Humic acids derived from Leonardite to improve enzymatic activities and bioavailability of nutrients in a calcareous soil

作     者：Qian Sun Jianlong Liu Lianfei Huo Yuncong C.Li Xue Li Liru Xia Zhongkai Zhou Meina Zhang Bin Li 

作者机构：Institute of Agricultural Facilities and EquipmentJiangsu Academy of Agricultural SciencesJiangsu 210014China Key Laboratory for Protected Agricultural Engineering in the Middle and Lower Reaches of Yangtze RiverMinistry of AgricultureJiangsu 210014China Department of Soil and Water SciencesTropical Research and Education CenterUniversity of FloridaHomestead 33031USA College of EngineeringNanjing Agricultural UniversityJiangsu 210031China School of EngineeringZhejiang A&F UniversityZhejiang 311300China 

出 版 物：《International Journal of Agricultural and Biological Engineering》 (国际农业与生物工程学报（英文）)

年 卷 期：2020年第13卷第3期

页      面：200-205页

核心收录：

学科分类：0710[理学-生物学] 0810[工学-信息与通信工程] 09[农学] 0903[农学-农业资源与环境] 0805[工学-材料科学与工程（可授工学、理学学位）] 0812[工学-计算机科学与技术（可授工学、理学学位）] 090301[农学-土壤学] 

基　　金：Funding was provided by the Natural Science Foundation of Jiangsu Province(BK20170614) National Natural Science Foundation of China(NO.61803187,31901419) Jiangsu Agriculture Science and Technology Innovation Fund(CX(18)3047) 

主　　题：humic acid molecular weight Leonardite enzyme nutrient content 

摘      要：Understanding the role of humic substances in soils is important for developing and utilizing organic fertilizers or soil amendments for sustainable *** objective of this study was to determine the effects of different fractions of humic acids derived from Leonardite on enzymatic activities and bioavailability of nutrients in a *** experiment was carried out by mixing different factions of humic acids with a soil and incubated for 70 *** treatments included five factions of humic acids(HS1(low molecular weight),HS2(medium molecular weight)),HS3(large molecular weight,SED(sediment of fractions),HS(mixture of HS1,HS2,and HS3)),raw Leonardite(IM)and a control(no addition of humic acid).Experimental results showed that application of humic acids significantly improved acid and alkaline phosphatase activities,especially with *** substances with high molecular weights significantly inhibit urease activity,and the optimal application rate was 600 kg/hm2 of humic substances with the high molecular *** of NH4+-N were decreased with increasing humus *** treatments(HSmix,HS1,HS2,HS3,IM,SED)did not affect the soil contents of Ca,although soil concentrations of K,P,Cu,Zn were increase significantly when small molecular weight humus(HS1)was applied.