优势高产蔬菜生产的关键技术——科学施肥 第七讲 蔬菜营养缺乏和过量障碍的诊断与防治

同其它高等植物一样 ,蔬菜正常生长发育需要按一定比例吸收利用 16种必需营养元素 ,这些必需营养元素在植物体内具有各自独特的无可替代的生理功能 ,当土壤中缺乏某种必需元素或土壤本身不缺乏 ,但植物吸收不足时 ,会造成植物体内一系列物质代谢和运转的障碍 ,严重时可在外观形态上表现出一些特殊症状。同样 ,某种元素过量 ,造成植物体中毒时 ,也会出现形态异样症状。一般也把营养缺乏和过量造成的植物生长发育异常叫生理性病害。营养诊断是生理病害防治的前提 ,而在诸多的营养诊断方法如土壤分析、植株诊断、组织诊断、代谢诊断和外观形态…     

土壤电导度的测定在蔬菜施肥中的应用

在日本设施栽培中,土壤电导度测定已成为一项非常重要的项目,它被广泛应用于土壤盐类浓度障害的有无,决定施肥量的诊断中。一、电导度与土壤盐类浓度障害的诊断     

柑桔营养诊断指导施肥的实践

近１０余年来，对福建南亚热带柑桔主栽品种叶片养分含量和桔园土壤有效态含量进行了研究，提出了叶片和土壤的营养诊断标准，并应用这些诊断标准指导合理施肥，取得了显著的经济效益。     

土壤和植物组织的化学速测

第一部分土壤养分的速测 一、土壤养分化学速测的意义: 无产阶级文化大革命以来,在毛主席革命路线指引下,农业科学有了新的发展。随着农业学大寨群众运动的深入开展,实行科学种田,搞好科学实验的群众运动更加广泛。比较及时地了解土壤供肥水平和果树的营养状况,进行土壤与果树营养诊断,具有一定的现实意义。 土壤与果树氮、磷、钾的化学诊断,是用简易的化学测定方法,测定土壤中有效养分和果树体内无机养分的含量,比较快而及时地了解土壤的供肥水平和果树的营养状况,以便为果树的经济合理用肥提供科学依据。 土壤养分含量不是固定不变的,也不…     

大连地区大樱桃树体营养及施肥量研究

通过对大连地区樱桃园植株、土壤测试,阐述大连地区樱桃园土壤肥力状况,提出在测土配方施肥的基础上,以植株营养诊断与土壤营养诊断为依据,实行以有机肥为主,化肥为辅,基肥和叶面喷施等措施予以控制和补充的大樱桃施肥建议。     

岷江上游干旱河谷葡萄栽培的土壤适宜性研究

 研究结果表明，在本区气候生态适宜的前提下，本区的土壤条件亦能确保鲜食和酿酒葡萄优质高产。运用叶片分析与土壤分析相结合诊断土壤对葡萄的养分供应，葡萄叶片的养分含量主要与品种特性有关，也因土壤条件而异，但又具有“中低氮、高中磷和高钾”的总体营养组合特征,同时铁、锌营养大多不足。这大致与供试土壤部分供氮不足、大部磷、钾丰富的状况相对应。此外,土壤pH、质地、土层 厚度等基本能满足葡萄建园的要求。因此葡萄园应根据不同品种和土壤，实施诊断、平衡施肥，同时注意 坡土的水土保持和改良培肥。     

果树营养、施肥及果园土壤管理和改良

第六讲 果园土壤管理 1 何谓果园土壤管理 果园土壤管理,就是指对果园果树行、株间及树盘的土壤进行合理的科学管理.其管理的具体内容包括果园土壤理化性状(如质地、结构、有害物质等)的改善、土壤培肥、土壤耕作、行间作物间作、除草剂使用、根据土壤诊断指导施用和浇水等.     

设施蔬菜土壤钼营养诊断与钼肥施用技术

钼是植物体内一种不可缺少和替代的微量元素,针对目前设施蔬菜土壤中存在有效钼供应水平偏低的问题,总结设施蔬菜土壤钼营养诊断与钼肥施用技术,供设施农业生产参考,可提升设施蔬菜土壤养分科学管理水平,为设施农业的绿色高效可持续发展创造有利条件。     

刍议果树园艺技术与果树营养诊断策略

果树的生长需要相应的科学技术,而科学的果树园艺技术包括果树的园艺培育和管理技术,同时要及时有效的对果树进行营养诊断,常用的诊断方法有:对土壤的诊断、对施肥的诊断、对休眠期枝条的诊断以及"四看诊断法"等。     

三七连作障碍发生机理及消减技术研究

连作障碍是三七产业发展的关键问题。以不同间隔年限土壤种植的三七和根际土壤为试材,开展了土壤微生物培养、土壤酶活性检测、土壤理化性状分析和三七根际化合物分析,研究三七连作障碍的影响因素。结果表明:导致三七连作障碍的原因在于土壤理化性状恶化、土壤微生物群落演变、土壤酶活性下降和三七根际自毒物质积累4个方面;土壤细菌与真菌数量比、土壤细菌与放线菌数量比、土壤好氧性细菌与厌氧性细菌数量比均随三七根腐病加重而降低,其比值可作为三七栽培土壤健康状况评价的生物学诊断参数;优化集成了调酸、减肥、通气和微生物修复的三七连作障碍消减技术。     

The consequences of cultural practices on growth and cropping of peach trees subjected to localized irrigation: Effects of soil management,nitrogen fertilization and tree density

SUMMARY

Cultural practices were studied in peach tree orchards irrigated with microsprinklers, herbicide strips being maintained along the tree rows. Differences in fruit cropping between treatments varied in the same way as tree vigour, the most vigorous trees having the highest production capacities. Concerning soil management, ground cover vegetation (permanent or temporary) improved fruit production compared with soil cultivation. According to leaf analysis, ground cover vegetation appeared to ameliorate the conditions of trees nutrition. This effect was probably mainly due to increasing soil resistance to compaction; applying organic matter was not effective in improving the performance of trees grown with soil cultivation compared with those grown with ground cover vegetation. Increasing fruit tree density also contributed to increased fruit production. Nevertheless, more than 600 trees per hectare did not allow further increase in fruit yield for the experimental cultivar. Lastly, nitrogen fertilization seemed particularly important for improving the fruiting of peach trees.     

The impact of soil compaction on soil aeration and fine root density of Quercus palustris

The soil around Quercus palustris trees, 30 cm (11.8 in) average diameter breast height (DBH) were treated by compaction (C) or C plus clay slurry (CS) treatments in November 1994 and repeated in May 1996. Soil oxygen diffusion rate (ODR), fine root density (FRD), DBH, twig growth, leaf area and dieback were monitored for 4 years beginning in 1996. Both compaction treatments significantly reduced ODR at 15 cm. Early each season, ODR was below the 0.20 g/cm²/min threshold level reported to inhibit root growth in several species [Stolzy, L.H., Letey, J., 1964. Correlation of plant response to soil oxygen diffusion rates. Hilgardia 35, 567–576] for all treatments and depths. In summer each year, ODR was adequate in the shallow soils of all treatments, though often still significantly lower in compacted soils. At 30 cm, there were no consistent differences in ODR between compacted and uncompacted soil. Significant differences in FRD due to compaction treatments were inconsistent and limited to the upper 9 cm of soil in years 2 and 3. Reduced FRD in compacted soils may be a response to the reduced ODR in spring. There were no differences in DBH, twig growth, leaf area or dieback rating. Given the minimal difference in root growth, the lack of differences in top growth are understandable. This controlled study, and others preceding it, have failed to clearly show the underlying causes of tree decline and death commonly associated with soil compaction and addition of fill soil in real landscapes.     

A review of nursery production systems and their influence on urban tree survival

Urban trees face a myriad of complex challenges growing in the built environment. The most common environmental conditions influencing urban tree mortality are water availability, nutrient deficiency and soil compaction. Long-term survival of recently installed trees has been directly attributed to site conditions, planting technique, and post-transplant maintenance. Tree survival is also dependent on selection of healthy, suitable plant material. Production methods for woody plants include traditional plastic containers (CG), pot-in-pot containers (PIP), and in-ground fabric containers (IGF). Field grown trees may be produced as bare-root (BR) or root ball-excavated and burlap-wrapped (B&B) trees. Each of these methods offers unique advantages in relation to production and installation. Many of the studies reviewed reveal varying post-transplant establishment and survival responses to production methods at a species-specific level.     

Predicting canopy and trunk cross-sectional area of silver linden (Tilia tomentosa) in confined planting cutouts

Urbanized land is characterized by the dominance of paved surfaces. Increasing tree canopy in urbanized areas has been identified as an effective way to reduce stormwater runoff, sequester carbon, improve air and water quality, and otherwise mitigate the environmental impacts and increase the livability of cities. However, attaining sufficient tree canopy in urban areas remains an elusive goal. Site design characteristics such as cutout size may limit urban tree growth and complicate efforts to predict future canopy, especially in highly paved systems such as parking lots. We studied 25 silver lindens (Tilia tomentosa Moench) grown for 14 years at one site, in pavement cutouts of various sizes. Regression analysis, even on these limited data, indicated a strong relationship between tree size and canopy projection area and unpaved soil surface area, but not soil depth. Cutout size explained 70% of the variability in tree canopy projection area and 77% of the variability in trunk cross-sectional area. The addition of other variables, such as soil bulk density, did not improve the model. Trees growing in parking lot cutouts <5.3 m² attained only limited size, regardless of the level of soil compaction. In larger cutouts, however, increases in soil bulk density from 1.1 to 1.5 Mg/m³ were associated with a 70% reduction in trunk cross-sectional area. In order to create urban sites with a sustainable tree canopy, site design must provide large areas of uncompacted soil for trees and protect this soil from compaction during use. Urban tree growth models that incorporate cutout characteristics are needed to predict future canopy area with confidence.     

Emergence and seedling growth of pepper as influenced by soil compaction,nutrient status and moisture regime

Studies on the influence of seed-bed condition on the emergence and development of pepper seedlings (Capsicum frutescens L.) revealed that seed-bed compaction delayed and reduced seedling emergence. High nutrient and organic matter content accentuated the severity of soil compaction, regardless of whether the soil moisture was low or high. Influence of compaction was less on “dry” poor soil. Best seedling emergence was obtained from “moist” crumbly “rich” soil. However, “moist” crumbly “poor” soil, moist compacted poor soil, “dry” crumbly rich soil and “dry” crumbly poor soil also gave very high seedling emergence. The dry compacted rich soil gave the poorest cumulative emergence figures. High soil moisture regime and high nutrient content reduced the severity of soil compaction on seedling root and shoot development. Soil compaction also caused abnormal hypocotyl morphology in seedlings that germinated but failed to emerge.     

Measurement of soil compaction tolerance of Lagestromia speciosa (L.) Pers. using chlorophyll fluorescence

Trees planted along roadsides and on public recreation areas are subjected to environmental stresses such as poor soil, air pollution and heat. However, very little information is available on the trees’ tolerance to the various stress factors faced in an urban environment in Malaysia, such as soil compaction. The effects of soil compaction on a range of chlorophyll fluorescence parameters (F₀,F_m,F_v/F_m) in foliar tissue of Lagestromia speciosa, a widely planted Malaysian street tree, were examined. Results showed that soil compaction was between 170 and 315 MPa in the study areas. Soil compaction above 180 MPa affected tree form and reduced chlorophyll fluorescence. It is concluded that chlorophyll fluorescence offers a rapid screening technique for assessing soil compaction tolerance of L. speciosa.     

Factors influencing urban tree planting program growth and survival in Florida,United States

High levels of mortality after installation can limit the long-term benefits associated with urban tree planting initiatives. Past planting projects funded by the Florida Forest Service were revisited two to five years after installation to document tree survival and growth and assess program success. Additionally, various site (e.g., soil compaction, installed irrigation) and tree-related (e.g., species, nursery production method, initial size at planting) factors were noted to assess their impact on tree growth. Results show that the overall establishment rate for the 26 sites (n = 2354 trees) was high, with 93.6% of trees alive at the time of final inspection. On-site irrigation played a significant role in tree survival and growth, especially for Magnolia grandiflora (97.7% survival on irrigated sites; 73.8% survival on non-irrigated sites). Findings from this work validate the effectiveness of current program policies which include maintenance of tree quality within the first year after planting, and offer further insights regarding the impacts of season of planting and initial size of nursery stock on plant growth and development.     

植物器官体积变化连续测微法指导果树自动化灌溉合理指标的研究

对盆栽葡萄（VitisviniferaL．）、苹果（MaluspumilaMill．）、山楂（CrataeguspinnatifidsBunge）和枣（ZiziphusjnyubaMill．）4种果树在不同水分营养状况下茎于微变化过程中的日最大收缩量（MDS）、日净增长量（DG）、当日完全复原所需时间（RT）等3个重要指标进行研究，结果表明：3个指标都比叶片日出前水势对土壤水分营养状况的反应灵敏得多；随着土壤可利用水分的不断减少，山楂和枣的MDS急剧增加，而葡萄和苹果的MDS减小，不同类型果树之间的反应不一致；在土壤水分状况较好时，4种果树的DG的变化平缓，变化幅度较小；在良好的土壤水分条件下，4种果树的RT随着土壤相对持水量的下降而迅速延长，并在土壤水分含量降低到一临界值以下时维持在24h。因此，在应用植物器官体积变化连续测微法指导果树灌溉时，MDS和DG并不适于单独作为所有果树的自动化灌溉指标，而RT作为果树自动化灌溉指标较为理想。     

环境因子对苹果粗皮病发生的影响

苹果粗皮病是苹果树严重的生理病害。为探讨苹果粗皮病致病机理,通过田间采样、土壤理化特性与气候因子分析,研究土壤等环境因子与苹果粗皮病发生的关系。结果表明,苹果粗皮病在棕壤土和滨海潮土上均可发生。土壤pH高低与苹果粗皮病的发生相关,土壤pH越低,土壤有效锰含量越高,苹果粗皮病发病程度越重,但土壤pH不是苹果粗皮病主要致病因子。不同感病地点的土壤有效锰含量相差悬殊,在0～80cm范围内,牟平最高锰含量为29.30mg/kg,而栖霞最低为57.39mg/kg,最高达114.43mg/kg,说明土壤有效锰含量不是苹果粗皮病发生的唯一因子,但发病率栖霞要高于牟平。土壤有效锰铁呈负相关性,锰铁比增大,可引起树体对锰的过量吸收,苹果粗皮病发生程度加重。因此,苹果粗皮病发生是土壤锰含量、锰铁比、土壤pH、降雨量等环境因子综合作用的结果。     

袋控缓释肥对桃幼树生长发育的影响

袋控缓释肥根据果树树体较大的特性,结合果树养分需求特性,采用纸塑材料做成的控释袋包裹掺混肥料,袋上针刺微孔,利用微孔控制养分释放,达到供肥和养分需求相一致。大田试验结果表明,施肥后袋控缓释处理土壤Nmin比撒施稳定,土壤Nmin含量维持在60mg/kg左右,养分释放缓慢、平稳,能满足幼树生长发育需要;1次撒施处理施肥2周后土壤Nmin含量达100mg/kg,随后急剧下降,8周后降至不施肥水平;2次撒施处理每次施肥2周后土壤Nmin含量达80mg/kg,即2个高峰。袋控缓释处理桃树根系含有大量的毛细根,与其它处理差异显著,但不施肥处理根系分布范围最广。袋控缓释处理桃树地上部树势中庸,不旺长;撒施处理在第2次施肥前以1次撒施地上部长势最旺,第2次施肥后以2次撒施地上部长势最旺。袋控缓释处理2007年开花观察时,开花数和坐果量均最高;2008年休眠期观察时,单位枝条长度花芽数量最多。