Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture.A pot experiment was conducted at Jilin Agricultural Universit...Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture.A pot experiment was conducted at Jilin Agricultural University,Jilin Province in northeast China to discover the influence of herb residue,animal excrement,woody residue,animal remnant on fulvic acid（FA） composition and structure using differential thermal analysis-thermogravimetric（DTA-TG）,fourier transform infrared spectroscopy（FTIR） and elemental analysis.DTA-TG showed the range of peak temperature in the first exothermic reaction increased following the trend： CK〉herb residue〉animal excrement〉woody residue=animal remnant,and the most weight loss was observed in animal excrement.Moreover,the second exothermic reaction of CK-and animal excrement-FA was presented as double peaks,the order of weight loss in that area was animal remnant〉CK〉woody residue〉animal excrement〉herb residue.According to FTIR,herb residue displayed higher adsorption intensity at 2 950,1 420,1 240 and 1 030 cm-1,animal excrement was in reverse.At the same time,herb residue-and animal excrement-FA had an absorption peak at 1 720 cm-1,while other organic materials didn＇t have this peak.As elemental analysis showed,FA isolated from various treatments was significantly distinct.It was clearly shown from our results that FA composition and structure in amended soils may be affected in different ways and at various extents on dependence of the nature and origin of amendment.展开更多
Biocrusts affect soil detachment through above-ground(top crust’s surface covering)and below-ground(sub-crust’s binding and bonding,B&B)effects,which might vary with biocrust development or coverage.However,thes...Biocrusts affect soil detachment through above-ground(top crust’s surface covering)and below-ground(sub-crust’s binding and bonding,B&B)effects,which might vary with biocrust development or coverage.However,these effects in humid climates are still unclear.This study was conducted to apportion and quantify the surface covering and B&B effects of moss biocrusts with five coverage levels(1%–20%,20%–40%,40%–60%,60%–80%,and 80%–100%)on soil detachment by overland flow in a subtropical humid climate.Two treatments with one being intact moss crusts and one removing the aboveground moss tissues were designed for each coverage level,and bare soil was used as the baseline.The results indicated that soil detachment capacity(Dc)and rill erodibility(Kr)decreased with biocrust coverage.After removing the above-ground moss tissues,the impeding effect of biocrusts on soil detachment weakened,but still increasing soil erosion resistance relative to bare soil.For intact crust,Dc was reduced by 50%–95%compared with bare soil,wherein 36%–55%and 14%–40%were attributed to the surface covering and B&B,respectively.The top crust contributed more than sub-crust to the soil detachment reduction,which were related to but not linear with biocrust coverage.When biocrust coverage reached mid-to-higher level(40%–100%),both top crust and sub-crust steadily contributed to soil detachment reduction with 60%and 40%,respectively.The findings advance a better understanding of the influencing mechanism of biocrusts on soil erosion in humid climates and highlight the importance of saving biocrusts as ecosystem functions.展开更多
为明确40%砜吡草唑悬浮剂土壤喷雾处理对大豆田一年生杂草的防效及对大豆的安全性,2021年采用随机区组设计进行田间药效试验。结果表明:40%砜吡草唑悬浮剂在150、180、210、360 g a.i./hm^(2)剂量下对大豆田主要杂草马唐、狗尾草、藜、...为明确40%砜吡草唑悬浮剂土壤喷雾处理对大豆田一年生杂草的防效及对大豆的安全性,2021年采用随机区组设计进行田间药效试验。结果表明:40%砜吡草唑悬浮剂在150、180、210、360 g a.i./hm^(2)剂量下对大豆田主要杂草马唐、狗尾草、藜、反枝苋、稗草、青葙、苘麻、马齿苋等均有较好防治效果。药后40 d总草株防效88.14%~97.58%,总草鲜重防效86.44%~97.73%,增产率3.52%~12.68%,且对供试大豆品种安全。40%砜吡草唑悬浮剂可作为大豆田备选除草剂,采用土壤喷雾法防治大豆田一年生杂草,推荐使用剂量150~180 g a.i./hm^(2)。展开更多
基金funded by the National Key Technology R&D Program of China (2012BAD14B05, 2013BAC09B01)the Major Achievement Transfer Project of Jilin Province, China (20130309005NY)
文摘Knowledge of different effects of various organic materials on soil humic substance is important for both environmental safety and sustainable agriculture.A pot experiment was conducted at Jilin Agricultural University,Jilin Province in northeast China to discover the influence of herb residue,animal excrement,woody residue,animal remnant on fulvic acid（FA） composition and structure using differential thermal analysis-thermogravimetric（DTA-TG）,fourier transform infrared spectroscopy（FTIR） and elemental analysis.DTA-TG showed the range of peak temperature in the first exothermic reaction increased following the trend： CK〉herb residue〉animal excrement〉woody residue=animal remnant,and the most weight loss was observed in animal excrement.Moreover,the second exothermic reaction of CK-and animal excrement-FA was presented as double peaks,the order of weight loss in that area was animal remnant〉CK〉woody residue〉animal excrement〉herb residue.According to FTIR,herb residue displayed higher adsorption intensity at 2 950,1 420,1 240 and 1 030 cm-1,animal excrement was in reverse.At the same time,herb residue-and animal excrement-FA had an absorption peak at 1 720 cm-1,while other organic materials didn＇t have this peak.As elemental analysis showed,FA isolated from various treatments was significantly distinct.It was clearly shown from our results that FA composition and structure in amended soils may be affected in different ways and at various extents on dependence of the nature and origin of amendment.
基金financially supported by the National Natural Science Foundation of China(Grant No.41877082)the Fundamental Research Funds for Central Public Welfare Research Institutes(Grant No.CKSF2021487/TB,CKSF2021447/TB)。
文摘Biocrusts affect soil detachment through above-ground(top crust’s surface covering)and below-ground(sub-crust’s binding and bonding,B&B)effects,which might vary with biocrust development or coverage.However,these effects in humid climates are still unclear.This study was conducted to apportion and quantify the surface covering and B&B effects of moss biocrusts with five coverage levels(1%–20%,20%–40%,40%–60%,60%–80%,and 80%–100%)on soil detachment by overland flow in a subtropical humid climate.Two treatments with one being intact moss crusts and one removing the aboveground moss tissues were designed for each coverage level,and bare soil was used as the baseline.The results indicated that soil detachment capacity(Dc)and rill erodibility(Kr)decreased with biocrust coverage.After removing the above-ground moss tissues,the impeding effect of biocrusts on soil detachment weakened,but still increasing soil erosion resistance relative to bare soil.For intact crust,Dc was reduced by 50%–95%compared with bare soil,wherein 36%–55%and 14%–40%were attributed to the surface covering and B&B,respectively.The top crust contributed more than sub-crust to the soil detachment reduction,which were related to but not linear with biocrust coverage.When biocrust coverage reached mid-to-higher level(40%–100%),both top crust and sub-crust steadily contributed to soil detachment reduction with 60%and 40%,respectively.The findings advance a better understanding of the influencing mechanism of biocrusts on soil erosion in humid climates and highlight the importance of saving biocrusts as ecosystem functions.
文摘为明确40%砜吡草唑悬浮剂土壤喷雾处理对大豆田一年生杂草的防效及对大豆的安全性,2021年采用随机区组设计进行田间药效试验。结果表明:40%砜吡草唑悬浮剂在150、180、210、360 g a.i./hm^(2)剂量下对大豆田主要杂草马唐、狗尾草、藜、反枝苋、稗草、青葙、苘麻、马齿苋等均有较好防治效果。药后40 d总草株防效88.14%~97.58%,总草鲜重防效86.44%~97.73%,增产率3.52%~12.68%,且对供试大豆品种安全。40%砜吡草唑悬浮剂可作为大豆田备选除草剂,采用土壤喷雾法防治大豆田一年生杂草,推荐使用剂量150~180 g a.i./hm^(2)。
