南京珍珠泉风景区林相改造探析

针对南京珍珠泉风景区主景点自生杂木林结构混乱、林相单一、缺乏层次和季相变化、观赏效果差的林相现状,提出了4种林相改造模式:景区道路两侧的改造,改造行道树及其道路两侧配置的观赏灌木和地被植物;近水区域林地植物配置,在近水面区域种植耐水湿、观赏性较高的树木、耐水湿乡土树种、开花或观叶地被植物及蕨类植物;离岸区域林相改造,保留原有骨干树种,根据景观需求和树种特性进行适当修整;远景的林相改造,即以现有自然植物群落为基础,加以人工辅助措施,加速其自然演替进程。最后对南京珍珠泉旅游度假区的发展前景进行了展望。     

草坪足球场的建植与改造

随草坪科学与体育事业的发展，国内正以草坪足球场逐步取代裸地足球场，目前我国对草坪足球场的研究仅刚开始，与世界先进国家差距很大。建植草坪足球场要求一定的质量标准，对场地规格、草坪草的种植与养护都要规范，特别是草坪足球场的土壤特性、草坪的水分平衡、草坪草的营养、草坪草的品种选择、肥水与植保养管等现尚无章可循，笔者多年从事大连、天津等草坪足球场建植与改造工作，总结出实践经验，可供借鉴。     

雾生绿蔓 流水听音——白云山蒲谷沟谷雨林改造构思

通过模拟雨林典型的生态现象，增加有雨林特色的植物，改造区域内的原有建筑等手法去改造蒲谷，以期达到沟谷雨林的效果。     

乳山寨滩涂缢蛏半人工采苗的研究

为解决北方沿海缢蛏养殖的苗种问题，在乳山寨滩涂建立缢蛏半人工采苗场，对苗坪适时进行翻耕平整，加强培育管理，１９９３年４ｈ采苗场共采蛏苗８７７０万粒，平均２２１５粒／，平均壳长２．５ｃｍ；１９９４年４０ｈ采苗场共采蛏苗５亿粒，平均１４２８粒／，平均壳长２ｃｍ。结果发现，附苗前翻松平整的苗坪附苗数量远高于未翻松平整的苗坪。山东沿海移养缢蛏性腺于９月中旬至１０月上旬进入成熟期，１０月上、中旬开始放散     

栅条式液压翻转调幅犁设计与试验

随着大功率拖拉机在新疆地区的推广使用,与其相配套农机具的研制相对滞后,使得大功率拖拉机的优势难以充分发挥。研制开发与大功率拖拉机相配套使用的栅条式液压翻转犁,对该犁的主犁体、悬挂装置、调幅装置等关键部件进行设计,通过该型犁的田间实地测试,对试验结果和机具工作状况进行记录分析。田间试验结果表明,栅条犁作业速度9.1 km/h,耕深350 mm,耕宽2 700 mm,运行平稳、翻垡均匀,各项指标均达到或者超过国外同类机具水平,为大功率拖拉机在新疆地区的应用起到积极的推进作用。     

晋西黄土丘陵沟壑区土壤抗侵蚀能力的试验研究

通过大量的野外试验及调查,探讨了晋西黄土丘陵沟壑区土壤抗蚀性的时空变化规律、天然撂荒地的抗冲刷性能以及表土生物结皮、农耕地的犁底层等对土壤抗侵蚀能力的影响。结果表明:(1)晋西黄土丘陵沟壑区小流域的坡地土壤抗剪力及抗蚀性存在明显的时空变化规律。总体上,旱季的土壤抗蚀性高于雨季;峁顶缓坡地的土壤抗蚀性高于梁坡下部陡坡地。(2)只要土壤的整体结构不被破坏,即便水流冲刷力很大,黄土易蚀的特点也不易表现。尽量避免人为破坏黄土的整体结构,也是减少黄土侵蚀的重要手段。(3)黄土生物结皮,可大大增强土壤的抗侵蚀能力,减沙效应同结皮覆盖率成正比;犁底层在黄土地区的农耕地普遍存在,且会加剧耕作层的侵蚀作用。     

内蒙古中西部草地整治与建立节水型饲料作物基地探讨

阐述了内蒙古自治区中西部草地普遍存在的退化问题,表现为生产力大幅度下降,草群质量降低;土壤裸露化、沙漠化土地面积日趋扩大;河流退缩,绿洲植被濒临大片枯亡;自2000年以来各地纷纷退耕还草,建立人工饲料作物基地,在实施中又出现人工草地生态系统不稳定,水资源浪费严重,建设成效落后于大面积资源损伤速度以及草地生态安全体系不健全等问题。并提出分片整治与异地育肥、重建草地生态安全保障体系及产业向多元化转移和建设节水型饲料作物基地的整治战略。     

三段式心土混层犁及其改良白浆土效果的研究

三段式心土混层犁为改造白浆土土体构型实现了“上翻20 cm，下混30～40 cm”的农艺要求，白浆层与淀积层的土壤混拌率M_x达到0.7，白浆层向淀积层的土壤转移率T_Aw→B达到了0.3。0～40 cm土层土壤物理性状明显改善，疏松透水，硬度下降，农田表涝现象得到缓解，效果持久稳定，连续4年测定，耕翻一次后至第4年其土壤硬度仍然明显低于常规耕作田块。1996年～1998年大面积示范试验，使用该犁耕翻地块作物增产达10%～27.9%。该犁作业幅宽50 cm，深度60 cm，总牵引阻力30～35 kN。     

The role of clay, organic carbon and long-term management on mouldboard plough draught measured on the Broadbalk wheat experiment at Rothamsted

Despite a high energy requirement, the mouldboard plough remains the dominant tillage tool in northwest Europe. The aim of this work was to evaluate the relative influences of soil texture (clay content), soil organic carbon (SOC) and long‐term management on soil‐specific draught (S), where S is the force per cross‐sectional area of worked soil. Measurements were made during autumn 2000 on the then 157‐year‐old Broadbalk wheat experiment at Rothamsted, UK, where clay contents vary from 19 to 39% and the different cropping history, mineral and organic fertilizer treatments lead to SOC values of 0.7–3.2%. Minimum SOC values increased with increasing clay and were associated with zero or low mineral N inputs, while higher SOC values (>2%) were associated with long‐term applications of farmyard manure (FYM), despite these being on the lighter (<24% clay) soils. S values ranged between 52 and 142 kPa, with higher values co‐located in areas with high clay contents. Contour maps were generated to illustrate the spatial variability of S and show similarity to those for clay. Where FYM had been added, S was 66 kPa compared with 74 kPa where only mineral or no fertilizer was applied on soils of the same texture. Increasing applications of mineral N resulted in relatively small increases in SOC but up to 12% reduction in S.     

Land management effects on the near-surface physical quality of a clay loam soil

Although agricultural land management is known to affect near-surface soil physical quality (SPQ), the characteristics of these affects are poorly understood, and diagnostic SPQ indicators are not well-developed. The objective of this study was to measure a suite of potential SPQ indicators using intact soil cores and grab samples collected from the 0–10 cm depth of a clay loam soil with the treatments: (i) virgin soil (VS); (ii) long-term continuous bluegrass sod (BG); (iii) long-term maize (Zea mays L.)—soybean (Glycine max (L.) Merr.) rotation under no-tillage (NT); (iv) long-term maize–soybean rotation under mouldboard plough tillage (MP); (v) short-term (1–4 years) NT after long-term MP; (vi) short-term MP after long-term BG; (vii) short-term MP after long-term NT. Organic carbon content, dry bulk density, air capacity, relative water capacity and saturated hydraulic conductivity appeared to be useful SPQ indicators because they were sensitive to land management, and proposed optimum or critical values are available in the literature. Soil macroporosity was also sensitive to land management, but optimum or critical values for this parameter are not yet established. Soil matrix porosity and plant-available water capacity did not respond substantially or consistently to changes in land management, and were thus not useful as SPQ indicators in this study. Converting long-term BG to MP caused overall SPQ to decline to levels similar to long-term MP within 3–4 years. Converting long-term NT to MP or vice versa caused only minor changes in overall SPQ. With respect to the measured SPQ indicators and their optimum or critical values, both VS and BG produced “good” overall SPQ in the near-surface soil, while long-term maize–soybean rotation under NT and MP produced equally “poor” SPQ.