| Due to the long-term unreasonable tillage system and application of chemical fertilizer,the yield of black soil farmland in China has decreased,and soil organic matter has degraded.In view of this problem,the present research shows that applying organic materials to enrich soil is an effective measure.Peat is a kind of organic material with superior properties.However,due to its rarity,it is mainly used in horticulture and soilless cultivation at present.There are few studies on its application in improving and fertilizing soil,and the quality of peat at different levels in peatland is very different.Therefore,this paper firstly studied the properties of peat at different depths in peatland,and used different analysis methods to find the peat layer with the best quality in peatland.Therefore,this paper firstly studies the properties of peat at different depths in peatland,finds the peat layer with the best quality by using different analysis methods,and select and use it to fertilizing soil.In addition,the micro-area experiment of different proportional mixtures of peat and corn straw under the same amount of carbon was designed,which provided a scientific basis for the effect of peat fertilizing soil and straw replacing peat.In this paper,the properties of peat at different depths in two artificial profiles of the peat land in Daqiao Township,Dunhua City,Yanbian Prefecture were studied firstly.Through the analysis of organic carbon,total humic acid carbon,element and stable isotope mass spectrometry,the peat level with the best quality in the peat profile was determined,and use it to fertilizing soil.Secondly,this paper designed the peat under such as carbon straw with different mixing proportion of micro area test,processing including:(ⅰ)no organic materials applied(CK),(ⅰ)Application of peat(P),(ⅲ)Peat and corn straw are 2:1(2/3P),(ⅲ)Peat and corn straw are 1:2(1/3P)and(ⅴ)Application of corn straw(0P).The changes of crop growth,soil physical and chemical properties,soil organic carbon content,soil humus composition and humic acid(HA)structure were analyzed.The research results of peat properties at different depths show that:(1)The total organic carbon(TOC)and humic acid carbon(HA-C)contents of peat at different depths in the two profiles were higher from below 80 cm in the surface layer to above40 cm in the gley layer,and gradually decreased from up to the surface and down to the gley layer.(2)The degree of oxidation and condensation of peat at different depths in the two profiles were lower from below 80 cm in the surface layer to above 40 cm in the gley layer,and gradually increased.from up to the surface and down to the gley layer.(3)The δ13C values of peat at different depths in the two profiles decreased gradually from surface layer to gley layer,while the δ15N values of peat were lower from below 80 cm in the surface layer to above 40 cm in the gley layer,and gradually increased.from up to the surface and down to the gley layer.(4)Although the thickness of the peat layer in the two profiles is different,but the quality of the peat layer from below 80 cm in the surface layer to above 40 cm in the gley layer is higher in both profiles.The results of the micro-area test show that:(1)Different proportional mixtures of peat and corn straw promoted the growth of maize and increased crop yield,and the degree of promotion and improvement increased with the increase of peat application.(2)Different proportional mixtures of peat and corn straw decreased soil bulk density and increased soil moisture content,and increased the contents of available nitrogen,available phosphorus and rapidly available potassium in the soil.The decreasing degree of bulk density and the increasing degree of water content increased with the increase of peat application amount,and the contents of available nitrogen,available phosphorus and rapidly available potassium in soil also increased with the increase of peat application amount.(3)Different proportional mixtures of peat and corn straw increased soil organic matter(SOM)and the carbon content of humus components,the content of water-soluble carbon(WSS-C)increased with the increase of corn straw application amount,and the SOM,humus degree(PQ)and the carbon content of other humus components increased with the increase of peat application amount.(4)Different proportional mixtures of peat and corn straw changed the structure of HA in the soil.The more the proportion of peat,the stronger the aromatic nature of HA structure,the more stable and complex HA’s structure,and the more the proportion of corn straw,the stronger the aliphatic nature of HA structure,and the simpler the structure of HA.(5)Comprehensive consideration of the crop yield,soil physical and chemical properties,humus composition and the change of the HA structure characteristics,it is more reasonable to use 1:2 ratio of peat and straw to fertilize black soil.Under this ratio,maize yield increased by 18.4%,soil physical and chemical properties improved obviously,SOC and WSS-C contents increased by 34.8%and 30.6%,respectively.And the HA structural aromaticity and aliphatic proportional were appropriate,it also indicated that peat could be replaced by corn straw to some extent(67%).The results of this study have a specific significance for guiding organic materials to fertilize black soil and the utilization of corn straw instead of peat. |
PDF Full Text Request