvements in methodologies and current understanding of process regulation, however the book also contains examples of integrated research on the significance of denitrification in environmental nutrient cycling.

Nitrous Oxide Soil Emissions from an Organic and Conventionally Managed Cropping System in Manitoba

Nitrous Oxide Soil Emissions from an Organic and Conventionally Managed Cropping System in Manitoba
Author: Megan Westphal
Publisher:
Total Pages: 0
Release: 2016
Genre:
ISBN:

In recent decades the knowledge of nitrous oxide (N2O) emissions after the application of nitrogen (N) fertilizers in agriculture soil has improved. However the understanding of emissions of N2O from Canadian organic agricultural systems has not been developed. The Glenlea Long Term Crop Rotation is the longest running organic conventional comparison study in western Canada and was used here to compare N2O emissions between the systems. In organic cropping systems forage legumes such as alfalfa are incorporated into the soil as an N source. The amount of N2O that is emitted after the incorporation and during the subsequent crop is not well known. The wheat and legume phases (alfalfa (Medicago sativa) in organic system and soybean (Glycine max L.) in the conventional) of the rotation were monitored for N2O. In 2014, 2015, and spring 2016 (data still being analysed) emissions of N2O were monitored using the vented static chambers method as well, soil conditions (temperature, moisture, inorganic N and extractable carbon) and yields were measured. Typical N2O emissions from spring applied urea were observed after application in the conventional system however no emission episode was seen after the fall alfalfa plough down or during spring thaw in the organic system. Greater NO3- accumulation was observed in the organic treatments however low emissions were observed. The organic system resulted in lower yields for both years, but still resulted in lower emissions per amount of grain produced (yield-scaled emissions) than the conventional system. This study adds to the knowledge that N2O emissions from organic systems do differ from conventional however yields need to be improve to fully exploit the benefits.

Environmental Chemistry and Recent Pollution Control Approaches

Environmental Chemistry and Recent Pollution Control Approaches
Author: Hugo Saldarriaga-Noreña
Publisher: BoD – Books on Demand
Total Pages: 226
Release: 2019-12-18
Genre: Technology & Engineering
ISBN: 1839680628

In recent years, there have been significant advances in the techniques of sampling and analysis, which has allowed the more accurate recording of environmental levels of many substances present in the environment. At the same time, processes for the remediation of contaminated matrices have evolved, through the application and/or combination of biological, physical, and chemical procedures.The purpose of this book is to present new studies aimed at determining levels of environmental pollution in various parts of the world. It also shows new alternatives for the remediation of contaminated matrices.

The effects of different mineral nitrogen fertilizer forms on N2O emissions from arable soils under aerobic conditions

The effects of different mineral nitrogen fertilizer forms on N2O emissions from arable soils under aerobic conditions
Author: Jens Tierling
Publisher: Cuvillier Verlag
Total Pages: 118
Release: 2017-05-02
Genre: Science
ISBN: 3736985061

Intensively managed agricultural soils are a major source of the greenhouse gas nitrous oxide (N2O), mainly due to the use of mineral nitrogen fertilizers which stimulate microbial processes in soils that form N2O. While oxidized N fertilizer forms can be subject to denitrification, reduced N forms must first be oxidized by nitrification to become available for denitrification. Because the contribution of these processes to N2O emissions depends on the prevailing soil conditions, the choice of the N fertilizer form has the potential to mitigate N2O emissions from fertilized soils. The present study focused on comparing amid-, ammonium- and nitrate-based mineral fertilizers with regard to nitrogen transformation dynamics and N2O production under controlled as well as field conditions. For this two distinct methodological approaches to measure N2O emissions were evaluated and deployed. Furthermore, the effects of soil pH and the alkalizing hydrolysis of urea were investigated. It was shown that especially under aerobic conditions the N fertilizer form can significantly affect N2O production in soils, and that nitrite dynamics are important especially for nitrification-derived N2O emissions. Thus, the careful consideration of the N fertilizer form can be a measure to mitigate emissions from farmland.