有机物料中铁锰锌最佳有机络合剂的筛选及其机理研究

The availability of iron ,manganese and zinc are low in calcareous soil because of high pH ..Crop and fruit tree always show some symptom owing to the shortage of these elements .One of.the effective methods to solve this problem is the application of chelated fertilizer which contains.these elements . In this project , the alcohol pricipitation method was used for the fractionation of.humic substance from the decayed organic materials during the decomposition processes . On the.basis of analyzing the properties of humic substance and its fractions , we studied the complex.characteristics between the cation(Fe2+,Zn2+ and Mn2+) and organic chelate , studied the.bio-availability of the chelated cations , and selected the conditions for the decomposition of.organic materials and the preparation of complexes fertilizer .The results showed that humic.国家自然科学基金资助项目结题报告.4.substances from different organic materials were with different fractional compositions .Fraction.one and fracton two were less in the humic substances extracted from straws or manure , while.fraction three to five were high . But the fractional composition of humic substances from peat and.weathered coal were on the contrary .The order of the complexes stability constant (logk) is.Zn>Fe>Mn for the same humic substance or the same fraction .Off all the fractions , there was one.fraction which had the highest ability to complex with cations . So we presented the concept of the.optical molecure state for complexes . The factors of temperature , ion strength and pH could.affect the stability of the complexes. According to the availability of Fe2+ and Zn2+ and Mn2+ for.plant , fracrion one of humic substance from decayed straw or manure was the best for improving.the avilability of Fe2+ , Zn2+ and Mn2+ ; fraction two of humic substances from peat and.weathering coat was the best for Fe2+ and Mn2+ , and fraction three was the best for Zn2+ .These.results were significant for solving the problem of symptom of shortage of Fe and Mn and Zn .

对不同有机物料、不同腐解期提取的有机活性物质按颗粒分子量大小进行分级，有机铁锰锌与不同级分有机活性物质（络合剂）的络合机理、络合物中金属离子的生物有效性与络合物结构、类型、稳定性以及有机络合剂的关系，筛选出适合于石灰性土壤铁锰锌生物有效性最佳的有机络合剂以及该络合剂的形成条件，为铁锰锌络合态肥料的研制打下基础。..