辽宁省观音阁水库上游水土保持规划研究

研究编制观音阁水库上游水土保持规划是为了保证水库的良好运行和水库上游流域经济社会的可持续发展,实现水资源的优化配置,保障用水安全和水库安全。调查水库上游区域自然、经济、社会和水土保持方面概况,分析流域内水土流失成因,诊断流域内对生态环境有威胁的各种因素。采取GIS等手段获取流域内土地利用分布情况,从而对流域进行分区。共划分成生态修复区、生态治理区和生态保护区3个区域,针对不同区域特点,有针对性的布设水土保持措施。按照规划要求治理完成后,流域内水土流失治理程度达到80%以上,综合治理措施保存率80%以上,人为水土流失得到控制并得到良好的管理;流域泥沙减少70%以上。     

浅谈大中型水库上游水土保持方略

水库淤积是危及水库寿命的一大难题。解决库区泥沙淤积应从水土保持入手,绿化库区山川。将库区上游流域按自然条件,分部治理。依辽西气候条件、经济发展现状,其水土流失治理方略为:山顶部石质山薄层土区营造分水岭生态防护林带;腹部石质山中层土区宜发展腹部薪炭林、经济林带;坡脚山麓厚层土区以发展农业为主,并配套各种水土保持措施。水库边缘淤积土区是库区塌岸的主要区域,其防治方法可采取岸顶截排、岸坡防浪、坡脚防冲加固。以水土保持为基础,以绿化山区为主线,开展多种经营,实现提高环境容量,减轻上游流域生态压力;提高居民经济收入,减轻上游流域水土流失,延长水库使用寿命的目的。     

西藏美曲藏布流域水土流失特点及分区防治对策

西藏美曲藏布流域生态环境脆弱,冻融侵蚀、水力侵蚀和风力侵蚀等分布范围广、危害重、治理难度大。根据流域的水土流失状况和特点,将其划分为3个水土保持类型区,即流域上游高原预防保护区、流域中游河谷生态修复区、流域下游宽谷盆地综合治理区,并针对各分区特点分别进行水土保持措施布置,以期为流域水土保持综合规划提供理论支持,为西藏地区水土保持治理提供借鉴。     

汾河上游植被修复模式试验初报

在山西省宁武县汾河上游左岸的校场流域,以自然恢复为主,人工适度干预加速恢复自然景观,建立具有较好的水土保持功能和稳定性的防护植被。研究生态修复后生物产量、群落空间结构、林地土壤水分养分动态变化等林分演化机理,为区域水土保持生态工程建设提供科学依据。     

南阳市丹江口库区及上游水土保持生态建设剖析

南阳市丹江口库区及上游流域水土流失严重,水环境条件恶化,其水土保持在采取工程措施治理的同时,充分依靠大自然的力量开展生态的自我修复工作,促进人与自然的和谐,加快水土流失的防治步伐,从而实现该地区的经济可持续发展和环境保护的可持续发展,确保丹江口库区的长久治安,保证水源区长期稳定达到南水北调中线工程水源地水质保护要求。     

参与式方法在水土保持规划中的探索

黑龙江省明水县赵家小流域属典型东北黑土区,在系统工程和环境可持续发展的理论指导下,针对流域内自然环境、社会经济情况和水土流失特点,运用参与式方法提出了水土保持生态修复、坡面拦蓄工程、水土资源综合利用等综合防护措施体系,详细论述了参与式水土保持规划设计的原理和过程。可为小流域综合治理提供一定的借鉴作用。     

鄂尔多斯市实施水土保持生态修复的实践与启示

鄂尔多斯市通过实施禁牧舍饲等水土保持生态修复措施,成功实现了由传统农牧业向现代农牧业的转变。近年来,鄂尔多斯市以农牧业"三区"经济发展规划为指导,统筹城乡发展,实施"收缩转移集中发展"战略,以禁休轮牧及草畜平衡、生态移民、农牧业产业化建设为重要抓手,开创了水土保持生态修复的新局面,为黄河流域加快推行水土保持生态修复提供了典型经验,树立了榜样。建议以国家功能区划总体意见为指导,进一步完善黄河流域水土保持规划,加强流域监督和监测评价,尽快探索和建立水土保持生态补偿机制,以促进流域水土保持生态修复。     

黄河生态系统特征及生态保护目标识别

根据黄河流域生态和环境状况,对黄河流域进行了生态分区,并阐述了各生态区的特征。在黄河河道湿地研究和黄河水体内顶级物种(鱼类)的调查分析基础上,确定了黄河不同类型生态保护区的生态保护目标:从流域角度而言,黄河上游的主要生态保护目标是植被和水源涵养林;中游应以水土保持为主,主要是恢复和保护植被;下游以保护湿地类型和维持湿地面积为重点,保护生物多样性和重要鸟类资源。黄河水生态系统中的主要保护物种应是珍贵经济鱼类北方铜鱼、河口洄游鱼类刀鱼、鲤鱼等,主要保护的生态区包括库区湿地、河口湿地、河道湿地以及景观娱乐水域等。     

官厅水库上游近20年土壤侵蚀强度时空变化分析

官厅水库上游地区从1982年就被列入国家级水土保持重点治理区，国家不仅在水土流失治理方面进行大力投入，而且进行了多次土壤侵蚀遥感调查。各次土壤侵蚀遥感调查的成果在时间上形成序列，客观上为进行区域土壤侵蚀状况和生态环境变化的趋势动态分析提供了可能。在历年土壤侵蚀调查结果的基础上，进行了官厅水库上游永定河流域近20年来土壤侵蚀强度的时空变化分析，确定区域内水土流失强度在空间和等级的变化情况。     

官厅水库流域产流产沙变化规律及其影响因素研究

官厅水库是我国在多沙河流上修建的第一座大型水库，探讨水库上游流域的产流产沙规律对水库的运行和管理具有重要的理论和现实意义。对官厅水库流域产流产沙的变化规律进行了研究，结果表明：20世纪50年代是官厅水库上游流域的丰水、丰沙期，以后随着时间的推移，流域产流量和产沙量逐渐减少，造成官厅水库上游流域产流量和产沙量变化的主要因素是降雨和人类活动两方面的因素。     

氮磷钾配比对木薯养分吸收动态及产量影响

【目的】木薯是重要的粮食作物,也是优质的淀粉工业原材料,被认为是非粮生物质能源的最合适原料。氮、 磷、 钾含量水平显著影响木薯产量,但有关木薯养分阶段性累积特征及其对生物量和产量形成影响的相关研究仍较少。本文比较了不同肥料配比情况下,木薯生物量, 氮、 磷、 钾累积量变化趋势,探讨了不同生育期氮、 磷、 钾含量及累积量的重要性及施肥对其影响。【方法】以我国主栽木薯品种华南205为材料,2009年在广东省郁南县丘陵坡地开展田间施肥试验,共设CK、 NP、 NK、 PK、 NPK 5个施肥处理。于苗期、 块根形成期、 块根生长早期、 块根快速膨大期和成熟期调查生物量和氮、 磷、 钾含量,得出氮、 磷、 钾累积动态。以各时期氮、 磷、 钾含量及累积量作为原始变量进行主成分分析,判断各时期氮、 磷、 钾含量及累积量的重要性,并分析不同肥料配比对各时期氮、 磷、 钾含量及累积量的影响。【结果】华南205的生物量累积动态呈S型曲线, 生物量在苗期较小,进入块根形成期后快速提高,当进入成熟期后增长逐渐减缓。氮肥对生物量影响最大,其次是钾肥,磷肥的影响最小。木薯氮含量的变幅为3.99%~0.93%, 磷含量为0.82%~0.26%, 钾含量为1.39%~0.89%。氮、 磷、 钾含量均在苗期最高,且随着生育期的推进不断降低,尤以氮含量降幅最大。不同氮、 磷、 钾肥料配比显著影响木薯的氮、 磷、 钾含量。PK处理的氮含量较NPK处理降低了32.96%,NK处理的磷含量较NPK处理降低了16.21%,NP处理的钾含量较NPK处理降低了50.37%。氮、 磷、 钾累积量与产量显著相关。主成分分析表明木薯整个生育期的营养状况与块根形成期的氮含量、 苗期的钾含量及块根生长阶段的磷含量相关性最大。氮、 磷、 钾的吸收累积量随着木薯生长不断提高,其中块根形成期、 块根生长早期、 块根快速膨大期的氮累积量较大,块根形成期、 块根快速膨大期的磷累积量较大,块根生长早期、 块根快速膨大期、 成熟期的钾累积量较大。主成分分析表明块根快速膨大期的氮、 磷、 钾累积量对整个生育期养分累积影响显著,同时,苗期及块根生长早期的氮、 钾累积量对养分累积总量影响也较大。【结论】木薯氮、 磷、 钾含量随着植株生长不断下降,而累积量却不断提高。不同氮、 磷、 钾肥料配比显著影响木薯的氮磷钾含量及累积量、 物质累积及产量形成,其中氮肥的影响最大,其次是钾肥,磷肥的影响最小。综合分析表明,苗期、 块根形成期、 块根生长早期为氮、 磷肥的最佳施用时期,块根形成期、 块根生长早期及块根快速膨大期为钾肥的补充阶段。     

Impact of quality and quantity of biochar and hydrochar on soil Collembola and growth of spring wheat

The effects of biochar (maize biochar – MBC, wood biochar – WBC) and unfermented or fermented hydrochar (HTC) on the euedaphic Collembola Protaphorura fimata and on spring wheat were investigated in greenhouse experiments. The impact of char type, amount of fermented HTC, and MBC-Collembola interactions were assessed. Generally, shoot and root biomass as well as abundance of P. fimata were not affected by the different chars. However, with increasing amounts of fermented HTC the abundance of P. fimata declined, whereas shoot biomass of wheat increased. Moreover, MBC altered root morphology and resulted in thicker roots with higher volume. The latter was not apparent when Collembola were present.     

Phytoavailability and toxicity of beryllium and vanadium

Greenhouse and laboratory studies were conducted to evaluate the toxic effects of Be and V on collards (Brassica oleracea, var. acephala L.). In the laboratory germination study, incremental increases in the Be concentrations of the growing medium induced a steady decline in the radicle length of seven-day-old collard seedling. Beryllium concentrations greater than or equal to 8 mg Be L^?1 totally inhibited seed germination. The presence of V in the growing medium had no effect on collard germination; however, it had a profound effect on subsequent radicle elongation. Concentrations of V less than 1 mg V L^?1 stimulated radicle elongation, while concentrations greater than or equal to 3 mg V L^?1 caused severe toxicity. In the greenhouse study, Be toxicity was observed in collards grown in a Blanton sand (Grossarenic Paleudult) received treatments greater than or equal to 150 mg Be kg ^?1 (as BeSO₄). Irrespective of treatment level, 97% of the Be taken up by the plants remained in the roots while only 3% was translocated to aboveground plant parts. Vanadium tissue concentrations and toxicity to collards varied with soil type. Additions as low as 80 mg V kg^?1 to the Blanton sand significantly reduced collard biomass while additions as high as 100 mg V kg^?1 to an Orangebury loamy sand (Typic Paleudult) had no effect on plant biomass. The differential response was attributed to greater accumulation of V by plants grown in the Blanton soil.     

Charge characteristics and exchangeable cation status of Korean Ultisols and Alfisols and Thai Ultisols and Oxisols

The charge characteristics of A₁ or Ap and B₂ horizon samples of total 23 Ultisols, Alfisols and Oxisols in Korea and Thailand were studied by measuring the retention of NH₄⁺ and NO₃^? at different pH values (4–8) and NH₄NO₃ concentrations (0.1–0.005 m ). The magnitude of their negative charge (σ^?; meq/100g) was dependent on pH and NH₄NO₃ concentration (C; m ) as represented by a regression equation: log σ^?=apH +blogC +c. The values of the coefficient a (0.04–0.226), b (0.03–0.264) and c (–0.676–1.262) were correlated with the kinds of the soil and horizon and with the region where the soil exists. The retention of NO₃^? was less than 1 and 2–3 meq/100 g for the A₁ or Ap and B₂ horizon samples, respectively. The sum of exchangeable base and Al (‘effective’ CEC) was close to and higher than the magnitude of permanent charge (=σ^? measured at pH = 4.3 and at C = 0.005 m ) for one-third and two-thirds of samples, respectively. A σ^? value of 16 meq/100 g clay at pH = 7 and C = 0.01 m was found appropriate to separate the B₂ horizons of Thai Ultisols and Oxisols from those of Korean Ultisols and Alfisols. Korean Alfisols and Ultisols and Thai Ultisols were distinguished from each other on the status of exchangeable base and Al     

氮钾配施对芋头产量和品质的影响

采用二次饱和D-最优设计,研究了氮钾肥配施对芋头产量和品质的影响,并建立了以氮、钾肥施用量为变量因子,芋头产量和品质为目标函数的二元二次数学模型。模型解析表明,氮、钾肥对芋头产量和品质均有显著影响,且钾肥的影响大于氮肥;氮、钾肥之间存在显著的交互效应。在氮(N)、钾(K2O)施用量分别为261.75kg/hm2、757.50kg/hm2以内,产量随施肥量的增加逐渐提高,超过此施用量,则产量下降。在本试验条件下,施肥量为N34.5～531.0kg/hm2,K2O.526.8～1057.2kg/hm2,芋头产量可达30000kg/hm2以上。     

Comparison of Antioxidant Components and Activity of Buckwheat and Wheat Flours

Plant phenolics and tocopherols content were determined in light and wholegrain buckwheat and wheat flour. Antioxidant activity of flours were comparatively assessed by scavenging activity on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH^•), hydroxyl (^•OH), and superoxide anion (O₂^•–) radicals, reducing activity, and chelating activity on Fe²⁺. Rutin, quercetin, and ferulic acid were quantified in both buckwheat flours, while ferulic acid was quantified in wholegrain wheat flour. Significantly higher content of phenolics and tocopherols was found in buckwheat than in wheat flours. Tocopherols in buckwheat flours were present in the order: γ‐ > α‐>> δ‐tocopherol, and in wheat flours: α‐ > γ‐ >> δ‐tocopherol. Buckwheat flours possessed better scavenging abilities on DPPH^•, ^•OH and O₂^•– radicals, as well as better reducing activity, while wheat flours showed better chelating activity on Fe²⁺, according to IC₅₀ values. Results suggest the possibility of improving the antioxidant properties of wheat‐based food products through addition of buckwheat flour.     

Visible injury and growth responses of tomato and soybean to combinations of nickel,copper and ozone

Tomato (Lycopersicon esculentum Mill.) plants were grown in silica sand in controlled environments. In the first experiment Ni was added as NiSO₄ · 6 H₂O to the nutrient solution at 0, 1.5, 7.5, or 37.5 mg L^?1 for 6 day beginning 14 day from seeding, them plants were exposed to 0, 0.15, or 0.30 μL L^?1 O₃, and harvested 3 day later. Visible symptoms of Ni injury developed rapidly and there was distinctive O₃ injury. Growth variables were markedly reduced by Ni but O₃ response depended on Ni level. In the second experiment 0, 0.3, or 1.5 mg L^?1 Ni was provided from the 5th or 14th day onward. There was little effect of duration of Ni treatment on growth. Increasing Ni and increasing O₃ decreased growth but there was no interaction. In the third experiment 0, 1.5, and 3.0 mg L^?1 Ni treatments were combined with 0, 3.0, and 6.0 mg L^?1 Cu prior to 0 or 0.25 μL L^?1 O₃ treatment. There were complex interactive effects of all three factors on plant growth. Soybean (Glycine max Merr.) plants exposed to Ni and O₃ were only slightly affected by Ni or O₃ and there was no interaction.     

Formation and remobilisation of soil microbial residue. Effect of clay content and repeated additions of cellulose and sucrose

In two studies, we assessed the mass balance of added ¹⁴C-labelled sucrose and ¹⁵NH₄¹⁵NO₃ by measuring ¹⁴CO₂, ¹⁴C and ¹⁵N in soil microbial biomass (SMB) and ¹⁴C and ¹⁵N in soil solution. Specifically, we assessed the potential of recently added ¹⁴C to be re-mobilised by cryptic growth using subsequent additions of sucrose and cellulose and the effect of physical protection on the stabilisation of the labelled substrate. We used both a constructed soil with low soil organic matter content and varied the clay content as well as a natural soil. We observed a substantial initial as well as a later stage transfer of ¹⁴C into unidentifiable form, hypothesised to be microbial residues. When using a standard k _EC value of 0.45, only roughly 50% of the added labelled substrates were accountable and therefore we explored the full range of reported k _EC values to assess the mass balance. Subsequent application of unlabelled sucrose and cellulose did not substantially increase turnover ¹⁴C and ¹⁵N. Contrary to our expectation, there was no effect of clay content on the amount of unidentified ¹⁴C and ¹⁵N. The unidentified ¹⁴C and ¹⁵N is ascribed to formation of soil microbial residue. The low recovery of added isotope suggests that our mechanistic models are missing a large and important pool in order to realistically simulate organic matter turnover in soil.     

Nematicides and field population of enchytraeids and earthworms

Enchytraeid and earthworm populations of a Typic Haplaquoll soil after application of the nematicides oxamyl and phenamiphos were examined for 1 yr. The nematicides had no effect on enchytraeid numbers, which were positively correlated with soil moisture and the previous month's rainfall. Earthworm populations were dominated by Allolobophora caliginosa (Savigny) with A. trapezoides (Duges) and Eiseniella tetraedra (Savigny) also present. Both nematicides initially depressed earthworm numbers and the effects of phenamiphos appeared to persist until the soil became wet in Autumn. Earthworm numbers were positively correlated with soil moisture and previous month's rainfall. Enchytraeid numbers at 2.5–5 cm depth were negatively correlated with soil temperature. Numbers of enchytraeids at 0–2.5 cm depth and earthworms were not significantly related to soil temperature.     

Rate of nitrapyrin and soil ph effects on nitrification of ammonium fertilizer and growth and composition of burley tobacco

Abstract

Laboratory and greenhouse experiments were conducted to determine the effects of rate of nitrapyrin and soil pH on nitrification of NH₄ ⁺ fertilizer in soil, and growth and chemical composition of burley tobacco (Nicotiana tabacum L. cv. ‘KY ‐14'). Such experiments were needed to develop information for increasing efficiency of N fertilizer use and to lessen the fertilizer‐induced soil acidity and salt effects on tobacco plants.

Results for laboratory and greenhouse incubations indicated that nitrification proceeeded slowly below pH 5.0 and the nitrapyrin necessary to delay nitrification increased with both increasing soil pH and length of incubation time. Generally, nitrification could be delayed 30 days by nitrapyrin rates of 0.25 or 0.5 μg g^‐1 regardless of soil pH. but rates of 1 μg g^‐1 nitrapyrin or higher were required for 60 days and longer incubation times, particularly at higher soil pH.

Growth and morphology of tobacco plants were either unaffected, or affected positively, by low rates of nitrapyrin (up to 2 μg g^‐1). However, rates of 4 μg g^‐1 and above reduced total plant dry weight, reducing sugars and contents of mineral elements. Concentrations and content of plant NO₃ ^‐ N and Mn were greatly decreased by application of nitrapyrin. Values for most parameters measured increased with increasing soil pH. The data show that low rates of nitrapyrin may be used to alter the ratio of NO₃ ^‐ to NH₄ ⁺ N absorbed by tobacco and possibly improve growth and safety of tobacco.