scholarly journals Geochemical conditions of natural wetland and paddy fields in the Poyang Lake area, China

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Evgeniya Soldatova ◽  
Yihui Dong ◽  
Jiale Li ◽  
Irina Ivanova ◽  
Andrey Toropov ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Irrigation Water ◽  
Paddy Soils ◽  
Paddy Fields ◽  
Geochemical Barrier ◽  
Natural Wetland ◽  
Geochemical Conditions ◽  
Geochemical Barriers ◽  
Soils And Sediments ◽  
Wetland Water

Abstract During the last several decades, wetlands are losing their ecological functions due to increasing anthropogenic loads. One of these functions is the ability to bind elements forming geochemical barriers. The research aimed to study the geochemical conditions of natural wetlands and flooded paddy fields (artificial wetlands) in the Ganjiang River basin to trace geochemical barriers. The research approach was based on a comprehensive analysis of water and aqueous extracts from bottom sediments and paddy soils, including chemical and mineral composition. The samples were collected in November 2019, during the dry season at the end of harvesting. Chemical analysis was performed using standard methods for natural substances: titrimetry, photometry, ionic chromatography, high-temperature oxidation, ICP-MS, and ICP-AES. The mineral composition of the soils and sediments was determined by XRD. It was found that the main physicochemical characteristics (TDS, pH, main component concentrations) of the natural wetland water correspond to the surface water of the study area, whereas the irrigation water is similar to shallow groundwater. The content of trace elements in the irrigation water is higher than in the natural wetland water. Generally, the trace element composition of the natural wetland water corresponds to the geochemical background of the study area. Analysis of the mineral and chemical composition of the paddy soils and sediments indicates the geochemical barriers that accumulate a wide range of elements. In the natural wetland, the geochemical barrier is likely associated with a decrease in oxygen content and advective transport rate in the sediments, whereas in the paddy fields, the precipitation of clay minerals in the soil profile forms the geochemical barrier related to a decrease in filtration properties and advection–diffusion transport. Graphic abstract

Cultivation of rice for animal feed with circulated irrigation of treated municipal wastewater for enhanced nitrogen removal: comparison of cultivation systems feeding irrigation water upward and downward

2015 ◽  
Vol 72 (4) ◽  
pp. 579-584 ◽  
Author(s):  
A. Muramatsu ◽  
H. Ito ◽  
A. Sasaki ◽  
A. Kajihara ◽  
T. Watanabe
Keyword(s):  
Nitrogen Removal ◽  
Irrigation Water ◽  
Rice Plant ◽  
Municipal Wastewater ◽  
Animal Feed ◽  
Paddy Fields ◽  
Treated Wastewater ◽  
Human Consumption ◽  
Cultivation System ◽  
Treated Municipal Wastewater

To achieve enhanced nitrogen removal, we modified a cultivation system with circulated irrigation of treated municipal wastewater by using rice for animal feed instead of human consumption. The performance of this modified system was evaluated through a bench-scale experiment by comparing the direction of circulated irrigation (i.e. passing through paddy soil upward and downward). The modified system achieved more than three times higher nitrogen removal (3.2 g) than the system in which rice for human consumption was cultivated. The removal efficiency was higher than 99.5%, regardless of the direction of circulated irrigation. Nitrogen in the treated municipal wastewater was adsorbed by the rice plant in this cultivation system as effectively as chemical fertilizer used in normal paddy fields. Circulated irrigation increased the nitrogen released to the atmosphere, probably due to enhanced denitrification. Neither the circulation of irrigation water nor its direction affected the growth of the rice plant and the yield and quality of harvested rice. The yield of rice harvested in this system did not reach the target value in normal paddy fields. To increase this yield, a larger amount of treated wastewater should be applied to the system, considering the significant amount of nitrogen released to the atmosphere.

scholarly journals Intra- versus inter-site macroscale variation in biogeochemical properties along a paddy soil chronosequence

2012 ◽  
Vol 9 (3) ◽  
pp. 1237-1251 ◽  
Author(s):  
C. Mueller-Niggemann ◽  
A. Bannert ◽  
M. Schloter ◽  
E. Lehndorff ◽  
L. Schwark
Keyword(s):  
Paddy Soil ◽  
Tidal Flat ◽  
Land Reclamation ◽  
Zhejiang Province ◽  
Rice Cultivation ◽  
Carbon Accumulation ◽  
Paddy Soils ◽  
Paddy Fields ◽  
Wetland Rice ◽  
Tidal Wetland

Abstract. In order to assess the intrinsic heterogeneity of paddy soils, a set of biogeochemical soil parameters was investigated in five field replicates of seven paddy fields (50, 100, 300, 500, 700, 1000, and 2000 yr of wetland rice cultivation), one flooded paddy nursery, one tidal wetland (TW), and one freshwater site (FW) from a coastal area at Hangzhou Bay, Zhejiang Province, China. All soils evolved from a marine tidal flat substrate due to land reclamation. The biogeochemical parameters based on their properties were differentiated into (i) a group behaving conservatively (TC, TOC, TN, TS, magnetic susceptibility, soil lightness and colour parameters, δ13C, δ15N, lipids and n-alkanes) and (ii) one encompassing more labile properties or fast cycling components (Nmic, Cmic, nitrate, ammonium, DON and DOC). The macroscale heterogeneity in paddy soils was assessed by evaluating intra- versus inter-site spatial variability of biogeochemical properties using statistical data analysis (descriptive, explorative and non-parametric). Results show that the intrinsic heterogeneity of paddy soil organic and minerogenic components per field is smaller than between study sites. The coefficient of variation (CV) values of conservative parameters varied in a low range (10% to 20%), decreasing from younger towards older paddy soils. This indicates a declining variability of soil biogeochemical properties in longer used cropping sites according to progress in soil evolution. A generally higher variation of CV values (>20–40%) observed for labile parameters implies a need for substantially higher sampling frequency when investigating these as compared to more conservative parameters. Since the representativeness of the sampling strategy could be sufficiently demonstrated, an investigation of long-term carbon accumulation/sequestration trends in topsoils of the 2000 yr paddy chronosequence under wetland rice cultivation restricted was conducted. Observations cannot be extrapolated to global scale but with coastal paddy fields developed on marine tidal flat substrates after land reclamation in the Zhejiang Province represent a small fraction (<1%) of the total rice cropping area. The evolutionary trend showed that the biogeochemical signatures characteristic for paddy soils were fully developed in less than 300 yr since onset of wetland rice cultivation. A six-fold increase of topsoil TOC suggests a substantial gain in CO2 sequestration potential when marine tidal wetland substrate developed to 2000 yr old paddy soil.

scholarly journals The pH-based ecological coherence of active canonical methanotrophs in paddy soils

2020 ◽  
Vol 17 (6) ◽  
pp. 1451-1462 ◽  
Author(s):  
Jun Zhao ◽  
Yuanfeng Cai ◽  
Zhongjun Jia
Keyword(s):  
Soil Ph ◽  
Rice Paddy ◽  
Low Ph ◽  
Paddy Soils ◽  
Paddy Fields ◽  
Type I ◽  
Type Ii ◽  
High Ph ◽  
Niche Specialization ◽  
Rice Paddy Soils

Abstract. Soil pH is considered one of the main determinants of the assembly of globally distributed microorganisms that catalyze the biogeochemical cycles of carbon (C) and nitrogen (N). However, direct evidence for niche specialization of microorganisms in association with soil pH is still lacking. Using methane-oxidizing bacteria (methanotrophs) as a model system of C cycling, we show that pH is potentially the key driving force selecting for canonical γ (type I) and α (type II) methanotrophs in rice paddy soils. DNA-based stable isotope probing (DNA-SIP) was combined with high-throughput sequencing to reveal the taxonomic identities of active methanotrophs in physiochemically contrasting soils from six different paddy fields across China. Following microcosm incubation amended with 13CH4, methane was primarily consumed by Methylocystis-affiliated type II methanotrophs in soils with a relatively low pH (5.44–6.10), whereas Methylobacter- or Methylosarcina-affiliated type I methanotrophs dominated methane consumption in soils with a high pH (7.02–8.02). Consumption of 13CH4 contributed 0.203 % to 1.25 % of soil organic C, but no significant difference was observed between high-pH and low-pH soils. The fertilization of ammonium nitrate resulted in no significant changes in the compositions of 13C-labeled methanotrophs in the soils, although significant inhibition of methane oxidation activity was consistently observed in low-pH soils. Mantel analysis further validated that soil pH, rather than other parameters tested, had significant correlation to the variation in active methanotrophic compositions across different rice paddy soils. These results suggest that soil pH might have played a pivotal role in mediating the niche differentiation of ecologically important aerobic methanotrophs in terrestrial ecosystems and imply the importance of such niche specialization in regulating methane emissions in paddy fields following increasingly intensified input of anthropogenic N fertilizers.

Relationship between mineral composition or soil texture and available silicon in alluvial paddy soils on the Shounai Plain, Japan

2009 ◽  
Vol 55 (2) ◽  
pp. 300-308 ◽  
Author(s):  
Shuhei Makabe ◽  
Ken-Ichi Kakuda ◽  
Yuka Sasaki ◽  
Tadashi Ando ◽  
Hiroshi Fujii ◽  
...  
Keyword(s):  
Mineral Composition ◽  
Soil Texture ◽  
Paddy Soils

DEVELOPMENT OF MOVIES AS THE TEACHING TOOL ON THE MOVEMENT OF IRRIGATION WATER IN PADDY FIELDS MANAGED UNDER VARIOUS CULTIVATION METHODS

2015 ◽  
Vol 76 (15) ◽  
Author(s):  
Nakamura Kazumasa ◽  
Sakai Miki ◽  
Koshiyama Naoko
Keyword(s):  
Irrigation Water ◽  
Large Scale ◽  
Farm Management ◽  
Direct Seeding ◽  
Paddy Fields ◽  
Farm Households ◽  
Farm Household ◽  
Teaching Tool ◽  
Cultivation Method ◽  
Local Farmers

Hokkaido, the northern most of the four major islands of Japan, is an important rice-producing area. In Hokkaido there are some areas where the numbers of farm households are decreasing and the management scale for one farm household is increasing. In such areas, labor shortage occurs if only the conventional transplant cultivation is used. The necessity for introducing direct-seeding cultivation method has been increasing because by using this method it is possible to save labor. In some of the areas with increasing number of large-scale farm management, the farms employ large lot paddy fields and install underground irrigation facilities, which are useful in direct-seeding cultivation, to improve work efficiency. It is thought that it requires 2 to 3 years for the farmers to learn to effectively use the underground irrigation facilities because use of such facilities is a new experience for many farmers. The authors conducted observation of the groundwater level and depth of ponding in the paddy fields where the above-mentioned improvements were done, and made a movie using the obtained data. The movie is also useful for the authors in understanding the inflow and outflow of the groundwater, which are phenomena occurring underground. At a meeting of local farmers, the authors explained the movement of irrigation water by using this movie. The authors expect that the explanation using the movie will promote the farmers' understanding in effectively using the underground irrigation facilities.

Runoff pattern of pesticides from paddy fields in the catchment area of Rikimaru reservoir, Japan

1994 ◽  
Vol 30 (7) ◽  
pp. 137-144 ◽  
Author(s):  
O. Nagafuchi ◽  
T. Inoue ◽  
S. Ebise
Keyword(s):  
Water Management ◽  
Linear Correlation ◽  
Irrigation Water ◽  
Catchment Area ◽  
Paddy Fields ◽  
Raw Water ◽  
Irrigation Water Management ◽  
Pesticide Runoff

Patterns of runoff behaviours in concentration and loading of pesticides from paddy fields have been intensively observed in the catchment area of Rikimaru Reservoir, mainly during the regular application period of fungicide during the summer. The runoff characteristics of three pesticides (pyroquilone, isoprothiolane and flutolanil) from paddy fields to the drainage river differed from one another due to their water solubilities. The linear correlation between the water solubilities and the amounts of pesticide runoff loadings from paddy fields to the drainage river and reservoir during dry weather days was confirmed as good on log-log paper. To reduce the risk to raw water for drinking in the reservoir the method of irrigation water management for paddy fields should be improved.

Impact of cultivation year, nitrogen fertilization rate and irrigation water quality on soil salinity and soil nitrogen in saline-sodic paddy fields in Northeast China

2015 ◽  
Vol 154 (4) ◽  
pp. 632-646 ◽  
Author(s):  
L. H. HUANG ◽  
Z. W. LIANG ◽  
D. L. SUAREZ ◽  
Z.C. WANG ◽  
M. M. WANG ◽  
...  
Keyword(s):  
Soil Ph ◽  
Soil Salinity ◽  
Irrigation Water ◽  
Northeast China ◽  
Paddy Fields ◽  
Inorganic N ◽  
N Application ◽  
Total N ◽  
Application Rates ◽  
Soil Inorganic N

SUMMARYSaline-sodic soils are widely distributed in the western Songnen Plain of Northeast China and planting rice has been found to be an effective and feasible approach for improving saline-sodic soil and increasing food production. Assessment of the effectiveness and sustainability of this method requires monitoring of the changes in soil salinity and nutrient content. The objective of the current study was to investigate the changes of soil salinity and nitrogen (N) contents over 1, 3, 6 and 9 years of cultivation, four application rates of N (N0: no N, N1: 100 kg N/ha, N2: 200 kg N/ha and N3: 300 kg N/ha) and two irrigation water types: ground water irrigation (GWI) and river water irrigation (RWI). Salinity and N contents of soil and water samples were analysed before planting and after harvest throughout the experiments. Soil pH and electrical conductivity (EC), especially in the surface layer of 0–40 cm depth, decreased with years of cultivation with both GWI and RWI, while soil inorganic N and total N contents increased. Moreover, with increasing N application rates, soil inorganic N and total N contents increased significantly in the 0–20 cm soil layer. Increasing N application had little effect on soil pH and EC. Reclaiming and planting rice promoted desalination of the surface and formation of a fertile tillage layer in saline-sodic paddy fields. In terms of irrigation and drainage in saline-sodic paddy fields, both soil salinity and N contents increased. Soil total salinity increased annually by 34 and 12·8 kg/ha, and inorganic N contents increased annually by 9 and 13·5 kg/ha with GWI and RWI, respectively. Therefore, comprehensive agricultural practices should be adopted for improving and cropping rice in saline-sodic paddy fields.

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