冀西北不同坡位油松林土壤理化性质差异

为探究坡位对油松林土壤理化性质的影响，以冀西北不同坡位油松林为研究对象，分析不同坡位土壤理化性质差异。结果表明：(1)冀西北油松林土壤容重在1.01～1.09 g/cm³之间变动，土壤容重坡上普遍高于坡下，二者差异显著；垂直梯度土壤容重随土层深度增加而增加。(2)土壤总孔隙度变化范围为43.48%～61.48%,随土层厚度增加而减少，坡上与坡下差异显著，平均来看坡下高于坡上。(3)土壤持水能力坡上与坡下差异较大，坡下总体高于坡上，其土壤饱和持水量最大相差108 t/hm²。(4)土壤养分坡上和坡下总体差异显著，均呈现坡下>坡上；从土壤垂直梯度来看，全氮、全磷与有效磷随土层厚度增加而增加，全钾、碱解氮与速效钾在土层垂直梯度上变化不明显。有机碳随土层厚度增加而减小，土壤pH值坡上与坡下差异不明显     

冀西北不同林分类型土壤贮水与入渗特征

为改善冀西北森林水土保持和水源涵养的能力,在河北省张家口市涿鹿县林场选择油松、华北落叶松、山杨、白桦4种林分类型,以撂荒地作为对照,进行了土壤入渗和贮水特征的研究。结果表明,土壤饱和贮水量排序为：白桦林(373.24 mm)>油松林(352.72 mm)>山杨林(325.20 mm)>华北落叶松林(306.28 mm)>撂荒地(286.30 mm)。土壤容重均值排序为：白桦林(0.90 g/cm³)<油松林(0.95 g/cm³)<山杨林(0.99 g/cm³)<华北落叶松林(1.00 g/cm³)<撂荒地(1.27 g/cm³)。土壤入渗速率与入渗时间呈现明显幂函数关系,林分的土壤渗透性能均高于撂荒地,其中白桦林稳渗速率最大(5.21 mm/min),水土保持能力最好。土壤容重与土壤孔隙度、贮水量呈负相关关系。森林对非毛管孔隙(滞留贮水)的改善作用要大于毛管孔隙(吸持贮水)的改善作用。     

接坝地区3种典型林分类型枯落物层和土壤层水文效应综合分析

以接坝地区3种典型林分类型为研究对象,对其枯落物层和土壤层水文效应进行研究,并运用熵权法对各林分类型水文效应进行综合分析。结果表明,枯落物总蓄积量与枯落物最大持水量规律一致,其大小排序为：油松华北落叶松混交林>油松林>华北落叶松林;枯落物持水量与浸水时间呈显著对数关系,枯落物吸水速率与浸水时间呈显著幂函数关系;枯落物有效拦蓄量排序为：油松华北落叶松混交林(26.04 t/hm2)>油松林(16.46 t/hm2)>华北落叶松林(11.36 t/hm2);土壤容重均值排序为：华北落叶松林(1.29 g/cm3)>油松林(1.24 g/cm3)>油松华北落叶松混交林(1.05 g/cm3);土壤最大持水量大小依次为：油松华北落叶松混交林(1 441.4 t/hm2)>油松林(963.5 t/hm2)>华北落叶松林(829.9 t/hm2);对入渗时间和入渗速率进行拟合,呈较显著的幂函数关系。对3种林分类型枯落物层和土壤层水文效应进行综合评价,结果表明水源涵养功能最强的为油松华北落叶松混交林。     

冀北山地不同坡位油松林土壤水文效应

对冀北山地不同坡位油松林土壤层水文效应进行初步研究,结果表明：（1）0~40cm土层内,土壤容重的变动范围在0.97~1.19g/cm3,土壤总孔隙度的变动范围在45.43%~54.50%,土壤容重随土层深度的增加而增大,总孔隙度随土层深度的增加而减小;（2）坡上样地Ⅱ和样地Ⅰ每10cm饱和持水量最大,分别为713.67t/hm2和708.56t/hm2,坡中样地Ⅲ饱和持水量最小,仅为583.00t/hm2,坡中样地Ⅲ和坡下样地Ⅳ每10cm土壤的有效持水量最大,分别为196.33t/hm2和185.00t/hm2,坡上样地Ⅱ有效持水量最小,仅为74.67t/hm2;（3）林下土壤初渗速率在76.09~20.81mm/min,稳渗速率在1.95~4.06mm/min,入渗速率与入渗时间存在明显幂函数关系。     

基于森林仿真优化系统(FSOS)确定塞罕坝主要森林类型全周期年采伐量

确定森林年采伐量是编制森林经营方案的核心内容之一。科学合理的森林年采伐量对于优化森林结构、提高森林质量,实现森林可持续经营具有重要意义。本研究基于河北省塞罕坝机械林场2019年更新的二类调查数据,以人工华北落叶松林、人工樟子松林和天然白桦林为对象,采用森林仿真优化系统（FSOS）分析多种采伐策略情境下主要森林类型龄组结构、蓄积量结构和经济效益等因素在未来100年期间的变化趋势确定不同森林类型最合理的年采伐量。结果表明：人工华北落叶松林年主伐量的优化结果为50 000 m³,年抚育间伐量的优化结果为100 000 m³;人工樟子松林年主伐量的优化结果为5 000 m³,年抚育间伐量的优化结果为40 000 m³;天然桦树林并无主伐设计,年抚育间伐量的优化结果为20 000 m³。3种森林类型的全周期采伐量优化结果显示,短期内采伐量会存在一定波动,但在未来80年后,采伐量将稳定在既定目标。FSOS系统以未来目标为导向,基于全周期经营理念,是编制新型森林经营方案的重要技术手段,为实现森林可持续经营奠定基础。     

重庆市公园绿化种植土壤渗滤性分析研究

公园绿化种植土壤作为城市绿地土壤的重要组成部分,研究分析影响其渗滤性的因素在海绵城市的建设中具有重要意义。经过对重庆市主城区几个公园38个土壤样品检测,土壤稳定入渗率在0.18～145mm/h范围内,平均值为29.9mm/h。经相关性分析发现,土壤稳定入渗率与土壤干容重、鲜样容重呈极显著负相关关系;与土壤田间最大持水量、土壤非毛管孔隙度、土壤总孔隙度、土壤有机质含量呈极显著正相关关系;与土壤田间最小持水量呈显著正相关关系;与土壤毛管孔隙度相关性较低。理论上土壤容重、土壤田间持水量都与土壤非毛管孔隙度有着关联,因此在考量公园绿化种植土壤渗滤性时可以将土壤非毛管孔隙度列为重点关注指标。     

间伐强度对油松林木生长的影响

抚育间伐是林场经营的重要方式,为了比较抚育间伐后林木生长的变化情况,以山西省关帝山国有林区的东葫芦林场油松为研究对象,以3500株/hm²为对照样地,分别进行10%(T₁₀)、20%(T₂₀)、30%(T₃₀)、40%(T₄₀)4种不同强度的间伐,对间伐后1年和3年的油松林木生长进行分析。结果表明,间伐有助于油松林木的生长,随间伐强度增加,油松树高、胸径、冠幅、单株材积和蓄积量均呈现逐渐变大的趋势。但胸径、冠幅、单株材积三者在一定间伐强度范围内,才有利于生长,并不是强度越大越好。而单位面积蓄积量在间伐后初期内,不会有增加,究其原因,是间伐后油松林木数量减少造成的,因此,应选择最适宜的间伐强度,以平衡单株材积和单位面积蓄积量。     

微生物菌肥与土壤调理剂配合施用对设施次生盐渍化土壤的改良作用

以黄瓜为试材,采用设施栽培的方法,研究了由于多年连续种植等造成的土壤板结、土壤盐分过高、微生物活性降低等土壤次生盐渍化问题,以期通过微生物菌肥和土壤调理剂配合施用,找到改良土壤次生盐渍化的方法。结果表明：次生盐渍化土壤同时添加微生物菌肥和土壤调理剂能改善土壤板结状况,降低土壤容重;降低表层土壤中的水溶性盐离子Ca²⁺、Na⁺、K⁺、HCO^-₃、Cl^-含量;同时,Ca²⁺和Na⁺向深层迁移,在20～40 cm的土层出现累积;能改变土壤微生物菌落结构,增加厚壁菌群、放线菌群等有益微生物的比例,增加土壤环境物种多样性和丰富度。     

不同灌溉方式下林地土壤水分物理性质的初探

对兰州市北山不同灌溉方式下人工林地50cm土壤深度以内的土壤容重、孔隙度、持水量等指标做测定,探讨不同灌溉方式下林地土壤水分物理性质。结果表明:在喷灌地中土壤容重比无水灌溉地和大水漫灌均有所降低;土壤总孔隙度、毛管孔隙度比无水灌溉和大水漫灌均有所增加,非毛管孔隙度由于一些未知的原因没有呈现出预期的结果;土壤饱和持水量、毛管持水量、田间持水量均比无水灌溉和大水漫灌有所增加。喷灌能在一定条件下降低土壤容重,改善土壤孔隙状况,提高土壤的持水能力,从而改善了土壤水分的物理性质。而大水漫灌不但不能改善土壤水分的物理性质,还导致水的利用率降低。因此在林地灌溉中应首选喷灌方式。     

如东沿海营造刺槐丰产林技术研究

如东县滩涂面积大,土壤含盐量高,平时海风较大,生态环境脆弱;目前刺槐作为盐碱地造林的先锋树种被广泛利用。从刺槐的育苗、造林、病虫害的防治、林分的抚育间伐、更新等技术方面进行研究,为提高刺槐林的生态及经济效益提供参考。     

雄安新区化肥使用及氮磷盈余空间分布特征研究

近年来，随着白洋淀内源污染与点源污染逐渐得到控制，农业面源污染逐渐成为制约白洋淀水质改善的重要因素。改善白洋淀生态环境状况，加强农业面源污染防控至关重要。然而，当前对雄安新区农业面源污染的认识尚待提高，尤其需要加强对种植业化肥使用及其氮磷盈余空间分布特征研究。因此，本研究以雄安新区主要种植模式小麦—玉米为研究对象，采用农田养分平衡方法，分析2016年雄安新区小麦—玉米氮、磷养分输入、输出与盈余情况，为雄安新区农业面源污染防控提供科学依据。结果表明：(1)雄安新区农田氮磷养分的输入以化肥为主，输出以籽粒为主，总体化肥氮、磷投入水平为446.82 kg/hm²、84.23 kg/hm²,籽粒输出氮、磷养分水平为312.71 kg/hm²、42.79 kg/hm²;(2)雄安新区小麦—玉米农田氮磷养分均表现为盈余状况，且氮磷养分盈余与氮肥、磷肥投入极显著正相关；(3)雄安新区氮素、磷素盈余强度分别为273.74 kg/hm²、44.99 kg/hm²,不同县市氮磷养分盈余量从高到低为安新县>雄县>容城县。建议进行合理的农田养分管理，开展养分平衡长期观测，实现化肥减量增效。     

苹果蠹蛾和梨小食心虫迷向剂复合干扰在南疆‘库尔勒香梨’园的应用效果

‘库尔勒香梨’园苹果蠹蛾、梨小食心虫同域混合发生,均钻蛀隐蔽为害,且抗逆性强,致使化学农药使用频繁而防效低下,已严重制约南疆特色‘库尔勒香梨’产业发展。通过田间性迷向干扰试验,测定了苹果蠹蛾和梨小食心虫性迷向剂在阿克苏地区‘库尔勒香梨’园(约9hm²)的应用效果。结果表明:苹果蠹蛾在该果园1年发生4代,梨小食心虫1年发生5代;性迷向剂胶条600、900、1200个/hm²处理的迷向率均在94%以上,复合迷向干扰效果明显优于对照。蛀果率调查结果显示,7月10日和8月10日性迷向剂胶条600、900、1 200个/hm²处理的蛀果率分别为0.50%、0.25%、0.13%和0.38%、0.25%、0.13%,均显著低于对照,整体上随时间延续防效更为明显。综上,采用性迷向剂对苹果蠹蛾和梨小食心虫进行复合干扰迷向防治有良好的效果,且具有环境友好的优势,综合考虑成本,建议田间使用性迷向剂胶条900个/hm²为宜。     

Effect of saline irrigation water on agronomical and phytochemical characters of chamomile (Matricaria recutita L.)

In arid and semi-arid regions, where water availability is a major limitation in crop production, using alternative water resources, such as saline water is one way to utilize lands. Chamomile (Matricaria recutita L.) as an annual medicinal herb may be considered as an economic substitute for field crops irrigated with fresh water since it has adaptability to wide range of climate and soil. A field examination was conducted during 2004–2005 using complete randomized block design with four replications in order to evaluate the effects of saline irrigation water on morphological characters, mineral content, oil quantity (content, yield), oil composition and apigenin content of chamomile. In each plot, 0.6 g/m² of seeds were grown in 4 rows. The irrigation water had five different salinity levels (0, 4, 8, 12 and 16 dS m⁻¹). The investigated characters through cultivation were fresh weight of flower (g), dry weight of flower (g), dry weight of aerial stems (g), dry weight of root (g), oil yield (kg/h), oil content (%), oil quality and apigenin content (%). After harvesting, the content of minerals (Na⁺, Cl⁻, K⁺, Ca²⁺, Mg²⁺) were evaluated in aerial parts and roots of each plot. Mean comparisons for fresh flower weight in different treatments showed that fresh flower yield decreased with increasing salinity and it was higher in control compared to others. Analysis of variance showed that saline irrigation water had no significant effect on oil quantity (yield and content), oil quality (chemical composition) or apigenin content. Our results showed that chamomile is able to maintain all its medical properties, under saline condition and could be cultivated economically in such conditions.     

园林植物土壤酶活性和微生物活性对盐碱胁迫的响应

以园林植物石楠为试材,通过混合2种中性盐(NaCl和Na2SO4)和2种碱性盐(NaHCO3和Na2CO3)分别模拟不同强度的盐、碱胁迫条件,对园林植物(石楠)进行3年(2015—2017年)的胁迫处理,以期探讨盐碱胁迫对园林植物土壤酶活性和微生物的影响。结果表明:1)土壤中有机酸含量随着盐碱浓度的增加呈逐渐降低趋势。随胁迫强度增加,盐、碱胁迫均使土壤中Na⁺浓度大幅度上升,K⁺浓度大幅度下降,但碱胁迫下Na⁺浓度上升幅度和K⁺浓度下降幅度均大于盐胁迫。2)随着盐碱浓度的增加,土壤中氨基酸类、碳水化合物类、羧酸类、聚合物类、胺类、酚酸类碳源呈逐渐降低趋势,总体而言,碳水化合物和羧酸类碳源是盐碱胁迫下园林植物土壤微生物的主要碳源,其次为氨基酸类、酚酸类和聚合物类,胺类碳源的利用率最小。3)土壤微生物物种丰富度指数(H)、均匀度指数(E)和碳源利用丰富度指数(S)、土壤微生物量碳、微生物呼吸和微生物代谢熵随盐碱浓度的增加而增加。4)土壤糖苷酶、几丁质酶、亮氨酸氨基肽酶、碱性磷酸酶、酚氧化酶δ和过氧化物酶δ随盐碱浓度的增加呈逐渐降低趋势。5)交互作用分析显示,盐胁迫、碱胁迫、盐胁迫×碱胁迫对有机酸、Na⁺、K⁺、Na⁺/K⁺、物种丰富度指数(H)、碳源利用丰富度指数(S)、土壤微生物量碳、土壤微生物呼吸、土壤微生物代谢熵、糖苷酶和碱性磷酸酶具有显著的影响(P<0.05),其中碱胁迫对土壤酶活性和微生物群落多样性的影响高于盐胁迫,并且盐胁迫×碱胁迫的影响高于单独盐胁迫或碱胁迫.     

Plant water stress and K starvation reduce absorption of foliar applied K by olive leaves

Three-month-old mist-rooted ‘Picual’ olive cuttings were transplanted into 2-l plastics pots containing perlite as substrate and fertigated with a complete nutrient solution containing 0.05, 0.1 or 2.5 mM KCl depending on the experiment. In the first experiment, plants were sprayed with RbCl (Rb⁺ is a K⁺ analog) at a rate of 4% at 63 days after transplanting (DAT). Foliar Rb⁺ uptake through leaves increased with K⁺ concentration in the nutrient solution, indicating that foliar Rb⁺ uptake was lower when plants were K⁺ deficient than when they were adequate. On the contrary, it was observed that translocation of Rb⁺ from leaves to other organs of the plant was higher under K⁺ deficiency conditions. In the second and third experiments, when differences appeared on shoot length due to K⁺ nutritional status (0.05 or 2.5 mM KCl) at 63 DAT, a group of plants were subjected to water stress during 7 weeks. On the other hand, another group of plants (control plants) did not receive any water stress treatment during the experiments. After this period of 7 weeks, all plants were sprayed with RbCl at 4%. Leaf K⁺ concentration diminished in water-stressed plants independently of plants nutritional status. Foliar Rb⁺ uptake through leaves was restricted by water stress either in plants with low K⁺ (0.05 mM KCl) or plants with high K⁺ (2.5 mM KCl). Translocation of Rb⁺ from leaves was greater under water stress conditions in both K⁺ nutritional statuses. In conclusion, the results obtained could explain the irregular response in olive trees to foliar K⁺ sprays, particularly, when they grow in rainfed orchards.     

兰州百合高效再生体系的建立

以兰州百合新鲜鳞片为试材进行高效再生体系的研究。结果表明：兰州百合中层、内层鳞片比外层鳞片容易再生不定芽,更适于作为外植体。鳞片在MS+0.5 mg·L^-1 6-BA+0.5 mg·L^-1 NAA 的诱导培养基上再生频率最高,可达90%;不定芽在MS+0.8 mg·L^-1 6-BA+0.05 mg·L^-1 NAA 的增殖培养基上增殖率最高,平均每芽新增芽4.5 个;不定芽在MS+0.8 mg·L^-16-BA+0.05 mg·L^-1 NAA+0.5 mg·L^-1 AC 的壮苗生根培养基上鳞茎的膨大倍数最高,生根数量较多,小苗长势优,移栽后成活率达98% 以上。     

Onion growth and yield are influenced by transplant tray cell size and age

Transplant tray cell size (volume) and age of containerized onion (Allium cepa L. cv. ‘Texas Grano 1015Y') transplants were evaluated for effects on survival, root and shoot growth, yield, and size. Transplant ages of 5, 7, 9, and 11 weeks and cell volume of 6.5 and 20.0 cm³ were used in Florida, and 6, 8, 10 and 12 wk, and 4.0 and 7.1 cm³ were used in Texas. Total yield in Florida was unaffected by transplant age in two planting seasons, but larger size bulb yield increased with increasing transplant age from 5 to 9 wk in 6.5 cm³ cells, and for 11-wk compared to ≤9-wk transplants in 20.0 cm³ in one season. Seed stem initiation was greatest in bulbs from 11-wk transplants in 20 cm³ cells. Survival in Texas was reduced for 6-wk compared to ≥8-wk containerized transplants. At planting, root number increased linearly with transplant age. Transplant cell volume in Texas did not affect root number, plant height or leaf number, but shoot dry weight was greater for seedlings grown in 7.1 cm³ cells compared to 4.0 cm³ cells. Total, jumbo and large size transplant yields in Texas were higher for 10 and 12-week transplants in 7.1 cm³ cells and 8, 10 and 12-week in 4.0 cm³ cells than yields in younger transplants. Total yields were unaffected by transplant cell volume but seedlings in 4.0 cm³ cells had a 16% decrease of jumbo size compared to those grown in 7.1 cm³ cells. Larger cell sizes are appropriate for 10–12-week transplants. The use of 8–10-week containerized transplants grown in small cell volume may be viable for onion stand establishment. Younger transplants may produce more large bulb yields if grown in larger cells, but they also have greater risk of reduced survival.