短期NaHCO3胁迫对3种冷季型草坪草生理生态特征的影响

土壤盐渍化严重威胁草坪草的可持续发展,选育和种植耐盐草坪草可改良和利用大面积盐渍土壤。以3种冷季型草坪草黑麦草(Lolium perenne L.)、高羊茅(Festuca arundinacea L.)和早熟禾(Poa pratensis L.)为试验材料,采用盆栽法研究不同浓度NaHCO3胁迫(0,0.2%,0.4%,0.6%,0.8%,1.0%)对3种冷季型草坪草生理生态特征的影响。结果表明:不同浓度NaHCO3胁迫下3种冷季型草坪草草坪外观质量、叶片萎蔫系数、叶片相对含水量、叶片叶绿素含量和K+含量均随着NaHCO3浓度的增加而逐渐降低,且浓度越高,下降越明显;0.4%～1.0%NaHCO3胁迫降低了3种冷季型草坪草的地上部分和根系干重,且随着NaHCO3浓度的增加,生长受到胁迫的抑制程度显著增大,根系部分的受抑制程度比地上部分更明显;不同浓度NaHCO3胁迫下3种冷季型草坪草叶片相对电导率、脯氨酸含量、丙二醛含量和Na+含量随着NaHCO3胁迫浓度的升高呈上升趋势,且浓度越高上升越明显;NaHCO3浓度0.4%时,3种冷季型草坪草已受到伤害;黑麦草、高羊茅和早熟禾在不同浓度NaHCO3胁迫下的隶属函数平均值均表现为早熟禾黑麦草高羊茅,说明3种冷季型草坪草抗NaHCO3胁迫的能力均为早熟禾强于黑麦草和高羊茅。     

北京地区典型冷季型草坪草灌水量模拟

为了减少北京地区草坪草灌水量、提高降水量的利用率,该文研究了充分利用降雨条件下的典型冷季型草坪草灌水量。根据典型冷季型草坪草（早熟禾、高羊茅）2003年的田间试验资料对灌溉制度模拟模型（ISAREG模型）进行了率定,然后用2004年的田间试验资料对ISAREG模型进行了验证,最后应用此模型对所研究的两种冷季型草坪草在干旱年、平水年和丰水年及不同养护条件下的灌水量进行了模拟研究。研究结果表明：生长季节内早熟禾、高羊茅的作物系数在0.5～1.0之间;在特级养护条件下,早熟禾和高羊茅所需灌水量分别为432～682 mm/a、462～752 mm/a;在一级养护条件下,早熟禾和高羊茅所需灌水量分别为252～432 mm/a、312～492 mm/a。研究结果可为北京地区冷季型草坪草的灌溉管理提供科学依据。     

污水灌溉对草坪土壤与植株氮含量影响的试验研究

污水灌溉是污水资源化利用的一个重要途径。该研究以草坪草的污水灌溉为例，选用了高羊茅、黑麦、早熟禾等3种典型的冷季型草坪草为主要试验草种，以地下滴灌和渗灌为2种灌水方式，以城市居民小区的生活污水经过沙过滤和沉淀处理的出水和自来水为2种灌溉水源，共设12个试验处理，进行了污水灌溉和清水(自来水)灌溉的田间对比试验研究，探讨了污水灌溉对土壤与植株氮含量的影响。实验结果表明，污水灌溉使草坪草根系层(0～30 cm土层)土壤中的全氮、速效氮和铵态氮的含量低于清水灌溉；与此相反，污水灌溉可使草坪草根系层及其以下土层硝态氮明显高于清水灌溉。污水灌溉也导致草坪草的植株中全氮的含量比清水灌溉平均高48%。两种污水灌溉方式下，土壤全氮、速效氮和铵态氮的含量差异不明显。但与滴灌相比，污水渗灌的土壤硝态氮的含量高于污水滴灌的情况，尤其是15～30 cm和30～45 cm土层，二者硝态氮含量差异显著。     

北京地区常用草坪草的耗水规律及适宜灌溉量研究

研究了在北京地区不同供水条件下，草地早熟禾、高羊茅、多年生黑麦草、野牛草、结缕草和狗牙根整个生长季的蒸散量差异和耗水规律。结果表明，蒸散量主要与草坪草的生物学特性有关，受水分条件影响；冷季型草坪草中多年生黑麦草耗水最少，暖季型草坪草中结缕草耗水最少；通过比较坪草和北方主要农作物的K_C值，得出草坪与大田作物的需水量相当；北京地区常用草坪草整个生长季的适宜灌溉量为：高羊茅(391.8 mm)>草地早熟禾(368.3 mm)>多年生黑麦草(315.1 mm)>狗牙根(300.7 mm)>野牛草(184.0 mm)>结缕草(110.5 mm)。     

作物残茬对农田土壤风蚀的影响

通过对不同留茬高度对地表风速的影响以及留残茬(保护性耕作主要方式)、旋耕和常规翻耕3种耕作方式对土壤风蚀的影响进行比较研究,得出如下结果:留茬高度对地表风速的影响程度不明显,仅与地面有无留茬有关,留茬20cm左右即可有效降低地表风速,减少田间扬沙,抵抗土壤风蚀,是比较适宜的留茬高度;留茬(保护性耕作)、旋耕和常规翻耕3种耕作方式对田间扬沙情况的影响差异明显,其中在60cm高度以内,留茬比常规翻耕减少田间扬沙量34.9%,比旋耕方式减少61.5%,因此,留茬(保护性耕作)是一种有效防止农田土壤风蚀的耕作方式。     

水土保持草坪草种抗旱及返青性研究

种植水土保持草坪是防治水土流失的一种有效措施。在气候干旱、土壤侵蚀严重地区研究草坪的抗旱性和返青率具有现实意义。甘肃省水土保持科学研究所于 1997～ 1998年对 10个供试草种进行测定分析 ,结果表明 :匍匐剪股颖、草地早熟禾、拉苏草地早熟禾、卡特多年生黑麦草、猎犬高羊茅、佛浪Ⅰ号高羊茅、皮歇高羊茅 7种草抗旱性较强。草地早熟禾、拉苏草地早熟禾的返青率最高     

留茬高度对带状留茬间作农田土壤防风蚀效果的影响

针对内蒙古阴山北麓农牧交错带土壤风蚀严重的问题,研究了带状留茬间作的防风蚀效果,通过测定风速、地表粗糙度和土壤风蚀量,揭示不同留茬高度对留茬地和相邻裸露地的防风蚀效果.结果表明,随着留茬高度的增加,作物残茬带近地表风速降低,且留高茬(30 cm)效果最明显;随着测定高度的增加,同一留茬高度对风速的降低程度减小.地表粗糙度随留茬高度的增加而增大,留高茬地(30 cm)和邻高茬裸地的地表粗糙度分别较对照增加了466.67％和126.98％.土壤风蚀量随留茬高度的增加而减少,留高茬地(30 cm)和邻高茬裸地的风蚀量分别较对照减少了90.21％和65.51％.因此,作物残茬既增强了自身带的防风蚀效果,又在一定程度上保护了邻茬裸露带,留茬高度30 cm时防风蚀效果最好,对相邻裸露带的保护作用最明显.     

大气CO2浓度增加对作物光合性能及叶片水分利用效率的影响

利用可精准控制CO_2浓度的大型气候箱设置2个CO_2浓度400和800μmol/mol,研究CO_2浓度升高对大豆(Glycine max (L.) Merr.)、冬小麦(Triticum aestivum L.)、草地早熟禾(Poa pratensis L.)、黑麦草(Lolium perenne L.)和高羊茅(Festuca arundinacea Schreb.)生理特性及叶片水分利用效率的影响。结果表明,大气CO_2浓度升高对大豆、冬小麦、草地早熟禾和高羊茅叶片的净光合速率没有产生显著影响,但却使黑麦草叶片的净光合速率显著增加43%(P0.05)。升高CO_2浓度增加冬小麦、黑麦草和高羊茅的最大羧化速率,而对大豆和草地早熟禾的最大羧化速率和最大电子传递速率没有产生显著的影响。另外,提高大气CO_2浓度导致黑麦草蒸腾速率的降低;同时,草地早熟禾、黑麦草和高羊茅的水分利用效率分别提高161%、175%和74%。不同作物水分利用效率对升高CO_2浓度的响应存在明显差异,3种草坪草的适应能力均高于大豆和冬小麦2种作物。研究结果有助于深入理解CO_2浓度倍增下不同农作物发生光合下调现象的潜在机理,为未来大气CO_2浓度升高情形下生态系统适应性管理提供理论支持。     

生草栽培对磷吸收及土壤有效磷积累风险缓解状况的影响

为了寻求改善果园土壤磷素积累问题的有效措施,通过设置低磷(100kg/hm2)和高磷(600kg/hm2)施肥处理及3种牧草(高羊茅、紫花苜蓿和早熟禾)田间小区栽培试验,研究了生草栽培对苹果幼树生长、磷吸收状况及土壤有效磷变化情况的影响。结果表明:与单作苹果相比,种植紫花苜蓿和早熟禾均显著增加了苹果幼树生物量和吸磷量,以高磷处理下种植紫花苜蓿后苹果幼树干重和吸磷量最高,分别为70.97g和0.42g/株;但种植高羊茅却抑制了苹果幼树的生长及对磷的吸收。施磷水平显著影响了牧草对磷的吸收,与低磷处理相比,高磷处理显著增加了3种牧草磷含量及磷积累量,且其磷含量均为紫花苜蓿高羊茅早熟禾,而磷积累量均为高羊茅紫花苜蓿早熟禾。高磷处理下与单作苹果相比,生草栽培后土壤0-20cm和20-40cm土层有效磷含量均显著降低,降低幅度最大的是种植紫花苜蓿处理,其次是种植高羊茅处理,种植早熟禾处理降低幅度最小。因此,针对不同牧草生物学特性并选取适宜的生草管理模式,生草栽培可望成为缓解果园土壤有效磷积累风险的有效措施。     

再生水灌溉草坪对土壤质量影响的试验研究

采用随机区组设计,研究了再生水(Reclaimed Water)灌溉黑麦草(Lolium perenne L.)、早熟禾(Poapratensis)、高羊茅(Festuca arundinacea)、结缕草(Zoysia japonica)、野牛草(Buchloe dactyloides)、麦冬(Radix liriopes)6种草坪草对土壤质量的影响,结果表明:(1)再生水灌溉能增加土壤养分,但根据养分在土壤中迁移的难易程度及不同草坪的根系分布特征,再生水灌溉输入的养分在土壤剖面分布不同;(2)再生水灌溉后的土壤虽然碱化度处在5%～10%弱碱化范围,但与自来水灌溉相比,其在土壤剖面中的分布有扩大的趋势;(3)在6种供试草坪草中,再生水灌溉后黑麦草和结缕草土壤质量最好,可见黑麦草和结缕草比较适宜进行再生水灌溉。     

再生水灌溉对草坪草生长和土壤的影响

随着城市绿地与人争水的问题日益突出,再生水作为替代水资源在草坪草上的应用日益广泛。本试验于2003-2005年用3种类型灌溉水(清水、“清水+再生水”、再生水)处理5种草坪草(草地早熟禾、高羊茅、结缕草、野牛草和山麦冬),从观赏品质和生长指标方面进行耐污性评价,并分析再生水对土壤的影响。结果表明:本研究使用的再生水对所供测试绿化草种的颜色、覆盖度、质地和均匀性无不良影响,再生水灌溉条件下,高羊茅表现出了最强的综合耐污能力,其次是结缕草和野牛草。灌溉水类型对于草坪草的生长指标的影响具有种的特异性。再生水灌溉和“清水+再生水”交替灌溉提高了土壤的阳离子交换量(CEC)和总孔隙度,有利于土壤物理性状的改善。     

蒸散视角下护坡植被滴灌技术评价

为探明以复合型人造土壤为边坡种植土的植物蒸散对于高陡边坡生态恢复评价体系制定及水资源利用的重要意义，以黑麦草、高羊茅、早熟禾和"黑麦草+高羊茅+早熟禾"混合草种为研究对象，采用壤中滴灌技术，通过改进后的Penman-Monteith公式研究草本植物实际蒸散量与作物系数，以此评价壤中滴灌技术的生态效益。结果表明：高羊茅的作物实际蒸散量和作物系数最大，黑麦草其次，早熟禾最小，拟合的决定系数不小于0.847；养护初期各植物蒸散量相差较小，均保持在4.2 mm/d左右；养护结束后混合草种的蒸散量最大，早熟禾最小，分别约6.2、5.7 mm/d；养护前20 d，除早熟禾外，黑麦草、高羊茅、混合草种实际蒸散量均差异不显著，养护20 d后黑麦草、早熟禾、混合草种开始发生显著变化；30 d后各草种蒸散量均差异不显著；4类草本植物蒸散量差值随时间递增，前期混合草种蒸散量低于黑麦草、高羊茅，后期有明显的提升，50 d起混合草种作物系数大于单草种作物系数。以30 d为界，30 d作物系数相近；生长初期的作物系数变幅最明显，且月增幅随时间呈下降趋势，但黑麦草和高羊茅的作物系数在任意时段均相近。边坡模型试验前期，以坡面喷灌方式灌溉的植物生态值较高，植物生长情况优于壤中滴灌方式，但自养护中期开始，壤中滴灌技术在生态效益上凸显优势，比坡面喷灌技术高出40.7%～1 444.0%的生态值。     

水分胁迫下几种冷季型草坪草抗旱机理研究

采用盆栽育苗法,在5种冷季型草坪草苗期连续干旱胁迫下测定植株高度,根系生长,叶片相对含水量和质膜透性等抗旱指标,以综合评价5种冷季型草坪草的抗旱性能。研究结果表明:供试材料在连续干旱胁迫下,叶片相对含水量呈下降趋势,质膜透性有所增加。综合分析可知,5种冷季型草坪草的苗期抗旱性能由强多弱依次为:多年生黑麦草>高羊茅>无芒雀麦>紫羊茅>匍匐翦股颖。     

The influence of grass density on effectiveness of contour grass strips for control of soil erosion on low angle slopes

Abstract. The effectiveness of contour grass strips in erosion control was investigated in a field experiment involving two grass treatments ( Festuca ovina and Poa pratensis ) and a bare soil control on an erodible sandy loam soil on a 5° slope using simulated rainstorms of 40 mm h^–1 for 45 minutes duration. The grass strips resulted in significantly ( P < 0.05) lower runoff and soil loss than the bare soil but there was no significant difference in the performance of the two grasses, despite their differences in density, height and leaf size. The effect of the lower density of the Poa pratensis was offset by its larger stem diameter so that the surface area facing the flow was similar for both grasses. Instead of acting as a filter with sedimentation occurring within the barrier, the grass strips operated by ponding water upslope of the barriers. Deposition then occurred in the ponded area above the barrier.     

Collection and preliminary evaluation of native turfgrass accessions in Italy

Despite a raising interest on turfs in Italy, all theavailable varieties of this kind in the Country are of foreign origin, and areoften poorly adapted to the prevailing climatic conditions. This prompted tobegin a collection activity of indigenous turfgrass species, with the ultimategoal of identifying promising materials for future breeding based on localgenetic resources. The collection was carried out in three areas of Italy, viz.the northern Po Plain, the coastal region of Liguria, and the island of Sardiniathat are characterised, respectively, by subcontinental, warm temperate, andtypical Mediterranean climate. Altogether, 141 sites were visited, yielding 226accessions belonging to eight species of potential interest for turfs:Poa pratensis, Poa trivialis,Festuca rubra, Festuca arundinacea,Lolium perenne, Agrostis stolonifera,Agrostis tenuis, and Cynodon dactylon,this last being a warm-season grass. Poa pratensis andCynodon dactylon were mostly collected in northern Italyand Sardinia, respectively, whereas Festuca arundinacea andLolium perenne were rather ubiquitous. The collection sitesranged from 0 to 1040 m asl, but sites over 750 m wereonly visited in the inner part of Sardinia. All the accessions, collected aswhole plants, were transplanted at Lodi, northern Italy, where they are beingevaluated. Their preliminary evaluation for traits of importance for turf use,such as sward colour and overall quality, highlighted the great variation andthe occurrence of interesting accessions in all species. Other characters wererecorded, bearing specific importance in individual species, and in all casespromising accessions were identified. The germplasm of Festucarubra, Festuca arundinacea, and Loliumperenne proved highly infected by endophytic (symbiotic) fungi of thegenus Neotyphodium.     

Salt Tolerance and K/Na Ratio of Some Introduced Forage Grass Species Under Salinity Stress in Irrigated Areas

Salinity is a limiting factor for forage productivity in irrigated areas. The aim of this study was to evaluate the salt tolerance index (STI), the K/Na ratio, and the forage quality of several introduced cool season grass species in irrigated agriculture. Four irrigated water salinity concentrations were used (control, 4000, 8000, and 12000 ppm sodium chloride (NaCl)), and four grass cultivars belonging to three species were established under greenhouse conditions at the Qassim University Agricultural Research and Experimental Station during the 2012 and 2013 growing seasons (perennial ryegrass (Lolium perenne L., cvs. Aries and Quartet), endophyte-free tall fescue (Festuca arundinacea Schreb., cv. Fawn), and orchardgrass (Dactylis glomerata L., cv. Tekapo)). A randomized complete block design (RCBD) using three replications was used. Cultivars were evaluated based on their dry weights (g m^?2) and forage quality. Additionally, the STI and potassium (K⁺) and sodium (Na⁺) concentrations in the studied grass cultivars were evaluated. The dry weights of the grasses decreased significantly as the salinity level of the irrigation water increased. At a salinity of 4000 ppm, the Aries perennial ryegrass had the highest dry weight at both sample cuttings. The Aries, Fawn, and Quartet grasses had the highest STI values. The percent of K⁺ and the K/Na ratio increased as the salinity of the irrigation water increased for the Fawn tall fescue and Quartet perennial ryegrass. In the previously cultivars, the percentage of Na⁺ decreased as the salinity level of the irrigation water increased, which was in contrast with the results observed for the Tekapo orchardgrass.     

Comparing cultivars of three cool‐season turf‐grasses for potassium uptake kinetics and potassium recovery in the field

Efficient use of potassium (K) by turf depends on the ability of roots to absorb a high proportion of the fertilizer K applied to the soil. Among turfgrass genotypes, variation in K absorption kinetics of roots and its inheritance is important in the development of genotypes that are more efficient in K absorption from the soil. Therefore, K uptake kinetics of six cultivars each of Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), and tall fescue (Festuca arundinacea Schreb.) were compared under greenhouse conditions. In 1990 and 1991, field studies of the same cultivars were conducted comparing clipping production rate, leaf blade K concentration, K recovery rate in clippings, K efficiency ratio and visual quality under a moderate K fertilization of 59 kg K/ha/year. Significant differences among species and cultivars were obtained for both absorption kinetics and field recovery of K. Significant correlations between some K uptake parameters and field performance were identified. These results show that genetic differences exist among turfgrasses for K utilization at both the interspecific and intraspecific levels and suggest that a screening program could be developed to identify turfgrass genotypes possessing superior K utilization.     

Effect of plant growth-promoting Bacillus sp. on color and clipping yield of three turfgrass species

A two-year irrigated field study was conducted to determine the effects of plant growth-promoting rhizobacteria (PGPR; Bacillus subtilis OSU-142 and Bacillus megaterium M3) as biofertilizer, and in combination with a chemical nitrogen (N) fertilizer, on turf color and clipping yield, and interaction of biofertilizer and chemical N fertilizers in perennial ryegrass (Lolium perenne L.), tall fescue (Festuca arundinacea L. Schreb.), and Kentucky bluegrass (Poa pratensis L.). The three turf species were tested separately in split-plot design experiments with three replications. Three fertilizer sources (ammonium nitrate only, ammonium nitrate + B. megaterium M3, and ammonium nitrate + B. subtilis OSU-142) were the main plots. N applications with monthly applications of 0.0, 2.5, 5.0, and 7.5 g N/m² were the subplots. Color ratings and clipping yields increased with increasing chemical N fertilizers in all species. Both Bacillus sp. significantly increased color ratings and clipping yields in perennial ryegrass and tall fescue. However, there were no significant differences among the three fertilizer sources in color and clipping yield of Kentucky bluegrass. The experiments showed that there is a small but significant benefit from applying biofertilizers for turf color, and that N fertilization may be reduced in some turf species when biofertilization are made for this purpose.     

EFFECTS OF NITROGEN APPLICATION TIMING ON GROWTH AND QUALITY OF A TURFGRASS MIXTURE

A 3-year field study was conducted to determine the influence of nitrogen (N) application timing on the growth and quality of a turfgrass mixture consisting of perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), creeping red fescue (Festuca rubra var. rubra L.), and chewings fescue (Festuca rubra var. commutata Gaud.) under irrigated conditions. Nitrogen was applied annually at the rate of 30 g m^?2 year^?1, with six application regimes: control (no N), single spring (30 g m^?2), single fall (30 g m^?2), spring + fall (15 + 15 g m^?2), spring + summer + fall (10 + 10 + 10 g m^?2), and monthly from April through September (5 g m^?2).

Color, turf quality, clipping weights, and shoot density were correlated with fertilizer rates and application timing in this study. Fertilization monthly or every 2 months resulted in more uniform color and turf quality and less clipping weights than with comparable heavy spring and fall fertilizations. Heavy N applications in the fall did not cause winter injury and produced significantly darker color and more uniform appearance in early spring than other N applications. All N-fertilization regimes increased shoot density, but spring fertilization stimulated density the most. Nitrogen applied monthly or every 2 months was enough to enhance the color, turf quality, and shoot density of the turf during the growing season but did not greatly affect the growth rate.