Effect of straw return on soil respiration and NEE of paddy fields under water-saving irrigation

The use of water-saving irrigation techniques has been encouraged in rice fields in response to irrigation water scarcity. Straw return is an important means of straw reuse. However, the environmental impact of this technology, e.g., nitrogen leaching loss, must be further explored. A two-year (2017–2018) experiment was conducted to investigate the vertical migration and leaching of nitrogen in paddy fields under water-saving and straw return conditions. Treatments included traditional flood irrigation (FI) and two water-saving irrigation regimes: rain-catching and controlled irrigation (RC-CI) and drought planting with straw mulching (DP-SM). RC-CI and DP-SM both significantly decreased the irrigation input compared with FI. RC-CI increased the rice yield by 8.23%~12.26%, while DP-SM decreased it by 8.98%~15.24% compared with FI. NH4+-N was the main form of the nitrogen leaching loss in percolation water, occupying 49.06%~50.97% of TN leaching losses. The NH4+-N and TN concentration showed a decreasing trend from top to bottom in soil water of 0~54 cm depth, while the concentration of NO3−-N presented the opposite behavior. The TN and NH4+-N concentrations in percolation water of RC-CI during most of the rice growth stage were the highest among treatments in both years, and DP-SM showed a trend of decreasing TN and NH4+-N concentrations. The NO3−-N concentrations in percolation water showed a regular pattern of DP-SM > RC-CI > FI during most of the rice growth stage. RC-CI and DP-SM remarkably reduced the amount of N leaching losses compared to FI as a result of the significant decrease of percolation water volumes. The tillering and jointing-booting stages were the two critical periods of N leaching (accounted for 74.85%~86.26% of N leaching losses). Great promotion potential of RC-CI and DP-SM exists in the lower reaches of the Yangtze River, China, and DP-SM needs to be further optimized.

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Organic fertilizer application increases the soil respiration and net ecosystem carbon dioxide absorption of paddy fields under water-saving irrigation

Environmental Science and Pollution Research ◽

10.1007/s11356-018-1285-y ◽

2018 ◽

Vol 25 (10) ◽

pp. 9958-9968 ◽

Cited By ~ 4

Author(s):

Shihong Yang ◽

Ya′nan Xiao ◽

Junzeng Xu

Keyword(s):

Carbon Dioxide ◽

Soil Respiration ◽

Organic Fertilizer ◽

Fertilizer Application ◽

Water Saving ◽

Paddy Fields ◽

Carbon Dioxide Absorption ◽

Ecosystem Carbon

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Simulation of Water Saving and Methane Mitigation Potential of Paddy Fields under Alternate Wetting and Drying Irrigation Regime in China

10.1109/agro-geoinformatics50104.2021.9530342 ◽

2021 ◽

Author(s):

Yidan Fan ◽

Zhan Tian ◽

Kai Wang ◽

Dongli Fan

Keyword(s):

Water Saving ◽

Paddy Fields ◽

Irrigation Regime ◽

Wetting And Drying ◽

Mitigation Potential ◽

Methane Mitigation ◽

Alternate Wetting And Drying

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Effects of Biochar Amendment on CO2 Emissions from Paddy Fields under Water-Saving Irrigation

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph15112580 ◽

2018 ◽

Vol 15 (11) ◽

pp. 2580 ◽

Cited By ~ 4

Author(s):

Shihong Yang ◽

Zewei Jiang ◽

Xiao Sun ◽

Jie Ding ◽

Junzeng Xu

Keyword(s):

Co2 Emissions ◽

Rice Yield ◽

Rice Paddy ◽

C Sequestration ◽

Sensitivity Coefficient ◽

Water Saving ◽

Paddy Fields ◽

Flood Irrigation ◽

Controlled Irrigation ◽

Biochar Amendment

The role of carbon pool of biochar as a method of long-term C sequestration in global warming mitigation is unclear. A two-year field study was conducted to investigate the seasonal variations of CO2 emissions from water-saving irrigation paddy fields in response to biochar amendment and irrigation patterns. Three biochar treatments under water-saving irrigation and one biochar treatment under flooding irrigation were studied, and the application rates were 0, 20, 40, and 40 t ha−1 and labeled as CI + NB (controlled irrigation and none biochar added), CI + MB (controlled irrigation and medium biochar added), CI + HB (controlled irrigation and high biochar added), and FI + HB (flood irrigation and high biochar added), respectively. Results showed that biochar application at medium rates (20 t ha−1) decreased CO2 emissions by 1.64–8.83% in rice paddy fields under water-saving irrigation, compared with the non-amendment treatment. However, the CO2 emissions from paddy fields increased by 4.39–5.43% in the CI + HB treatment, compared with CI + NB. Furthermore, the mean CO2 emissions from paddy fields under water-saving irrigation decreased by 2.22% compared with flood irrigation under the same amount of biochar application (40 t ha−1). Biochar amendment increased rice yield and water use efficiency by 9.35–36.30% and 15.1–42.5%, respectively, when combined with water-saving irrigation. The CO2 emissions were reduced in the CI + MB treatment, which then increased rice yield. The CO2 emissions from paddy fields were positively correlated with temperature. The highest value of the temperature sensitivity coefficient (Q10) was derived for the CI + MB treatment. The Q10 was higher under water-saving irrigation compared with flooding irrigation.

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Evaluation of Water-Storage and Water-Saving Potential for Paddy Fields in Gaoyou, China

Water ◽

10.3390/w10091176 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1176 ◽

Cited By ~ 1

Author(s):

Chuanjuan Wang ◽

Shaoli Wang ◽

Haorui Chen ◽

Jiandong Wang ◽

Yuan Tao ◽

...

Keyword(s):

Southern China ◽

Financial Burden ◽

Water Shortage ◽

Water Saving ◽

Paddy Fields ◽

Balance Model ◽

Agricultural Water ◽

Average Water ◽

Agricultural Water Resources ◽

Water Fee

In China, the stress on agricultural water resources is becoming increasingly severe. In response, a range of water-saving irrigation (WSI) policies and practices have been promoted to improve irrigation efficiency. In this study, a water-balance model in paddy fields was calibrated and validated using a 2-year field experimental dataset collected from an irrigated area in Gaoyou, China, in 2014–2015. The model was used to assess the effects of WSI practices and provides options for implementing water-price reforms. Results show that paddy fields effectively retain rainfall with utilization rates greater than 70% for both shallow wet irrigation (SWI) and shallow humidity-regulated irrigation (SHRI) scenarios. The estimated average water-saving rates from 1960 to 2015 using SWI and SHRI are 33.7% and 43%, respectively, which represent considerable reductions in water consumption. The benefits of WSI practices combined with water management policies are also evident. For example, conversion of irrigation water to industrial water yields a 3-year average water fee of 205.2 yuan/ha using SWI and 20.6 yuan/ha using SHRI, considerably reducing farmers’ financial burden for agricultural water supplies. In conclusion, we recommend the adoption of SWI and SHRI practices in southern China as a means of partially alleviating China’s water-shortage problem.

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The potential of vegetation indices: estimating methane emissions in paddy fields under nighttime warming and water saving conditions

Greenhouse Gases Science and Technology ◽

10.1002/ghg.1973 ◽

2020 ◽

Vol 10 (3) ◽

pp. 545-556

Author(s):

Zhang Zhen ◽

Lou Yunsheng ◽

Li Rui ◽

Ma Li ◽

Li Jun ◽

...

Keyword(s):

Vegetation Indices ◽

Methane Emissions ◽

Water Saving ◽

Paddy Fields ◽

Nighttime Warming

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How Inoculation with Arbuscular Mycorrhizal Fungi Impact on Soil Respiration?

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1073-1076.628 ◽

2014 ◽

Vol 1073-1076 ◽

pp. 628-631

Author(s):

Fang Ma ◽

Shu Juan Zhang ◽

Li Wang ◽

Dan Shan ◽

Xiao Feng Jiang ◽

...

Keyword(s):

Soil Respiration ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Root Biomass ◽

Arbuscular Mycorrhizal ◽

Net Photosynthesis ◽

Paddy Fields ◽

Shoot Biomass ◽

Respiratory Capacity ◽

P Content

Soil respiration can be altered by changing substance supply, respiratory capacity and the demand for the products. We carried out a field experiment in the northeast of China to understand how inoculation with arbuscular mycorrhizal fungi (AMF) alters soil respiration in paddy fields. Soil respiration and factors contributing to it were measured for paddy fields either inoculated or non-inoculated with AMF, with or without fertilization. We found that inoculation increased soil respiration, net photosynthesis of rice leaves, N and P content of rice shoots and the abundance of actinomyces and fungi in rhizosphere; while the negative effect was only observed on root biomass. We also found that fertilization decreased the responses of soil respiration, root biomass and the abundance of bacteria and fungi in rhizosphere to inoculation. However, it decreased the responses of net photosynthesis, shoot biomass and shoot N and P content to inoculation. Conclusively, AMF inoculation promoted soil respiration by enhancing substrate supply, respiratory capacity and the demand for products; while the impacts of inoculation were weakened by fertilization via respiration capacity and the demand for the products.

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Effects of Micropore Group Spacing and Irrigation Amount on Soil Respiration and Yield of Tomato with Microsprinkler Irrigation under Plastic Film in Greenhouse

Journal of Sensors ◽

10.1155/2021/6658059 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Mingzhi Zhang ◽

Xiaoqun Yan ◽

Zhenguang Lu ◽

Qingjun Bai ◽

Yushun Zhang ◽

...

Keyword(s):

Soil Respiration ◽

Respiration Rate ◽

Dynamic Balance ◽

Water Saving ◽

Plastic Film ◽

Irrigation Amount ◽

Yield Increase ◽

Soil Respiration Rate ◽

Tomato Yield ◽

Relationship Of

Microsprinkler irrigation under a plastic film in the greenhouse (MSPF) is a water-saving way which adopts the porous discharge form of a pipe under the plastic film. The effects of different micropore group spacings (L1:30 cm, L2: 50 cm) and irrigation amounts [I1: 0.7 Epan; I2: 1.0 Epan; and I3: 1.2 Epan (Epan is the diameter of 20 cm standard pan evaporation, mm)] of the MSPF on the soil respiration and yield of tomato were studied. A completely randomized trial design was used, and drip irrigation under plastic film (CK1) and microsprinkler irrigation (CK2) were also used as controls. The results showed that under the same irrigation amount, the soil respiration rate, tomato yield, and water use efficiency (WUE) of MSPF in spring and autumn are 8.09% and 6.74%, 19.39% and 4.54%, and 10.03% and 2.32% higher than those of CK1, respectively; they are significantly increased by 31.02% and 20.46%, 49.22% and 38.38%, and 58.05% and 34.66% compared with those of CK2, respectively, indicating that MSPF increased the amount of CO2 emission, but tomato yield and WUE were effectively improved, and a dynamic balance was reached among them. Compared with the 50 cm micropore group spacing, the spring and autumn tomato yields and WUE under the 30 cm micropore group spacing were significantly increased by 16.00% and 13.01% and 20.85% and 14.25%, respectively, and the micropore group spacing had no significant effect on the soil respiration rate in both root and nonroot zones. When the I increased from 0.7 Epan to 1.2 Epan, the soil respiration rate and yield in the root and nonroot zones of the spring and autumn tomatoes increased at first and then decreased, and the WUE showed a decreasing trend. The relationship of soil respiration rate between the nonroot and root zones obeys a logarithmic function, and the soil respiration rate in the nonroot zone has a quadratic curve relationship with the yield of tomato. This study can provide data support for the development of water-saving irrigation and yield increase of facility agricultural tomato and the analysis of the soil carbon cycling mechanism.

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