[Objective] The soil nutrient characteristics and influencing factors of surface soil gully erosion for low hilly terrain in the black soil area were studied in order to provide data and theoretical support for the rational use of land resources, accurate management of soil fertility, and restoration of degraded soil in the black soil area. [Methods] Surface soil gully erosion for different types of eroded ditches in Yanshou County, Heilongjiang Province was determined by measuring and analyzing soil samples from the 0—40 cm layer in each part of the erosion gully. [Results] ① The contents of soil organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen were significantly different (p<0.05) for different erosion gully types compared with the check treatment. As an erosion gully developed, soil organic matter decreased in the 0—40 cm layer, and the contents of total nitrogen, total phosphorus, total potassium, available phosphorus, available potassium, and alkali hydrolyzable nitrogen also decreased. These nutrient contents were significantly different (p<0.05) in different soil layers. Soil nutrient contents decreased with increasing depth. Because of erosion deposition, the contents of soil organic matter, total nitrogen, total potassium, and alkali hydrolyzable nitrogen decreased dramatically at the head of the gully, and at the same time, the contents of soil organic matter, available phosphorus, and available potassium decreased slowly. ② The soil degradation index followed the order of CK>A2>A1>A3 in the 0—40 cm layer as erosion gullies developed, and the soil was gradually degraded. [Conclusion] Soil nutrients had an overall significant negative correlation with bulk density, and soil nutrients were positively correlated with water stable aggregates and clay content. Soil profile differences were the fundamental reason for the variation in soil nutrients. Erosion gully development was the secondary reason for nutrient changes. The contents of soil organic matter, total nitrogen, and total potassium were also affected by positional differences.

[Objective] The effects of erosion on the surface soil of erosion gullies in sloping cropland soils in a black soil area were studied in order to provide theoretical support for the rational utilization of soil resources and regional soil and water conservation work in black soil areas. [Methods] The study was conducted on erosion gullies with different degrees of development in Yanshou County, Harbin City, Heilongjiang Provicne. Particle size distribution and water storage properties of soil on the slope, at the bottom of the gullies and at the head of the gullies were quantitatively described. [Results] ① Soil bulk density, maximum water-storage capacity, maximum water-retention capacity, total storage capacity, dead storage capacity, and maximum effective storage capacity at different depths were significantly different (p<0.05). As soil depth increased, soil bulk density also increased, and water-storage, water-retention, and effective water storage capacity decreased. Each layer had a maximum water-storage capacity of about 90% of its saturated capacity, and the effective water utilization rates were 44.79% and 41.87%, respectively. The development of erosion gullies had a clear influence on effective soil water. ② The infiltration characteristics generally showed that the initial infiltration rate>the 30-minute infiltration rate>the stable infiltration rate. As soil depth increased, the infiltration characteristics of the three indicators decreased between gully A2 and A4 for different erosion degree gullies. In the 20—40 cm layer, the infiltration characteristics of gully A1 to A4 followed the order of CK (control group)> gully A1> gully A4> gully A2> gully A3. Infiltration initially declined and then increased. With the development of the erosion gully, soil infiltration decreased and then increased. ③ The development of erosion gullies was the main reason for the change in clay content. The percentage of clay in the 0—40 cm layer tended to increase first and then decrease. The percentage of sand in the 0—20 cm layer tended to decrease first and then increase, showing a trend toward increased coarseness. ④ The soil degradation index followed the order of gully A1> gully A2> gully A3> gully A4 in the 0—20 cm layer. Soil degradation increased with the development of erosion gullies. Soil degradation was most severe in gully A4. [Conclusion] The differences in soil profiles was the main reason for the differences in physical properties of black soil. Soil water-holding capacity in the 0—20 cm layer was weakened and soil degradation became severe as erosion gullies developed.

东北黑土区作为我国重要的粮食产区,侵蚀沟发育导致土壤地力下降,严重制约了黑土区农业发展.为了分析黑土区侵蚀沟发育对表层土壤酶活性的影响,探究酶活性对侵蚀-沉积作用的响应机制,选取黑龙江省哈尔滨市延寿县双奎河双安村河段不同发育程度的侵蚀沟作为研究对象,测定不同发育程度侵蚀沟沟头、沟中、沟尾段 0～40 cm土层的碱性磷酸酶、脲酶、蔗糖酶、过氧化氢酶活性和土壤理化性质,并进行相关性分析和冗余分析,结果表明:①随着侵蚀发育,土壤酶活性总体呈下降趋势,随着土层加深,土壤酶活性降低;②4 类酶活性和土壤养分指标呈显著正相关、和土壤密度呈显著负相关,有机质含量是影响土壤酶活性最主要的因子;③在侵蚀-沉积作用下,土壤酶活性基本呈现沟头、沟中段随侵蚀发育而下降明显,沟尾段因沉积作用而下降减缓的规律.

【Objective】Litter is an important nutrient reservoir in the ecosystem, and its decomposition plays a vital role in the nutrient cycle of volcanic ecosystems. This work aimed to explore the dynamic variation of nutrient release (or loss) of litter in volcanic ecosystems.【Method】In this study, the litter decomposition bag method was adopted, and the litters of dominant plants represented by Larix gmelinii, Betula platyphylla and Populus davidiana in the lava terrace of Wudalianchi Volcano were studied as the research objects, and the decomposition rate and the dynamic difference of nutrient release were analyzed.【Result】The residual rates of leaf mass of six kinds of litters were significantly different under different time, tree species and sources. According to the Olson exponential decay model, the 50% decomposition time of different litters was 5.73-9.17 years, the decomposition time of 95% was 8.04-13.03 years, and the decomposition coefficient was 0.545-0.994. The decomposition rate was shown as “source kipuka > source lava plateau” and“Populus davidiana > Betula platyphylla > Larix gmelinii”. In terms of the source, in the decomposition process of the leachate, its C, N and P contents all showed “source kipuka > source lava plateau”, and litter N∶P values were below 14. The mass residual rate of fallout was significantly positively correlated with the C element, positively correlated with the N element, and negatively correlated with the value of C∶N. The C∶N value was negatively correlated with the N∶P value, and negatively correlated with mass residual rate.【Conclusion】The decomposition of leaf litter of coniferous trees is slower than that of deciduous trees. There is no obvious law of the C content of litter matters, the P content consistently shows a tendency to decrease first and then increase, and the P element is less likely to be dissolved in comparison with the C element and the N element. During the decomposition process, the litter sample is most significantly affected by the N element. The higher the N content and the lower the C∶N value, the faster the decomposition.

[目的]阐明侵蚀作用对黑土区坡耕地侵蚀沟土壤结构及抗蚀性的影响机制,为黑土区坡耕地侵蚀沟道演变提供基础数据和理论支撑.[方法]以哈尔滨市延寿县不同发育程度侵蚀沟为研究对象,对切沟的沟头、沟坡和沟底土壤进行系统采样,采用常规方法测定土壤的结构及抗蚀性特征.[结果](1)各沟道间 WSA(10～0.25 mm 水稳性团聚体含量)、MWD(水稳性团聚体平均重量直径)、GMD(水稳性团聚体几何平均直径)、分形维数均差异性显著(p<0.05).随着侵蚀沟发育,MWD,GMD,分形维数在 0-20 cm土层均呈[CK(对照)>A1(稳定沟)>A2(半稳定沟前期)>A3(半稳定沟后期)>A4(发展沟)],为递减趋势;随着土层加深,大颗粒水稳性团聚体含量下降,结构恶化.(2)各沟道间分散系数、<0.05 mm分散率差异性显著(p<0.05).二者在 0-40 cm 土层总体呈递增趋势;主成分分析表明 0-20 cm与 20-40 cm土层的抗蚀性综合得分表现为CK>A1>A2>A3>A4.[结论]侵蚀沟发育是造成黑土土壤结构与抗蚀性差异的主要原因,0-40 cm土层中土壤结构趋于恶化,土壤抗蚀性减弱,可蚀性增强.

为了阐明森林凋落物分解各方面的研究,本文针对森林凋落物分解的研究进展进行了阐述,主要包含凋落物(落叶层)的概念和研究历史、凋落物的分解过程与养分释放、凋落物分解的影响因子以及其在主/客场生境中的研究情况,对森林资源的可持续利用具有重要意义.随着全球气候变化日益受到人们的关注,目前关于CO2排放和N沉降影响凋落物分解的报道越来越多,但是要想更好地应对这些变化,综合性、可广泛使用的凋落物分析预测技术与指标却尚未建立.面对今后外部环境和学科的发展,还需要更多的学者提出全面有效的措施.本文在总结森林凋落物研究进展的基础上,旨在为该领域的进一步探索奠定基础.

土壤化学特性和酶活性与施肥水平密切相关,是衡量土壤肥力状况的重要指标.本研究以黑土区连续四年种植豆科作物(绿豆和红小豆)和禾本科作物(高粱)的施肥定位试验为研究平台,选取不施肥、施化肥和施有机肥3种施肥处理,分析施肥对不同杂粮作物的土壤有机质、pH、土壤养分含量和土壤酶活性的影响.结果表明,施肥降低了连作杂粮作物土壤pH值,但与不施肥相比差异不显著,禾本科植物土壤pH降低的幅度高于豆科作物土壤.连作绿豆的土壤中,与不施肥相比,施化肥处理增加了土壤全氮、碱解氮、全磷和速效磷含量,分别显著增加了18.4％,23.1％,21.7％和67.2％;施有机肥显著增加了土壤全氮和速效钾含量,且显著高于施化肥处理.连作红小豆的土壤中,与不施肥相比,施化肥显著增加了土壤速效磷和速效钾的含量,有机肥显著增加了土壤速效钾含量.连作高粱土壤中,与不施肥相比,化肥施用显著增加了土壤碱解氮含量而显著降低了速效钾含量,有机肥施用显著增加土壤碱解氮、速效磷和速效钾含量.土壤酶活性方面,除施化肥处理下连作红小豆土壤磷酸酶活性低于连作高粱外,其他相同施肥处理下种植豆科作物的土壤蔗糖酶活性、脲酶活性和磷酸酶活性均高于高粱土壤,种植高粱土壤过氧化氢酶活性高于豆科作物.因此,施肥和杂粮作物种类均是影响土壤化学特性和土壤酶活性的重要因素.

东北典型黑土区是我国重要的黑土聚集区,黑土是世界上重要的土地资源,肥力强,适宜中国主要农作物生长.通过收集第二次全国土壤普查、2007及2017年东北典型黑土区的土壤养分数据,分析东北典型黑土区土壤养分现状.结果表明,虽然现阶段黑土区肥力依旧丰富,但明显相对之前降低很多,土壤pH值下降.建议通过改善不同肥料的施用、优化耕作制度以及对侵蚀沟的治理来减少对土壤养分的流失.

Bacillus属由于其成员表现出广泛的多系性以及彼此间几乎没有共同点,长期以来一直被认为是分类和系统发育异常的属.随着测序技术和纯培养技术的进步,自Cohn建立Bacillus属以来,不断有新的菌株从不同生境中被分离,也有许多该属的成员被重新分类为其他的属.Bacillus属由于其具有芽孢的特性而广泛分布于自然界的不同环境,其嗜盐嗜碱成员已经成为人们高度重视的双重极端微生物类群,在盐碱的双重压力下经过长期的进化选择,形成了独特的生物活性物质代谢途径、新的调控机制及与这些生理生化特征有关的新基因类型.因此,针对Bacillus属中嗜盐嗜碱菌的发现历史、分布与分类现状、生理生化特征及应用前景进行综述,以期为嗜盐嗜碱芽孢杆菌新物种资源的挖掘及功能的开发利用提供参考.

盐碱土壤放线菌抗逆能力强,是一种存在于高盐高碱区域中的极端微生物,其特殊的生理机制和代谢产物的多样性广受各领域的关注.为了更有效地挖掘盐碱土壤放线菌资源及其功能基因,充分了解盐碱土壤放线菌物种的多样性,选择最适分离方法至关重要.笔者综述了中国盐碱土壤放线菌的地理分布和资源多样性,统计并总结2000-2021年盐碱土壤放线菌新物种的情况,整理归纳盐碱土壤放线菌的主要分离筛选方法,并对之后的研究工作提出展望.

为了研究不同施肥处理对谷稗的生物量及品质的影响,以'朝牧一号'稗子为试验材料,设置4种施肥方式(A有机肥、B有机肥+无机肥、C无机肥、D不施肥).收集样品后,用烘干恒重的方法测得谷稗生物量的数据.结果表明,处理C的生物量为871g/m2,比A、B和D处理分别增加了27.2％、11.9％、56.6％;处理C的粗蛋白含量为10.38％,分别比处理A、B和D增加了 19.8％、2.9％、13.2％;B处理的谷稗粗脂肪含量为1.29％,比D处理减少了 60.3％;D处理的谷稗酸性洗涤纤维(ADF)和中性洗涤纤维(NDF)最低,分别为35.11％和66.11％.在4种施肥方式中,以有机肥+无机肥处理的综合表现较好.本研究结果为东北黑土区高产优质谷稗栽培技术的制定奠定了理论基础.

[目的]研究小兴安岭红松林林外降雪、林内穿透雪和林冠截雪特征,深入认识森林冠层对降雪截留再分配的影响,为定量评价该区域红松林的生态雪水文效应提供理论依据.[方法]连续2年冬季定位观测红松林林外降雪和林内穿透降雪特征,并调查林分结构因子,利用基于物理机制的半经验性理论降雪截留模型模拟红松林冠次截留雪量.[结果]2013年11月至2014年4月和2014年11月至2015年4月,共观测到17场降雪,平均次降雪量10.3 mm,平均次降雪强度4.41 mm·d-1;平均次穿透降雪量7.4 mm,平均次穿透率69.3％,次穿透降雪量和次穿透率均随次降雪量增加而增大;林冠次截留雪量与次降雪量呈较好的幂函数正相关关系,并与郁闭度显著正相关(P<0.05),而林冠次降雪截留率与次降雪量呈负指数函数关系(P<0.05),次降雪量、胸径、郁闭度、树高和坡度对林内次穿透雪量有显著影响;林冠截留降雪存在饱和截留量限制,林冠次降雪截留率随次降雪量增加逐渐降低;林冠次降雪截留率与次降雪量和郁闭度紧密相关(P<0.05),而与胸径、树高、胸高断面积、林冠高度、林冠宽度、叶面积指数和坡度等指标相关性不显著.[结论]次降雪量和林冠郁闭度对林冠次截留雪量影响显著,次降雪量、胸径、郁闭度、树高和坡度对林内次穿透降雪量有显著影响.Pomeroy等(2002)和修正的降雪截留模型能较好拟合小兴安岭地区红松林冠次截留雪量.

侵蚀沟造成了东北黑土区坡耕地大量的土壤流失,开展有关黑土区坡耕地侵蚀沟的研究对于土壤流失防治、耕地保护以及生态恢复具有重要意义.目前,在黑土区坡耕地侵蚀沟的发生发展的影响因素、预测、防治措施等方面进行了相关的研究.本文对当前的研究进行了深入的讨论和总结,指出当前对黑土区侵蚀沟分级分类缺乏细致标准的分类依据,对黑土区侵蚀沟影响因子的研究不够全面,对侵蚀沟治理的经济、生态效益以及各种治理措施的效果差异缺乏有效的定量评价.针对现有研究不足,提出了开展黑土区侵蚀沟分类分级体系的标准化,加强土壤、植物、工程措施和耕作措施等因子对侵蚀沟影响研究以及进行侵蚀沟治理措施效果的定量评价将是今后研究重点.

为了筛选出最适宜黑龙江哈尔滨地区种植的产质量高并抗根腐病的糖用甜菜品种.2020年在黑龙江省哈尔滨市黑龙江大学呼兰校区试验基地,以21个引种的KWS系列及1个BTS2730糖用甜菜品种(KWS1197为对照)为试材,采用主成分分析和灰色关联度分析法对根产量、含糖率、产糖量和根腐病4个指标进行综合评价.两种方法得出的甜菜品种的排序大致一致;第一主成分根产量的贡献率为69.704％,第二主成分含糖率的贡献率为26.283％,累计贡献率为95.987％,因此能够全面地反映甜菜的产质量性状;最适合本地种植的综合评价值高于对照的6个品种为:KWS0023(0.8231)＞KWS0015(0.7685)＞KWS6661(0.7511)＞KWS9921(0.7103)＞KWS0860(0.7097)＞BTS2730(0.7065)＞CK(0.6823);其他品种的综合评价值低于对照.主成分分析法和灰色关联度分析能够较为全面得分析甜菜品种,得出的结果具有可靠性.

为探究常见有机物料对于土壤钾素形态有效性及对作物生长的影响,本文基于常用有机物料种类及施用方式,对当下有机物料包括秸秆、畜禽粪便、草木灰、生物炭、绿肥等的应用研究现状,以及对土壤中不同形态钾素的影响及肥效发挥情况进行综述,并提出了研究展望.有机物料在不同地区及土壤间作用效果差异显著,应根据实际情况开展还田应用.有机物料还田时需综合考虑土壤、作物的承载力,施用效果和还田成本等因素.

生物炭作为一种土壤改良剂应用到农田土壤中,能够在很大程度上改善土壤物理结构、提高土壤养分转化效率,缓解不合理生产制度所造成的土壤退化问题,对促进农业增产、保障国家粮食安全、提高土壤资源的可持续利用具有重要意义.本文通过分析和总结国内外专家对秸秆生物炭在农田中应用的研究成果,提出今后的研究方向,为农业生产中生物炭的应用提供理论支持.通过查阅和分析相关文献、资料,重点讨论了不同材料、热解温度的生物炭对农田土壤理化性质和作物生长的影响.目前,国内外对生物炭在改善土壤质量和生产力等方面的应用进行大量的试验,虽取得了一定的成果,但尚未形成一套完整的理论体系来阐述生物炭的生产方式、施用量等对农业生产的影响.土壤是一个复杂的环境,多种因素起着冲突作用,土壤—生物炭的相互作用还未完全被了解,在今后的研究中可适当调整实验设计,最大限度提高生物炭性能.

近几年来,台风、暴雨、干旱等自然灾害在我国发生的频率比以往有所增加,这不仅给人类自身造成严重的伤害,同时也给农业方面带来难以补救的巨大打击.如,最近河南发生特大暴雨,导致全省1048.5千hm2农作物受灾,成灾面积527.3千hm2,绝收面积198.2千hm2,直接经济损失超过5亿元;养殖业方面,畜禽死亡1114万头只,圈舍损毁639万m2.在这场突如其来的灾难降临后,有些农户由于事先参与了农业保险,损失能够得到减少,但有些未参保的农户却损失惨重,这也从侧面反映出农业保险在灾难来临时的重要性.基于此,本文对我国农业保险存在的问题进行分析,并提出相关解决建议.

为促进农业废弃物资源化利用和生物炭在农业中的应用推广,本文通过对目前用于生物炭制备的原料种类及特性、制备工艺对生物炭特性的影响进行综述,分析目前生物炭的生产制备、应用以及风险评估等情况,并提出今后还需加强农用生物炭工艺的标准化,土壤特性与生物炭的关系,以及生物炭作用机理等方面的研究.

调查和测定了拜泉县上升乡进步小流域内的土壤养分、重金属以及水质pH值、氟化物、氰化物、重金属等的含量,并对土壤质量和水质量进行了分析和评价,以期为在实际生产中为绿色肉鹅食品的生产基地的选择提供理论依据和数据支撑.研究结果表明:本区域的土壤肥力高,为1等级别;土壤重金属含量均符合绿色食品产地的土壤环境质量标准,综合指数P综≤0.7,属于安全等级,达到了1级标准;水质量符合绿色食品产地环境质量中的禽畜用水质量的标准,水质单项污染指数均＜1.0,综合污染指数≤0.5,水质量等级为1级.因此,在典型调查区域内,利用不同的土地利用类型推行肉鹅的放牧式散养模式,是发展寒地绿色肉鹅食品的理想场所.

为了开展黑龙江省大豆抗旱育种,进行现有大豆种植区域布局,本研究选用以黑龙江省不同类型春大豆40份为材料,利用溶液聚乙二醇(PEG-6000)进行芽期抗旱鉴定和苗期抗旱鉴定,对筛选出的抗旱品种进行干旱胁迫,对抗旱品种苗期根系总长度、根表面积、根体积、根冠比等指标进行研究.结果 表明:芽期抗旱鉴定,绥字号、黑农号、合丰号及小粒型大豆品种抗旱性较强,耐旱和较耐旱型品种为‘绥农22’、‘合丰48’、‘绥农30’、‘龙小粒2号’、‘黑河52’、‘绥农28’、‘垦豆26’、‘黑农65’、‘龙小粒1号’、‘垦丰17’、‘垦豆25’、‘绥农10’、‘抗线12’、‘黑农61’、‘黑农64’、‘龙豆2号’;苗期抗旱鉴定,合丰号、绥农号及黑农号品种抗旱性较强,包括‘合丰50’、‘黑农60’、‘绥农28’、‘合丰48’、‘合丰51’、‘黑农61’、‘龙小粒豆2号’、‘黑河51’、‘黑河50’、‘合丰56’、‘黑农65’、‘黑农64’.结合春大豆芽期和苗期抗旱鉴定结果共筛出抗旱品种‘合丰48’,‘绥农28’、‘龙小粒2号’,‘黑农65’,‘黑农61’,‘黑农64’;随着抗旱胁迫增强,品种总根长、根总面积、根体积、及根冠比总体表现增加趋势,特别是从中度干旱到严重干旱时增加幅度最大.