Effects of Carbon Nanomaterials on Soil Enzyme Activity of Turfgrass

[Objectives]This study was conducted to evaluate the effects of carbon nanomaterials on soil ecosystem and explore the ecological risks of environmental exposure of carbon nanomaterials. [Methods] The effects of carbon nanomaterials on soil enzyme activity was studied by adding graphene, graphene oxide and carbon nanotubes to turfgrass soil. [Results] Compared with the control(CK), the activity of soil protease, sucrase, alkaline phosphatase and catalase was not significantly affected by carbon nanomaterials. Under the treatment of carbon nanotubes, urease activity was significantly lower than that of graphene and graphene oxide, and dehydrogenase activity was significantly lower than that of the CK, graphene and graphene oxide. [Conclusions] This study provides a theoretical basis for the safe application of carbon nanomaterials.

Heavy metal accumulation of urban domestic rubbish compost in turfgrass by EDTA chelating

Seven kinds of heavy metal accumulation of rubbish compost in turfgrass by EDTA chelating were investigated. With EDTA application, heavy metal accumulation by two species of turfgrass was increased significantly. The enrichment coefficients of Lolium perenne L（L） and Festuca arundinacea L（F） to Cr reached 9.4.5 and 6.15 respectively. In the range of EDTA dosages given, heavy metal accumulation in turfgrass increased with increasing EDTA level. There were significant differences in remediation of different metals by applying EDTA. L had high ability to accumulate Cr, Cd, Ni and Zn, showing better remediation to heavy metals of rubbish compost. In contrast, F showed high ability to accumulate Cr, Ni, Cu and Zn. Low EDTA level increased aboveground net primary production （ANP） of turfgrass, but EDTA would considerably inhibit it when EDTA was higher than 20 mmol/kg. The results demonstrated that the optimum dosage of EDTA for remediating heavy metals in rubbish compost by turfgrass was between 10 mmol/kg and 20 mmol/kg.

Heavy Metal Control in Domestic Rubbish by Source Screening and Suitability of Nutrient Elements as Turfgrass Medium

This paper, probing into heavy metal control in domestic rubbish by source screening and nutrient element analysis, revealed the feasibility of source control of heavy metals and the suitability of rubbish as turfgrass medium. Heavy metals in domestic rubbish were controlled by source screening before composting. The study consisted of a control with garden soil. The contents of main mineral elements and heavy metals in rubbish compost and control were determined by the method of ICP-AES. The results showed that heavy metal concentrations in rubbish were lower than those in garden soil, and little difference occurred between rubbish and garden soil in main mineral element concentrations. Based on this, it was concluded that rubbish compost was favorable for using as turfgrass medium and heavy metal control in rubbish by source screening was effective.

Seasonal Variation of Carbon and Nitrogen Emissions from Turfgrass

The role of turfgrasses in C and N cycling in the southeastern U.S. has not been well documented. The objectives of this research were to determine the characterization of chemical quality, clipping decomposition rates, and C and N release from warm- and cool-season turfgrasses. The study was conducted for 46 weeks in 2012 in Auburn, AL. Four warm season turfgrasses were used included (bermudagrass [Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt Davy], centipedegrass (Eremochloa ophiuroides (Munro) Hack), St. Augustinegrass (Stenotaphrum secundatum (Walter) Kuntze), zoysiagrass (Zoysia japonica Steud.), and one cool season turfgrass (tall fescue (Festuca arundinacea Schreb)). Litter was placed into nylon bags at an oven dry rate of 3.6 Mg?ha?1. Litter bags were retrieved after 0, 1, 2, 4, 8, 16, 24, 32, and 46 weeks, and analyzed for total C and N. A double exponential decay model was used to describe mass, C, and N loss. Results indicated that tall fescue decomposition occurred rapidly compared to warm season turfgrasses. Litter mass loss measured after 46 weeks was determined to be 61.7%, 73.7%, 72.2%, 86.8%, and 45.4% in bermudagrass, centipedegrass, St. Augustinegrass, tall fescue, and zoysiagrass respectively. Zoysiagrass litter had a higher lignin concentration, while tall fescue had the lowest lignin. Over 46 weeks’ release of C was in the order: zoysiagrass > bermudagrass = centipedegrass = St. Augustinegrass > tall fescue, and release of N was in the order zoysiagrass > centipedegrass > bermudagrass = St. Augustinegrass > tall fescue. Our study concluded that, zosiagrass is a better choice for home lawns.

Effects of Turfgrass Thatch on Water Infiltration, Surface Runoff, and Evaporation

The development of a (layer of) thatch in turfgrass causes important changes to near-surface eco-hydrological processes. In this study, we investigated the effects of turfgrass thatch, specifically Kentucky bluegrass (Poa pratensis L.) and red fescue (Festuca rubra L.) on water infiltration, surface runoff, and soil moisture evaporation. The thatches were collected from the field for controlled experiments using packed soil columns under various rainfall conditions. Results indicated that the presence of thatch delayed the onset of infiltration compared with situations without a thatch at the soil surface. Infiltration was delayed for a longer period in thicker red fescue thatch than thinner Kentucky bluegrass thatch. The presence of a thatch reduced runoff by holding more water locally during the rainfall period and allowing a longer period of time for infiltration. Additionally, evaporative water loss was reduced with the presence of thatch than that of bare soil. Our results highlight that the presence of thatch changes the near-surface hydrological processes, which may help improve turf management practices in terms of thatch control and irrigation scheduling.

Effects of Nitrogen Fertilization on Some Turfgrass Characteristics of Perennial Ryegrass (Lolium perenne L.)

The paper aimed to study the effects of nitrogen fertilization on the yield and some plant characteristics of perennial ryegrass (Lolium perenne L.). The study was conducted at Agricultural Research and Application Center of the Faculty of Agriculture in Igdir University in 2013. In the experiment, eight levels of fertilizers: 0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 and 70.0 kg N/ha per month were applied in perennial ryegrass (Lolium perenne L.) during the sixth growing season. A randomized complete block with three replications was used as the experimental design. Nitrogen application affected plant height, green grass yield, plant covering rate, canopy color and turfgrass quality values of perennial ryegrass positively. In both monthly and as the average of nitrogen application, times of application (spring, summer and fall) caused the most uniform turfgrass quality and establishment. Results indicated that although a significant impact was on the character investigated, such as the leaf length, green grass yield, plant cover ratio, canopy color and turfgrass quality, the doses of nitrogen fertilizer have created close to each other in groups. In the stand point of view of all characters, N1, N2 and N3 were located in first group, N4 and N5 in the second group, N6 and N7 in the third group, expect for control (N0). It can be concluded that 40.0-50.0 kg N/ha per month may be more suitable to be used in ryegrass production in the landscape.

不同暖季型草坪草品种对盐碱地土壤理化性质和微生物群落的影响

在江苏盐碱地中种植暖季型草坪草狗牙根〔Cynodon dactylon(Linn.)Pers.〕品种‘阳江’(‘Yangjiang’)和杂交结缕草(Zoysia sinica×Z.matrella)品种‘苏植3号’(‘Suzhi No.3’),探索这2个品种对盐碱地的植株地下部生物量以及土壤理化性质和微生物群落的影响。结果表明:‘阳江’和‘苏植3号’种植样地的植株地下部生物量和土壤有机质含量均显著高于对照样地;土壤的pH值和电导率均显著低于对照样地。细菌群落结构和真菌群落结构与对照样地均有显著差异,‘阳江’和‘苏植3号’种植样地的细菌Shannon-Wiener多样性指数均显著高于对照样地;固氮细菌、丛枝菌根真菌和粪腐生真菌的相对丰富度均显著高于对照样地。总体上看,‘阳江’和‘苏植3号’种植样地土壤中功能细菌类群关系较近,二者与对照样地的关系均较远;而3种样地土壤中功能真菌类群关系均较远。‘阳江’和‘苏植3号’种植样地的植株地下部生物量和土壤理化性质明显影响土壤中细菌多样性,植株地下部生物量以及土壤的pH值和电导率明显影响土壤中部分功能细菌的丰富度,植株地下部生物量和土壤pH值明显影响土壤中部分功能真菌的丰富度。综合分析认为,在江苏滨海盐碱地中种植‘阳江’和‘苏植3号’对盐碱地的植株地下部生物量以及土壤理化性质和微生物群落有明显的积极影响,在盐碱地生态修复中具有重要作用。

两种冷季型草坪草的EMS诱变及突变体筛选

为确定甲基磺酸乙酯(EMS)诱变多年生黑麦草‘爱神特’(Lolium perenne‘Accent’)和高羊茅‘赤道’(Festuca arundinacea‘Equator’)种子的最佳条件,获得性状稳定的突变材料和后代。利用不同浓度EMS在不同时间下诱变两个草坪草种,根据半致死浓度确定诱变组合。通过形态学、SCoT分子标记和生理指标测定筛选M1和M2代突变苗。结果表明:使用0.8%EMS溶液处理两个草坪草种36 h后播种,发芽率接近50%,诱变效果最佳。以该参数大规模诱变后,M1代两个草坪草种诱变株移栽成活933株,再经短期干旱胁迫,共筛选出18株耐旱单株。对M2代诱变株形态学分析发现,有叶面狭窄型和根长增长型两种突变类型。利用SCoT分子标记技术验证M2代诱变株发现,筛选的5条SCoT标记引物对20份草坪草样品扩增后,多态性比率为84.09%。其中SCoT-35引物扩增产物条带最为清晰稳定,诱变株与野生型差异明显。M2代三叶期变异单株经干旱、高温胁迫处理后,丙二醛含量、脯氨酸含量及相对电导率呈升高趋势,叶绿素含量呈下降趋势。最终得到两株多年生黑麦草耐旱突变体A5和A8,1株高羊茅耐旱突变体B9;两株多年生黑麦草耐热突变体A8和B9,1株高羊茅耐旱耐热突变体B9。本研究结果为草坪草抗性品种选育提供了帮助。

Heavy Metal Accumulation and Ecological Responses of Turfgrass to Rubbish Compost with EDTA Addition

Domestic rubbish compost is a complex-polluted system, containing multiple heavy metals, which limits its application. In the present study, Cr, Mn, Ni, Cu, Zn, Cd, and Pb accumulation and ecological responses of turfgrass to rubbish compost were investigated following the addition of EDTA. The results showed that the addition of EDTA significantly increased heavy metal accumulation in Lolium perenne L. and Festuca arundinacea L. Most heavy metal concentrations in L. perenne increased with increasing EDTA supply. The concentrations of Cr, Mn, Ni, Cu, and Cd in L. perenne were highest following the addition of 30 mmol/kg EDTA and the concentrations of Cr and Ni at this point reached concentrations of 1 914.17 and 521.25 μg/g, respectively. When the EDTA level was 〈 20 mmol/kg, the accumulation of most heavy metals in F. arundinacea increased with increasing EDTA supply, but showed a tendency to decrease at EDTA concentrations 〉20 mmol/kg. The highest concentrations of Mn, Ni, Cu, and Zn in F. arundinacea reached 268.01, 110.94, 161.52 and 1 354.97 μg/g, respectively, following the addition of 20 mmol/kg EDTA. The EDTA-induced increase in the accumulation of heavy metals in turfgrass was plantand metal-specific. L. perenne had a relatively high ability to accumulate Cr, Ni, and Zn. The highest Zn concentration was 2 979.58 μg/g and, following the addition of EDTA, the concentrations of the three metals were increased 26.23, 20.03, and 10.49-fold, respectively, compared with control. However, F. arundinacea showed a high ability to accumulate Cr, with the highest concentration （596.02 μg/g） seen following the addition of 30 mmol/kg EDTA; the concentration of Cr increased 15.51-fold compared with control. With EDTA addition, ecological responses of both turfgrass species showed that EDTA at concentrations 〈10 mmol/kg increased seed germination and aboveground net primary production （ANP） of L. perenne and slightly inhibited those of F. arundinacea, but EDTA at concentrations 〉20 mmol/kg inhibited these parameters significantly for both species. Moreover, EDTA increased the chlorophyll and proline content at all concentrations tested. On the basis of the synthetic remediation index, the optimal EDTA concentration for turfgrass remediation of heavy metals in compost is approximately 10 mmol/kg.

干旱度对西南荩草有性繁殖指数及种子产量的影响

为研究乡土草坪草种质资源西南荩草的开发利用潜力,通过设置4个干旱梯度(水分充足、轻度、中度和重度干旱),测定花芽分化期、花数、种子数、生物量等指标,分析干旱对荩草繁殖分配、繁殖指数、繁殖效益及种子产量的影响。结果表明:干旱度显著影响繁殖期和繁殖器官数量,重度干旱可提前18d开花,轻度和中度干旱可增加花穗数和小花数;干旱度显著影响生物量结构,影响为总生物量>非繁殖器官生物量>繁殖器官生物量,干旱限制非繁殖器官生物量,轻度和中度可增加繁殖器官生物量;干旱度显著影响繁殖效益指标,影响为繁殖比率>繁殖效率指数>繁殖指数>繁殖分配,轻度和中度干旱可显著提高繁殖效益指标;干旱度显著影响种子产量,影响为实际种子产量>潜在种子产量>表现种子产量,轻、中、重度干旱使实际种子产量分别下降14.02%、29.07%、55.54%;干旱度对发芽指标影响大小为种子发芽率>发芽势>发芽指数>活力指数,仅显著降低发芽率和发芽势。综上,干旱度显著影响西南荩草有性繁殖指数及种子产量,荩草可依据干旱度调节繁殖投入和维持繁殖收益,为护坡草坪自播和种群更新奠定种子基础。

高温冲击对细叶结缕草幼苗生长和生理反应的影响

依据亚热带地区夏季超高温出现及持续特点,设置5个高温梯度(36℃、38℃、40℃、42℃、44℃),对细叶结缕草幼苗进行30 d(2 h/d)冲击处理,通过测定株高、分蘖数、叶面积、生物量、叶绿素和生理活性物质含量等指标,研究高温冲击细叶结缕草幼苗生长和生理反应的影响。结果表明:1)高温冲击显著影响形态指标,≥38℃降低株高、叶数和总叶面积,≥40℃降低分蘖数,对形态指标影响大小为总叶面积>分蘖数>株高>叶数>叶厚。2)高温冲击显著影响生物量累积和分配,≥40℃降低总生物量和根冠比,生物量优先向地上部分分配。3)高温冲击显著影响叶绿素含量,≥38℃降低叶绿素a含量,≥40℃降低叶绿素b,叶绿素a/b受影响较小。4)高温冲击显著影响生理物质,温度越高SOD、POD活性和MDA、Pro含量越大,影响大小为MDA>POD>SOD>Pro>CAT,抗性物质含量对不同高温的响应差异较大。综上,高温冲击影响细叶结缕草生长、分生和光合能力,通过调节抗性物质抵抗高温伤害,可抵御44℃高温冲击安全越夏。

火炬树根蘖幼苗对3种草坪草种子萌发和幼苗生长的化感效应

以白三叶、苇状羊茅和多年生黑麦草3种北方常见草坪草为对象,通过室内砂培试验,研究了火炬树幼苗根、皮和叶的水浸提液在12.5、25.0和50.0 g·L^(-1)浓度下对受体植物种子萌发、幼苗生长以及生理指标的影响。并基于不同指标对应化感效应指数进行主成分分析获取的综合主成分值(F)评价各处理对3种草坪草的综合抑制程度,以期明确火炬树幼苗的潜在化感效应及其作用规律。结果表明:火炬树幼苗对受体植物各类指标的化感效应普遍受到化感物质来源器官、浸提液浓度和受体植物种类,以及上述因素交互作用的显著影响(P<0.05)。其中,火炬树所有器官的浸提液在各浓度下均使白三叶在苗期全部死亡。其根、皮和叶浸提液均显著抑制了苇状羊茅的种子萌发和幼苗生长,但仅后两者的综合抑制程度随浸提液浓度增加持续增强(F值降低1.07~2.77);浓度一致时,火炬树对苇状羊茅的综合抑制程度均为叶和皮>根(F值较后者低0.98~3.23)。火炬树根和皮浸提液对多年生黑麦草的综合抑制程度随浓度增加呈先增后降趋势,叶浸提液的抑制程度则随浓度增加呈持续增强趋势(F值降低1.11),且所有器官浸提液对多年生黑麦草的化感抑制普遍强于其对苇状羊茅的抑制(F值较后者低0.64~2.96);浓度一致时,在12.5和50.0 g·L^(-1)浓度下叶浸提液的综合抑制程度强于其他器官(F值较其他器官低0.44~1.55),而在25.0 g·L^(-1)浓度下皮浸提液的抑制程度最强(F值低0.51~0.69)。综上所述,在火炬树下种植草坪植物时建议优先考虑苇状羊茅而应避免种植白三叶。

基于高光谱的草坪草光合参数模拟估算

【目的】光合参数是衡量草坪草生长状况的重要生理指标,探索基于高光谱技术的草坪草光合参数的模拟估算对于草坪养护管理具有重要意义。【方法】以3个常用草坪草品种红象高羊茅(Fes⁃tuca arundinacea cv.Hongxiang)、百灵鸟多年生黑麦草(Lolium perenne cv.Bailingniao)和肯塔基草地早熟禾(Poa pratensis cv.Kentucky)为试验材料,通过盆栽试验,在草坪草生长旺盛期,使用SOC710VP成像光谱仪和CIRAS⁃3便携式光合仪分别测定了草坪草冠层光谱数据、净光合速率(P_(n))和蒸腾速率(T_(r)),筛选与两种光合参数显著相关的原始光谱波段与植被指数,构建偏最小二乘法(PLS)估算模型,并利用PLS模型中变量投影重要性(Variable Importance Projection,VIP)方法筛选VIP值>1.2的重要波段与植被指数。【结果】1)共筛选与P_(n)显著相关的54个原始光谱波段(435、450、460、475、490~550、560~565、590~725、990~1000、1015~1030 nm)与9个植被指数(GI、NDVI、NDVI_(670)、CI、PSRI、NRI、SIPI、PRI、SR),其中原始光谱460 nm与植被指数CI相关系数绝对值最高,分别为0.46和0.77,共筛选与T_(r)显著相关的115个原始光谱波段(435~440、450~1010 nm)与7个植被指数(SIPI、SR、NDVI、NDVI_(670)、MSR_(705)、CI、DVI),其中原始光谱475 nm与植被指数SIPI相关系数绝对值最高,分别为0.61与0.54;2)P_(n)偏最小二乘法模型因变量方差解释率为75.24%,模型拟合精度R2为0.95,均方根误差RMSE为0.1,T_(r)偏最小二乘法模型因变量方差解释率为73.43%,模型拟合精度R2为0.73,均方根误差RMSE为0.5,可满足反演需求;3)根据偏最小二乘法中变量投影重要性VIP法筛选最优指标,得出反演P_(n)的最优指标为CI,T_(r)最优指标为SR。【结论】草坪草净光合速率与蒸腾速率的偏最小二乘法光谱反演模型,为草坪草光合指标评估提供了更便利的方案。

不同种类草坪对土壤微生物量和活性有机碳的影响

人工草坪具有防止水土流失、美化环境、配置景观、提供户外休闲活动场所和改善区域生态环境等多种功能。为探究不同种类草坪对土壤微生物量和活性有机碳的影响,本研究以常见的狗牙根等6种草坪草为试验材料,设置保持自然状态和人工去杂2个试验处理,连续管理养护5年后采集0~10 cm表层土,测定其土壤全碳和全氮含量、土壤微生物碳和氮含量、土壤活性有机碳含量及其转化率6组数据。结果表明,保持自然状态试验处理中野牛草、多年生黑麦草和白花三叶草3种草坪中上述6组数据均达到最大值,均值分别为50.00 g/kg、7.00 g/kg、1.90 g/kg、0.40 g/kg、5.70 g/kg和0.65/cycle;狗牙根草坪上述6组数据均最小。说明野牛草、多年生黑麦草和白花三叶草3种草坪对土壤微生物量和活性有机碳的影响较大,匍匐翦股颖和高羊茅次之,狗牙根最小。同一种试验材料,保持自然状态试验处理的上述6组数据均明显高于人工去杂试验处理的。野牛草、多年生黑麦草和白花三叶草3种草坪对上述6组数据的影响大部分达到了统计学上的显著水平。因此,草坪建设者和管理者应根据不同种类草坪草的植物学特性,结合当地气候因子和土壤条件、草坪使用目的来选择合适的草坪草,以保证草坪质量和提高草坪使用效率的同时,促进其地下土壤生态系统的健康发展。

我国牧草与草坪草种子生产技术的研究进展

草种子是天然草原修复、人工草地建设和草坪建植所必需的播种材料,牧草及草坪草种子产量和质量是关注的焦点及草产业发展的基础。针对我国牧草及草坪草种子产量低、质量差的问题,搜集1980~2022年我国草种业生产技术相关文献资料,系统梳理牧草与草坪草种子生产技术研究发展的阶段性动态,阐述了不同发展阶段的技术动态和研究重点,提出高效扩繁体系是解决草种业发展瓶颈的重要途径,并展望了我国牧草及草坪草种子国产化、专业化生产的技术潜力和发展趋势。

安全剂缓解草坪草酰胺类除草剂药害作用评价

为建立草坪草的杂草防治技术,通过室内盆栽法测定了安全剂解草酮、解草啶缓解酰胺类除草剂丙草胺、精异丙甲草胺对黑麦草、高羊茅、早熟禾、剪股颖4种草坪草药害的作用。结果表明,黑麦草种子经解草啶浸种处理后,丙草胺30~60 g/hm^(2)(有效成分,下同)处理下出苗抑制得到有效缓解,同时黑麦草鲜质量抑制中剂量(GR_(50))增加17.9%;黑麦草种子经解草啶浸种处理后,精异丙甲草胺3.75~30 g/hm^(2)处理下出苗抑制得到有效缓解,缓解率达到10.0%~23.2%,黑麦草鲜质量GR_(50)增加42.3%;高羊茅种子经解草啶浸种处理后,精异丙甲草胺30、60 g/hm^(2)处理下出苗抑制率降低到10%以下,高羊茅鲜质量GR_(50)增加95.3%;解草酮、解草啶与丙草胺、精异丙甲草胺联用对早熟禾、剪股颖的出苗抑制情况基本无缓解效果。综上所述,解草啶与丙草胺联用可提高丙草胺对黑麦草的安全性,解草啶与精异丙甲草胺联用可提高精异丙甲草胺对黑麦草、高羊茅的安全性,而解草酮和解草啶对早熟禾和剪股颖的丙草胺和精异丙甲草胺药害缓解作用不明显。

应用型人才培养视角下草坪学实践教学存在的问题及对策

草坪学是草业科学本科专业的重要核心专业课程,具有极强的实践性和应用性,尤其是实验实践教学可为培养草坪行业人才提供重要保障。为更好地满足社会对应用型人才培养的需求,本文综合分析了当前草坪学实验实践教学中存在的问题,探讨了教学改革的措施与方向,以期为增强本科院校草坪学实验实践教学效果,提升人才培养水平,更好地符合当前社会经济发展对高层次专业技术人才的需求。

Pb^(2+)和Zn^(2+)胁迫下3种草坪草光合特征及吸附重金属能力差异性

【目的】探索Pb^(2+)、Zn^(2+)污染地区最适宜的修复草坪草品种。【方法】采用盆栽的方法,以黑麦草(Lolium perenne)、高羊茅(Festuca arundinacea)和草地早熟禾(Poa pratensis)为研究对象,以河沙为栽培基质,测定各处理的光合指标和重金属含量。设置不加重金属(CK)、Pb^(2+)胁迫(500、1000、1500、2000 mg/L)、Zn^(2+)胁迫(500、800、1100、1400 mg/L)处理。测定不同重金属浓度胁迫下的草坪草的光合特征及其对重金属吸收能力。【结果】研究表明:随着Pb^(2+)、Zn^(2+)浓度的增加,3种草坪草净光合速率、气孔导度、蒸腾速率和胞间CO_(2)浓度均呈先升高后降低趋势,但是出现峰值的浓度梯度各异;当Pb^(2+)胁迫浓度为500 mg/L时,对高羊茅和黑麦草叶片光合能力具有促进作用;当Pb^(2+)胁迫为1000 mg/L时,对草地早熟禾叶片光合能力具有促进作用。当Zn^(2+)胁迫为800 mg/L时对黑麦草和高羊茅叶片净光合速率具有促进作用;当Zn^(2+)胁迫为500 mg/L时,对草地早熟禾叶片净光合速率具有促进作用。【结论】综合分析3种草坪草的光合特征和对植物体内重金属富集能力表明,高羊茅和黑麦草适用于低于1000 mg/L的Pb^(2+)、Zn^(2+)污染土壤的修复。