Rainfall-associated chronic N deposition induces higher soil N2O emissions than acute N inputs in a semi-arid grassland

In semi-arid vineyard agroecosystems, highly vulnerable in the context of climate change, the soil organic matter (OM) content is crucial to the improvement of soil fertility and grape productivity. The impact of OM, from compost and animal manure, on soil properties (e.g., pH, oxidisable organic C, organic N, NH4+-N and NO3−-N), grape yield and direct greenhouse gas (GHG) emission in vineyards was assessed. For this purpose, two wine grape varieties were chosen and managed differently: with a rain-fed non-trellising vineyard of Monastrell, a drip-irrigated trellising vineyard of Monastrell and a drip-irrigated trellising vineyard of Cabernet Sauvignon. The studied fertiliser treatments were without organic amendments (C), sheep/goat manure (SGM) and distillery organic waste compost (DC). The SGM and DC treatments were applied at a rate of 4600 kg ha−1 (fresh weight, FW) and 5000 kg ha−1 FW, respectively. The use of organic amendments improved soil fertility and grape yield, especially in the drip-irrigated trellising vineyards. Increased CO2 emissions were coincident with higher grape yields and manure application (maximum CO2 emissions = 1518 mg C-CO2 m−2 d−1). In contrast, N2O emissions, mainly produced through nitrification, were decreased in the plots showing higher grape production (minimum N2O emissions = −0.090 mg N2O-N m−2 d−1). In all plots, the CH4 fluxes were negative during most of the experiment (−1.073−0.403 mg CH4-C m−2 d−1), indicating that these ecosystems can represent a significant sink for atmospheric CH4. According to our results, the optimal vineyard management, considering soil properties, yield and GHG mitigation together, was the use of compost in a drip-irrigated trellising vineyard with the grape variety Monastrell.

Download Full-text

Effects of N and P fertilization on the greenhouse gas exchange in two nutrient-poor peatlands

Biogeosciences Discussions ◽

10.5194/bgd-6-4803-2009 ◽

2009 ◽

Vol 6 (3) ◽

pp. 4803-4828 ◽

Cited By ~ 1

Author(s):

M. Lund ◽

T. R. Christensen ◽

M. Mastepanov ◽

A. Lindroth ◽

L. Ström

Keyword(s):

Gas Exchange ◽

Primary Production ◽

Greenhouse Gas ◽

Nutrient Availability ◽

Gross Primary Production ◽

N Deposition ◽

N2o Emissions ◽

N Availability ◽

P Fertilization ◽

Organic C

Abstract. Peatlands are important ecosystems in the context of biospheric feedback to climate change, due to the large storage of organic C in peatland soils. Nitrogen deposition and increased nutrient availability in soils following climate warming may cause changes in these ecosystems affecting greenhouse gas exchange. We have conducted an N and P fertilization experiment in two Swedish bogs subjected to high and low background N deposition, and measured the exchange of CO2, CH4 and N2O using the closed chamber technique. During the second year of fertilization, both gross primary production and ecosystem respiration were significantly increased by N addition in the northernmost site where background N deposition is low, while gross primary production was stimulated by P addition in the southern high N deposition site. In addition, a short-term response in respiration was seen following fertilization, probably associated with rapid growth of nutrient-limited soil microorganisms. No treatment effect was seen on the CH4 exchange, while N2O emissions peaks were detected in N fertilized plots indicating the importance of taking N2O into consideration under increased N availability. In a longer term, increased nutrient availability will cause changes in plant competitive patterns. The related effect on the future net greenhouse gas exchange is likely dependent on the mixture of nutrients being made available and which plant functional types that benefit from it, in combination with other changes related to global warming.

Download Full-text

Understanding N2O Emissions in African Ecosystems: Assessments from a Semi-Arid Savanna Grassland in Senegal and Sub-Tropical Agricultural Fields in Kenya

Sustainability ◽

10.3390/su12218875 ◽

2020 ◽

Vol 12 (21) ◽

pp. 8875

Author(s):

Laurent Bigaignon ◽

Claire Delon ◽

Ousmane Ndiaye ◽

Corinne Galy-Lacaux ◽

Dominique Serça ◽

...

Keyword(s):

Agricultural Land ◽

Pore Space ◽

Seasonal Pattern ◽

Arid Ecosystems ◽

N2o Emissions ◽

African Continent ◽

1D Model ◽

Dry Seasons ◽

Grassland Site ◽

Semi Arid

This study is based on the analysis of field-measured nitrous oxide (N2O) emissions from a Sahelian semi-arid grassland site in Senegal (Dahra), tropical humid agricultural plots in Kenya (Mbita region) and simulations using a 1D model designed for semi arid ecosystems in Dahra. This study aims at improving present knowledge and inventories of N2O emissions from the African continent. N2O emissions were larger at the agricultural sites in the Mbita region (range: 0.0 ± 0.0 to 42.1 ± 10.7 ngN m−2 s−1) than at the Dahra site (range: 0.3 ± 0 to 7.4 ± 6.5 ngN m−2 s−1). Soil water and nitrate (NO3−) contents appeared to be the most important drivers of N2O emissions in Dahra at the seasonal scale in both regions. The seasonal pattern of modelled N2O emissions is well represented, though the model performed better during the rainy season than between the rainy and dry seasons. This study highlighted that the water-filled pore space threshold recognised as a trigger for N2O emissions should be reconsidered for semi-arid ecosystems. Based on both measurements and simulated results, an annual N2O budget was estimated for African savanna/grassland and agricultural land ranging between 0.17–0.26 and 1.15–1.20 TgN per year, respectively.

Download Full-text

Mixed grazing and clipping is beneficial to ecosystem recovery but may increase potential N2O emissions in a semi-arid grassland

Soil Biology and Biochemistry ◽

10.1016/j.soilbio.2017.07.002 ◽

2017 ◽

Vol 114 ◽

pp. 42-51 ◽

Cited By ~ 7

Author(s):

Lei Zhong ◽

Xiaoqi Zhou ◽

Yanfen Wang ◽

Frank Yonghong Li ◽

Shutong Zhou ◽

...

Keyword(s):

N2o Emissions ◽

Ecosystem Recovery ◽

Semi Arid

Download Full-text

Controls over N2O, NOx and CO2 fluxes in a calcareous mountain forest soil

Biogeosciences Discussions ◽

10.5194/bgd-2-1423-2005 ◽

2005 ◽

Vol 2 (5) ◽

pp. 1423-1455 ◽

Cited By ~ 2

Author(s):

B. Kitzler ◽

S. Zechmeister-Boltenstern ◽

C. Holtermann ◽

U. Skiba ◽

K. Butterbach-Bahl

Keyword(s):

Forest Soil ◽

Co2 Emissions ◽

Temporal Variations ◽

Beech Forest ◽

N Deposition ◽

Measuring System ◽

Mountain Forest ◽

N2o Emissions ◽

Minor Importance ◽

Forest Site

Abstract. We measured nitrogen oxides (N2O and NOx), dinitrogen (N2) and carbon dioxide (CO2) emissions from a spruce-fir-beech forest soil in the North Tyrolean limestone Alps in Austria. The site received 12.1 kg nitrogen via wet and dry deposition. Fluxes of nitric oxide (NO) were measured by an automatic dynamic chamber system on an hourly basis over a two year period. Daily N2O emissions were obtained by a semi-automatic gas measuring system. In order to cover spatial variability biweekly manual measurements of N2O and CO2 emissions were carried out, additionally. For acquiring information on the effects of soil and meteorological conditions and of N-deposition on N-emissions we chose the autoregression procedure (time-series analysis) as our means of investigation. Hence, we could exclude the data's autocorrelation in the course of the time. We found that soil temperature, soil moisture and wet N-deposition followed by air temperature and precipitation were the most powerful influencing parameters effecting N-emissions. With these variables up to 89% of observed temporal variations of N-emissions could be explained. During the two-year investigation period between 2.5 and 3.5% of deposited N was reemitted in form of N2O whereas only 0.2% were emitted as NO. At our mountain forest site the main end-product of microbial activity processes was N2 and trace gases (N2O and NO) were only of minor importance.

Download Full-text

Impacts of Nitrogen Addition on Nitrous Oxide Emission: Model-Data Comparison

10.5194/bg-2018-126 ◽

2018 ◽

Author(s):

Yujin Zhang ◽

Minna Ma ◽

Huajun Fang ◽

Dahe Qin ◽

Shulan Cheng ◽

...

Keyword(s):

Nitrous Oxide ◽

Global Climate ◽

Pore Space ◽

Terrestrial Ecosystem ◽

N2o Emission ◽

N Deposition ◽

N2o Emissions ◽

Emission Model ◽

N Addition ◽

N2o Production

Abstract. The contributions of long-lived nitrous oxide (N2O) to the global climate and environment have received increasing attention. Especially, atmospheric nitrogen (N) deposition has substantially increased in recent decades due to extensive use of fossil fuels in industry, which strongly stimulates the N2O emissions of the terrestrial ecosystem. Several models have been developed to simulate N2O emission, but there are still large differences in their N2O emission simulations and responses to atmospheric deposition over global or regional scales. Using observations from N addition experiments in a subtropical forest, this study compared six widely-used N2O models (i.e. DayCENT, DLEM, DNDC, DyN, NOE, and NGAS) to investigate their performances for reproducing N2O emission, and especially the impacts of two types of N additions (i.e. ammonium and nitrate: NH4+ and NO3−, respectively) and two levels (low and high) on N2O emission. In general, the six models reproduced the seasonal variations of N2O emission, but failed to reproduce relatively larger N2O emissions due to NH4+ compared to NO3− additions. Few models indicated larger N2O emission under high N addition levels for both NH4+ and NO3−. Moreover, there were substantial model differences for simulating the ratios of N2O emission from nitrification and denitrification processes due to disagreements in model structures and algorithms. This analysis highlights the need to improve representation of N2O production and diffusion, and the control of soil water-filled pore space on these processes in order to simulate the impacts of N deposition on N2O emission.

Download Full-text

Emission of nitrous oxide and carbon dioxide from semi-arid tropical soils in Chiapas México

Revista Brasileira de Ciência do Solo ◽

10.1590/s0100-06832010000500015 ◽

2010 ◽

Vol 34 (5) ◽

pp. 1617-1628 ◽

Cited By ~ 2

Author(s):

Alejandro Ponce-Mendoza ◽

Juan Manuel Ceballos-Ramírez ◽

Federico Gutierrez-Micelli ◽

Luc Dendooven

Keyword(s):

Arable Land ◽

Tropical Soils ◽

Co2 Production ◽

Sampling Location ◽

N2o Emissions ◽

Acacia Angustissima ◽

Fertilized Soil ◽

Different Seasons ◽

Semi Arid Region ◽

Semi Arid

The semi-arid region of Chiapas is dominated by N2 -fixing shrubs, e.g., Acacia angustissima. Urea-fertilized soil samples under maize were collected from areas covered and uncovered by A. angustissima in different seasons and N2O and CO2 emissions were monitored. The objective of this study was to determine the effects of urea and of the rainy and dry season on gas emissions from semi-arid soil under laboratory conditions. Urea and soil use had no effect on CO2 production. Nitrons oxide emission from soil was three times higher in the dry than in the rainy season, while urea fertilization doubled emissions. Emissions were twice as high from soil sampled under A. angustissima canopy than from arable land, but 1.2 lower than from soil sampled outside the canopy, and five times higher from soil incubated at 40 % of the water-holding capacity (WHC) than at soil moisture content, but 15 times lower than from soil incubated at 100 WHC. It was found that the soil sampling time and water content had a significant effect on N2O emissions, while N fertilizer and sampling location were less influent.

Download Full-text