保水剂底施对沙子剖面水分和硝态氮运移的影响研究

【目的】解决沙土地区漏水漏肥的核心问题,建立保水防渗漏新技术体系,促进沙土地区农业可持续发展。【方法】基于保水剂的吸水保肥等物理化学特点,以保水剂和土壤混合物底施为技术方法,选用聚丙烯酸钠和壤土为材料,采用沙柱模拟试验,研究了不同施用厚度的保水剂-土壤混合物对剖面水分运移及硝态氮淋洗的影响。【结果】聚丙烯酸钠在壤土中的质量分数为1%时,可以对水分有效截流;混合物底施,以0.9～1.5 cm厚度为最佳;淋溶试验表明硝态氮主要集中在表层和保水剂层,占比为87.2%,有效防止了硝态氮的下移。【结论】保水剂壤土混合物底施,可以起到显著的水分养分截流作用,本试验中聚丙烯酸钠质量分数1%及1 cm厚度时,可获得较好效果。     

浅谈无人机遥感技术在土地整治项目中的应用

随着科学技术水平不断推进,计算机技术与遥感技术等有机结合,无人机遥感技术凭借其轻便、高效、精确的数字地形测绘技术被广泛应用于各类工程领域,本文结合土地整治项目对无人机遥感技术发展现状以及在土地整治项目中的应用优势和特点进行研究分析,并探讨了无人机遥感技术应用在土地整治项目中的优势和不足,无人机遥感技术虽能提供基础的数据资料和技术支持,但项目实施中仍要对部分区域进行必要的实地核查。     

黄土高原地区土壤石油污染状况及生物修复技术研究进展

概述了黄土高原地区土壤石油污染状况及近年来该区油污土壤生物修复的研究进展,分别对微生物、植物及微生物-植物联合修复方法进行综述,强调生物强化技术在生物修复中的突出地位及植物-微生物联合修复方法的应用潜能。由于石油污染物的复杂性,现存技术在实际修复中效果并不明显,提出运用分子生物学技术研究酶功能基因、将代谢组研究融入油污土壤的修复、深入探究植物根际分泌物与微生物作用及菌根真菌生物降解机制的建议,旨在对黄土高原地区石油污染土壤修复探究工作奠定理论基础,对促进黄土高原地区土壤的保护及可持续利用具有重大意义。     

Reduction of soil heavy metal bioavailability by nanoparticles and cellulosic wastes improved the biomass of tree seedlings

The purpose of this study was to use zero‐valent iron nanoparticles (nZVI) and cellulosic wastes to reduce bioavailability of lead (Pb) and cadmium (Cd), and to establish Persian maple seedlings (Acer velutinum Bioss.) in contaminated soil. One‐year‐old seedlings were planted in pots filled with unpolluted soil. Lead [Pb(NO₃)₂] and Cd [Cd(NO₃)₂] were added with concentrations of 0 (Control), 100 (Pb100), 200 (Pb200), and 300 (Pb300) mg kg⁻¹ and 10 (Cd10), 20 (Cd20), and 30 (Cd30) mg kg⁻¹. Cellulosic wastes were mixed with soil at the same time of planting [four levels: 0, 10 (W1), 20 (W2), 30 (W3) g 100 g⁻¹ soil]. The nZVI was prepared by reducing Fe³⁺ to Fe⁰ and injected to pots [four levels: 0, 1 (N1), 2 (N2), and 3 (N3) mg kg⁻¹]. Height, diameter, biomass, tolerance index of seedlings, bioavailability of heavy metals in soil, and removal efficiency of amendments were measured. The highest values of seedling characteristics were observed in N3. The highest removal efficiency of Pb (Pb100: 81.95%, Pb200: 75.5%, Pb300: 69.9%) and Cd (Cd10: 92%, Cd20: 73.7%, Cd30: 68.5%) was also observed in N3. The use of nZVI and cellulosic waste could be a proper approach for seedling establishment in forests contaminated with heavy metals.     

有机物-金属相互作用对重金属负载土柱中粘土矿物吸附剂再生的影响

Natural clay minerals can play an important role in crude remediation of wastewater polluted with the heavy metals (HMs) Cu,Zn and Ni.The presence and timing of addition of natural dissolved organic matter (DOM) have a significant effect on the HM removal by clay mineral sorbents.However,the influence of the presence of DOM on the remediation of the used clay mineral sorbents once saturated with HMs is largely unknown.To resolve this,clay mineral-rich soil column of varying composition,loaded (i) with Cu,Zn and Ni only,(ii) first with DOM followed by Cu,Zn and Ni,or (iii) with DOM,Cu,Zn and Ni simultaneously,was used in a set of desorption experiments.The soil columns were leached with 0.001 mol L-1 CaCl2 dissolved in water as control eluent and 0.001 mol L-1 CaCl2 dissolved in DOM as treatment eluent.During the preceding loading phase of the sorbent,the timing of DOM addition (sequential or concurrent with HMs) was found to have a significant influence on the subsequent removal of the HMs.In particular when the column was loaded with DOM and HMs simultaneously,largely irreversible co-precipitation took place.Our results indicate that the regeneration potential of clay mineral sorbents in wastewater treatment will be significantly reduced when the treated water is rich in DOM.In contrast,in manured agricultural fields (where HMs enter together with DOM),HM mobility will be lower than expected from interaction dynamics of HMs and clay minerals.     

Soil Carbon Dynamics Under Changing Climate——A Research Transition from Absolute to Relative Roles of Inorganic Nitrogen Pools and Associated Microbial Processes: A Review

It is globally accepted that soil carbon (C) dynamics are at the core of interlinked environmental problems,deteriorating soil quality and changing climate.Its management remains a complex enigma for the scientific community due to its intricate relationship with soil nitrogen (N) availability and moisture-temperature interactions.This article reviews the management aspects of soil C dynamics in light of recent advances,particularly in relation to the availability of inorganic N pools and associated microbial processes under changing climate.Globally,drastic alterations in soil C dynamics under changing land use and management practices have been primarily attributed to the variation in soil N availability,resulting in a higher decomposition rate and a considerable decline in soil organic C (SOC) levels due to increased soil CO2 emissions,degraded soil quality,and increased atmospheric CO2 concentrations,leading to climate warming.Predicted climate warming is proposed to enhance SOC decomposition,which may further increase soil N availability,leading to higher soil CO2 efflux.However,a literature survey revealed that soil may also act as a potential C sink,if we could manage soil inorganic N pools and link microbial processes properly.Studies also indicated that the relative,rather than the absolute,availability of inorganic N pools might be of key importance under changing climate,as these N pools are variably affected by moisture-temperature interactions,and they have variable impacts on SOC turnover.Therefore,multi-factorial studies are required to understand how the relative availability of inorganic N pools and associated microbial processes may determine SOC dynamics for improved soil C management.     

Behavioral and cardiopulmonary effects of dexmedetomidine–midazolam and dexmedetomidine–midazolam–butorphanol in the silver fox (Vulpes vulpes)

Objective

To evaluate the behavior and some cardiopulmonary variables of dexmedetomidine–midazolam or dexmedetomidine–midazolam-butor-phanol in the silver fox (Vulpes vulpes).

重金属污染胁迫对杂交狼尾草生理生化特性的影响

为了探讨杂交狼尾草(Pennisetum americanum×P.purpureum)的耐重金属性,用杂交狼尾草为试验材料,就不同程度重金属污染胁迫对其叶片中叶绿体色素、可溶性蛋白质、丙二醛(MDA)质量浓度,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性以及叶膜电解质相对渗透率的影响进行了研究.结果表明,随着重金属胁迫的加重,杂交狼尾草叶片中的叶绿体色素、可溶性蛋白质质量浓度呈下降趋势,MDA质量浓度和叶膜电解质相对渗透率呈上升趋势,SOD、CAT和POD活性呈先上升后下降趋     

磁化水处理技术在农林业中的应用进展

为了研究磁化水技术对干旱盐碱地区植物生长、土壤、灌溉水理化性质等影响,笔者综述了国内外十多年的研究,发现灌溉水经过磁化处理后,能显著提高盐渍化土壤的脱盐效果;矿化度高的地下水磁化后灌溉,能显著减轻对植物的伤害,促进植物的生长,提高产量和质量,提高土壤矿质营养的利用率,减少化肥使用量。但是,磁化水的作用机理和农业上应用的技术参数尚未得到确定。今后还需要对磁化机理做进一步研究,统一技术参数,扩大磁化水技术在农业生态修复上的应用。     

连作草莓根际土壤特征及修复技术研究进展

连作障害是制约草莓(Fragaria ananassa)发展的最大因素。笔者对国内外草莓连作障害的研究亮点进行了综述。土壤根际微生物区系变化,有益微生物减少,病原菌增加,有害化感物质积累是产生连作障害的主要原因。杀灭土壤病原菌,去除有害化感物质,把“病土”修复成“健康土”,是克服连作障害,实现草莓连茬种植的根本之路。对草莓连作障害机理的深入研究、土壤修复技术的应用研究仍然是未来发展的方向。