不同覆盖材料对苗床补光效应的研究

在放帘后的温室内 ,日光灯在苗床上同一高度平行悬挂 ,用反光膜、蓝膜和无覆盖进行三种不同的覆盖处理 ,测定灯下与灯间下各点的光强 ,研究各处理灯下与灯间下光强分布规律和对苗床上的增光效果。结果表明 ,覆盖材料对光强分布规律影响不大 ,蓝膜对苗床上灯下与灯间下各点光强增加效果不显著 ,而反光膜对上述各点光强增加显著 ,说明反光膜的反光与聚光效果非常好。     

Germination Syndromes and Their Relevance to Rangeland Seeding Strategies in the Intermountain Western United States

Rangelands in the western United States exhibit extremely high temporal variability in seedbed microclimate, and this variability contributes to poor establishment of revegetation species that are typically planted in the fall. We conducted long-term simulations of cumulative germination as a function of planting date and identified alternative germination syndromes based on population-level responses to environmental variability. These germination syndromes reveal ecologically significant differences but also noteworthy similarities in species and seed lot response that can inform rangeland restoration planning and management. Seed germination may occur much sooner than assumed under the traditional paradigm of fall-planting/spring-emergence in the intermountain western United States, and seed germination per se does not appear to be a bottleneck for successful establishment in most years. Instead, simulations of germination response support recent hypotheses that postgermination/preemergent mortality may be the larger contributor to poor seedling establishment. Our data support two general strategies to improve the likelihood of seedling survival into the spring: seeding as late as possible in the fall and active diversification of germination syndromes within a given seed mix. Consistent application of these strategies could increase the probability that some seeds are always available to take advantage of any pulse of seedbed favorability in the late fall, winter, or early spring.     

Crop Response to Improved Drainage of Vertisols in the Ethiopian Highlands

The effect of flat seedbed, traditional ridge and furrow and improved drainage of broad bed and furrow (BBF) on grain and straw yield of durum wheat, chickpea and lentil at several Vertisol sites between 1988—1991 was such that on three crops the BBF system gave the highest grain and straw yields at all locations and seasons. This was followed by traditional ridge and furrow system and the least yield was obtained from flat seed beds. The extent of drainage influence on yield was dependent on rainfall quantity, location (clay content) and crop species. The advantages of the BBF technology in improving drainage and increasing crop yield are discussed in their contexts of better cropping systems.     

烤烟托盘水床育苗大田示范效应研究

对烤烟托盘水床育苗和常规(营养袋)育苗的烟苗素质及其大田生长发育情况和产量、质量进行了对比分析,结果表明:托盘水床育苗烟苗素质优于常规育苗;托盘水床苗移栽大田后生长迅速,植物学性状优于常规苗,并对烟株上部叶开秸开片作用明显,收获叶片平均增加2片左右;托盘水床苗抗花叶病效果明显,且大田生育期延长,对叶片干物质的形成和积累有利;其产量、产值、均价和上等烟比例等各项指标均优于常规苗,特别是产值和上等烟比例提高幅度较大,分别达到25.52%和24.15%。     

石灰苗床阔叶树容器育苗技术研究

石灰苗床阔叶树容器育苗试验结果表明：石灰苗床容器苗主根和高生长受到一定程度的抑制，但地径、侧根生长发育、须根数量及根系含水量均有显著改善，并避免了苗木的畸形．石灰苗床容器苗的规格质量及造林成活率也明显比对照组好．     

提高冬培马铃薯苗抗逆适应的隔地苗床模式研究

以无膜垫层隔地苗床为对照,研究了全膜垫层苗床和孔膜垫层苗床对冬培马铃薯苗生物量构成、光合效率、渗透调节性能和膜脂过氧化伤害的影响。结果表明,①膜垫层隔离苗床使不同生育期马铃薯株高、茎粗、叶面积、根、匍匐茎和块茎生长加快,总生物量增加;②膜垫层隔地苗床使马铃薯净光合速率、蒸腾效率和脯氨酸增加;③不同模式隔地苗床中,马铃薯叶片丙二醛表现为:无膜>全膜>孔膜;根部丙二醛表现为:全膜>无膜>孔膜。在马铃薯隔地冬培中,孔膜垫层苗床和全膜垫层苗床使马铃薯生长加快,光和效率和渗透调节功能加强,而且,孔膜垫层能有效减少冬培中亚低温、弱光和高湿所诱发的膜脂过氧化伤害。     

自动覆膜控温移动苗床控制器的设计

随着农业现代化进程的不断推进,传统农业育苗技术逐渐向着自动化、智能化方向发展。针对具有电动覆膜和加热功能的新型移动苗床,设计了一种基于嵌入式和传感技术而开发的移动苗床控制器。控制器通过感知苗床内的温度、湿度,适时自动控制收、卷覆膜和加温装置,从而使苗床内"小环境"适宜种苗生长。控制器对移动苗床精准化、个性化的控制,能够达到解放劳动力、提高生产效率、节能降耗的目的。     

山皂角营养钵和苗床育苗效果浅析

通过对山皂角采取营养钵和苗床两种方法进行育苗试验,结果表明:山皂角采用营养钵育苗,无论是树高还是地径生长量,均较对照苗床育苗高,出苗率达到96.4%,平均苗高达到59.3cm,平均地径达到0.41cm。山皂角的营养钵育苗有利于生产高品质的苗木,提高造林成活率。     

基于毛细管网的日光温室苗床加温系统研究

针对日光温室冬春季育苗温度低且传统加温设备能耗高的特点,设计基于毛细管网的日光温室苗床热水加温系统,并于冬季在河北省永清县对系统的加温效果进行实际测试。以无加温育苗区为对照,研究分析毛细管网加温对空气温度和基质温度的影响,探讨了隔热层在加温苗床中的作用。结果表明:毛细管网苗床加温可使育苗基质夜间温度平均值及最低值提高3.2~3.4℃和0.8~1.4℃;铺设聚苯板可使夜间基质温度平均值提高0.6℃;基质温度的最低值偏离度为0~9.4%,平均值为1.5%~2.5%。基于毛细管网的苗床加温系统可有效提高苗床局部温度环境且加温均匀,对幼苗长势一致提供有力保障。     

Longevity of seeds of Poa pratensis and Lolium perenne as affected by simulated soil tillage practices and its implications for contamination of herbage seed crops

In grass-seed production, the purity of the product is of major importance and high purity can only be obtained by preventing contamination with other species and cultivars during the whole crop rotation. In this context, seeds of previously grown grass species or varieties are particularly important. This study investigated the influence of different soil tillage practices on persistence of newly shed seeds of two grass species, Poa pratensis and Lolium perenne . Leaving the seeds at or close to the soil surface reduced seed survival of both species to low levels compared with strategies that involved a deep incorporation of the seeds shortly after seed-shedding. Survival rate of seeds of P. pratensis after 1 year was reduced to a low level when seeds were left at the soil surface for 2–3 months before incorporation. Seeds of L. perenne were less persistent and survival rate after 1 year was generally very low if the seeds were left near the soil surface for approximately 1 month before deeper incorporation. Use of the stale seedbed technique to reduce the seedbank of the two species in the autumn ahead of a spring-established grass-seed crop was also found to be effective in reducing the potential risk of contamination.