Composition and properties of soil humus in a mixed forest of Cunninghamia lanceolata and Tsoongiodendron odorum

This study was conducted in Xinkou Experimental Forestry Farm of Fujian Agricultural and Forestry University, Sanming, Fujian Province in January 1999. Taking pure stand of Chinese fir as control, the authors measured and studied the content of organic carbon, content of humic acid (HA), ratio of HA to fulvic acid (FA), and the characteristics of infrared light spectrum and visible light spectrum of soil humus in the mixed forest of Chinese fir and Tsoong?tree. Compared to humus composition in the pure stand of Chinese fir, the content of soil organic C, HA content, and the E4 value of HA for different layers of soil, except for the ratio of HA to FA, showed a significant increase in the mixed forest, while the ratios of E4 to E6 had a little decrease. The infrared light spectrum of humic acid had an absorptive peak at 1650 cm-1. It is concluded that the levels of humification and aromaticity of soil humus are higher in the mixed forest, which is favorable for the improvement of soil structure and nutrient supply, thus improving the soil fertility to a certain degree.

Dissolution and Fractionatoon of Calcium-Bound and Iron-and Aluminum-Bound Humus in Soils

This paper deals with the development of a sequential extraction method to separate the Ca-bound and Fe-and Al-bound humus from soils.First,comparative analyses were carried out on dissolution of synthetic organo-mineral complexes by different extractants,i.e.0.1M Na4P2O7,0.1M NaOH+0.1M Na4P2O7 mixture,0.1M NaOH,0.5M (NaPO3)6 and 0.5M neutral Na2SO4.Among the five extractants,0.1M NaOH+0.1M Na4P2O7 mixture was the most efficient in extracting humus from various complexes.0.5M Na2SO4 had a better specificity to Ca than 0.5M (NaPO3)6,by only extracting Ca-bound humus without destorying Fe-and Al-bound organo-mineral complexes.Then sequential extractions first with 0.5M Na2SO4 and then with 0.1M NaOH+0.1M Na4P2O7 mixture were applied to a series of soil samples with different degrees of base saturation.The cations were dominated by Ca in the 0.5M Na2SO4 extract and by Al in the 0.1M NaOH+0.1M Na4P2O7 mixture.The sequential extraction method can efficiently separate or isolate Ca-bound and Fe-and Al-bound humus from each other.

Dicyandiamide Sorption-Desorption Behavior on Soils and Peat Humus

The sorption-desorption behavior of dicyandiamide (DCD) is an importantchemical process that affects DCD fate and mobility in soils. Therefore, this study quantified DCDsorption-desorption on a phaeozem (Mollisol), a burozem (Alfisol), a soil with organicmatter-removed and peat humus using the batch-equilibration procedure, and identified soilproperties that influenced DCD sorption. The sorption on peat humus was higher than that on thephaeozem and the burozem, with much lower sorption observed on the soil with organic matter-removed,indicating that soil organic matter was the main carrier of DCD sorption. Due to its amphipathicproperty the DCD molecule sorption on the phaeozem and the burozem decreased as pH increased fromabout 2 to 5, but a further increase in pH led to a rise in DCD sorption. The DCD desorptionhysteretic effect for peat humus was greater than that for the phaeozem and the burozem using 0.01mol L^(-1) CaCl_2 as the background electrolyte, suggesting that the hydrophobic domains of organicmatter may play an important role in DCD sorption.

Effect of crude oil pollution on organic carbon and humus content in grey-brown soils in Mangyshlak, Pre-Caspian Sea Region

The organic carbon and humus content in oil polluted brown and grey-brown soils in Mangyshlak,Pre-Caspian Sea Region,was analyzed from 2000 to 2008.The results indicated that bitumen substances from crude oil pollution deteriorated the soil property,however,the organic carbon content increased significantly.The products of oil pollution changed the composition of car-bonaceous substances which formed soil humus,and changed the ratios of the humus components.Residual insoluble carbon increased with the rise of oil organic carbon.The mobility of humus components was significantly increased because of the high oxidation-reduction process in the topsoil,and the humus content and microorganism activity increased.The organic carbon content increased significantly,while it decreased with the distance away from the oil well.The rearrangement of physical,physical-chemical and chemical properties of the polluted soils was significant.

Straw ^(14)C Decomposition and Distribution in Humus Fractions as Influenced by Soil Moisture Regimes

14C-tracer technique and closed incubation method were used to study straw 14C decomposition and distribution in different fractions of newly formed humus under different moisture regimes. Decomposition of straw 14C was faster during the initial days, and slower thereafter. Decay rate constants of straw 14C varied from 3.29x10-3 d-1 to 7.06x10-3 d-1. After 112 d incubation, the amount of straw 14C mineralized was 1.17～1.46 times greater in submerged soils than in upland soils. of the soil residual 14C, 9.08%～15.73%was present in humic acid (HA) and 31.01%～37.62% in fulvic acid (FA). Submerged condition favored the formation of HA, and HA/FA ratio of newly formed humus (labelled) was greater in submerged soils than in upland soils. Clay minerals affected the distribution of straw 14C in different humus fractions. Proportion of 14C present in HA to 14C remaining in soil was greater in Vertisol than in Ultisol.

Effect of Humus on Activity of Mineral-Bound Hg: III.Effect on Leachability and Transfer of Mineral-Bound Hg Under Acid Leaching Condition

Effects of humus fractions (fulvic acid, brown humic acid and grey humic acid) on the leachability and transferring activity of five types of mineral-bound Hg were investigated. Under the acid leaching condition: fulvic acid could promote leachability and vertical transference of all the mineral-bound Hg. Brown humic acid could retard the leaching and transferring processes of CaCO3-Hg, Fe2O3-Hg, MnO2-Hg and kaolinite Hg but not bentonite-Hg. Grey humic acid could greatly enhance residing ability of the mineral-bound Hg in the soil column and restrain them from vertical transferring. The effect of humus on leachability and transferring activity on the mineral-bound Hg was closely related to its ability to convert the mineral-bound Hg into organic-bound form and the transferability of the latter in the soil column. The characteristics of the mineral-bound Hg in speciation were the internal factors that determined the extent and rate of the influence of the humus.

Rice Crop Application for Humus Bioreactor by Rural Sewage System

In this paper, author will report on the process of rice cultivation in paddy fields using treated water which treated domestic sewage wastewater. Odor problems from sewage treatment plants have been solved by confinement and ventilation, but reducing the color and odor of treated water is economically difficult and is a subject of recycling of discharged water. Humus pellet bioreactors can be attached to existing sewage treatment plants to suppress the odor of the sewage treatment plants as a whole and to prevent sludge from deteriorating and to improve the quality of treated water. The odor and color of the treated water discharged from the sewage treatment plant was reduced. In addition, we were able to obtain performance of treated water with nitrogen 3 mg/L, phosphorus 1 mg/L or less throughout the year. On the other hand, there are many cases of results that cannot be used for paddy rice cultivation and vegetable production etc. by ignoring plant growth and physiology (fertilizer). For that reason, laws and guidance such as having to dilute more than 50 times in order to use processed water for agriculture are being conducted without learning. It is a case of using humus pellets in sewage treatment system and using deodorized wastewater of sewage by adjusting fertilizer when used in paddy field rice production.

Stability on the ^(109)Cd,^(65)Zn Complex with Humus Acids

The radioactive isotope tracer and ion exchange balanced method was used to study the stability of 109Cd, 65 Zn complexes with humus acids. In the 109Cd and 65 Zn single existing system with humic acids, the stability constants of the humic-109Cd(65Zn) complex compound was higher than the fulvic-109 Cd(65Zn) complex compound. The stability constant of the humic (fulvic) -65Zn was higher than that of the humic (ful-vic)-109Cd. In the 109Cd and 65 Zn coexisting system, the stability constant and the co-ordination number of the humic (fulvic)-65Zn complex obviously increased, but the stability constant and the co-ordination number of the humic (fulvic)-109Cd complex obviously decreased as compared with its respectively single existing system . The result showed that the humus matter with higher molecular weight could more effectively reduce plant availability of heavy metals than that with lower molecular weight in polluted soil by heavy metals. The humus matter could more effectively reduce plant availability of Zn than that of Cd. Application of humus-acid increased the harm of Cd and decreased the harm of Zn to plants in Cd-Zn coexisting system.

Effects of Long-term Located Fertilization on the Physico-chemical Property of Soil Humus

A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil, but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of f ulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of f ulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and f ulvic acid increased in the three types of soil. But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil. Single application of chemical fertilizer had less effect on the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil.

Composition and Structural Features of Calcium—Bound and Iron—and Aluminium—Bound Humus in Soils

Calcium-bound and iron-and aluminium-bound humus extracted from different soils collected from north to south of China were characterized by chemical and spectroscopic methods. Meaningful differences in the composition and structure between them were revealed by (13)C NMR, visible spectroscopy and elemental analysis. Results showed that the contents of carbon, hydrogen and nitrogen were higher in iron-and aluminium-bound humus than in calcium-bound humus while oxygen content in calcium-bound humus was shown to be higher. The calcium-bound humus had hasher C/N and O/C ratios than iron- and aluminumbound humus. The calcium-bound humic acid (HA1) showed higher E4/E6 ratios than iron- and aluminumbound humic acid (HA2) while iron- and aluminum-bound pulvic acid (FA2) showed higher E4/E6 ratios than calcium-bound fulvic acid (PA1). An inverse relationship between E4/E6 ratios and aromaticity as determined by (13)C NMR spectra was observed for HA and FA from black soil. The (13)C NMR spectroscopy revealed that HA2 was more aromatic than HA1. On the other hand, FA1 exhibited a higher aromaticitythan FA2.

Thermal Characterization and Lifetime Estimation of the Humus Lombricospt

Through this study, the humus produced in the breeding place of Universidad Autonoma de Occidente was thermally characterized. The humus was submitted to a heating program controlled by the Differential Scanning Calorimetry (DSC) technique to characterize the type of transition, Thermogravimetry (TGA) to study the equilibrium of phasesand Mass Spectrometry (MS) coupled to TGA to identify detached elements in a temperature range. The temperature range used in this study was 30℃ ℃. The energy required for the water desorption in the humus has been found in this study. The humus showed a quick desorption between 30℃ ≤ TDesorption ≤ 110℃ at a heating rate of 10℃/min and presented decomposition around 250℃. Moreover, the kinetics of the desorption of the humus was studied to obtain the activation energy three TGA measures for three different heating rates. The average activation energy was about 26 kJ/Mol. This result was carried out to obtain an estimation of the desorption time of water in the range from room temperature to the decomposition temperature around 350℃.

Humus Content in Soil and Yield in the Permanent Cotton Cultivated Fields

The article presents the data of a long-term experience on the reproductive capacity of the soil during the permanent cultivation of cotton, which has been carried out for 96 years at the Institute of Breeding, Seed Production and Agrotechnology for Growing Cotton in the Kibray district of the Tashkent region. The article presents the results of analyses by determining the content of humus, from which it can be seen that the decrease in humus was more marked on the control variant without fertilizers, and the amount of humus decreased after 20 years compared to the initial indicator by 11.4 t/ha, after 40 years 16 46 t/ha, after 60 years by 19.05 t/ha, after 80 years by 26.29 t/ha and after 96 years by 29.17 t/ha. It was also determined by the decrease in humus content in option 2, where NPK 250:175:125 kg/ha was applied annually, respectively: 6.487 t/ha;9.225 t/ha;10.09 t/ha;16.95 t/ha;19.65 t/ha;with an annual application of 30 t/ha of manure + 25 kg/ha of P2O in option 1, respectively: 0.335 t/ha;3.683 t/ha;11.40 t/ha;22.44 t/ha;32.58 t/ha. In addition, the article also provides data on the yield of cotton by options for permanent cultivation. It was determined that in the control variant, the yield decreased from 16.8 centners per hectare to 9.9 centners per hectare;in the variant where NPK was applied every year 250:175:125 kg/ha was 31 - 34 c/ha, where 30 t/ha of manure + 25 kg/ha P2O 29 - 32 c/ha were used every year.

ON THE DIVISION OF NORTH BOUNDARY OF SUBTROPICALZONE ACCORDING TO THE COMPOSITIONS AND PROPERTIES OF SOIL HUMUS

In this paper predecessors′achievements about the division between subtropical zone and warm temperate zone on the south slope of Funiu Mountain are firstly summarized, and the cause why these viewpoints about the division are different also has been presented. Seven soil profiles at different heights above sea level are dug along the south slope of Funiu Mountain. Many compositions and properties of soil humus have been analyzed in laboratory. A comprehensive study has been made about the division according to the compositions and properties of soil humus with mathematical method. During the analysis process eight indexes have been used, such as altitude, organic carbon, humic acid (HA), fulvic acid (FA), the ratio of humic acid and fulvic acid (HA/FA), two extinction coefficients (E4,E6), and their ratio (E4/E6).The result indicates that the boundary is at about 1000 meters above sea level.

Effects of Humus Fertilizer from Fermented Branches on Microorganisms and Enzyme Activity in the Soil under Dracontomelon duperreranum Trees

[Objective] This study aimed to explore the effect of humus fertilizer from fermented branches on pH, total porosity, contents of organic matter, alkaline hy- drolysable nitrogen, available phosphorus, rapidly available potassium, the number of microorganisms and the activity of enzymes in the soil under Dracontomelon duper- reranum trees. [Method] Experiments were carried out to study the physical and chemical properties of soil under Dracontomelon duperreranum trees, and soil with- out any fertilizer treatment was used as control. [Result] The results showed that application of humus fertilizer from fermented branches raised the total porosity of soil, and improved the contents of soil organic matter, available phosphorus, rapidly available potassium, the number of soil microorganisms and the activity of soil en- zymes. In addition, the number of soil microorganisms was positively related to the activity of soil enzymes. [Conclusion] Application of humus fertilizer from fermented branches markedly raised the ratio of the number of bacteria to the number of fungi, and promoted the transformation of fungi-rich soil into bacteria-rich soil, which thus significantly enhanced the soil fertility and improved the soil environment under Dracontomelon duperreranum trees.

羊肚菌栽培方法优化研究

为了探究不同环境条件对羊肚菌产量和品质的影响,分别研究了品种、单播混播、菌种形态、低畦、腐殖质添加量等因素对羊肚菌生产性能的影响。选取ZHS-3、ZHS-5、四川-6和MZ-8等品种,在冬春季节分别做了品比试验、单一菌种和混合菌种栽培试验、固体菌种和液体原种栽培试验、低畦栽培试验和土壤基质栽培试验。结果表明,品比试验中四川-6的栽培效果更好,较ZHS-3、ZHS-5和MZ-8产量分别高22.27%、32.17%和19.74%;单一菌种和混合菌种栽培试验中单一菌种的栽培效果更好,产量较混合菌种高22.72%,说明若早发菌种和晚发菌种同时存在则无协同作用;液体原种和固体菌种栽培试验中固体菌种的栽培效果更好,产量较液体菌种高28.78%,液体菌种虽然发菌快但个体小;低畦栽培试验中平栽的栽培效果更好,产量较下挖组高53.24%,说明通风不足会影响产量;腐殖质添加试验中添加腐殖质含量在5%时栽培效果更好,产量较添加10%腐殖质区域高20.10%,较对照组高31.12%,说明腐殖质添加不宜过量。

工业固废-水泥固化腐殖土的力学响应和微观机制

为了推动腐殖土在岩土工程领域的资源化利用,采用工业固废(包括生物质飞灰、电石渣和磷石膏)协同水泥对腐殖土进行固化处理。以中国广东省某陈旧型简易垃圾填埋场开采的腐殖土为研究对象,通过常规三轴试验、干湿和冻融循环试验、扫描电镜(SEM)、X射线衍射(XRD)、傅立叶红外光谱(FTIR)和压汞(MIP)测试探究了工业固废-水泥固化腐殖土的三维力学特性、耐久性能及微观机制。试验结果表明:随着P_(o-b)(即工业固废替代水泥的比率)的增加,试样偏应力与轴向应变的关系逐渐由应变软化向应变硬化过渡。三元工业固废的适当掺入(P_(o-b)为25%~50%)有利于减缓干湿循环作用下工业固废-水泥固化腐殖土试样的劣化速率,而纯水泥固化腐殖土试样表现出相对优异的极限偏应力和抗冻性。微观结构分析表明大量钙矾石晶体和C―(A)―S―H凝胶等产物增强了腐殖土颗粒之间的黏结,同时填充了微观孔隙。研究结果可为垃圾填埋场开采的腐殖土修复及再利用提供理论依据。

生活垃圾腐殖土土工特性室内试验研究

为探究垃圾填埋场内腐殖土的土工特性随填埋深度的变化规律,以陈旧型垃圾填埋场内不同填埋深度的腐殖土为研究对象,采用室内试验和理论分析相结合的方法研究腐殖土的理化性质和力学性质。研究结果表明:随着填埋深度的增加,陈腐垃圾中腐殖土的占比以及颗粒级配、有机质含量、比重和浸出液pH值等理化性质均发生变化,进而影响腐殖土的抗压强度、抗剪强度、饱和渗透性和压缩性等力学性质。研究结果为腐殖土的资源化利用提供了理论参考。

宁夏农田土壤有机碳特征及提升机理研究

有机碳是土壤质量与肥力的核心,直接影响着土壤物理、化学和生物学性质的变化过程,提升土壤有机碳是维持农田土壤肥力的重要途径。基于相关调查研究,分析了宁夏农田土壤有机碳及其腐殖质碳组分的含量特征与土壤养分之间的相关性,阐述了宁夏农田有机碳提升研究需要揭示的机制问题,提出农田土壤有机碳提升机理的研究方向,旨在为宁夏农田土壤有机碳提升技术的不断优化提供理论依据。

腐殖质对干旱胁迫下多花黄精叶片生理生化特性的影响

【目的】通过研究干旱胁迫下多花黄精生理生化指标的变化,综合评价腐殖质对其抵御干旱胁迫的影响,为多花黄精节水栽培提供理论依据。【方法】采用盆栽实验,分别以腐殖质土和黄土(对照基质)为培养基质,设置正常供水(土壤含水量80%~85%)、轻度干旱(土壤含水量60%~65%)、中度干旱(土壤含水量40%~45%)、重度干旱(土壤含水量20%~25%)4个控水梯度,测定多花黄精叶片相对电导率、丙二醛含量、可溶性糖含量、可溶性蛋白含量、超氧化物歧化酶活性和过氧化物酶活性等生理生化指标的变化。【结果】轻度干旱胁迫不会导致多花黄精叶片生理生化抗旱指标发生明显变化;中度干旱胁迫对多花黄精叶片生理生化产生较明显影响,腐殖质土基质中多花黄精叶片相对含水量、叶绿素含量、SOD活性、POD活性比对照基质分别少下降0.34%、4.99%、18.37%、2.90%,相对电导率、MDA含量分别少增加10.30%、9.12%,可溶性糖含量、可溶性蛋白含量分别多增加3.60%、1.79%;重度干旱胁迫对多花黄精叶片生理生化产生明显影响,腐殖质土基质下多花黄精叶片的相对含水量、叶绿素含量、SOD活性、POD活性比对照基质分别少降低2.16%、5.14%、19.92%、8.56%,相对电导率、MDA含量分别少增加14.16%、16.86%,可溶性糖含量、可溶性蛋白含量分别多增加4.06%、2.35%。隶属函数法综合评判得出腐殖质土基质栽培下多花黄精抗旱隶属函数值比对照基质提高了151%。【结论】腐殖质作为多花黄精促生长的栽培基质,在干旱胁迫下可提高多花黄精生理生化抗旱指标的稳定性,并通过增加渗透调节物质含量的方式在一定程度上抵御干旱胁迫。