Zhang W.,Chinese Academy of Agricultural Sciences |
Xu M.,Chinese Academy of Agricultural Sciences |
Wang X.,Xinjiang Institute of Ecology and Geography |
Wang X.,The Interdisciplinary Center |
And 6 more authors.
Journal of Soils and Sediments | Year: 2012
Purpose: Although organic amendments have been recommended as one of the practices for crop production and soil carbon sequestration, little has been done to evaluate soil organic carbon (SOC) dynamics following long-term application of organic amendments. The objective of this research were to (1) assess the effect of long-term organic amendments on SOC dynamics in rice-based systems; (2) evaluate the relationship between soil carbon sequestration and carbon input based on various mineral and organic fertilization treatments. Materials and methods: A multi-sites analysis was conducted on four long-term experiments with double-rice (three sites) and rice-wheat (one site) cropping systems which started in the 1980s in Southern China. We selected three groups of treatments in common at each site: (1) control (no fertilizer), (2) mineral nitrogen-phosphorus with and without potassium (NPK/NP), and (3) the combined treatments of mineral NP/NPK with pig manure (M), green manure (G, Astragalus sinicus L.), rice straw (S), and/or their combinations. Harvestable crop biomass was annually recorded for all plots. SOC in topsoil was determined in 1-5 yearly intervals after rice harvest. Results and discussion: Analysis showed that organic amendments sustained or significantly increased carbon biomass, but had little effects on the coefficient of variance (CV) of the carbon biomass production compared with the mineral NPK/NP treatments. With additional carbon input, organic amendments increased SOC significantly by 7-45% after 25-28 years of fertilization compared with the mineral treatments. These combined treatments sequestered carbon at a rate from 0.20 to 0.48 t ha-1 year-1 under the double-rice and 0.70 to 0.88 t ha-1 year-1 under rice-wheat cropping system. The estimated annual SOC decomposition rate ranged from 0.15 to 0.82 t ha-1 at these studied sites. Our analyses revealed strong positive correlations between soil carbon sequestration and carbon input for all sites. Conclusions: We concluded that organic amendments applied as substitution and extra nutrients had significant effect on soil carbon sequestration and served as a carbon sink for the duration of the experiments. Paddy soil high in clay content had the potential to sequester more carbon. Soil carbon sequestration efficiency-declined with carbon input at some sites with loam soil texture, suggesting applying a large amount of organic amendments is not recommended as a sustainable agricultural management practice because of the high risk of non-point environment pollution. © 2012 Springer-Verlag.
Zhang H.-L.,China Agricultural University |
Bai X.-L.,China Agricultural University |
Xue J.-F.,China Agricultural University |
Chen Z.-D.,China Agricultural University |
And 2 more authors.
PLoS ONE | Year: 2013
Understanding greenhouse gases (GHG) emissions is becoming increasingly important with the climate change. Most previous studies have focused on the assessment of soil organic carbon (SOC) sequestration potential and GHG emissions from agriculture. However, specific experiments assessing tillage impacts on GHG emission from double-cropped paddy fields in Southern China are relatively scarce. Therefore, the objective of this study was to assess the effects of tillage systems on methane (CH4) and nitrous oxide (N2O) emission in a double rice (Oryza sativa L.) cropping system. The experiment was established in 2005 in Hunan Province, China. Three tillage treatments were laid out in a randomized complete block design: conventional tillage (CT), rotary tillage (RT) and no-till (NT). Fluxes of CH4 from different tillage treatments followed a similar trend during the two years, with a single peak emission for the early rice season and a double peak emission for the late rice season. Compared with other treatments, NT significantly reduced CH4 emission among the rice growing seasons (P<0.05). However, much higher variations in N2O emission were observed across the rice growing seasons due to the vulnerability of N2O to external influences. The amount of CH4 emission in paddy fields was much higher relative to N2O emission. Conversion of CT to NT significantly reduced the cumulative CH4 emission for both rice seasons compared with other treatments (P<0.05). The mean value of global warming potentials (GWPs) of CH4 and N2O emissions over 100 years was in the order of NT
PubMed | RAS Institute of Basic Biological Problems, Soil and Fertilizer Institute of Hunan Province, RAS Institute of Chemistry and Hunan University of Humanities, Science and Technology
Type: | Journal: Journal of environmental management | Year: 2016
Heavy metal mining includes several procedures producing water and solid wastes. These wastes may have high content of heavy metals and other pollutants. Usually, traditional technologies for purification of solid and liquid wastes are expensive and require a lot of special constructions. Recent investigations have shown that some Si-rich substances enable to regulate the mobility of pollutants in soil and water and enhance the plant resistance to its toxicity. Based on these findings, new way for purification of waste-waters and detoxification of pollutants can be elaborated. Laboratory test was conducted with contaminated solid and liquid wastes from Xikuangshan mine. In column and incubation tests, the contents and mobility of the following pollutants were evaluated in Si-treated and untreated samples: As, Cd, Co, Cr, Cu, Hg, Pb, Ni and Zn. The investigations have shown that the Si-rich substances can be used for filtration of contaminated waste-water. The concentrations of soluble pollutants were reduced by 5-10 times and more. The incubation tests with solid wastes and Si-rich compounds have demonstrated that some Si-based substances reduced the contaminant mobility by 2-4 times. The efficiency of tested substances depended on their solubility on Si. The data has demonstrated that some types of local materials including industrial wastes can be used for purification of waste-waters and detoxification of solid wastes.
Xu S.-Q.,China Agricultural University |
Xu S.-Q.,Key Laboratory of Farming System |
Zhang M.-Y.,China Agricultural University |
Zhang M.-Y.,Key Laboratory of Farming System |
And 6 more authors.
Pedosphere | Year: 2013
Tillage practices can potentially affect soil organic carbon (SOC) accumulation in agricultural soils. A 4-year experiment was conducted to identify the influence of tillage practices on SOC sequestration in a double-cropped rice (Oryza sativa L.) field in Hunan Province of China. Three tillage treatments, no-till (NT), conventional plow tillage (PT), and rotary tillage (RT), were laid in a randomized complete block design. Concentrations of SOC and bulk density (BD) of the 0-80 cm soil layer were measured, and SOC stocks of the 0-20 and 0-80 cm soil layers were calculated on an equivalent soil mass (ESM) basis and fixed depth (FD) basis. Soil carbon budget (SCB) under different tillage systems were assessed on the basis of emissions of methane (CH4) and CO2 and the amount of carbon (C) removed by the rice harvest. After four years of experiment, the NT treatment sequestrated more SOC than the other treatments. The SOC stocks in the 0-80 cm layer under NT (on an ESM basis) was as high as 129.32 Mg C ha-1, significantly higher than those under PT and RT (P < 0.05). The order of SOC stocks in the 0-80 cm soil layer was NT > PT > RT, and the same order was observed for SCB; however, in the 0-20 cm soil layer, the RT treatment had a higher SOC stock than the PT treatment. Therefore, when comparing SOC stocks, only considering the top 20 cm of soil would lead to an incomplete evaluation for the tillage-induced effects on SOC stocks and SOC sequestrated in the subsoil layers should also be taken into consideration. The estimation of SOC stocks using the ESM instead of FD method would better reflect the actual changes in SOC stocks in the paddy filed, as the FD method amplified the tillage effects on SOC stocks. This study also indicated that NT plus straw retention on the soil surface was a viable option to increase SOC stocks in paddy soils. © 2013 Soil Science Society of China.
Ji X.-H.,Soil and Fertilizer Institute of Hunan Province |
Ji X.-H.,Hunan Agricultural Environment Research Center |
Zheng S.-X.,Soil and Fertilizer Institute of Hunan Province |
Shi L.-H.,Soil and Fertilizer Institute of Hunan Province |
And 3 more authors.
Pedosphere | Year: 2011
A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dongting Lake area. The results showed that N concentration in the leachate did not differ significantly among the treatments of urea, controlled release N fertilizer and pig manure and that all these fertilizers produced higher total nitrogen (TN) concentrations in the leachate compared to the case where no fertilizer was applied. The TN leaching loss following urea treatment accounted for 2.28%, 0.66%, and 1.50% of the amount of N applied in the alluvial sandy loamy paddy soil (ASL), purple calcareous clayey paddy soil (PCC), and reddish-yellow loamy paddy soil (RYL), respectively. Higher TN loss was found to be correlated with the increased leachate volume in ASL compared with RYL, and the lowest TN loss was observed in the PCC, in which the lowest leachate volume and TN concentration were observed. Organic N and NH+ 4 -N were the major forms of N depleted through leachate, accounting for 56.8% and 39.7% of TN losses, respectively. Accordingly, soil-specific fertilization regimens are recommended; in particular, the maximum amount of fertilizer should be optimized for sandy soils with a high infiltration rate. To avoid a high N leaching loss from rice fields, organic N fertilizers such as urea or coated urea should primarily be used for surface topdressing or shallow-layer application and not for deep-layer application. © 2011 Soil Science Society of China.
Liu X.,China Agricultural University |
Xiao X.,Soil and Fertilizer Institute of Hunan Province |
Yang G.,Soil and Fertilizer Institute of Hunan Province |
Ren T.,China Agricultural University
Soil Science | Year: 2011
The soil-water retention curve (WRC), applied in hydrology, agronomy, and ecology, is an important soil parameter for assessing soil quality and soil functions. Agricultural practices influence WRC by modifying other soil properties, such as soil organic matter content and aggregation. In this study, we investigated the changes in WRC among aggregate fractions as related to fertilizer management in the 0-to 10-cm layer of a paddy soil. The long-term experiment was established in 1986 with five fertilizer treatments: no fertilizer, chemical fertilizer alone, rice residues plus chemical fertilizer, low manure rate plus chemical fertilizer, and high manure rate plus chemical fertilizer. The results demonstrated that at larger water suctions (pF >1.6), the shapes of WRC for different aggregate fractions were similar, but larger aggregates (>2 mm) retained more water than smaller ones (<2 mm). Intra-aggregate water retention capacity was closely related to the interaction of aggregate mineralogy and organic carbon content, as the larger aggregates had lower sand content and higher silt and organic carbon contents than the smaller ones. Under the intensive rice-rice-barley cropping system, joint application of organic materials and chemical fertilizer improved aggregate water retention capacity, but the change of aggregate water retention from chemical fertilizer alone was not significant. © 2011 by Lippincott Williams & Wilkins.
Ji X.,Soil and Fertilizer Institute of Hunan Province |
Liu S.,Soil and Fertilizer Institute of Hunan Province |
Huang J.,Soil and Fertilizer Institute of Hunan Province |
Bocharnikova E.,RAS Institute of Chemistry |
Matichenkov V.,RAS Institute of Basic Biological Problems
Chemosphere | Year: 2016
The contamination of agricultural areas by heavy metals has a negative influence on food quality and human health. Various remediation techniques have been developed for the removal and/or immobilization of heavy metals (HM) in contaminated soils. Phytoremediation is innovative technology, which has advantages (low cost, easy monitoring, high selectivity) and limitations, including long time for procedure and negative impact of contaminants on used plants. Greenhouse investigations have shown that monosilicic acid can be used for regulation of the HM (Cd, Cr, Pb and Zn) mobility in the soil-plant system. If the concentration of monosilicic acid in soil was increased from 0 to 20 mg L-1 of Si in soil solution, the HM bioavailability was increased by 30-150%. However, the negative influence on the barley by HM was reduced under monosilicic acid application. If the concentration of monosilicic acid was increased more than 20 mg L-1, the HM mobility in the soil was decreased by 40-300% and heavy metal uptake by plants was reduced 2-3 times. The using of the monosilicic acid may increase the phytoremediation efficiency. However the technique adaptation will be necessary for phytoremediation on certain areas. © 2016 Elsevier Ltd.
Yang Z.-P.,Soil and Fertilizer Institute of Hunan Province |
Yang Z.-P.,Hunan Agricultural University |
Xu M.-G.,Chinese Academy of Agricultural Sciences |
Zheng S.-X.,Soil and Fertilizer Institute of Hunan Province |
And 4 more authors.
Journal of Integrative Agriculture | Year: 2012
Soil physical properties are important indicators of the potential for agricultural production. Our objective was to evaluate the effects of long-term inputs of green manures on physical properties of a reddish paddy soil (Fe-Typic Hapli-Stagnic Anthrosols) under a double cropping system. The common cropping pattern before the study was early-late rice-fallow (winter). The field treatments included rice-rice-fallow (R-R-WF), rice-rice-rape (R-R-RP), rice-rice-Chinese milk vetch (R-R-MV), and rice-rice-ryegrass (R-R-RG). The rape, Chinese milk vetch and ryegrass were all incorporated as green manures 15 d before early rice transplanting during the following year. The soil bulk density in all green manure treatments was significantly reduced compared with the winter fallow treatment. Soil porosity with green manure applications was significantly higher than that under the winter fallow. The green manure treatments had higher 0.25-5 mm water stable aggregates and aggregates stabilities in the plow layer (0-15 cm depth) compared with the fallow treatment. The mean weight diameter (MWD) and normalized mean weight diameter (NMWD) of aggregates in the green manure treatment were larger than that with the winter fallow. Soil given green manure retained both a higher water holding capacity in the plow layer soil, and a larger volume of moisture at all matric potentials (-10, -33 and -100 kPa). We conclude that the management of double-rice fields in southern central China should be encouraged to use green manures along with chemical fertilizers to increase SOC content, improve soil physical properties and soil fertility. © 2012 Chinese Academy of Agricultural Sciences.
Liu Q.,Hunan Agricultural University |
Liu Q.,Soil and Fertilizer Institute of Hunan Province |
Li M.,Soil and Fertilizer Institute of Hunan Province |
Duan J.,Hunan Agricultural University |
And 2 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013
Contamination of suburban, agricultural soils with heavy metals draws great attention because of its potential threat to food safety and its detrimental effects on the ecosystem. The origins of soil heavy metals in the suburban interface are usually controlled by many factors, such as parent material, industrial activities, and agriculture. To decrease heavy metals pollution risks effectively in suburban areas and further to establish reliable protection measures, it is quite necessary to understand their sources and spatial patterns. The ordinary linear regression model (OLS) has been frequently used to analyze the relationship between soil heavy metals and their influential factors. However, OLS is only in a global or an average sense to estimate parameters, and it is unable to reflect spatial local variation or test spatial non-stationarity.Geographically weighted regression models (GWR) are a powerful tool for exploring spatial heterogeneity. The underlying idea of GWR is that parameters may be estimated anywhere in the study area given a dependent variable and a set of one or more independent variables which have been measured at known locations. Not only can it test spatial non-stationarity, but it can also provide the corresponding solutions. As a local model, GWR modeling has been applied in research on urban housing land prices and the spatial factors of economic development, but it has seldom been applied to the origins and spatial structure of soil heavy metals. A survey was conducted in this study to determine the possible sources of heavy metals in agricultural soils of the suburban area of Changsha. A total of 513 surface soil samples were collected, and the concentrations of Pb and Cd were analyzed. Typical influences on soil Pb and Cd concentration were identified from soil properties and geographic locations, such as soil pH, organic matter, alkali-hydro nitrogen, rapidly available phosphorus, rapidly available potassium, slowly available potassium, the distance from cropland to town, the distance from cropland to settlement, the distance from cropland to industrial construction sites, and the distance from cropland to a river. The OLS and GWR were applied to determine the relationships among both the influential factors and their spatial structure. The results indicate that spatial autocorrelations were detected for Pb and Cd. The high-high spatial clusters districts had high concentrations of Pb and Cd and were the most important regions for controlling the pollution risk of Pb and Cd in agricultural soil of the suburban area of Changsha. The GWR models for Pb and Cd had a better goodness-of-fit than OLS models and indicated the same tendency of spatial correlation between the Pb and Cd measured values with their estimated values. Soil Pb was highly significantly and positively related with Cd. The concentrations of soil pH, organic matter, alkali-hydro nitrogen and rapidly available phosphorus were the important influential factors for the content of Pb and Cd. The distance from cropland to river, from cropland to town, and from cropland to construction sites also had some influence on the concentrations of Pb and Cd in the agricultural soils of suburban Changsha.
PubMed | Hunan Normal University and Soil and Fertilizer Institute of Hunan Province
Type: | Journal: Journal of environmental management | Year: 2016
In this study, the efficiency and mechanism of aqueous phosphate removal by magnetic biochar derived from water hyacinth (MW) were investigated. The MW pyrolyzed at 450C (MW450) exhibited the most prominent phosphate sorption capacity, which was estimated to be 5.07mgg