梧州市六堡茶有性系茶园改造关键技术探讨

结合广西梧州市六堡茶有性系茶园现状和存在的问题,从茶园补植、茶园修剪、提纯复壮、茶园机械化、套种绿肥、种植模式、品种搭配等方面提出了茶园改造的关键技术要点。     

浅谈茶树树冠培育和修剪技术

根据茶树生长发育进程、气候条件等因素,着重论述幼龄茶树、壮年茶树、衰老茶树、冻害茶园茶树树冠培育和修剪技术,并介绍了茶树树冠培育和修剪技术应配合的其他相关措施。     

吉首市茶园修剪管理问题及其对策措施

茶树修剪是茶园优质高产的关键技术措施。通过对湖南省吉首市茶园修剪作业中存在的主要问题进行梳理和总结,就如何把握合适的修剪方式、选择恰当的修剪时机、合理控制留养叶、科学跟进剪后培管措施等提出了具体改进措施,并开展了建设性思考,旨在为吉首茶农增产增收提供技术参考。     

机械采摘茶园的农艺工程技术研究

茶叶采摘,不但耗工多,且季节性强,在当前是制约茶叶生产发展的一个因素,必须从手工采摘发展到机械采摘。本文系统地论述了机械采摘茶园园地设计、品种选择、树形确定等基础工程技术。同时,以机采茶树的生育性状为依据,提出修剪周期,采摘适期,留蓄秋梢、施肥水平等几种关键栽培技术。试验证明,这些配套技术是必不可少,而又行之有效的。此外,在大量测试各种采茶,修剪机械作业性能的基础上,依据我国茶园现状,提出了采茶,修剪机械的选型原则和配套方案,可以用来指导采茶机生产和推广应用,具有较好的投资效益。     

3ZFC-7型全方位复式中耕机的设计与试验

针对中国对大马力拖拉机配套复式作业装备发展的需要,结合中耕和除草关键技术,设计一种与59.2～88.9 kW系列拖拉机配套的可一次性完成深松、侧深施肥和智能计量、行间和苗间除草等多项作业的全方位复式中耕机。应用虚拟样机技术和田间试验相结合,完成了平行四杆随行仿形单体、螺旋梳齿除草器和振动施肥装置有机组合,使机构紧凑合理,中耕和除草性能更加稳定。经试验测试,该机具结构简单,通用性好,作业适应性强,各项作业性能指标完全满足农艺要求,符合农场集约化、规模化和大机械化作业,为开发系列大型全方位复式中耕机型奠定基础。     

抛送辊式百合收获机的设计与试验

为了解决黏重土壤条件下百合收获时果土分离效果差、埋果率高、破碎率高的问题,设计了一种适合黏重土壤条件下作业的抛送辊式百合收获机。结合百合生长状况以及种植农艺要求,对果土混合物在振动输送装置、抛送辊组上的运动过程及分离作业机理进行分析,构建了黏重土块在抛送辊上抛掷碎土、碰撞碎土的动力学模型,通过分析得到了振动输送装置结构及最大摆动角度、抛送辊组级数、抛送辊轮齿数、抛送辊轮直径及轮廓尺寸等参数。根据设计结果搭建了样机并进行了作业参数的多因素试验,以果土分离机构前进速度、抛送辊转速、挖掘深度为试验因素,百合埋果率、破碎率为试验指标,运用Box-Benhnken试验方法,建立因素与试验指标的回归方程,并得到因素对百合收获指标的影响规律。当试验取最优参数组合为果土分离机构前进速度为0.6 m/s,抛送辊转速为90 r/min、挖掘深度为170 mm时,百合埋果率、百合破碎率的田间试验值分别为6.3%和7.1%。机具各项性能符合设计要求,该研究成果可为百合机械化收获技术及装备研究提供参考。     

机械化吨粮田配套技术的研究

本研究从农业机械化技术的角度,结合北京顺义县具体条件,以提高小麦、玉米播种质量为主攻方向与有关学科配合展开。通过采取正确选型、合理配套、改制并完善机具、优化田间机械化作业工艺以及培训农艺、农机人员等措施,在三夏和三秋两个关键时期,提高了作业效率,争得农时,提高了播种质量,达到苗齐、苗壮。从而为实施吨粮田的栽培管理技术提供了良好的基础,较好地完成了单产吨粮目标,建立起一套具有中国特色的新型机械化吨粮田技术体系。     

Development of vineyard ditcher with reversal twin rotary tillage wheels

开沟施肥是葡萄园生产过程中的重要环节。传统的葡萄园开沟施肥通常是人工挖掘填埋,劳动强度大,工作效率低。为了提高开沟效率,通过对葡萄园环境及其开沟农艺要求的分析,设计制造了一种驱动型葡萄园小型开沟机,该机为旋耕刀以反转方式进行开沟工作,抛出的土由挡土导流板引导落在沟的两旁。对开沟机进行的性能试验结果表明：该开沟机2次作业开出的沟深可达500 mm左右,沟宽超过200 mm,且沟壁光滑、沟型整齐平直、沟中残留碎土少,满足葡萄园农艺要求;该机开沟部件碎土、抛土性能好,整机操作灵活,能适应葡萄园管理要求,也可用于其他果园、茶园、农田等开沟作业;该开沟机成本低,经济效益较好。     

旋转圆盘式开沟机的改造试验

针对现有开沟机不能适应西南丘陵山区开沟作业的问题，通过对前置式圆盘弯刀式开沟机的技术分析和结构改造，实现农艺要求的开沟效果。田间试验表明，开沟部件田间开沟作业性能良好，工作可靠，能够基本满足丘陵山区开沟作业要求。     

葡萄园反转双旋耕轮开沟机的研制

开沟施肥是葡萄园生产过程中的重要环节。传统的葡萄园开沟施肥通常是人工挖掘填埋,劳动强度大,工作效率低。为了提高开沟效率,通过对葡萄园环境及其开沟农艺要求的分析,设计制造了一种驱动型葡萄园小型开沟机,该机为旋耕刀以反转方式进行开沟工作,抛出的土由挡土导流板引导落在沟的两旁。对开沟机进行的性能试验结果表明:该开沟机2次作业开出的沟深可达500mm左右,沟宽超过200mm,且沟壁光滑、沟型整齐平直、沟中残留碎土少,满足葡萄园农艺要求;该机开沟部件碎土、抛土性能好,整机操作灵活,能适应葡萄园管理要求,也可用于其他果园、茶园、农田等开沟作业;该开沟机成本低,经济效益较好。     

Humic substrates facilitated nitrogen uptake in tea bushes by influencing biochemical and microbiological properties in soil of Northeast India

Abstract

Several groups of microorganisms are involved in converting applied urea into plant-available nitrate nitrogen (N) in soil. The objective of this study was to evaluate efficacy of humic substrates (HS) for maximizing crop yield by enhancing N availability in soil. In this experiment, HS was applied in soil of tea garden in such a way that active substrate was applied at 0, 400, 800, 1,200, 1,600, and 2,000?g ha^?1 in six treatments. Chemical fertilizers were applied in all the treatments (including control) following the recommended doses. This study indicated that applied HS enhanced tea shoot yield and N uptake by tea bushes. Improved biochemical and microbiological properties increased N availability in HS-treated soil and that in turn facilitated N uptake by tea bushes. It was determined that HS substrate application at 1.2?kg ha^?1 could enhance the yield of tea shoots up to 18% higher than control treatment.     

Pruned tea bushes secrete more root exudates to influence microbiological properties in soil

Pruning is adopted at 3–4 years interval as an agronomic practice during tea cultivation. It was hypothesized that biomass loss during pruning will imply stress on tea bushes. The aim of this study was to quantify changes in different parameters (labile organic carbon fractions, phosphatase activity, microbial biomass and microbial respiration) in tea rhizosphere due to pruning by collecting soil samples from the rhizosphere of ten of each pruned and un-pruned tea bushes. Hot-water extractable and dissolved organic C contents in rhizosphere soil of pruned tea were significantly (P ≤ 0.05) higher than those in the soil of un-pruned tea bushes. Analysis of phospholipid fatty acids (PLFA) revealed that the rhizosphere of pruned tea plants had higher population of Gram (+) and Gram (-) bacteria, fungi, actinomycetes and lower denitrifying bacterial population as compared to un-pruned tea plants. Activity of acid phosphatase enzyme in soil was also increased due to pruning. A separate study revealed that de-centering may induce production of up to 50% more labile organic carbon compounds by young tea as compared to un-pruned plants. Therefore, it could be concluded that pruned tea bushes secrete more root exudates to influence microbiological and biochemical properties in rhizosphere.     

The rhizosphere effect of tea on soil microbes in a Himalayan monsoonal location

Monthly investigations of the microbial population associated with tea soils, in terms of colony-forming units assessed by the plate-count method, were carried out at three different soil depths for a period of 12 months. Three groups of microbes, bacteria, actinomycetes, and fungi, were examined. Contrary to general observations, the rhizosphere: soil ratios were found to be consistently below 1 in samples taken from established tea bushes, indicating an overall negative rhizosphere effect. Interactions among certain microorganisms may also have contributed to this effect. Nevertheless, the rhizosphere of young tea plants and that of a number of other perennial plants, of different ages, growing in established tea fields, appeared to stimulate microbial growth. The negative effect of the rhizosphere of older tea bushes does not appear to be a common phenomenon that is related to the aging of plants in general, but seems to be unique and specific to tea plants.     

Sustainable green tea production through agroecological management and land conversion practices for restoring soil health,crop productivity and economic efficiency: Evidence from Northern Vietnam

Tea is a very important cash crop in Vietnam as it provides crucial income and employment for farmers in poor rural areas. Unfortunately, the dominance of long-term, conventional tea cultivation has caused severe soil health degradation and environmental pollution. At the same time, as tea production may provide a better net income compared with other annual crops such as rice and vegetables, farmers have been converting parts of their allocated land to cultivate tea plants. Little is known about the benefit of agroecological management as an alternative to conventional tea management practices, and thus, there is a need to understand how it can improve tea yields, quality and the livelihoods of the farmers. Conducted in Northern Vietnam from 2019 to 2022, this study examined the impacts of agroecological tea management practices on soil health indicators, tea yield and quality, and net income of tea farmers. We showed that agroecological management practices significantly enhanced soil organic matter by 0.8% and soil pH by 0.5 units on average. Conversely, conventional management based on chemical fertilizer applications, significantly increased soil total nitrogen by 0.15%–0.2%. No significant differences were observed between soil texture and other soil chemical characteristics. Soil biological parameters were also significantly higher in agroecological tea soil and root samples than in conventional tea plots. Average AMF frequency and intensity of the agroecological tea roots were 98% and 37%, respectively, compared with 73% and 15% of the conventional tea roots. Likewise, soil macrofauna and mesofauna abundance in the agroecological tea plantations was 76 individuals/m² and 101 individuals/100 g fresh soil on average, respectively, while that of conventional tea farms were 34 and 63 individuals/100 g fresh soil, respectively. Interestingly, a comparison between the converted and nonconverted lands did not show any significant effect of the conversion on soil physicochemical and biological characteristics, apart from tea root AMF colonization. Conventional tea management consistently resulted in higher tea yield and yield components, even though the differences were not always statistically significant. Despite lower tea yields, agroecological tea adopters earned around USD 8400 ha/year more than the farmers still practicing conventional management. This study shows that it is economically and environmentally more sustainable to produce organic tea than conventional tea, and our results should encourage more farmers to adopt such agroecological practices in Northern Vietnam.     

辐照降解绿茶甲氰菊酯和溴氰菊酯的可行性研究

对^60Coγ射线辐照降解茶叶中甲氰菊酯和溴氰菊酯的可行性进行了探讨。经5kGy辐照后,分别喷施过2种农药的茶鲜叶中,甲氰菊酯的降解率为7.3%,溴氰菊酯为14.7%;加工为成茶后的绿茶中甲氰菊酯的降解率为2.2%,溴氰菊酯为12.1%。甲氰菊酯在茶鲜叶中的辐照降解率比在绿茶中高5.1%,溴氰菊酯在茶鲜叶中的辐照降解率...     

Effect of a commercial plant growth regulator on the elemental content of tea plants

Abstract

Response of field grown mature tea to the foliar application of Biozyme Crop Plus, a commercial plant growth regulator, applied at different concentrations ranging from 250 to 1000 ppm was evaluated. Tea shoots were analysed to determine their N, P, K, Ca, and Mg contents. The treated tea plant shoots contained significantly higher contents of N and K followed by Ca and Mg than the untreated control plant shoots. The total chlorophyll content of Biozyme treated tea shoots was also increased significantly. Yield response to Biozyme applied to tea bushes were also determined.     

响应面法优化茉莉花茶茶多糖提取工艺

本实验以茉莉花茶为供试材料,优化茶多糖的提取工艺,旨在提高茶多糖的提取率,为茶叶深加工提供理论依据。在单因素实验的基础上,利用Box-Benhnken的中心组合设计,选定温度、水料比和沉淀茶多糖时所用的乙醇浓度3个因素分别选3水平进行中心组合实验,通过响应面分析实验,拟合出数学模型：Y=6.55＋1.30A＋0.83B＋1.10C-0.092AB＋0.11AC＋0.34BC-1.56A2-0.64B2-1.48C2。利用该函数关系来优化茶多糖提取条件,最终确定茶多糖的最佳浸提条件为：浸提温度100℃;水料比为26.8;乙醇浓度为90%。在该条件下茶多糖得量有所提高,且验证值为7.8610mg/g,比单因素最高提取率高25.6%,表明响应面法可有效用于茶多糖提取方法的优化。     

Factors affecting the levels of tea polyphenols and caffeine in tea leaves

An isocratic HPLC procedure was developed for the simultaneous determination of caffeine and six catechins in tea samples. When 31 commercial teas extracted by boiling water or 75% ethanol were analyzed by HPLC, the levels of (-)-epigallocatechin 3-gallate (EGCG), and total catechins in teas were in the order green tea (old leaves) > green tea (young leaves) and oolong tea > black tea and pu-erh tea. Tea samples extracted by 75% ethanol could yield higher levels of EGCG and total catechins. The contents of caffeine and catechins also have been measured in fresh tea leaves from the Tea Experiment Station in Wen-Shan or Taitung; the old tea leaves contain less caffeine but more EGCG and total catechins than young ones. To compare caffeine and catechins in the same tea but manufactured by different fermentation processes, the level of caffeine in different manufactured teas was in the order black tea > oolong tea > green tea > fresh tea leaf, but the levels of EGCG and total catechins were in the order green tea > oolong tea > fresh tea leaf > black tea. In addition, six commercial tea extracts were used to test the biological functions including hydroxyl radical scavenging, nitric oxide suppressing, and apoptotic effects. The pu-erh tea extracts protected the plasmid DNA from damage by the Fenton reaction as well as the control at a concentration of 100 microg/mL. The nitric oxide suppressing effect of tea extracts was in the order pu-erh tea >/= black tea > green tea > oolong tea. The induction of apoptosis by tea extract has been demonstrated by DNA fragmentation ladder and flow cytometry. It appeared that the ability of tea extracts to induce HL-60 cells apoptosis was in the order green tea > oolong > black tea > pu-erh tea. All tea extracts extracted by 75% ethanol have stronger biological functions than those extracted by boiling water.     

Shredded Hard Stems of Pruning Litters Supported the Growth of Young Tea Plants by Supplementing Nitrogen in Soil: Evaluating Suitable Combination of Urea and Prunings

Tea is an evergreen shrub, and tea bushes (plants) are periodically pruned at 3-year intervals. This practice generates tons of pruning litters (leaves and stems) in tea gardens. In spite of availability, the hard nature and slow decomposition rate limit the use of pruning litters as soil amendments. In this study, an attempt was made to cycle pruning litters in shredded form to evaluate their effect on young tea plants under greenhouse condition. It was observed that shredded prunings were decomposed in soil within study duration and enhanced nitrate-N content in the soil. The study revealed that different parameters like plant height, biomass weight, and N uptake were enhanced due to the application of suitable combinations of pruning litter and urea in the soil. Based on this study, it could be concluded that application of shredded prunings had potential to replace up to 15% of recommended urea during tea cultivation.     

Humic substrates application in diluted form enhanced availability of phosphorus (P) and its uptake by tea bushes in the tea-growing soil of Northeast India

Tea (Camellia sinensis L.) is an evergreen perennial crop, which is cultivated for its shoots in acidic soil under sub-tropical humid climatic condition. The availability of phosphorus (P) to plants is naturally limited in acidic tea-growing soils. Humic substrates (HS) are often applied to enhance availability of nutrients, especially P in horticultural and vegetable crop fields. However, its effect on soil of a perennial crop like tea was not studied before. In this study, application of HS enhanced P availability mainly by facilitating growth of phosphate-solubilizing bacteria (PSB) and enhancing phosphatase activity in soil. Application of same amount of HS in diluted form was more effective to enhance PSB population and phosphatase activity, which in turn increased P availability in soil and P uptake by tea bushes. This experiment indicated that application of 1.5 kg HS ha^?1 as 0.3% solution might be applied to enhance P availability to improve P availability and P uptake by plants in tea-growing soil.