Search

This paper is intended to probe into the mechanism and environmental effects of modified chitosan, a kind of new materials, on heavy-metal contaminated soil under acid rain condition. Thereby, a leaching experiment of soil-column with simulated acid-rain trickling was conducted, leachate being collected from the soil-column, and ephehydrin modified chitosan-biochar composite (ECS-B) and protochitosan were used as stabilizers. The parameters of pH, conductivity and heavy metals (Cu, Pb, Zn and CD) of the leachate were analyzed in terms of contents and morphological change, and an accumulation-release model of heavy metals under leaching condition were put forward. The results of the experiment showed that compared with the control group, the pH value of leachae increased by 1.32 when ECS-B stabilizer had been added. EC changed significantly, rising up to 1.75 times of that of the control group; compared with the control group, the accumulative contents of Cu, Pb, Zn and Cd were decreased by 82.35%, 71.47%, 61.88% and 90.44%, respectively; and after leaching, the residual state of each heavy metal was 2.59 times higher than that of the control group. As to the study on the release of heavy metals from soil, it was considered involving a complex reaction process controlled by a variety of diffusion mechanisms. Besides, ECS-B stabilizer can inhibit the acid-rain leaching of heavy metals in soil by the increase of soil base ions, and the actions of surface complexation, precipitation and ion exchange, thus effectively reducing the ecological environment risk. [ABSTRACT FROM AUTHOR]

Copyright of Forest Engineering is the property of Forest Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aluminum toxicity in acidic soil has become one of the main factors limiting crop growth and yield. Rapeseed is an important oil crop in China, which is mainly planted in the provinces and regions of the Yangtze River Basin where soil acidification is more serious. Rapeseed is one of the crops sensitive to aluminum toxicity, but the mechanisms of aluminum tolerance are still poorly understood. This paper reviewed the production of aluminum toxicity, the effect of aluminum toxicity on crop growth, the mechanism of crop aluminum tolerance, and the research progress on aluminum tolerance of rapeseed, and provide reference for the cultivation of new varieties of aluminum tolerant and high yielding rapeseed. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to investigate the function of, biochar and fulvic acid on improving coastal salty, alkalinity land, this paper adopted field corn planting experimental method in June 2015, and set up 6 treatments: CK, BC1, BC2, FA, BC1+FA, BC2+FA,applying biochar 7.5 t/ hm² (BC1), 30 t/ hm² (BC2), fulvic acid 1.5 t/ hm² (FA) and their combinations, and studied the effects of additional materials on characteristic indexes of important soil sanility, alkalinity situation. The results indicated that BC2 treatment could reduce soil bulk density, but soil bulk density was not reduced under treatment of low biochar application quantity (BC1), and soil in research area showed a gradual degradation state of natural hardening. With the increase of biochar applying quantity, soil water holding capacity showed a degeneration tendency. Applycation of biochar and fulvic acid significantly improved the organic matter contents in soil, which was the highest level under BC2+FA condition, reaching 6.31 g/ kg. Among all treatment, the phenomenon of periodic desalting and accumulation of salt in the surface soil showed an identical rule, but the salt accumulation under BC1+FA and BC2+FA treatments was obviousely lower than that of the other treatments. The results indicated that applycation of biochar and fulvic acid could increase soil fertility, improve soil structure, restrain salt accumulation and was in favour of remoulding coastal beach saline, alkali land for rapid arable land utilization. The treatment of 30 t/ hm² biochar combined with 1.5 t/ hm² fulvic acid had the best result. [ABSTRACT FROM AUTHOR]

[Objectives] This paper was aimed to study the remediation effects of phosphate-solubilizing fungi and bone char in different soils. [Methods] Three different types of lead-contaminated soils (neutral yellow brown soil, alkaline sand soil and acidic red soil)were mixed with the bone char sintered at different temperatures. We measured the contents of phosphorus and lead, and the remediation differences of different soils. The Pb bioavailability of lead-contaminated soil was then determined by planting non-heading Chinese cabbage. The application potential of compound remediation materials was confirmed by adding compound remediation agents to the soil with the best remediation effect. [Results] The bone char had the best effect of promoting the release of phosphorus in yellow brown soil, and the available phosphorus content was 64 times higher than that of the control, showing a high potential of lead remediation. The pH of yellow brown soil was neutral, and the available P in the soil would not be fixed by Ca, Fe, Al, etc., thus increasing the probability of its reaction with Pb. When bone char was solely used, the material treated at 200-300 ℃ had qualified remediation effect. We planted non-heading Chinese cabbage to verify the bioavailability of lead in yellow brown soil after bone char application. It was observed that addition of a certain proportion of bone char to yellow brown soil (the initial mass ratio of bone char to lead was over 0.5:1) could not only increase the absorption of phosphorus by 2.0 to 3.5 times, but also reduce the absorption of lead by non-heading Chinese cabbage(content of lead in pakchoi leaves was reduced by 70% to 80% compared with blank treatment). A composite of bone char and Aspergillus niger was further applied to yellow brown soil, and the effective lead was reduced to 14.36 mg·kg-1. In particular, the growth of the A. niger proved the remediation potential of the composite. [Conclusions] The composite of bone char and A. niger was suitable for lead remediation in neutral soils, and the suitable heating temperature for preparing bone char was 200-300 ℃. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to explore the effects of manganese stress on acid soil nitrogen conversion, enzyme activity and sugarcane nitrogen absorption and utilization, and provide a reference for the rational fertilization of sugarcane on acid soil. [Method JSimula- ted acidic soil manganese stress cultivation experiment in the indoor, and the sugarcane pot experiment in the glasshouse were carried out, and the difference of soil nitrogen component content, pH and soil enzyme activity under manganese stress and its relationship with sugarcane nitrogen absorption and accumulation relationship were measyured and analyed. [Result] Manganese stress significantly increased soil ammonium nitrogen content and net ammonification rate(P < 0. 05,the same as below), significantly reduced soil nitrate nitrogen content and net nitrification rate, and significantly increased soil net mineralization rate. At the same time, manganese stress significantly reduced soil urease activity and significantly increased soil invertase activity, but had no significant effect on soil protease activity (P >0. 05). The results of correlation analysis showed that soil urease activity was significantly and extremely (P < 0. 01, the same as below) positively correlated with soil ammonium nitrogen content and pH, soil protease activity was significantly positively correlated with soil ammonium nitrogen content, and extremely and significantly negatively correlated with soil nitrate nitrogen content and net nitrification rate respectively. Under manganese stress, sugarcane plant height, biomass, plant nitrogen accumulation and nitrogen absorption efficiency were significantly reduced. [Conclusion] Manganese stress can inhibit the nitrification of acid soils, reduce the conversion of ammonium nitrogen to nitrate nitrogen, and at the same time reduce the activity of soil urease and increase the activity of soil invertase, thereby reducing the available nitrogen content of sugar- cane in acid soil, reducing the absorption and utilization of nitrogen by sugarcane. [ABSTRACT FROM AUTHOR]

[Objective] The aim of this paper is to explore the relationship between the main chemical components of flue-cured tobacco and soil chemical properties. [Method] All of 235 tobacco leaf samples and soil samples were collected from typical aromatic tobacco growing areas in Yunnan province. The main soil factors affecting the chemical quality of Yunnan fragrant tobacco leaves were studied by correlation analysis, stepwise regression analysis and principal component analysis. [Result] The contents of total sugar and reducing sugar in Yunnan tobacco were 30.87% and 27.21, respectively ;the contents of total nitrogen, nicotine and potassium were in the appropriate range, which were 1.91, 2.63% and 1.91% respectively ;The results showed that the pH value of the main tobacco planting soils in Yunnan was moderate, with an average of 6.3. The contents of total nitrogen, total phosphorus, available molybdenum and available sulfur were in the rich level. The contents of total potassium and humic acid were on the low level. The contents of organic matter, fulvic acid, available boron, water-soluble chloride ion, salt content and CEC (total amount of cation exchange) were in the middle level. The contents of total sugar, reducing sugar, starch and potassium in tobacco leaves were significantly positive correlation with total potassium in soil. Two sugar difference and sugar alkali ratio were significantly positive correlation with soil available molybdenum content. Two sugar difference was significantly positive correlation with soil humic acid content, and was significantly negative correlation with soil chloride ion content. [Conclusion] The contents of total potassium, available molybdenum, humic acid and water-soluble chloride ion in tobacco growing soil of Yunnan tobacco growing areas are the most important indicators affecting the chemical quality of tobacco leaves in Yunnan. [ABSTRACT FROM AUTHOR]

[Objective ] The objective of the paper is to provide the scientific basis for reducing chemical fertilizer and improving efficiency for vegetable in acidic yellow soil area of Guizhou. [ Method] The effects of combined application of biochar and yellow phosphorus slag on yield and nutrient uptake and utilization of Chinese cabbage cultivated in acidic yellow soil are studied by a pot experiment in green house. [ Result] The yield of Chinese cabbage under different treatments of biochar and yellow phosphorus slag combination is increased by 37.22 % - 82.07% compared with that of non-fertilization treatment, and the yield of Chinese cabbage applied with chemical fertilizer + 70 glpot biochar + 11.7 glpot yellow phosphorus slag is the highest ( 553. 5 g/ pot) . The nitrogen, phosphorus and potassium content in Chinese cabbage under different treatments of biochar and yellow phosphorus slag combination is increased by 39.9% - 57.9%, 1.31% - 35.22% and 1.99 % -39.09% respectively compared with that of non-fertilization treatment. The nitrogen, phosphorus and potassium uptake of Chinese cabbage under different treatments of biochar and yellow phosphorus slag combination is increased by 107.8% - 188.9%, 65.89% - 128.82% and 61.73 % - 122.97% separately. Except there is no obvious difference in phosphorus uptake of Chinese cabbage applied chemical fertilizer + 18.0 glpot yellow phosphorus slag and non-fertilization treatment, the nitrogen, phosphorus and potassium uptake of Chinese cabbage under other treatments of biochar and yellow phosphorus slag combination is higher than that of nonfertilization treatment significantly. Among various fertilization treatment, chemical + 70 glpot biochar + 11.7 g/pot yellow phosphorus slag has the highest nitrogen and phosphorus utilization efficiency, respectively 59. 01 % and 8. 83 %, while chemical fertilizer+ 100 glpot biochar + 9.00 glpot yellow phosphorus slag has the highest potassium utilization efficiency, which is 92. 10 % . [Conclusion ] Rationally combined application of biochar and yellow phosphorus slag can improve yield, nutrient uptake and utilization of Chinese cabbage, and low amount of biochar combined with high amount of yellow phosphorus slag has the best effect. [ABSTRACT FROM AUTHOR]

With the continuous development of industry, environment pollution such as soil acidification and heavy metal pollution of soil becomes increasingly serious, especially in the acidic soil region of southern China. Liming is a traditional and effective method to improve acidic soil. Manual spreading is a kind of traditional method of liming, but it is inefficient and has some side effects like skin damage of workers because of the corrosive property of lime. In order to solve the deficiencies of manual liming and compensate the technology gap of liming machine between domestic and overseas market, we designed a lime spreading machine which was able to be assembled with other agricultural machinery to become combined machine. The development of liming machine has great significance to improve liming efficiency and working conditions. This paper discussed the structure and working principle of the pros spiral lime spreading machine. The machine used the spread roller which was similar to the structure of pros spiral as working parts, used the overlapped waist-shaped hole as the lime spreading outlet, and controlled the waist-shaped hole overlapping area through adjusting assembly to adjust the lime spreading amount. Through experiment we determined the lime outlet size and the lime spreading roller's rotation speed of the lime spreading machine, and experiment results showed that: Firstly, when the lime spreading roller speed was below 125 turn per minute, for the same waist-shaped lime spreading outlet, the lime spreading amount per turn of lime spreading roller could be treated as a constant value, i.e. the spreading amount and lime spread roller's rotation speed were in a linear relationship; Secondly, when the number of lime spreading plate was 40, the hole was waist-shaped hole with the size of 25 mm*10 mm and the rotation speed of the roller was in 120 turn per minute, we got the lime spreading amount of 1 500 kg/h which met the maximum requirements of lime spreading. Considering the linear relationship between the lime spreading amount and the number of lime spreading hole, and the complex conditions after assembled with rotary cultivator, we increased the number of the waist-shaped hole and decreased the rotation speed of lime spreading roller meanwhile kept the lime spreading speed unchanged, and at last determined the lime spreading hole number to be 60 and the roller's rotation speed to be 80 turn per minute as the optimal scheme. We also analyzed the power consumption condition of the lime spreading process and calculated the total power consumption of the working process. Finally, the field test of the lime spreader was carried out, which was conducted in the dry paddy field. Field test results showed that, under the conditions of the lime spreading cultivator at a speed of 5 km per hour, the lime spreading roller at a speed of 80 turn per minute and the overlapping area of the lime spreading hole at maximum size, when the adjusting bar of adjusting mechanism was located in Location XIII, the lime spreading amount reached 1 566.7 kg per hectare. When the adjusting bar of adjusting mechanism were located in Location XII, X and VII, respectively, the lime spreading amounts met the demands of annual lime spreading amount for the first, second and third year, respectively; and when the adjusting bar was at Location II, lime spreading machine almost closed all the lime spreading holes. [ABSTRACT FROM AUTHOR]

[Objective] In this paper, the problem of acidifying soil in Baoshan tobacco-growing area was studied.[Method] Six kinds of soil conditioner were selected as soil remediation measures to study the effects of different soil conditioner on the chemical properties of acid soil and the quality and yield of flue-cured tobacco.[Result] In addition to calcium magnesium phosphate fertilizer, the other soil conditioners could improve the soil pH, of which lime was the best, however, application lime was alone, it was easy to produce calcium magnesium potassium antagonism, and soil fertility declined.Potassium fertilizer and new pattern potassium fertilizer could increase the content of soil a-vailable K, slow K and tobacco potassium to achieve increased potassium content and improve quality.The contents of available potassium and slowly available K in the 0 - 15 cm soil mineral potassium (hydrothermal) with 62.13 %, 33.97 % were significantly higher than those iii lime treatment, and mineral potash (calcination) with 82.59 %, 24.01 % were significantly higher than those in lime treatment.Soil conditioner mainly affected the chemical composition of tobacco leaves and the smoking quality of the middle and upper leaves.The content of alkali-hydrolysable N in soil and the yield of flue-cured tobacco under the new-type potassium organic fertilizer treatment were higher than that of CK 13.04 %, 316.85 kg/hm2, respectively.The effects of two kinds of soil amendment on the chemical composition of tobacco leaf and the smoking quality of tobacco leaf were the best with the new type potassium bio-organic fertilizer and mineral potassium fertilizer (hydrothermal method).[Conclusion] The effects of soil pH, nutrient and the quality, yield of flue-cured tobacco by mineral potassium fertilizer (hydrothermal method) and new type potassium bio-organic fertilizer were improved. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper studied molecular identification and biological characteristics of 29 stains rhizobia isolated and purified from soybean nodules grown on different acidic soils with different soybean cultivation histories at Yingtan, Jiangxi province and Jinhua, Zhejiang province. The nifH gene fragment were amplified from 16 strains of 29 isolates. Sequence analysis of nifH showed that these strains belonged to the genus of Bradyrhizobium. Ten rhizobial strains were from Jinhua and showed no obviously difference among soybean cultivars. Six rhizobial strains were from the nodules of BX10 (A1 -tolerant) and BD2 (A1 -sensitive) at Yingtan and showed differences between these two soybean genotypes. Based on the phylogenetic analysis of nifH sequence, the species of selected soybean rhizobia were confirmed by 16S rDNA sequence analysis and rhizobial inoculants. Four rhizobial strains showed nodules in the roots of BX10 and BD2, and the growth curve and physiological and biochemical characteristics of them were further identified. Results suggested that dominant rhizobia in acidic soils showed regional differences. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Oil Crop Sciences is the property of Oil Crops Research Institute of Chinese Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)