NITROUS OXIDE (N2O) EMISSION FROM MINED LANDS RECLAIMED USING MANURE-BASED ORGANIC AMENDMENTS
Open Access
- Author:
- Dutta, Tanushree
- Graduate Program:
- Soil Science
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- July 08, 2011
- Committee Members:
- Richard Charles Stehouwer, Dissertation Advisor/Co-Advisor
Maryann Victoria Bruns, Committee Member
Jason Philip Kaye, Committee Member
Curtis James Dell, Committee Member
John Michael Regan, Committee Member
Richard Charles Stehouwer, Committee Chair/Co-Chair - Keywords:
- Mine land reclamation
Nitrous oxide emissions - Abstract:
- Nitrous oxide (N2O) is an important greenhouse gas (GHG) and the use of fertilizers in terrestrial systems is one of the main sources. Treating mined lands with manure-based materials gives an opportunity to make use of excess nutrients of animal waste products in a nutrient-starved system. However, due to the presence of high amounts of both organic matter and nitrogen, use of these materials could create a soil environment suitable for N2O emission, an issue that has remained largely uninvestigated in reclaimed mined systems. Three experiments including one 37 day controlled laboratory incubation experiment followed by 2 field trial experiments in an active mine site at Clearfield County, Pennsylvania were conducted to address this issue. The objectives of the study were to determine if manure-based applications would produce more N2O than soils treated with inorganic amendments and non-amended soils and to examine the effects of increased C quantity and labile versus stabilized forms of C on mine soil N2O emissions at two different soil moisture conditions. Amendment materials used in the incubation experiment and field experiment 2009 included ground agricultural limestone and inorganic fertilizer (L+F), poultry layer manure (Man), manure combined with primary paper mill sludge (PMS) in C/N ratios of 14, 21, and 28 (Man+PMS14, Man+PMS21 and Man+PMS28); and composted poultry layer manure (Comp). Field experiment 2010 focused more on the C effects on N2O emissions with manure only and Man+PMS14, Man+PMS21 and Man+PMS28 amendments. Application rates of the amendments matched with application rates commonly used in mine reclamation. Manure-based amendments increased N2O emission compared to non-amended and inorganic fertilizer-treated soils under controlled laboratory conditions within the first 2 days of amendment mixing, but the response was quite short-lived. Increase in soil moisture content caused an increase in emissions. Contrary to laboratory experimental findings, field experiment data revealed very poor evidence of amendment application and soil moisture content effects on emissions. A denitrification potential experiment conducted using the soils from the same field site showed that the soil did not have the capability for denitrification even when the conditions were best suitable for denitrifying activity. The soil showed potential for denitrifying activity only when it was treated with manure-based products. Both in incubation and field experiments, manure-based materials increased the availability of substrate N. Field soil moisture data suggested that the soil dried out quickly due to coarse nature of the soil. This drying of soil diminished the difference between the moisture content of the ambient and water-added soils and created air filled pores less suitable for soil N2O production. This study demonstrated that in soils with a high percentage of coarse fragments, good drainage conditions and drying of soils reduce the chances of increased soil N2O emissions from manure-based applications.