秸秆深还及配施化肥对土壤理化性质和腐殖质的影响

发布时间：2018-04-15 15:52

  本文选题：秸秆深还 + 土壤腐殖质组分　； 参考：《吉林农业大学》2016年硕士论文

【摘要】：中国每年农作物秸秆总量巨大,能有效回收的秸秆数量却非常有限,大部分农民选择就地焚烧,焚烧秸秆会使土壤表层有机质减少,损害土壤墒情,引起环境污染,进而威胁人类健康。作物秸秆中含有丰富的氮、磷、钾和微量元素成分,将玉米秸秆施入土壤亚表层(20~40cm之间),即“秸秆深还”(Corn Stover Deep Incorporation,CSDI)。深还秸秆的同时可以打破犁底层,有效解决土壤耕作层逐渐变浅的问题。本试验以吉林农业大学试验站玉米连作耕地土壤为研究对象,设未施用秸秆(CK)、秸秆深还(CS)、单施化肥(NPK)、秸秆深还配施化肥(CS+NPK)4种处理,主要研究秸秆深还及配施化肥对土壤理化性质、腐殖质组成以及胡敏酸结构的影响。腐殖质按胡敏酸(HA)、富里酸(FA)和胡敏素(HM)分组,采用腐殖质组成修改法测定,胡敏酸样品采用IHSS方法提取纯化,其结构经元素组成、红外光谱进行研究。本文创新之处在于秸秆深还配施化肥对土壤性质的影响以及对整个土壤剖面各层次腐殖质组分含量的影响,以期为如何合理利用秸秆深还提高土壤固碳能力以及构建合理耕层提供理论依据。研究结果表明:(1)秸秆深还可以促使土壤紧实度、容重降低;对土壤pH、电导率均无显著影响;促使土壤速效养分含量略增加。秸秆深还配施化肥促使土壤紧实度、容重降低;对土壤pH、电导率均无显著影响;土壤速效养分含量显著增加。(2)秸秆深还配施化肥对土壤有机碳(SOC)的积累作用优于秸秆深还,更优于单施化肥。SOC含量一般表现为表层(0~20cm)高于亚表层(20~40cm),CS和CS+NPK处理在秸秆层(50~55cm)处的SOC含量均达最高,且增幅也最高。(3)秸秆深还及配施化肥促使土壤腐殖质各组分含碳量显著增加,CS处理FA含碳量在20~40 cm最大值处,HA和HM含碳量在50~55cm处均最高。而CS+NPK处理HA、FA和HM含碳量最大值均在50~55cm处。随土层深度增加,PQ值变化整体呈现随深度增加先上升后下降趋势,但变化不显著。秸秆深还降低了土壤表层及亚表层HA及FA的Δlg K值,CS处理和CS+NPK处理对秸秆层上层的土壤HA的ΔlgK值无显著影响,对FA的ΔlgK值影响表现为上层影响较显著,下层影响不显著。(4)秸秆深还及秸秆配施化肥均能使HA分子的芳香结构比例增加,但CS处理还能同时增加脂族链烃的比例;而CS+NPK处理则使HA的缩合度提高,氧化度下降。说明CS和CS+NPK使HA变稳定的机制有所不同,除了分子结构芳香性提高的作用以外,前者还体现在疏水性的提高上;而后者则体现在分子结构变复杂上。
[Abstract]:The total amount of crop straw in China is huge every year, but the amount of straw that can be recovered effectively is very limited. Most farmers choose to burn on the spot. Burning straw will reduce the organic matter in the surface layer of soil, damage soil moisture and cause environmental pollution.And then threaten human health.There are abundant nitrogen, phosphorus, potassium and trace elements in crop straw. Corn straw was applied to the soil between 20 ~ 40 cm below the surface layer, that is, Corn Stover Deep Incorporation (CSDI).At the same time, it can break the bottom of plow and solve the problem of soil layer becoming shallower.In this experiment, the soil of continuous cropping cultivated corn in Jilin Agricultural University was used as the research object. The soil was treated with NPK)4 without straw, with the straw returning to CSN, applying chemical fertilizer alone, and applying chemical fertilizer with CS NPK)4 seed.The effects of straw depth and chemical fertilizer on soil physical and chemical properties, humus composition and Hu Min acid structure were studied.The humus was divided into two groups: Hu Min acid (Ham), fulvic acid (FAA) and humin (HM). The humus was determined by humus composition modification method, and Hu Min acid sample was extracted and purified by IHSS method. Its structure was studied by elemental composition and IR spectra.The innovation of this paper lies in the effect of straw depth and chemical fertilizer on soil properties and the content of humus in all layers of soil profile.In order to provide the theoretical basis for how to make rational use of straw depth and to improve the carbon sequestration capacity of soil and to construct rational tilling layer.The results showed that the straw depth could also promote soil compactness and bulk density, had no significant effect on soil pH and conductivity, and promoted soil available nutrient content to increase slightly.The soil compactness and bulk density were decreased by applying chemical fertilizer to straw depth; the pH and electrical conductivity of soil were not significantly affected; the content of available nutrients in soil increased significantly. 2) the accumulation of soil organic carbon (SOC) by straw depth and chemical fertilizer was better than that of straw depth, and the effect of application of chemical fertilizer on soil organic carbon (SOC) accumulation was better than that of straw depth.The content of SOC was higher than that of 20 cm in the surface layer and 20 cm in the surface layer. The content of SOC was the highest in the treatment of CS and CS NPK at 50 ~ 55 cm in the straw layer, and the content of SOC was higher than that in the subsurface layer of 20 ~ 40 cm ~ (-1) C ~ (2 +).And the straw depth and chemical fertilizer could significantly increase the carbon content of humus components in soil. The carbon content of FA in CS treatment was the highest at the maximum value of 2040 cm. The carbon content of HA and HM was the highest in 50~55cm.The maximum carbon contents of Hafa FA and HM treated with CS NPK were both at 50~55cm.The change of PQ value with soil depth increased firstly and then decreased with the increase of soil depth, but the change was not significant.Straw depth also decreased 螖 LG K value of HA and FA in surface layer and subsurface layer of soil. CS treatment and CS NPK treatment had no significant effect on 螖 lgK value of soil HA in the upper layer of straw layer, but the effect on 螖 lgK value of FA was significant in upper layer.The effects of straw depth and chemical fertilizer on HA molecule were not significant in the lower layer, but CS treatment also increased the proportion of aliphatic chain hydrocarbons, while CS NPK treatment increased the condensation degree of HA and decreased the degree of oxidation.The results show that CS and CS NPK have different mechanisms for stabilizing HA. In addition to the effect of enhancing the aromaticity of the molecular structure, the former is also reflected in the improvement of hydrophobicity, while the latter is reflected in the complexity of the molecular structure.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S153
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本文编号：1754774