共查询到19条相似文献，搜索用时 250 毫秒
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从2010年4月开始，在北京丁香园小区研究不同处理方法对草坪草生长速度的影响。以高羊茅草坪为例，不同施肥种类：尿素、磷酸二铵、包裹型草坪专用肥（10g／m^2的等N量分别施入），以及不同施肥时期对草坪成坪速度的影响。试验数据及分析结果表明：施肥方面包裹型草坪专用肥肥效最长，施用后草坪分蘖密度和地下生物量适中并且变化较平缓，而草坪在每月均有养分供给的平均施肥情况下质量表现优于春、秋2次施肥的处理，草坪草生长较为平缓，有利于草坪草健康生长。 相似文献
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两种包膜尿素的氮释放特性及对高羊茅生长的影响 总被引：2，自引：0，他引：2
采用水浸泡法对2种包膜尿素(CU-1和CU-2)的初期溶出率和微分溶出率进行测定。2种包膜尿素的初期溶出率分别为9.5%和1.36%,符合国际上公认的缓/控释肥的初期溶出率小于15%的指标,而微分溶出率分别为2.48%和1.72%,也符合国际上公认的缓/控释肥的微分溶出率(0.25%~2.5%)的指标。通过盆栽试验研究了普通尿素(S1)、包膜尿素(H1和H2)以及二者配比(F1、F2、F3和F4)对高羊茅建植期生长的影响。结果表明:单一施用CU-2处理以及CU-2配施50%普通尿素处理明显促进了高羊茅地上部与地下部生物量的积累,促进了高羊茅对氮的吸收,尤其是生长后期,叶片中氮含量显著高于尿素与空白处理。另外,包膜尿素的应用减小了草坪生长速率的波动。 相似文献
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肥料袋控缓释对沾化冬枣氮素利用率与生长结果的影响 总被引：6，自引：0，他引：6
袋控缓释肥根据果树个体较大的特点, 改变一般控释肥颗粒包膜的设计思路, 利用控释袋包装达到控制肥料释放的目的。以沾化冬枣为试材对袋控缓释肥进行大田试验, 结果表明: 肥料袋控缓释处理生长季土壤有效养分浓度稳定, 而肥料散施处理土壤养分浓度波动大; 施用10袋/株(16.5 g/m2 ) 纯氮时, 袋控缓释处理氮素利用率约为一次性散施处理的2.8倍, 约为分次散施处理的115倍; 养分稳定供应,冬枣植株生长健壮, 能有效克服肥料散施导致短期内土壤有效氮水平过高, 刺激枣头大量萌发造成营养竞争的问题; 同一施肥水平, 袋控缓释处理植株的叶片叶绿素含量与Pn值高且稳定, 产量与果实品质显著提高。 相似文献
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采用从其他作物转移与利用自身EST序列设计两种方法为高羊茅（Festuca arundinacea L.）开发EST-SSR分子标记,并利用所开发标记对高羊茅品种（系）进行遗传多样性分析。利用来自小麦、大麦、玉米、高粱和水稻的732对EST-SSR在高羊茅上进行通用性分析,得到406个有效的扩增引物对（55.46%）。利用高羊茅EST数据库（GenBank/dbEST）中63 853条EST序列进行微卫星序列的查找,共发现包含微卫星的EST序列420条,占整个EST总数的0.658%。其中三核苷酸基序出现频率最高（43.33%）,次之为二核苷酸基序（33.57%）。二核苷酸基序以CT/GA出现频率最高（16.90%）,三核苷酸基序以CAG/GTC出现的频率最高（10.63%）。进一步运用Primer 5.0软件设计了108个引物对,并交上海桑尼公司合成。PCR检测表明,92个引物对（85.19%）在高羊茅中均可以扩增出稳定清晰的带型。从498对（其中5种作物的406对,高羊茅的92对）有效扩增的EST-SSR引物中随机选取81对引物,对12个高羊茅品种（系）进行扩增。79个引物对显示出多态性（97.53%）。共检测到133个等位变异,平均每对引物有1.68个等位变异;多态性信息含量（PIC）值最高为0.66,最低为0.14,平均为0.48。聚类分析结果表明,12份材料在相似系数为0.61处可分为5大类：第Ⅰ类为‘爆发力’和‘法思’;第Ⅱ类为‘强劲’、‘家园’和‘翠碧A’;第Ⅲ类为‘可其思3号’和‘凌志’;第Ⅳ类为‘雅典娜2号’、‘美洲虎3号’、‘火凤凰’和‘TF160’;‘球道’单独为第Ⅴ类。 相似文献
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In recent years, environmental concerns have created a desire for the sustainable care of grass swards, with a specific goal of reducing resources needed for turfgrass maintenance by utilising low-input species best adapted to specific local environmental conditions. A two-year field experiment was conducted to compare the aesthetic or ornamental quality, and function potential, of different swards. The treatments consisted of four monostands of white clover (Trifolium repens L.), yarrow (Achillea millefolium L.), strong creeping red fescue (Festuca rubra L. ssp. rubra Gaudin), and tall fescue (Festuca arundinacea Schreb. = Schedonorus arundinaceus Schreb. Dumort.), three two-species mixtures of white clover + yarrow, white clover + strong creeping red fescue, and yarrow + strong creeping red fescue, and one three-species mixture of white clover + yarrow + strong creeping red fescue. Within each plot, a botanical survey was performed each spring to estimate species relative abundance by determining the proportions of different species present. All plots were evaluated every two weeks during the growing period for visual quality and normalised difference vegetative index. Vegetation canopy height in each plot was measured before each biweekly mowing event, and clippings were collected to measure vegetative dry matter. Relative abundance of yarrow, strong creeping red fescue, and tall fescue was stable throughout the entire study period. The mixtures including yarrow displayed sufficient or higher quality ratings (≥6) in all seasons with the exception of winter, however, yarrow + strong creeping red fescue compensated each other's defects by maintaining their relative abundance (≥ 80%) over time as well suppressing or prevent significant weed invasion (relative abundance <15%). Moreover, yarrow or strong creeping red fescue monostands, or yarrow + strong creeping red fescue could be maintained with lower number of mowing events, due to their lower vertical growth. In conclusion, alternative plant species to turf-type grasses produced a visual quality equal to or better than tall fescue maintained under low fertilisation and mowing frequency. All swards that included yarrow produced better visual quality, exhibited better weed control, had lower vertical growth rate, and provided an aesthetically pleasant, persistent, and sustainable vegetative ground cover than other swards, and can be utilised as a low-input species. 相似文献
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Nitrogen fertilization during planting and establishment of the urban forest: A collection of five studies 总被引：1，自引：0，他引：1
Today's urban forest increasingly consists of planted trees, especially as native forest fragments yield to urban sprawl. These trees are usually larger (over 2-m tall) than typical reforestation trees and grow very little for the first few years after planting. Stressful urban sites exacerbate this effect and many practitioners hope to shorten the time required to reach environmentally functional size by fertilizing at planting. This is a controversial practice since nitrogen (N) application creates the potential for water quality impairment and effectiveness is uncertain. It is not clear how nitrogen application affects large trees with radically altered root:shoot ratios or how nursery production methods and restrictive sites affect response. In a series of five separate studies, we tested several N rates on ten shade tree species (both field- and container-grown) and transplanted to a range of urban sites, from a relatively undisturbed forest fragment to a highly compacted cutover soil with an absent A horizon. Trunk diameter increase, as an integrative metric of tree biomass accumulation, was followed for up to 4 years on each experiment. Overall, we saw little effect from fertilizing at planting at any rate we tested, regardless of location. Three studies that included leaf analysis with a SPAD-502 chlorophyll meter indicated that neither SPAD meter values or N concentration within leaves was increased by fertilizing at planting, suggesting that the newly planted shade trees took up very little of the applied N. Overall, SPAD-502 readings correlated well with actual leaf N concentration (r=0.692). This group of studies indicates that fertilization at planting does not increase post-transplant growth, even in stressful urban sites and it is therefore not effective at shortening the establishment period of transplanted shade trees. 相似文献
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Managed turf areas are both a source and a sink for greenhouse gases (GHGs). Management practices, including turfgrass selection and mowing, influence the amount of carbon (C) and nitrogen (N) stored in the soil, as well as the associated GHG emissions. The objective of this research was to determine the net C and N balance (i.e. the amount of C and N stored less the amount emitted) of managed turfgrass systems with different grasses (species and cultivars) and management practices (mowing frequency and grass clippings management). Data explicitly quantified in this experiment include annual mowing requirements and accompanying GHG emissions, annual dry matter yield, soil C and N accumulation, and GHG flux of tall fescue (Schedonorus arundinaceus) and Kentucky bluegrass (Poa pratensis) cultivars with varying growth rates. Leaf, verdure, and root tissue C and N were also determined, along with the corresponding biomass. Estimations of emissions from fertilization, irrigation, and pesticide applications were also included in the net balance calculations.All of the turfgrasses and management practices in this experiment resulted in a system-wide net C sink, though the magnitude of the sink varied by turfgrass selection and management strategy. In general, higher-yielding grasses and management practices increased soil C but also increased mowing requirements and thus emissions. Returning grass clippings was found to increase yield, soil and leaf tissue N, and soil C, but it also marginally increased mowing requirements. The results of this experiment support the assertion that managed turfgrass areas can act as a net C sink to help curb the increasing atmospheric GHG concentrations. The C sequestration potential of managed turfgrass is another of the numerous functional benefits of urban grasslands. 相似文献
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设不施氮、施普通尿素、施控释尿素80％、施控释尿素60％4个处理,研究控释尿素对鸭梨产量、品质和土壤氮素的影响.结果表明:与100％普通尿素比较,控释尿素的用氮量为普通尿素的80％,0～30 cm土壤的碱解氮与硝态氮的含量及梨果的产量显著增加.用氮量60％,与普通尿素的接近.控释尿素处理的梨果品质、氮肥利用率显著提高,且以用氮量60％的肥效最佳. 相似文献