scholarly journals The Effects of Returning Straw and Milk Vetch on Rice Growth and Greenhouse Gas Emissions

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Lijin Zhang ◽  
Guoqin Huang
Keyword(s):  
Greenhouse Gas ◽  
Rice Yield ◽  
N2o Emission ◽  
Emission Flux ◽  
Nitrogen Application ◽  
Cross Combination ◽  
Ch4 Emissions ◽  
Combined Action ◽  
Set Up ◽  
Late Rice

The effects of different nitrogen application levels on rice yield and greenhouse gas (NO2, CH4) emissions from rice fields under the combined action of straw and milk vetch. Two treatments were set up in the main area of this experiment: R0 (no straw returned to the field, 0); R1 (amount of straw returned to the field under normal conditions, 6000kg·hm-2). Before turning the straw back into the field, use a circular knife to cut the straw into 10~13cm.And 3 kinds of nitrogen application treatments in the sub-district: N1 (no nitrogen application, 0), N2 (nitrogen application, 15 kg·hm-2), N3 (nitrogen application, 30kg·hm-2), two-factor cross-combination,and a non-nitrogen control CK, total of 7 treatments. The results showed that in 2017, early rice R1N2 treatment increased the most obvious yield, which was 32.44% higher than CK, and late rice R1N1 treatment increased the most significantly, which was 17.91% higher than CK. CH4 emissions is positively correlated with the amount of straw returned to the field, while the amount of N2O is the opposite.The N2O emission flux was highest in the treatment of R1N3, and the CH4 emission flux was the highest in the treatment of R1N2.

scholarly journals Effects of the Autumn Incorporation of Rice Straw and Application of Lime Nitrogen on Methane and Nitrous Oxide Emissions and Rice Growth of a High-Yielding Paddy Field in a Cool-Temperate Region in Japan

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1298
Author(s):  
Fumiaki Takakai ◽  
Mimori Goto ◽  
Haruki Watanabe ◽  
Keiko Hatakeyama ◽  
Kentaro Yasuda ◽  
...  
Keyword(s):  
Rice Straw ◽  
Paddy Field ◽  
N2o Emission ◽  
Nitrous Oxide Emissions ◽  
Nitrogen Application ◽  
Straw Decomposition ◽  
Ch4 Emissions ◽  
Rice Growth ◽  
Ch4 And N2o ◽  
Set Up

The effects of autumn plowing and lime nitrogen application on rice straw decomposition, CH4 and N2O emission and rice growth in the following year in a high-yielding rice cultivated paddy field were evaluated for two years. The experimental plots were set up, combining different times of rice straw (750 g m−2) incorporation into the soil by plowing (autumn or the following spring), with and without lime nitrogen application in autumn (5 g-N m−2). Autumn plowing promoted the decomposition of rice straw, but the application of lime nitrogen did not show a consistent trend. The soil pH was high (7.3) at the studied site, and the alkaline effect of lime nitrogen may not have been significant. As with straw decomposition, CH4 emissions were suppressed by autumn plowing, and no effect from the lime nitrogen application was observed. It was also suggested that the straw decomposition period may be shorter and the CH4 emissions may be higher in high-yielding cultivars that require a longer ripening period than in normal cultivars. The effect of both treatments on N2O emission was not clear. Both the autumn plowing of rice straw and lime nitrogen application were effective in promoting rice growth and increasing rice yield.

scholarly journals Drainage and tillage practices in the winter fallow season mitigate CH<sub>4</sub> and N<sub>2</sub>O emissions from a double-rice field in China

2016 ◽  
Vol 16 (18) ◽  
pp. 11853-11866 ◽  
Author(s):  
Guangbin Zhang ◽  
Haiyang Yu ◽  
Xianfang Fan ◽  
Yuting Yang ◽  
Jing Ma ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Rice Field ◽  
Rice Fields ◽  
N2o Emissions ◽  
No Tillage ◽  
Ch4 Emissions ◽  
Double Rice ◽  
Ch4 And N2o ◽  
Late Rice ◽  
Winter Fallow

Abstract. Traditional land management (no tillage, no drainage, NTND) during the winter fallow season results in substantial CH4 and N2O emissions from double-rice fields in China. A field experiment was conducted to investigate the effects of drainage and tillage during the winter fallow season on CH4 and N2O emissions and to develop mitigation options. The experiment had four treatments: NTND, NTD (drainage but no tillage), TND (tillage but no drainage), and TD (both drainage and tillage). The study was conducted from 2010 to 2014 in a Chinese double-rice field. During winter, total precipitation and mean daily temperature significantly affected CH4 emission. Compared to NTND, drainage and tillage decreased annual CH4 emissions in early- and late-rice seasons by 54 and 33 kg CH4 ha−1 yr−1, respectively. Drainage and tillage increased N2O emissions in the winter fallow season but reduced it in early- and late-rice seasons, resulting in no annual change in N2O emission. Global warming potentials of CH4 and N2O emissions were decreased by 1.49 and 0.92 t CO2 eq. ha−1 yr−1, respectively, and were reduced more by combining drainage with tillage, providing a mitigation potential of 1.96 t CO2 eq. ha−1 yr−1. A low total C content and high C / N ratio in rice residues showed that tillage in the winter fallow season reduced CH4 and N2O emissions in both early- and late-rice seasons. Drainage and tillage significantly decreased the abundance of methanogens in paddy soil, and this may explain the decrease of CH4 emissions. Greenhouse gas intensity was significantly decreased by drainage and tillage separately, and the reduction was greater by combining drainage with tillage, resulting in a reduction of 0.17 t CO2 eq. t−1. The results indicate that drainage combined with tillage during the winter fallow season is an effective strategy for mitigating greenhouse gas releases from double-rice fields.

scholarly journals Carbon and nitrogen dynamics and greenhouse gas emissions in constructed wetlands treating wastewater: a review

2016 ◽  
Vol 20 (1) ◽  
pp. 109-123 ◽  
Author(s):  
M. M. R. Jahangir ◽  
K. G. Richards ◽  
M. G. Healy ◽  
L. Gill ◽  
C. Müller ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Empirical Evidence ◽  
Constructed Wetlands ◽  
Nutrient Removal ◽  
Management Practices ◽  
N2o Emissions ◽  
Knowledge Gaps ◽  
Ch4 Emissions ◽  
N Removal ◽  
C And N

Abstract. The removal efficiency of carbon (C) and nitrogen (N) in constructed wetlands (CWs) is very inconsistent and frequently does not reveal whether the removal processes are due to physical attenuation or whether the different species have been transformed to other reactive forms. Previous research on nutrient removal in CWs did not consider the dynamics of pollution swapping (the increase of one pollutant as a result of a measure introduced to reduce a different pollutant) driven by transformational processes within and around the system. This paper aims to address this knowledge gap by reviewing the biogeochemical dynamics and fate of C and N in CWs and their potential impact on the environment, and by presenting novel ways in which these knowledge gaps may be eliminated. Nutrient removal in CWs varies with the type of CW, vegetation, climate, season, geographical region, and management practices. Horizontal flow CWs tend to have good nitrate (NO3−) removal, as they provide good conditions for denitrification, but cannot remove ammonium (NH4+) due to limited ability to nitrify NH4+. Vertical flow CWs have good NH4+ removal, but their denitrification ability is low. Surface flow CWs decrease nitrous oxide (N2O) emissions but increase methane (CH4) emissions; subsurface flow CWs increase N2O and carbon dioxide (CO2) emissions, but decrease CH4 emissions. Mixed species of vegetation perform better than monocultures in increasing C and N removal and decreasing greenhouse gas (GHG) emissions, but empirical evidence is still scarce. Lower hydraulic loadings with higher hydraulic retention times enhance nutrient removal, but more empirical evidence is required to determine an optimum design. A conceptual model highlighting the current state of knowledge is presented and experimental work that should be undertaken to address knowledge gaps across CWs, vegetation and wastewater types, hydraulic loading rates and regimes, and retention times, is suggested. We recommend that further research on process-based C and N removal and on the balancing of end products into reactive and benign forms is critical to the assessment of the environmental performance of CWs.

scholarly journals Urban greenhouse gas emissions from the Berlin area: A case study using airborne CO2 and CH4 in situ observations in summer 2018

2020 ◽  
Author(s):  
Theresa Klausner ◽  
Mariano Mertens ◽  
Heidi Huntrieser ◽  
Michal Galkowski ◽  
Gerrit Kuhlmann ◽  
...  
Keyword(s):  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Urban Areas ◽  
Ghg Emissions ◽  
Capital City ◽  
Detailed Knowledge ◽  
Emission Flux ◽  
Gas Emissions ◽  
Mixing Ratios

&lt;p&gt;Urban areas are recognised as a significant source of greenhouse gas emissions (GHG), such as carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) and methane (CH&lt;sub&gt;4&lt;/sub&gt;). The total amount of urban GHG emissions, especially for CH&lt;sub&gt;4&lt;/sub&gt;, however, is not well quantified. Here we report on airborne in situ measurements using a Picarro G1301-m analyser aboard the DLR Cessna Grand Caravan to study GHG emissions downwind of the German capital city Berlin. In total, five aircraft-based mass balance experiments were conducted in July 2018 within the Urban Climate Under Change [UC]&lt;sup&gt;2&lt;/sup&gt; project. The detection and isolation of the Berlin plume was often challenging because of comparatively small GHG signals above variable atmospheric background concentrations. However, on July 20&lt;sup&gt;th&lt;/sup&gt; enhancements of up to 4 ppm CO&lt;sub&gt;2&lt;/sub&gt; and 21 ppb CH&lt;sub&gt;4&lt;/sub&gt; were observed over a horizontal extent of roughly 45 to 65 km downwind of Berlin. These enhanced mixing ratios are clearly distinguishable from the background and can partly be assigned to city emissions. The estimated CO&lt;sub&gt;2&lt;/sub&gt; emission flux of 1.39 &amp;#177; 0.75 t s&lt;sup&gt;-1 &lt;/sup&gt;is in agreement with current inventories, while the CH&lt;sub&gt;4&lt;/sub&gt; emission flux of 5.20 &amp;#177; 1.61 kg s&lt;sup&gt;-1&lt;/sup&gt; is almost two times larger than the highest reported value in the inventories. We localized the source area with HYSPLIT trajectory calculations and the high resolution numerical model MECO(n) (down to ~1 km), and investigated the contribution from sewage-treatment plants and waste deposition to CH&lt;sub&gt;4&lt;/sub&gt;, which are treated differently by the emission inventories. Our work highlights the importance of a) strong CH&lt;sub&gt;4&lt;/sub&gt; sources in the surroundings of Berlin and b) a detailed knowledge of GHG inflow mixing ratios to suitably estimate emission rates.&lt;/p&gt;

scholarly journals N2O emission and bacterial community dynamics during realization of the partial nitrification process

RSC Advances ◽  
2018 ◽  
Vol 8 (43) ◽  
pp. 24305-24311 ◽  
Author(s):  
Xiaolin Liu ◽  
Shou-Qing Ni ◽  
Wenshan Guo ◽  
Zhibin Wang ◽  
Hafiz Adeel Ahmad ◽  
...  
Keyword(s):  
Microbial Community ◽  
Bacterial Community ◽  
Greenhouse Gas ◽  
Community Dynamics ◽  
N2o Emission ◽  
Partial Nitrification ◽  
Community Succession ◽  
Bacterial Community Dynamics ◽  
Nitrification Process ◽  
Microbial Community Succession

In this study, greenhouse gas emissions and microbial community succession during the realization of the partial nitrification (PN) process were studied.

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