In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey w...In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.展开更多
Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(...Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.展开更多
This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative ...This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative sequencing method was employed to study the response characteristics of soil bacterial community composition and species absolute abundance to environmental factors under three fertilization treatments[chemical fertilizer(NPK),organic fertilizer replacing 30%of chemical fertilizer(30M,estimated in terms of pure nitrogen,same below),and organic fertilizer replacing 60%of chemical fertilizer(60M)]for two consecutive years.Furthermore,the changes of bacterial metabolic functions of different fertilization treatments were predicted by PICRUSt2.The results showed that replacing chemical fertilizer with organic fertilizer at different proportions significantly increased the total nitrogen(TN),total potassium(TK),hydrolyzable nitrogen(HN),soil organic carbon(SOC),and significantly decreased the soil bulk density(SBD).Moreover,60M demonstrated better performance than 30M.Different fertilization treatments did not cause significant difference in soil bacterial richness index(Chao1)or diversity index(Shannon)but significantly affected bacterial community composition and species abundance.Particularly,60M significantly increased the abundance of 227 species,and it increased the total bacterial abundance by 25.30%and 56.58%compared with NPK and 30M,respectively.Redundancy analysis and Spearman correlation analysis revealed that SOC,TN,and AK were the key factors for shaping specific bacterial community structures under different fertilization treatments.The 60M treatment significantly increased the abundance of bacterial species involved in xenobiotic biodegradation and metabolism,amino acid metabolism,and lipid metabolism,thus improving the metabolic functions of soil microorganisms.展开更多
Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescenc...Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescence sensor for quantitative detection of Cd^(2+)in paddy rice based on inner filter effect(IFE)combined with enzyme inhibition mechanism.The AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine(oxTMB)catalyzed by horseradish peroxidase(HRP)enzymes.Without addition of Cd^(2+),the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and oxTMB.With addition of Cd^(2+),HRP enzyme activity was inhibited by Cd^(2+),leading to the decreased oxTMB,resulting in the enhance upconversion fluorescence intensity.As a result,the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd^(2+)in a wide range from 0.5μmol/L to 6μmol/L and the limit of detection(LOD)was 24.6 n mol/L.In addition,our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd^(2+)detection in paddy rice in 30 min.展开更多
[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Trit...[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.展开更多
[Objective] The research aimed to explore how to use the soil reasonably,prevent the degradation of soil fertility,maintain soil fertility,improve the ecological environment of paddy field and improve the soil product...[Objective] The research aimed to explore how to use the soil reasonably,prevent the degradation of soil fertility,maintain soil fertility,improve the ecological environment of paddy field and improve the soil productivity of paddy field from the cultivation aspect.[Method] Taking kenjiandao 10 as the material,the variation laws of root weight,soil physical and chemical characteristics,soil enzyme,straw decomposition rate,soil temperature,microorganism of rice under the planting patterns of water-saving pro...展开更多
[Objective] The purpose of this study was to investigate the role of breeding Misgurnus anguillicaudatus in paddy field in vertical distribution of sediment particles. [Method] Using chemically stable glass beads as t...[Objective] The purpose of this study was to investigate the role of breeding Misgurnus anguillicaudatus in paddy field in vertical distribution of sediment particles. [Method] Using chemically stable glass beads as tracers, the effects of Misgurnus anguillicaudatus bioturbation on the vertical distribution of sediment particles in paddy field were investigated, and the bioturbation role of benthic fish in the coupling process of benthic-pelagic interface was discussed. [Result] After ten days of Misgurnus anguillicaudatus bioturbation, 43.2% of the glass beads on the surface were transferred downwardly with the maximum distance of 7.5 cm, and the vertical transportation rate of sediment particles was 7.676×10-4g-1·cm-2·d-1. At a depth of 6 cm, 39.7% and 9.9% of the glass beads were respectively transferred upwards and downwards, to the maximum distanc of 4.5 cm and 5.1 cm, respectively; and the vertical transportation rates of sediment particles were 7.597×10-4g-1·cm-2·d-1 and 1.894×10-4g-1·cm-2·d-1, respectively. [Conclusion] Misgurnus anguillicaudatus bioturbation could promote the circulation and transformation of nutrients at water/soil interface through affecting the vertical distribution of sediment particles.展开更多
[Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism（microflora,biomass,and special physiological groups） of paddy field.[Method]The expe...[Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism（microflora,biomass,and special physiological groups） of paddy field.[Method]The experiments were conducted locally and quantitatively in field,using plate count and MPN methods.[Result]In the microflora of paddy soil tested,the quantity of bacteria is the largest,followed by actinomycetes and fungus.Compared with the control paddy fields,in rice-fish paddy fields the quantities of bacteria,actinomycetes and fungus were higher,at significance level P 〈0.05,P 〈0.01,and P 〈0.01 respectively.The microbial biomass C and N in rice-fish paddy fields is remarkably higher than those in control paddy fields,both at significance level P 〈0.01;the microbial biomass P in rice-fish paddy fields is higher than that in control paddy fields,but at significance level P 〈0.05.Benthic fish promotes the growth of soil azotobacter,cellulolytic bacteria,nitrobacteria,sulfur bacteria,and ammonifying bacteria,restricts the reproduction of nitrate reducing bacteria and sulfate reducing bacteria.[Conclusion]The benthic fish had important effects on microflora,microbial biomass,and special microorganism physiological groups of paddy soil,improves the living conditions of soil microorganisms,promotes the soil fertility and bio-chemical activity,which is beneficial for improving the supply ability of soil nutrients such as N,P,S,as well as the efficiency of nutrient utilization.展开更多
[Objective] The research aimed to investigate the bioturbation effects of Branchiura sowerbyi （Tubificidae） on the vertical transport of sedimentary particles in paddy field,and explore the bioturbation effects and ...[Objective] The research aimed to investigate the bioturbation effects of Branchiura sowerbyi （Tubificidae） on the vertical transport of sedimentary particles in paddy field,and explore the bioturbation effects and mechanism of benthic Annelida in coupling process of benthic-pelagic interface.[Method]Using chemically stable glass beads as tracers,the vertical transport of sedimentary particles in paddy field was analyzed comparatively with and without B.sowerbyi.[Result]After 10 days＇ bioturbation of B.sowerbyi,41.3% of the glass beads on the surface of sedimentary particles were transferred downward to the maximum depth of 9.4 cm,and the vertical transportation rate of sedimentary particles was 1.370×10-3/（g·cm2·d）. 25.8% and 17.3% of glass beads at a depth of 6 cm were transferred upwards and downwards respectively after bioturbation,to the maximum depth of 5.2 and 2.7 cm respectively,and the vertical transportation rates of sedimentary particles were 8.557×10-4 and 5.738×10-4/（g·cm2·d） respectively.[Conclusion]The sedimentary particles on the surface and deep layer of the paddy field were vertically shifted by the physical activities of B.sowerbyi,thus changed the sedimentary environment.展开更多
The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has ...The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by＂forest-vil age-terrace-river＂, including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.展开更多
The low temperature cold damage of paddy rice is the major agricultural meteorological disaster in Ningxia.The real-time monitoring and early warning of low temperature cold damage are very important to develop the ad...The low temperature cold damage of paddy rice is the major agricultural meteorological disaster in Ningxia.The real-time monitoring and early warning of low temperature cold damage are very important to develop the advantages,avoid the disadvantages and reduce the disaster losses.Based on the prior researches on the low temperature cold damage indexes of paddy rice,we improved the small grid reckoning method of temperature and the reckoning precision with the support of GIS.By using the multitemporal remote sensing data,the paddy rice planting zone was picked.The calculation results of low temperature cold damage monitoring indexes were combined with the paddy rice planting zone,which judged the grade distribution and zone of low temperature cold damage in real time.Meanwhile,the low temperature cold damage of paddy rice was done the early warning,and the automatic monitoring early warning system was developed by using the weather forecast data.This method and system were applied to the business works,and the monitoring and early warning products of paddy rice low temperature cold damage business were made.The monitoring results basically corresponded with the actual situation,and the better monitoring service effect was gained.展开更多
The change rules of the fertility of red soil paddy under the long-term different fertilization were investigated, and the reasonable fertilization mode to improve the fertility of red soil paddy was discussed. There ...The change rules of the fertility of red soil paddy under the long-term different fertilization were investigated, and the reasonable fertilization mode to improve the fertility of red soil paddy was discussed. There were eight treatments in the experiment, which were CK （no fertilizer）, N1 （N of 60 kg/hm2）, N2 （N of 120 kg/hm2）, N1P1 （P2O5 of 30 kg/hm2）, N2P1 and N2P2 （P2O5 of 60 kg/hm2）, N2P2K1 （K2O of 45 kg/hm2） and N2P2K2 （K2O of 90 kg/hm2）. All treatments were applied with composted cow dung as the base fertilizer, and each season 50% of the straws were returned to the field. The content of organic matter, nitrogen, phosphorous and potassium in red soil paddy was observed continuously for ten years and their correlation was also analyzed. Under cow manure and straw return to field, organic matter content of different treatments was positively correlated to year. After ten years, organic matter content of surface soil rose by 2.5 g/kg averagely with an annual increase of 0.25 g/kg. Total nitrogen content and organic matter content of different treatments presented similar variation trend. Total nitrogen content rose by 0.35 g/kg averagely with an annual increase of 0.035 g/kg. Among all the treatments, N2P2K1 and N2P2K2 showed the biggest increase, which went up by 0.052 and 0.48 g/kg, respectively. Phosphorous-free treatments （CK, N1, N2） had steady phosphorous content with irregular changes of different years. Total phosphorous content of phosphorous treatments increased year by year. Total phosphorous content of N1P1 and N2P1 rose by 0.008 g/kg every year. The increment range of total phosphorous content of N2P2, N2P2K1 and N2P2K2 was 0.012 -0.013 g/kg annually. Available phosphorous content varied vastly among different treatments. Available phosphorous content of organic fertilizer treatments basically remained stable with irregular changes of different years. Available phosphorous content of organic fertilizer with phosphate fertilizer treatments rose year by year. Available phosphorous content of N1P1 and N2P1 rose approximately by 0.8 mg/kg. Available phosphorous content of N2P2, N2P2K1 and N2P2K2 rose approximately by 1.4 -1.6 mg/kg annually. Potassium fertilizer amount greatly affected total potassium content. Total potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） remained the same. Total potassium content of N2P2K markedly increased year by year, which was 0.014 g/kg annually. Rapid available potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） showed a decreasing trend. With phosphate fertilizer, rapid available potassium content of N2P2K1 and N2P2K2 remained the same or increased year by year. The change trend of slow available potassium content and rapid available potassium content resembled. Rational allocation of organic fertilizer, nitrogenous fertilizer, phosphate fertilizer and potassium fertilizer can significantly improve soil fertility and economic benefits. Balanced fertilization is an effective measure for soil fertility improvement as it＇s shown that nutrients of surface soil accumulate annually.展开更多
[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were ...[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were collected from Jiangxi Province and used as experimental materials to investigate single and com- petitive adsorption and desorption behaviors of cadmium and lead by batch equilib- rium method. The environmental risk of the presence of cadmium and lead in paddy soils was assessed using distribution coefficients. [Result] Under equal ratio condi- tions, the adsorption capacity of lead by two types of paddy soils was higher than that of cadmium, and the adsorption rate in waterloggogenic paddy soil was higher than that in gleyed paddy soil. The desorption capacity of cadmium by two types of paddy soils was higher than that of lead, and the desorption rate in gleyed paddy soil was higher than that in waterloggogenic paddy soil. Under competitive condi- tions, the adsorption capacity of cadmium and lead by paddy soils was significantly reduced compared with single ion system, while the desorption rate was remarkably improved. The potential environmental risk of cadmium contamination was greater than that of lead in paddy soils. Moreover, environmental risks of cadmium and lead were reduced with the increase of pH, which increased significantly under the coex- istence state. [Conclusion] In the coexistence of cadmium and lead, cadmium con- tamination should be controlled and avoided compared with lead contamination in paddy soils.展开更多
[Objective]The research aimed to investigate the bioturbation effects of benthic fish Misgurnus anguillicaudatus on phosphorus dynamic in overlying water of paddy field,as well as to explore the bioturbation mechanism...[Objective]The research aimed to investigate the bioturbation effects of benthic fish Misgurnus anguillicaudatus on phosphorus dynamic in overlying water of paddy field,as well as to explore the bioturbation mechanism.[Method]Based on simulation experiment,the phosphorus contents in overlying water were analyzed comparatively with and without Misgurnus anguillicaudatus by the using of ion chromatography and spectrophotometry.[Result]The concentrations of total phosphorus(TP),dissolved total phosphorus(DTP)and particular phosphorus(PP)in bioturbation group had no significant differences with those in control group in initial stage of experiment,and became significantly higher than control group in middle and late stages of experiment(P<0.05). The PP/TP ratios in bioturbation group were bigger than those in control group,the increase of TP concentration in bioturbation group was mainly due to the increase of PP. The ratios of dissolved inorganic phosphorus(DIP) to DTP (DIP/DTP) were significantly bigger than those in control group in middle and late stages of experiment(P<0.05).[Conclusion]The benthic fish had bioturbation effects on phosphorus in overlying water of paddy field,which increased the available phosphorus for rice growth.展开更多
Due to the growing concern about the agricultural phosphorus (P) losses pollution, an in-depth understanding of P in paddy soils of China would be helpful in providing a national perspective of the environmental impac...Due to the growing concern about the agricultural phosphorus (P) losses pollution, an in-depth understanding of P in paddy soils of China would be helpful in providing a national perspective of the environmental impact of P cycling and fertility on China's farms. In this study, we evaluated the P storage and the P density of paddy soils in China, characterized the spatial variations of P among the subgroups of paddy soils and soil regions in China, and evaluated the P data using GIS-based analysis, which included a newly compiled 1:1 000 000 digital soil map of China, and using 1 490 soil profiles. The available and total P densities of paddy soils were 6.7 and 698.5 g m -3 , respectively. Overall in China, the total P storage within 1 m of paddy soils was estimated to be 330.2 Tg. The P density of paddy soils varied substantially with subgroups due to the different soil water regimes such as groundwater table and soil drainage. The P availability in paddy soils, especially in surface layer, was higher in high temperature and precipitation areas. Further research is needed to examine more anthropogenic impact factors, such as increasing use of chemical fertilizer.展开更多
This study was conducted to investigate the dissipation pattern and runoff of herbicides to the river basin from the paddy fields. Pesticide paddy field model(PADDY) was applied to predict herbicide concentration in p...This study was conducted to investigate the dissipation pattern and runoff of herbicides to the river basin from the paddy fields. Pesticide paddy field model(PADDY) was applied to predict herbicide concentration in paddy fields. A field study was conducted in a paddy farm of Higashi Hiroshima City, Hiroshima Prefecture, Japan in the year of 2003 paddy season. The herbicides were mefenacet, thiobencarb, and bensulfuron methyl. The sample water was analyzed by using gas chromatography and HPLC after solid phase extraction. Predicted dissipation rate of thiobencarb in paddy water was higher(DT_ 50 = 4 36) than that measured, with a lower k value(-0 069). Two weeks after application no thiobencarb was detected in the drainage channel and down stream. In the down stream, thiobencarb was detected until 3 d after application, with a range of 0 02% to 0 08% of applied herbicide. The predicted dissipation rate(k) and half-life(DT_ 50 ) of mefenacet was not significantly different from that of measured. In the drainage channel, upstream and downstream mefenacet was found during the whole study period. In downstream, the maximum concentration of mefenacet was present 0 61% of applied in the paddy field on 3DAH. The dissipation rate(k) of BSM varied from -0 0860 to -0 1059 to with half-life(DT_ 50 ) 3 5 and 2 84 d. In upstream water, no BSM was detected except trace amounts(0 01 μg/L) at 3 d after application. However, in the drainage channel 8%, 6% and 1 58% of applied BSM was present at 0, 1 and 3 d after application respectively. In the down stream, the highest concentration was 1 06%, shortly after application.展开更多
The relationship of the chemical compositions in the paddy kernel to the paddy's moisture-adsorption cracking rate is studied by multivariate linear regression analysis, and the results show that the contents o...The relationship of the chemical compositions in the paddy kernel to the paddy's moisture-adsorption cracking rate is studied by multivariate linear regression analysis, and the results show that the contents of starch (x5) and protein (x4) have greater effect on the cracking rate (y), the duality linear regression equation is y=296.84 - 2.2lx5- 8.32x4, the significance level is 0.014, and the effect of starch content is greater than that of protein. Generally, the contents of starch, protein and amylose are negatively correlated to the cracking rate.展开更多
A field experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejiang Province to elucidate the effect of excess P application on some importan...A field experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejiang Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P (15 kg P hm-2) could increase the content of soil available P at the tillering stage of early rice, the contents of N, P and K in the shoots of early rice at primary growth stages, and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains, which was mainly related to the higher contents of reduced, non-reduced and total sugar in the shoots at the heading stage. And early rice supplied with excessive P could not yield more than that applied with adequate P, due to the reduction in the valid grain percentage and weight per thousand grains.In addition, onestime excess P supply at a rate as high as 90 kg P hm-2 could not improve the soil P fertility in case the soil available P content was lower than the initial (3.74 mg kg-1 soil) after an early rice-late rice rotation, and made a decline in the grain yield increased by per kilogram fertilizer P. Thus, one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.展开更多
[Objective] To provide a scientific basis for the management of Cd contamination, the status of Cd contamination in paddy soil of Guangxi Province, as well as the effect of silicon fertilization on Cd content in brown...[Objective] To provide a scientific basis for the management of Cd contamination, the status of Cd contamination in paddy soil of Guangxi Province, as well as the effect of silicon fertilization on Cd content in brown rice, was investigated. [Method] A total of 157 topsoil（0-20 cm） samples were collected from the major rice-growing paddy fields in Guangxi Province. The Cd contents in the topsoil samples were determined. The paddy soil environment quality and potential ecological risk were evaluated by single factor index and potential ecological index methods. In addition, in the Cd-contaminated paddy fields, the effects of different silicon fertilization treatments（no application（CK）, soil application of 750 kg/hm^2 silicon fertilizer（S）, leaf application of 1 500 L/hm^2 0.2% nanometer silicon（L）, soil application of 750 kg/hm^2 silicon fertilizer ＋ leaf application of 1 500 L/hm^2 0.2% nanometer silicon（SL）） on Cd content in brown rice were investigated. [Result] The total Cd contents in the 157 topsoil samples from paddy fields of Guangxi Province ranged from 0.02 to 7.33 mg/kg with an average content of 0.53 mg/kg. The Cd contents in 35.03% of the topsoil samples exceeded the grade II of national soil environment quality standards, and the topsoil samples were dominated by moderate and mild Cd contamination. Different silicon fertilization treatment all significantly reduced the Cd content in brown rice（P〈0.05）. In the treatment III, the Cd content in brown rice was lowest. Compared with that in the CK group, the Cd content in brown rice in the treatment III was reduced by 73.45%, in the treatment II was reduced by 62.07%, and in the treatment I was reduced by 34.48%. [Conclusion] The Cd in paddy fields of Guangxi Province showed a moderate to high ecological risk,and rational application of silicon fertilizer could effectively reduce the Cd content in brown rice.展开更多
[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable d...[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.展开更多
基金Supported by the Special Study on Mineral Resources Planning in Changchun City(No.JM-2020-11-13594)Jilin Agricultural Geological Survey Project(No.12120105111208)。
文摘In order to identify the nutrient level and environmental quality of paddy fields in Wanchang area,and to provide scientific basis and technical support for planting rice in Wanchang area, the soil geochemicalsurvey was carried out, 30 samples were collected from paddy soil in Wanchang area, and 20 elements(indicators) were analyzed. The characterization of the elemental content of soils in the study area was carriedout, and the geochemical level for soil nutrients, the geochemical level for the soil environment, and thecomprehensive geochemical level of soil quality were evaluated. The results showed that the average valuesof K content and pH of the soil in the study area were smaller than the background values of Jilin Province,and the average values of 18 elements including N, P, Ca, S, Pb, Zn etc. were bigger than the backgroundvalues of Jilin Province. The results of the evaluation of soil single element nutrient in the study area showedthat the available state nutrient levels of Mn, Zn, Cu, and K increased compared with the total amounts ofnutrients level, with Cu increasing the most;the available state nutrient level of N, P, B, and Mo decreasedcompared with the total amounts of nutrients level, with Mo decreasing the most. The comprehensive levelof soil nutrients geochemistry in paddy fields was mainly Level III (medium), accounting for 53.33%, andthe low abundance level was caused by the lack of P element;the comprehensive level of soil environmentalgeochemistry was mainly Level I (clean), accounting for 96.67%, with only slight pollution caused byCd. The comprehensive geochemical level of soil quality was mainly Level II, accounting for 66.67%.Suggestions were put forward for the rational utilization of soil resources in paddy fields in the study area.
基金supported by the National Natural Science Foundation of China(32171683)the Shenzhen Science and Technology Program,China(JCYJ20220530145606015)+4 种基金the Agricultural and Social Development Project of Guangzhou Municipal Science and Technology Bureau,China(202206010058)the Special Fund for Agro-scientific Research in the Public Interest of China(201503122)the Natural Science Foundation of Guangdong Province,China(2020A1515010494)the Yangfan Innovative&Entrepreneurial Research Team Project,China(2015YT02H032)the Zhang Hong-da Science Research Fund of Sun Yat-sen University,China。
文摘Winter planting green manures in southern China effectively improve soil properties and rice production through microbial community construction.However,the effects of soil communities of arbuscular mycorrhizal fungi(AMF)from different winter planting green manures on the soil properties and post-cropping rice production remain unclear.In this study,the soil AMF communities of three common winter planting patterns in southern China,winter fallow,winter ryegrass(Lolium multiflorum L.),and winter Chinese milk vetch(Astragalus sinicus L.),were explored and their effects on post-cropping rice production were investigated.Compared with winter fallow,the winter ryegrass and winter Chinese milk vetch patterns could alleviate soil acidification,significantly increase soil AMF spore density,and improve the soil AMF community structure.Based on sterilized soil,rice production indicators such as thousandseed weight,theoretical yield,and the grain amylose and total sugar contents of rice inoculated with AMF spores from winter Chinese milk vetch soil were 6.68–53.57%higher than those without AMF inoculation.Rice panicle weight,seed setting rate,and theoretical yield were 15.38–22.71%higher in the treatment with AMF spores from winter ryegrass soil than in the treatments with no AMF inoculation.In addition,the protein,amylose,and total sugar contents of rice grains were 14.92,104.82,and 802.23 mg kg^(–1),respectively,which were 31.31,14.25 and 34.47%higher than those without AMF inoculation.The AMF community dominated by Glomus and Acaulospora in winter Chinese milk vetch had a more positive effect on the improvement of rice yield,while the AMF community dominated by Glomus in winter ryegrass soil was more conducive to rice quality improvement.These findings have revealed the critical role of AMF communities from green manure in rice production,which lays the theoretical basis for a promising strategy to promote the sustainable development of southern winter agriculture.
文摘This study aimed to explore the effect of different proportions of organic fertilizer replacing chemical fertilizer on the bacterial community and metabolic function in paddy fields.The 16S rRNA absolute quantitative sequencing method was employed to study the response characteristics of soil bacterial community composition and species absolute abundance to environmental factors under three fertilization treatments[chemical fertilizer(NPK),organic fertilizer replacing 30%of chemical fertilizer(30M,estimated in terms of pure nitrogen,same below),and organic fertilizer replacing 60%of chemical fertilizer(60M)]for two consecutive years.Furthermore,the changes of bacterial metabolic functions of different fertilization treatments were predicted by PICRUSt2.The results showed that replacing chemical fertilizer with organic fertilizer at different proportions significantly increased the total nitrogen(TN),total potassium(TK),hydrolyzable nitrogen(HN),soil organic carbon(SOC),and significantly decreased the soil bulk density(SBD).Moreover,60M demonstrated better performance than 30M.Different fertilization treatments did not cause significant difference in soil bacterial richness index(Chao1)or diversity index(Shannon)but significantly affected bacterial community composition and species abundance.Particularly,60M significantly increased the abundance of 227 species,and it increased the total bacterial abundance by 25.30%and 56.58%compared with NPK and 30M,respectively.Redundancy analysis and Spearman correlation analysis revealed that SOC,TN,and AK were the key factors for shaping specific bacterial community structures under different fertilization treatments.The 60M treatment significantly increased the abundance of bacterial species involved in xenobiotic biodegradation and metabolism,amino acid metabolism,and lipid metabolism,thus improving the metabolic functions of soil microorganisms.
基金financially supported by the National Natural Science Foundation of China(32202132,32172229)Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Priority Academic Program Development of Jiangsu Higher Educations(PAPD)。
文摘Cadmium ion(Cd^(2+))detection technology plays a prominent role in food safety and human health.Herein,we designed and constructed an 2-aminoethyl dihydrogen phosphate(AEP)@upconversion nanoparticles(UCNPs)fluorescence sensor for quantitative detection of Cd^(2+)in paddy rice based on inner filter effect(IFE)combined with enzyme inhibition mechanism.The AEP modification UCNPs can offer a stable fluorescence donor at 658 nm and be quenched by the oxidized tetramethylbenzidine(oxTMB)catalyzed by horseradish peroxidase(HRP)enzymes.Without addition of Cd^(2+),the fluorescence of AEP@UCNPs fluorescence sensor was weaken due to the IFE between AEP@UCNPs and oxTMB.With addition of Cd^(2+),HRP enzyme activity was inhibited by Cd^(2+),leading to the decreased oxTMB,resulting in the enhance upconversion fluorescence intensity.As a result,the fluorescence intensity signal at 658 nm of the IFE-based AEP@UCNPs fluorescence sensor increased linearly with the increase in Cd^(2+)in a wide range from 0.5μmol/L to 6μmol/L and the limit of detection(LOD)was 24.6 n mol/L.In addition,our proposed IFE-based AEP@UCNPs fluorescence sensor can achieve Cd^(2+)detection in paddy rice in 30 min.
基金Supported by the National Natural Science Foundation of China(21067003,51364015)the National High-Tech Research and Development Program of China(2012BAC11B07)the Jiangxi Natural Science Foundation(20114BAB203024)~~
文摘[Objective] The effects of yttrium nitrate （YNO3） on biomass and antioxi- dant systems of paddy rice （Yttrium （Y）; Oxidative stress; Dismutases （SOD）; Per- oxidases （POD）, Catalases （CAT）, Paddy rice （Triticum aestivum）） together with the occurrences of Y in soils were investigated to assess its ecotoxicological effects on plant. [Method]Y solutions with various concentrations were sprinkled on soil sam- ples, which were well mixed and then put into culture dishes to culture paddy rice seeds for further evaluation. [Result] The results indicated that 25-100 mg/kg Y treatments significantly increased the biomass （total weight, root weight, shoot weight and leaf weight）, chlorophyll （CHL） content and protein content of paddy rice, whereas 200-800 mg/kg Y treatments had a converse effect. Similarly, biomarker for the antioxidant systems including superoxide dismutases （SOD）, peroxidases （POD） and catalases （CAT） all exhibited similar trends in both shoots and roots of paddy rice. At the same time, the malonaldehyde （MDA） content increased at from 25 to 100 mg/kg and decreased with concentrations of Y from 100 to 800 mg/kg in both shoots and roots of paddy rice. This indicated that Y could stimulate the growth of plant at low concentration, but inhibit the growth at relatively high concen- tration. [Conclusion] The levels of Y were 641＋49, 328_＋16 and 473_＋40 mg/kg in soils collected from mining area, farmland and navel orange orchard respectively. The levels of Y in the investigated area were higher than the benefit level （100 mg/kg）, which could cause low biomass as well as low activity of SOD, POD and CAT in paddy rice. Therefore, a more careful use of Y is necessary in crop management.
基金Supported by The National Project of Science & Technique Achievement Transformation(2008GB2B200089)Heilongjiang Nongken Zongju Science & Technological Key Project(HNKXI-01-06-01)Heilongjiang Nongken Zongju Science & Technological Development Project(NKKF06-10-1)~~
文摘[Objective] The research aimed to explore how to use the soil reasonably,prevent the degradation of soil fertility,maintain soil fertility,improve the ecological environment of paddy field and improve the soil productivity of paddy field from the cultivation aspect.[Method] Taking kenjiandao 10 as the material,the variation laws of root weight,soil physical and chemical characteristics,soil enzyme,straw decomposition rate,soil temperature,microorganism of rice under the planting patterns of water-saving pro...
基金Supported by the Project of Talent Exploitation Foundation of Jilin ProvinceScientific and Technological Developing Scheme of Jilin Province(20060577)+5 种基金the Science and Technology Planning Project of Education Department of Jilin Province(200716920061132006117)High-level Overseas Returned Talents by Ministry of Personnel,Ministry of Personnelthe Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(2005-546)Science Foundation for Young Teachers of Northeast Normal University(20050406)~~
文摘[Objective] The purpose of this study was to investigate the role of breeding Misgurnus anguillicaudatus in paddy field in vertical distribution of sediment particles. [Method] Using chemically stable glass beads as tracers, the effects of Misgurnus anguillicaudatus bioturbation on the vertical distribution of sediment particles in paddy field were investigated, and the bioturbation role of benthic fish in the coupling process of benthic-pelagic interface was discussed. [Result] After ten days of Misgurnus anguillicaudatus bioturbation, 43.2% of the glass beads on the surface were transferred downwardly with the maximum distance of 7.5 cm, and the vertical transportation rate of sediment particles was 7.676×10-4g-1·cm-2·d-1. At a depth of 6 cm, 39.7% and 9.9% of the glass beads were respectively transferred upwards and downwards, to the maximum distanc of 4.5 cm and 5.1 cm, respectively; and the vertical transportation rates of sediment particles were 7.597×10-4g-1·cm-2·d-1 and 1.894×10-4g-1·cm-2·d-1, respectively. [Conclusion] Misgurnus anguillicaudatus bioturbation could promote the circulation and transformation of nutrients at water/soil interface through affecting the vertical distribution of sediment particles.
基金Supported by Human Resources and Social Security Department Students Abroad Science and Technology Activities Preferred Foundation (Human and Social Council Issued 2008-86)Talent Development Fund Project in Jilin Province (Jilin 2007-259)+6 种基金Jilin Province Science and Technology Development Project (20060577 )Technology Project Jilin Provincial Ministry of Education (200943520061132007169)The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry (2005-546 )Science Foundation of Changchun Teachers University (2009002)Northeast Normal University Natural Science Foundation for Young Scholar (20050406)~~
文摘[Objective]The research aimed to explore the bioturbation effects of benthic fish Misgurnus anguillicaudatus on soil microorganism（microflora,biomass,and special physiological groups） of paddy field.[Method]The experiments were conducted locally and quantitatively in field,using plate count and MPN methods.[Result]In the microflora of paddy soil tested,the quantity of bacteria is the largest,followed by actinomycetes and fungus.Compared with the control paddy fields,in rice-fish paddy fields the quantities of bacteria,actinomycetes and fungus were higher,at significance level P 〈0.05,P 〈0.01,and P 〈0.01 respectively.The microbial biomass C and N in rice-fish paddy fields is remarkably higher than those in control paddy fields,both at significance level P 〈0.01;the microbial biomass P in rice-fish paddy fields is higher than that in control paddy fields,but at significance level P 〈0.05.Benthic fish promotes the growth of soil azotobacter,cellulolytic bacteria,nitrobacteria,sulfur bacteria,and ammonifying bacteria,restricts the reproduction of nitrate reducing bacteria and sulfate reducing bacteria.[Conclusion]The benthic fish had important effects on microflora,microbial biomass,and special microorganism physiological groups of paddy soil,improves the living conditions of soil microorganisms,promotes the soil fertility and bio-chemical activity,which is beneficial for improving the supply ability of soil nutrients such as N,P,S,as well as the efficiency of nutrient utilization.
基金Supported by National Natural Science Foundation of China(31070421 )Human Resources and Social Security Department Students Abroad Science and Technology Activities Preferred Foundation (Human and Social Council Issued 2008-86)+8 种基金Talent Development Fund Project in Jilin Province (Jilin 2007-259)Jilin Province Science and Technology Development Project (20060577 )Technology Project Jilin Provincial Ministry of Education (20094352006113 20071692010150)The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2005-546)Changchun Normal University Natural Science Foundation(2009002)Northeast Normal University Natural Science Foundation for Young Scholar(20050406)~~
文摘[Objective] The research aimed to investigate the bioturbation effects of Branchiura sowerbyi （Tubificidae） on the vertical transport of sedimentary particles in paddy field,and explore the bioturbation effects and mechanism of benthic Annelida in coupling process of benthic-pelagic interface.[Method]Using chemically stable glass beads as tracers,the vertical transport of sedimentary particles in paddy field was analyzed comparatively with and without B.sowerbyi.[Result]After 10 days＇ bioturbation of B.sowerbyi,41.3% of the glass beads on the surface of sedimentary particles were transferred downward to the maximum depth of 9.4 cm,and the vertical transportation rate of sedimentary particles was 1.370×10-3/（g·cm2·d）. 25.8% and 17.3% of glass beads at a depth of 6 cm were transferred upwards and downwards respectively after bioturbation,to the maximum depth of 5.2 and 2.7 cm respectively,and the vertical transportation rates of sedimentary particles were 8.557×10-4 and 5.738×10-4/（g·cm2·d） respectively.[Conclusion]The sedimentary particles on the surface and deep layer of the paddy field were vertically shifted by the physical activities of B.sowerbyi,thus changed the sedimentary environment.
基金Supported by Project of Ministry of Human Resources and Social Security~~
文摘The ecology system of Hani Terraced Paddy Fields is the typical repre-sentative of the ecological agriculture in the southwestern mountainous areas of our country. After long-term development, Hani ecology system has developed, cored by＂forest-vil age-terrace-river＂, including paddy cultivation system, forests and ecologi-cal maintenance, folk culture and construction of water facilities. This research ex-plored the details of the structure and functions of the ecology system of Hani ter-raced fields. And il ustrates that the system is a new model of agriculture ecological civilization and deserves further study and more applications.
基金Supported by The New Technology Popularization Item of China Meteorological Administration(CMATG005M44)~~
文摘The low temperature cold damage of paddy rice is the major agricultural meteorological disaster in Ningxia.The real-time monitoring and early warning of low temperature cold damage are very important to develop the advantages,avoid the disadvantages and reduce the disaster losses.Based on the prior researches on the low temperature cold damage indexes of paddy rice,we improved the small grid reckoning method of temperature and the reckoning precision with the support of GIS.By using the multitemporal remote sensing data,the paddy rice planting zone was picked.The calculation results of low temperature cold damage monitoring indexes were combined with the paddy rice planting zone,which judged the grade distribution and zone of low temperature cold damage in real time.Meanwhile,the low temperature cold damage of paddy rice was done the early warning,and the automatic monitoring early warning system was developed by using the weather forecast data.This method and system were applied to the business works,and the monitoring and early warning products of paddy rice low temperature cold damage business were made.The monitoring results basically corresponded with the actual situation,and the better monitoring service effect was gained.
基金Supported by the Natural Science Foundation of Guagnxi(2015GXNSFBA139098)the Special Fund for Science and Technology of the Ministry of Agriculture of China(201203030-07-02)+1 种基金the Fund Program of Guangxi Academy of Agricultural Sciences(2015YT30,2014JZ18,2013YF06)the Science and Technology Planning Project of Qingxiu District,Nanjing(2012N15)~~
文摘The change rules of the fertility of red soil paddy under the long-term different fertilization were investigated, and the reasonable fertilization mode to improve the fertility of red soil paddy was discussed. There were eight treatments in the experiment, which were CK （no fertilizer）, N1 （N of 60 kg/hm2）, N2 （N of 120 kg/hm2）, N1P1 （P2O5 of 30 kg/hm2）, N2P1 and N2P2 （P2O5 of 60 kg/hm2）, N2P2K1 （K2O of 45 kg/hm2） and N2P2K2 （K2O of 90 kg/hm2）. All treatments were applied with composted cow dung as the base fertilizer, and each season 50% of the straws were returned to the field. The content of organic matter, nitrogen, phosphorous and potassium in red soil paddy was observed continuously for ten years and their correlation was also analyzed. Under cow manure and straw return to field, organic matter content of different treatments was positively correlated to year. After ten years, organic matter content of surface soil rose by 2.5 g/kg averagely with an annual increase of 0.25 g/kg. Total nitrogen content and organic matter content of different treatments presented similar variation trend. Total nitrogen content rose by 0.35 g/kg averagely with an annual increase of 0.035 g/kg. Among all the treatments, N2P2K1 and N2P2K2 showed the biggest increase, which went up by 0.052 and 0.48 g/kg, respectively. Phosphorous-free treatments （CK, N1, N2） had steady phosphorous content with irregular changes of different years. Total phosphorous content of phosphorous treatments increased year by year. Total phosphorous content of N1P1 and N2P1 rose by 0.008 g/kg every year. The increment range of total phosphorous content of N2P2, N2P2K1 and N2P2K2 was 0.012 -0.013 g/kg annually. Available phosphorous content varied vastly among different treatments. Available phosphorous content of organic fertilizer treatments basically remained stable with irregular changes of different years. Available phosphorous content of organic fertilizer with phosphate fertilizer treatments rose year by year. Available phosphorous content of N1P1 and N2P1 rose approximately by 0.8 mg/kg. Available phosphorous content of N2P2, N2P2K1 and N2P2K2 rose approximately by 1.4 -1.6 mg/kg annually. Potassium fertilizer amount greatly affected total potassium content. Total potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） remained the same. Total potassium content of N2P2K markedly increased year by year, which was 0.014 g/kg annually. Rapid available potassium content of no-potassium treatments （CK, N1, N2, N1P1, N2P1 and N2P2） showed a decreasing trend. With phosphate fertilizer, rapid available potassium content of N2P2K1 and N2P2K2 remained the same or increased year by year. The change trend of slow available potassium content and rapid available potassium content resembled. Rational allocation of organic fertilizer, nitrogenous fertilizer, phosphate fertilizer and potassium fertilizer can significantly improve soil fertility and economic benefits. Balanced fertilization is an effective measure for soil fertility improvement as it＇s shown that nutrients of surface soil accumulate annually.
基金Supported by Science and Technology Research Project of Jiangxi Education Department(GJJ14289)Science and Technology Research Project of Environmental Protection Department of Jiangxi Province(JXHBKJ2013-4)Special Fund for Visiting Scholars from the Development Program for Middle-aged and Young Teachers in Colleges of Jiangxi Province(GJGH[2014]N0.15)
文摘[Objective] This study aimed to investigate the adsorption and desorption characteristics of cadmium and lead in typical paddy soils of Jiangxi Province. [Method] Gleyed paddy soil and waterloggogenic paddy soil were collected from Jiangxi Province and used as experimental materials to investigate single and com- petitive adsorption and desorption behaviors of cadmium and lead by batch equilib- rium method. The environmental risk of the presence of cadmium and lead in paddy soils was assessed using distribution coefficients. [Result] Under equal ratio condi- tions, the adsorption capacity of lead by two types of paddy soils was higher than that of cadmium, and the adsorption rate in waterloggogenic paddy soil was higher than that in gleyed paddy soil. The desorption capacity of cadmium by two types of paddy soils was higher than that of lead, and the desorption rate in gleyed paddy soil was higher than that in waterloggogenic paddy soil. Under competitive condi- tions, the adsorption capacity of cadmium and lead by paddy soils was significantly reduced compared with single ion system, while the desorption rate was remarkably improved. The potential environmental risk of cadmium contamination was greater than that of lead in paddy soils. Moreover, environmental risks of cadmium and lead were reduced with the increase of pH, which increased significantly under the coex- istence state. [Conclusion] In the coexistence of cadmium and lead, cadmium con- tamination should be controlled and avoided compared with lead contamination in paddy soils.
基金Supported by Human Resources and Social Security Department Students Abroad Science and Technology Activities Preferred Foundation (Human and Social Council Issued 2008-86)Talent Development Fund Project in Jilin Province (Jilin 2007-259)+6 种基金Jilin Province Science and Technology Development Project (20060577 )Technology Project Jilin Provincial Ministry of Education (20094352006113 2007169)The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry ( 2005-546 )Science Foundation of Changchun Teachers University (2009002)Northeast Normal University Natural Science Foundation for Young Scholar (20050406)~~
文摘[Objective]The research aimed to investigate the bioturbation effects of benthic fish Misgurnus anguillicaudatus on phosphorus dynamic in overlying water of paddy field,as well as to explore the bioturbation mechanism.[Method]Based on simulation experiment,the phosphorus contents in overlying water were analyzed comparatively with and without Misgurnus anguillicaudatus by the using of ion chromatography and spectrophotometry.[Result]The concentrations of total phosphorus(TP),dissolved total phosphorus(DTP)and particular phosphorus(PP)in bioturbation group had no significant differences with those in control group in initial stage of experiment,and became significantly higher than control group in middle and late stages of experiment(P<0.05). The PP/TP ratios in bioturbation group were bigger than those in control group,the increase of TP concentration in bioturbation group was mainly due to the increase of PP. The ratios of dissolved inorganic phosphorus(DIP) to DTP (DIP/DTP) were significantly bigger than those in control group in middle and late stages of experiment(P<0.05).[Conclusion]The benthic fish had bioturbation effects on phosphorus in overlying water of paddy field,which increased the available phosphorus for rice growth.
基金Project supported by the National Key Basic Research Program (973 Program) of China (No. 2007CB407206)the National Natural Science Foundation of China (No. 40621001)the Frontier Project of the Chinese Academy of Sciences (No. ISSASIP0715)
文摘Due to the growing concern about the agricultural phosphorus (P) losses pollution, an in-depth understanding of P in paddy soils of China would be helpful in providing a national perspective of the environmental impact of P cycling and fertility on China's farms. In this study, we evaluated the P storage and the P density of paddy soils in China, characterized the spatial variations of P among the subgroups of paddy soils and soil regions in China, and evaluated the P data using GIS-based analysis, which included a newly compiled 1:1 000 000 digital soil map of China, and using 1 490 soil profiles. The available and total P densities of paddy soils were 6.7 and 698.5 g m -3 , respectively. Overall in China, the total P storage within 1 m of paddy soils was estimated to be 330.2 Tg. The P density of paddy soils varied substantially with subgroups due to the different soil water regimes such as groundwater table and soil drainage. The P availability in paddy soils, especially in surface layer, was higher in high temperature and precipitation areas. Further research is needed to examine more anthropogenic impact factors, such as increasing use of chemical fertilizer.
文摘This study was conducted to investigate the dissipation pattern and runoff of herbicides to the river basin from the paddy fields. Pesticide paddy field model(PADDY) was applied to predict herbicide concentration in paddy fields. A field study was conducted in a paddy farm of Higashi Hiroshima City, Hiroshima Prefecture, Japan in the year of 2003 paddy season. The herbicides were mefenacet, thiobencarb, and bensulfuron methyl. The sample water was analyzed by using gas chromatography and HPLC after solid phase extraction. Predicted dissipation rate of thiobencarb in paddy water was higher(DT_ 50 = 4 36) than that measured, with a lower k value(-0 069). Two weeks after application no thiobencarb was detected in the drainage channel and down stream. In the down stream, thiobencarb was detected until 3 d after application, with a range of 0 02% to 0 08% of applied herbicide. The predicted dissipation rate(k) and half-life(DT_ 50 ) of mefenacet was not significantly different from that of measured. In the drainage channel, upstream and downstream mefenacet was found during the whole study period. In downstream, the maximum concentration of mefenacet was present 0 61% of applied in the paddy field on 3DAH. The dissipation rate(k) of BSM varied from -0 0860 to -0 1059 to with half-life(DT_ 50 ) 3 5 and 2 84 d. In upstream water, no BSM was detected except trace amounts(0 01 μg/L) at 3 d after application. However, in the drainage channel 8%, 6% and 1 58% of applied BSM was present at 0, 1 and 3 d after application respectively. In the down stream, the highest concentration was 1 06%, shortly after application.
文摘The relationship of the chemical compositions in the paddy kernel to the paddy's moisture-adsorption cracking rate is studied by multivariate linear regression analysis, and the results show that the contents of starch (x5) and protein (x4) have greater effect on the cracking rate (y), the duality linear regression equation is y=296.84 - 2.2lx5- 8.32x4, the significance level is 0.014, and the effect of starch content is greater than that of protein. Generally, the contents of starch, protein and amylose are negatively correlated to the cracking rate.
文摘A field experiment with an early rice-late rice rotation was carried out on a paddy soil derived from red soil in the southern part of Zhejiang Province to elucidate the effect of excess P application on some important characteristics of soil properies and its relation to nutrient status and grain yields of rice crops.The experimental results indicated that adequate fertilizer P (15 kg P hm-2) could increase the content of soil available P at the tillering stage of early rice, the contents of N, P and K in the shoots of early rice at primary growth stages, and the grain yield of early rice by increasing valid ears per hectare and weight per thousand grains, which was mainly related to the higher contents of reduced, non-reduced and total sugar in the shoots at the heading stage. And early rice supplied with excessive P could not yield more than that applied with adequate P, due to the reduction in the valid grain percentage and weight per thousand grains.In addition, onestime excess P supply at a rate as high as 90 kg P hm-2 could not improve the soil P fertility in case the soil available P content was lower than the initial (3.74 mg kg-1 soil) after an early rice-late rice rotation, and made a decline in the grain yield increased by per kilogram fertilizer P. Thus, one-time excess P supply should not be adopted for soils with a large P fixation capacity like the paddy soils derived from red soils.
基金Supported by Guangxi Scientific Research and Technological Development Projects(GKG1123001-9B)Fundamental Research Funds of Guangxi Academy of Agricultural Sciences(GNK2013YZ19,GNK2015YT32)~~
文摘[Objective] To provide a scientific basis for the management of Cd contamination, the status of Cd contamination in paddy soil of Guangxi Province, as well as the effect of silicon fertilization on Cd content in brown rice, was investigated. [Method] A total of 157 topsoil（0-20 cm） samples were collected from the major rice-growing paddy fields in Guangxi Province. The Cd contents in the topsoil samples were determined. The paddy soil environment quality and potential ecological risk were evaluated by single factor index and potential ecological index methods. In addition, in the Cd-contaminated paddy fields, the effects of different silicon fertilization treatments（no application（CK）, soil application of 750 kg/hm^2 silicon fertilizer（S）, leaf application of 1 500 L/hm^2 0.2% nanometer silicon（L）, soil application of 750 kg/hm^2 silicon fertilizer ＋ leaf application of 1 500 L/hm^2 0.2% nanometer silicon（SL）） on Cd content in brown rice were investigated. [Result] The total Cd contents in the 157 topsoil samples from paddy fields of Guangxi Province ranged from 0.02 to 7.33 mg/kg with an average content of 0.53 mg/kg. The Cd contents in 35.03% of the topsoil samples exceeded the grade II of national soil environment quality standards, and the topsoil samples were dominated by moderate and mild Cd contamination. Different silicon fertilization treatment all significantly reduced the Cd content in brown rice（P〈0.05）. In the treatment III, the Cd content in brown rice was lowest. Compared with that in the CK group, the Cd content in brown rice in the treatment III was reduced by 73.45%, in the treatment II was reduced by 62.07%, and in the treatment I was reduced by 34.48%. [Conclusion] The Cd in paddy fields of Guangxi Province showed a moderate to high ecological risk,and rational application of silicon fertilizer could effectively reduce the Cd content in brown rice.
基金Supported by the Important Science and Technology Program for Agriculture of Zhejiang Province(2009C2001-TZ)the Taizhou Research and Development of Applied Technology,Zhejiang Province(091TG06)~~
文摘[Objective] The effects of ploughing Astragalus sinicus at maturity stage as green manure on paddy soil properties were studied to provide references for ad- vancing the green manure production and field sustainable development. [Methods] A three-year field positioning experiment was carried out. In the first year, five differ- ent levels （0, 2.81, 5.61, 8.42, 11.23 t/hm~） of Astragalus sinicus ploughed at matu- rity stage were designed. And in the next two years, the amounts of ploughed As- tragalus sinicus at maturity stage were based on the natural growth amounts of As- tragalus sinicus at maturity stage of the former year in each plot field. The yields of Astragalus sinicus at maturity stage were estimated and ploughed directly before rice transplanting. Rice yield, soil nutrients, biological properties and water-stable aggre- gates of paddy fields were measured as well. [Results] The effective panicles and rice yields increased significantly after ploughing Astragalus sinicus at maturity stage. Meanwhile, the organic acid content in paddy field increased and the activities of soil phosphatases, invertase and catalase were higher. The soil dissolved organic carbon also increased with the increasing application of green manure. However, excess amount of green manure inhibited the soil microbial biomass carbon content. The macro aggregates and micro aggregates gathered to middle aggregates. [Conclusion] As green manure, the use of Astragalus sinicus at maturity stage could improve soil physiochemical and biological properties, improve soil fertility and increase rice yield significantly. But the ploughing amount of Astragalus sinicus at maturity stage before rice transplanting should be less than 8.42 t/hm2 （dry weight.
