基于双波段作物长势分析仪的东北水稻长势监测

为了实现水稻精细栽培和变量管理的目的,利用独立开发的双波段作物长势分析仪,进行了水稻生长监测的试验与分析。传感器分别在610与1220 nm处测量太阳光与作物冠层反射光的强度,进而计算光谱反射率。利用双波段作物长势分析仪于2008年在黑龙江省农垦总局建三江分局2处水稻试验田,在分蘖期与抽穗早期进行了氮肥胁迫试验,结果表明水稻叶片氮浓度及生物质干质量与RVI、NDVI都具有很高的相关性,但与NDVI的相关性比与RVI的更高。分蘖期的测量结果表明,NDVI与施肥量的相关性非常显著,R2大于0.94。但NDVI并不与施肥量成线性相关,过量的施氮量反而会引起NDVI值的降低。分蘖期、抽穗早期的NDVI值都与最终产量有着显著的相关,其中抽穗早期的NDVI与产量的决定系数（R2）达到了0.96。分析结果显示利用双波段作物长势分析仪监测水稻冠层,可达到控制投入和提高产量的目的,为水稻的精细栽培提供理论与技术支持。     

Microbial growth in the rhizosphere

Barley plants were grown for up to 16 days in solution culture either under axenic conditions or in the presence of a mixed population of microorganisms. The quantities of soluble carbohydrate released by the roots grown in the absence of microorganisms and the numbers of bacteria which developed in the inoculated solutions were determined. Except for the first 4 days after germination, a greater biomass was produced than could be accounted for by the utilization of the carbohydrates released by the roots grown in the absence of microorganisms; this supports the view that the microorganisms stimulate the loss of soluble organic materials. These results are considered in relation to microbial activity in the soil and in particular to the significance of N₂ fixation by free-living rhizosphere bacteria in the nitrogen economy of plants.     

基于生长函数的大豆根系生长的三维可视化模拟

植物的可视化模拟与仿真能为植物生长研究提供直观、迅捷的科学研究方法.植物根系在生长介质中的三维空间造型与分布,对水分养分的利用具有十分重要的作用.为了避免植物根系生长环境的不可见性和次要因素的影响,定量地直观地研究根构型的适应性变化,将植物根构型的多个生长函数和植物根系的形态发生模型耦合起来,结合可视化方法,建立了植物根系生长的三维可视化模拟系统.以大豆根系为研究对象,根构型的生长函数采用前期研究已获得的三次多项式形式;形态发生模型采用微分L系统理论编译其生成规则;可视化方法采用一系列连接在一起并平滑处理的圆台代表根轴.系统设计成只需输入三次多项式形式的生长函数的系数,就可直观地、连续地、可控地获得该根系生长的可视化图形和根构型几何参数.     

增硝营养对水稻不同生育时期生长及氮素吸收同化的影响

The effect of nitrate （NO3^-） on rice （Oryza sativa L.） growth as well as N absorption and assimilation during different growth stages was examined using three typical rice cultivars. Dry weight, yield, N uptake, nitrate reductase activity （NRA） in leaves, and glutamine synthetase activity （GSA） in roots and leaves during their entire growth periods, as well as the kinetic parameters of ammonium （NH4^＋） uptake at the seedling stage, were measured with solution culture experiments. Results indicated that addition of NH4^＋-N and NO3^-N at a ratio of 75：25 （NH4^＋＋NO3^- treatment） when compared with that of NH4^＋-N alone （NH4^＋ treatment） increased the dry weight of ‘Nanguang＇ cultivar by 30% and ‘Yunjing 38＇ cultivar by 31%, and also increased their grain yield by 21% and 17%, respectively. For the four growth stages, the total N accumulation in plants increased by an average of 36% for ‘Nanguang＇ and 31% for ‘Yunjing 38＇, whereas the increasing effect of NO3^- in the ‘4007＇ cultivar was only found at the seedling stage, in the NH4^＋＋NO3^- treatment compared to the NH4^＋ treatment, NRA in the leaves increased by 2.09 folds, and GSA increased by 92% in the roots and 52% in the leaves of the three cultivars. NO3^- supply increased the maximum uptake rate （Vmax） in the ‘Nanguang＇ and ‘Yunjing 38＇ cultivars, reflecting that the NO3^- itself, not the increasing N concentration, increased the uptake rate of NH4^＋ by rice. There was no effect on the apparent Michaelis-Menten constant （Kin） of the three cultivars. Thus, some replacement of NH4^＋ with NO3^-could greatly improve the growth of rice plants, mainly on account of the increased uptake of NH4^＋ promoted by NO3^-, and future studies should focus on the molecular mechanism of the increased uptake of NH4^＋ by NO3^-.     

Long-term plant growth legacies overwhelm short-term plant growth effects on soil microbial community structure

Plant-soil feedbacks are gaining attention for their ability to determine plant community development. Plant-soil feedback models and research assume that plant-soil interactions occur within days to weeks, yet, little is known about how quickly and to what extent plants change soil community composition. We grew a dominant native plant (Pseudoroegneria spicata) and a dominant non-native plant (Centaurea diffusa) separately in both native- and non-native-cultivated field soils to test if these species could overcome soil legacies and create new soil communities in the short-term. Soil community composition before and after plant growth was assessed in bulk and rhizosphere soils using phospholipid fatty acid analyses. Nematode abundance and mycorrhizal colonization were also measured following plant growth. Field-collected, native-cultivated soils showed greater bacterial, Gram (−), fungal, and arbuscular mycorrhizal PLFA abundance and greater PLFA diversity than field-collected, non-native-cultivated soils. Both plant species grew larger in native- than non-native-cultivated soils, but neither plant affected microbial composition in the bulk or rhizosphere soils after two months. Plants also failed to change nematode abundance or mycorrhizal colonization. Plants, therefore, appear able to create microbial legacies that affect subsequent plant growth, but contrary to common assumptions, the species in this study are likely to require years to create these legacies. Our results are consistent with other studies that demonstrate long-term legacies in soil microbial communities and suggest that the development of plant-soil feedbacks should be viewed in this longer-term context.     

干旱胁迫对花生生育中后期根系生长特征的影响

花生是较耐旱的经济和油料作物, 长期少雨或季节性干旱是限制花生产量提高的重要环境因子, 也是花生收获前黄曲霉素感染的重要因素。根系是植物吸水的主要器官, 不同土壤水分状况下植物的根系构型可能会表现出显著差异, 进而影响植物根系吸收养分和水分的能力。研究不同土壤水分状况下花生根系形态的发育特征与抗旱性的关系对进一步理解花生的水分吸收、运输、利用和散失机制以及培育抗旱性花生具有非常重要的作用。为明确不同抗旱性花生品种的根系形态发育特征, 探讨其根系形态发育特征对不同土壤水分状况的响应机制, 在防雨棚旱池内进行土柱栽培试验, 研究抗旱型花生品种"花育22号"和干旱敏感型花生品种"花育23号"生育中后期根系生长特征及其对干旱胁迫的响应。设置正常供水和中度干旱胁迫(分别控制土壤含水量为田间持水量的80%~85%和45%~50%)2个水分处理, 分别在花针期、结荚期和饱果期进行取样,根长、根表面积和体积扫描后通过WinRhizo Pro Vision 5.0a程序进行分析; 收获时测定产量和抗旱系数(干旱胁迫处理与正常供水处理下产量之比)。结果表明, "花育22号"具有较高的产量和抗旱系数, "花育23号"对干旱胁迫的适应性小于"花育22号"。抗旱型品种"花育22号"具有较大的根系生物量、总根长和根系表面积, 且深层土壤内根系表面积和体积大于"花育23号"。与正常供水处理相比, 干旱胁迫显著降低2个品种花针期的根系总根长、根系总表面积和总体积, 对结荚期和饱果期根系性状无显著影响; 干旱胁迫增加2个品种生育中后期40 cm以下土层内的根长密度分布比例、根系表面积和体积, 但"花育23号"各根系性状增加幅度小于"花育22号"。干旱胁迫处理下20~40 cm和40 cm以下土层内根系表面积和体积分别与总根长、总表面积和总体积呈显著或极显著正相关, 而正常供水处理下0~20 cm土层内根系表面积和体积与整体根系性状表现极显著正相关。总体而言, 具有较大根系和深层土壤内较多的根系分布是抗旱型花生的主要根系分布特征; 土壤水分亏缺条件下, 花生主要通过增加深层土壤内根长、根系表面积和体积等形态特性调节植株对水分的利用。     

Potato growth and nutrient diagnosis as affected by systemic pesticide and physiological growth stage

Abstract

Growth and chemical composition of crop plants may be subject to alteration by systemic compounds employed for pest control. A field study was implemented to examine the effects of aldicarb on growth, chemical composition, and nutrient diagnosis of a potato crop at various growth stages. Aldicarb use resulted in increased dry matter production of leaves, stems, and tubers, and final fresh tuber weight during the second year of the study. Higher tuber yields were likely due to greater photosynthetic capacity because the increase in leaf dry matter production with time was greater in the aldicarb treatment than in control. Leaf nutrition was not influenced by aldicarb; however, leaf nutrient content varied greatly with growth stage. Similar nutrient status evaluations were generated by DRIS, regardless of pesticide treatment or growth stage. DRIS was able to diagnose nutrient limitations as early as tuber initiation     

不同生育阶段洪涝淹没时长对水稻生长发育及产量构成的影响

夏季小流域洪涝常常导致南方稻田受淹并成灾。为探究小流域洪涝淹没时长对水稻生长发育及产量的影响,于2015—2016年在广西象州县选用丝香1号和百香139进行双季稻淹水试验,分别设分蘖期、孕穗期和开花期淹没0(对照CK)、2、4、6、8、10 d处理,测定淹没前后的茎蘖数变化、抽穗期及收获后的每穗粒数、结实率、千粒质量和每盆稻谷产量,并对产量构成因素进行相关分析和通径分析。结果表明:与对照组相比,同一生育期内淹没时间越长茎蘖死亡率越高、植株恢复生长越慢,但不同的淹没时期影响程度和主要影响对象存在差异。分蘖期淹没超过6d则死苗率大于80%,且不能完全恢复生长,收获时水稻茎蘖数显著低于对照组;孕穗期淹没超过6d则死苗率大于50%,而淹没小于4 d的处理水稻能恢复生长,收获时水稻茎蘖高于对照组;开花期淹没10 d死苗率不足50%,收获时茎蘖数与对照组差异不显著。分蘖期淹没小于4 d水稻始穗期及抽穗持续时间均无显著变化,大于8 d则水稻始穗期显著推迟,抽穗持续时间增加;孕穗期受淹没则会使水稻始穗期推迟,抽穗持续时间显著增加,甚至收割时也未能达到齐穗期标准。分蘖期淹没小于4 d,单株产量无显著下降,淹没6 d及以上则减产率大于80%;孕穗期及开花期淹没超过2 d则减产率大于50%。不同生育期淹没处理下产量的主要因素不同,分蘖期主要受有效穗数和结实率影响,孕穗期受结实率及每穗粒数影响,开花期受结实率和有效穗数影响。研究可为建立西南地区双季稻洪涝灾害指标体系和提出减灾管理措施提供依据。     

Triticale,wheat, and rye growth rates and mineral accumulation at various growth stages

Abstract

Cultivars of triticale, wheat, and rye were grown with different N‐fertilizer rates and sampled at various maturity stages in 1975 to 1977. ‘6TA 131’ triticale, ‘Arthur’ wheat, and ‘Abruzzi’ rye were used as checks. Increasing N fertilizer rates increased dry matter and N accumulation in the above‐ground plant parts. However, after flowering losses of dry matter and N from the plants increased with N fertilizer rates. Triticale and rye generally absorbed more N from the soil than wheat. Triticale and wheat straw had higher P concentrations than rye. The head/straw concentration ratios were: triticale and rye>wheat for P, wheat>triticale and rye for K while Ca and Mg ratios were triticale>wheat>rye.     

Mechanical impedance to root growth: a review of experimental techniques and root growth responses

Mechanical impedance to root growth is one of the most important factors determining root elongation and proliferation within a soil profile. Penetrometers overestimate resistance to root growth in soil by a factor of between two and eight and, although they remain the most convenient method for predicting root resistance, careful interpretation of results and choice of penetrometer design are essential if improved estimates of soil resistance to root elongation are to be obtained. Resistance to root growth through pressurized cells containing ballotini considerably exceeds the confining pressure applied externally to these cells. Results from this work are reappraised. Existing models of soil penetration by roots and penetrometers are reviewed together with the factors influencing penetration resistance. The interpretation of results from mechanical impedance experiments is examined in some detail and root responses, including possible mechanisms of response, are discussed.     

Effects of aluminium on growth and nutrition in birch seedlings under magnesium- or calcium-limiting growth conditions

Growth and nutrition of birch seedlings (Betula pendula Roth) with and without 0.5 mM Al³⁺ were studied. The seedlings were cultivated at growth-limiting Mg- or Ca-conditions by adding one of these elements at relative addition rates (R_Mg, R_Ca) of 0.15 day^?1. The concentration of Ca²⁺ in the Mg-limited treatments was 0.01.0.1 or 1 mM and Mg²⁺ was given in equal molarities in the Ca-limited treatments. The relative growth rates, R_G, of the plants and plant parts attained values close to R_Mg or R_Ca and were not affected by the concentration of Ca²⁺, Mg²⁺ or Al³⁺ in the culture solution. Uptake of Ca, at Ca-limitation, increased significantly in the roots after addition of Al, and decreased in all plant parts when the Mg concentration of the culture solution was raised. Less clear effects were found on Mg uptake at Mg-limitation. The inhibitory effect of Al on Mg uptake decreased with time as a result of the growth technique. The root mass fraction was significantly larger in plants limited in Ca (24%) than in plants limited in Mg (20%). The usefulness in using the balance between Ca and Al or ratios between Ca, Mg, K and Al as diagnostic tools for assessing the nutritional status of trees is discussed.     

Interactive effects of plant growth regulators and nitrogen on corn growth and nitrogen use efficiency

Our objective was to determine the combined effect of some plant growth regulators and nitrogen (N) on corn growth, yield and nitrogen use efficiency. A potted experiment was conducted with two levels of growth regulators [i.e. with or without treatment with Seed king (Kinetine), Root king (Indole-butyric acid) and More king (Chitosan)], two maize cultivars (Calabar White and Obatanpa-98 and three nitrogen rates (0, 90 and 180 kg/ha in the form of urea). The measured parameters were growth attributes, nitrogen uptake, dry matter yield, harvest-index, shoot to root ratio, yield attributes and agronomic and physiological nitrogen use efficiency. Calabar White had taller plants (154.53 cm) more leaves (12.00) and larger leaf area (466.98 cm²) than obatanpa-98 at 6 weeks after sowing. The dry matter yield of both leaf and stem increased significantly (P ≤ 0.05) with increasing N rates but the growth regulators significantly (P ≤ 0.05) increased only the leaf dry matter. The interaction between growth regulators and nitrogen significantly affected the leaf dry matter but not the stem dry matter. There was a considerable (P ≤ 0.05) increase in harvest-index (HI) at the 90 kg/ha N rate with growth regulators and Obatanpa-98 had better HI (30.81%) than Calabar White (27.41%). Obatanpa 98 also had much (P ≤ 0.05) higher grain yield (87.42 g/plant) than Calabar White (65.40 g/plant) but for both cultivars, the grain yield increased progressively with increasing N rate. The uptake of N differed significantly (P ≤ 0.05) among the different partitions of maize (leaves, stems and grains) at various growth stages. Calabar White had the highest N uptake in the leaves and stem whether at silking or at harvest. Obatanpa-98 partitioned more N to the grains than Calabar White. Agronomic nitrogen use efficiency (ANUE) was highest (21.31 gg^?1) at the 90 kg/ha N rate with Obatanpa-98 having a superior (20.26 gg^?1) ANUE to Calabar White (15.94 gg^?1). The physiological nitrogen use efficiency (PNUE) was also highest (8.14 g/kg) at the 90 kg/ha N rate with Obatanpa-98 being more efficient (8.08 gkg) than Calabar White (6.26 g/kg). Thus, both cultivars treated with 90 kgN/ha with or without growth regulators would best optimize nitrogen fertilizer use. However, the growth regulators increased the yield of Calabar White significantly only when no N was applied. In contrast, they increased the yield of the hybrid Obatanpa-98 at all N rates especially at the 180 kgN/ha rate. Thus, under the low input cropping common with Calabar White, treatment with the growth regulators would boost yield. A combined treatment of 180 kg N/ha with the growth regulators would ensure the best yield of Obatanpa-98.     

Foliar application of silicon at different growth stages alters growth and yield of selected wheat cultivars

To evaluate the response of some selected wheat cultivars to silicon application at different growth stages under drought stress, an experiment was carried out in the greenhouse of College of Agriculture, Shiraz University, Iran, during 2012 using a completely randomized factorial design with four replications. Experimental treatments included drought stress (100% F.C. as control and 40% F.C. as drought) and foliar application of 6 mM sodium silicate (control, application at mid tillering stage, at anthesis stage, and application at tillering + anthesis stages) and wheat cultivars (Sirvan and Chamran, relatively drought-tolerant, and Shiraz and Marvdasht, drought-sensitive cultivars). Drought stress significantly reduced chlorophyll content, leaf area, relative water content, grains per spike, 1000-grain weight, grain yield and biomass of all wheat cultivars. Furthermore, drought stress increased electrolyte leakage of the flag leaves of all cultivars. In contrast, foliar-applied silicon significantly increased these parameters and reduced electrolyte leakage. Furthermore, highest positive influence of silicon application was observed at combined use of silicon both at the tillering + anthesis stages in wheat plants under both stress and non-stress conditions. Significant differences were found in physiological responses among wheat cultivars. The drought tolerant cultivars (Sirvan and Chamran) had significantly higher growth and yield than those of drought sensitive cvs. Shiraz and Marvdasht under drought stress. In conclusion, foliar application of silicon especially at the tillering + anthesis stages was very effective in promoting resistance in wheat plants to drought conditions by maintaining cellular membrane integrity and relative water content, and increasing chlorophyll content.     

Soil aluminum toxicity and plant growth

Abstract

Soluble aluminum (Al) exists in a variety of forms in the soil system and is responsible for limiting plant growth in many areas of the world. Some phytotoxic forms of soluble Al have been identified in solution culture experiments, but current soil test methods do not effectively discriminate between toxic and nontoxic forms of Al. Large differences in Al tolerance exist within and among plant species. Efforts to select or breed plants for Al toxic soils have been somewhat successful, but accelerated progress will occur when plant Al tolerance mechanisms are more fully understood.     

植物生长剂和固沙剂对民勤沙区植被生长的影响

 为探讨植物生长调节剂、固沙剂的保水、增产及其固沙效果,挽救濒临死亡的地表植被,修复地区生态平衡,在民勤干旱沙区开展了有关应用技术研究。结果表明:1)植物生长调节剂及固沙剂具有一定的保水能力,可使农田作物含水率（耕作层）提高1.0～1.5百分点,使梭梭林分100cm内土壤层平均含水率提高2.3百分点,流动沙丘80cm内土壤层平均含水率提高3.5～3.9百分点。2)种子包衣制剂处理对小麦、玉米生长发育具有滞后作用,但均存在增产效果,能使小麦增产12.2%,玉米增产2.0%。3)利用液体试剂进行籽瓜灌根处理可促使植株较对照的主根增长9.1cm,主蔓增长33.0 cm,平均增产率为11.5%。4)用植物生长调节剂对退化植被梭梭、唐古特白刺进行根部追施后,梭梭新梢增长0.6～3.0 cm,唐古特白刺冠幅增大45.1～96.2 cm。5)固沙剂固定流动沙丘后,使沙丘结皮厚度增加0.2～0.3cm,风蚀减小50%～80%,沙丘植被盖度增加1.9%～2.7%。     

新型有机无机复合肥对冬小麦产量及关键期生长的影响

合理灌溉和施用肥料是实现冬小麦节水增产增效的关键,本研究选用"小偃22号"小麦品种,通过田间试验,于2009~2010年研究了不同施用量新型有机无机复合肥(SAF)对冬小麦农田关键期土壤剖面含水量以及作物生长与产量的影响。结果表明:1)各SAF处理较常规施肥(NF)增产在10%~30%之间;随着灌水量的增大,SAF最佳施肥量也随之增大,3种灌水处理中,理论最大产量出现在灌1水处理中,为8 894.11 kg·hm-2,此时对应的SAF施肥水平为1 350 kg·hm-2。2)小麦拔节初期,SAF处理土壤剖面含水量从表层到深层呈现缓慢减小再持续增大的"V"型分布,而常规施肥处理则呈现为减小增大再减小再增大的"W"型分布;在小麦灌浆期,SAF处理土壤剖面含水率的峰、谷值的深度均深于常规施肥处理。3)小麦分蘖期,SAF处理使小麦植株相对低矮,根相对粗短,这种趋势随着肥料施量的增大越发明显。在灌浆期,中SAF处理植株最为低矮,而穗重及地上干物质量最大;小麦灌浆速率差异主要表现在中SAF处理的小麦灌浆速率明显高于其余处理。上述结果表明:SAF使土壤垂直剖面含水率峰、谷值出现的位置更深;SAF处理的灌浆速率高于常规施肥处理,相比常规施肥处理,SAF处理可使作物在低灌水条件下(拔节期灌水60 mm)更好地实现最优产量。     

The effects of triacontanol on seedling growth and polyphenol oxidase activity in dark and light growth lettuce

The present study was designed to study the effects of various concentrations (0.00; 0.01, 0.10 and 1.00‐mg/ml) of triacontanol on root, stem and leaf growth and polyphenol oxidase activity in each respective tissue; in Grand Rapids and Great Lakes varieties of eleven‐day‐old dark and light grown lettuce seedlings.

Root, stem and leaf growth was less than in non‐triacontanol‐treated Grand Rapids seedlings in both TC‐treated dark and light exposed seedlings. With respect to Great Lakes seedlings, all dark‐grown roots exhibited greater growth than the corresponding untreated control. Light‐grown Great Lakes roots treated with 0.01‐mg/ml and 1.0‐mg/ml or triacontanol respectively, grew more than control or 0.1‐mg/ml triacontanol‐treated seedlings. Both dark and light‐grown triacontanol‐treated stem and leaf tissues of Great Lakes seedlings all produced less growth than the untreated controls.

The Grand Rapids variety had less polyphenol oxidase activity in both dark and light‐grown root and stem tissues than in untreated controls; however, both dark and light‐grown leaf tissue, treat ed with 0.01‐mg/ml and 1.0‐mg/ml of triacontanol respectively exhibited more polyphenol oxidase activity than 1.0‐mg/ml triacontanol ‐treated or untreated control tissues.

TC treatment of 0.1‐mg/ml caused no enhancement of PPO activity in dark or light‐grown root, stem and leaf tissues of Great Lakes tissue, however, seedlings treated with a concentration of 0.01‐mg/ml TC exhibited more PPO activity than non‐TC‐treated controls.     

根际促生菌Bacillus subtilisY-IVI在香草兰上的应用效果研究

【目的】香草兰为多年生热带经济作物,随着种植年限的增加,植株长势弱,土壤有益微生物减少,土壤微生物区系失衡,严重制约了香草兰产业的可持续发展。枯草芽孢杆菌作为一种根际促生菌,被广泛应用于促进作物生长,改善土壤微生物环境。本文将枯草芽孢杆菌Y-IVI接种在有机肥上,生产了生物有机肥,并就该生物有机肥对香草兰生长的影响进行了研究。【方法】采用温室盆栽试验,调查施用根际促生菌枯草芽孢杆菌(Bacillus subtilis)Y-IVI及其经固体发酵制得的微生物有机肥料(Y-IVI:3×108cfu/g)后,香草兰植株地上部及根系的生长状况,采用选择性培养基方法研究了Y-IVI在香草兰根际土壤中的定殖能力及对香草兰根茎腐病致病菌-尖孢镰刀菌数量的影响。【结果】施用Y-IVI及BIO 4个月后,香草兰根际土壤Y-IVI数量仍可达到106cfu/g土,二者无显著差异,在处理OF和对照中未检测到菌株Y-IVI。施用生物有机肥香草兰地上部干重和根系干重均显著高于对照,分别增加了63.1%和59.4%,与不接种Y-IVI的有机肥处理(OF)相比,地上部干重显著提高了43.2%,根系干重提高了18%,差异不显著;施用Y-IVI菌液的处理植株地上部干重和根系干重均高于对照,但无显著性差异;处理BIO根系直径、根系表面积和总体积与对照相比分别增加了41.9%、88.9%和80.4%,均显著高于对照,总根长与对照差异不显著;处理BIO根系表面积和总体积与有机肥处理OF相比分别显著增加了41.9%和30.8%,根系直径与OF相比增加了10.1%,差异不显著;处理Y-IVI根系直径与对照相比显著增加了25.5%,但根系表面积和总体积与对照差异不显著;与对照相比,施用BIO及Y-IVI的处理根际土壤尖孢镰刀菌数量分别明显降低了52.2%和41.8%,施用有机肥OF的处理降低了10%,差异不显著。【结论】Y-IVI可稳定定殖于香草兰根际土壤对其生长起有益作用,含促生菌Y-IVI的生物有机肥料比单独使用促生菌菌液可以更有效地减少根际土壤中尖孢镰刀菌数量,降低连作生物障碍。施用生物有机肥料比施用化肥和有机肥更有效地促进香草兰地上部及根系生长,因此,施用由根际促生菌枯草芽孢杆菌(Bacillus subtilis)Y-IVI制得的生物有机肥是解决香草兰连作生物障碍和提高收益的有效手段。     

植物生长延缓剂对万寿菊穴盘苗生长的控制作用研究

试验研究不同浓度的植物生长延缓剂比久(B9)、矮壮素(CCC)和多效唑(PP333)溶液对万寿菊穴盘苗生长的控制作用结果表明,B9、CCC及PP333处理万寿菊穴盘苗的最佳浓度分别为2500mg/kg、0.3%和60mg/kg,适宜浓度分别为1000~2500mg/kg、0.1%~0.3%、10~60mg/kg。3种延缓剂最佳浓度处理对万寿菊穴盘苗生长的控制作用60mg/kg PP333处理>0.3?C处理>2500mg/kg B9处理,且60mg/kg PP333处理成本最低。当CCC处理浓度>1.0%时万寿菊穴盘苗出现药害现象。     

Vermicomposting with rock powder increases plant growth

The growth of earthworms in substrates enriched with rock (gneiss and steatite) powder, and the potential of vermicomposting in increasing solubilisation of minerals present in rock powder and in promoting plant growth were evaluated. Cattle manure (400 g), was enriched with 0, 5 and 20% of gneiss or steatite powder. Each pot with this mixture received nine earthworms (Eisenia andrei), at a density of 1000 indiv. m⁻³. After 60 d, earthworms were collected, counted and weighed (fresh and dry). Maize was cultivated in a greenhouse in pots with an Oxisol that was fertilised with the vermicompost obtained above. Treatments with Oxisol fertilised with gneiss or steatite only and unfertilised soil were used as controls. Shoot length was measured weekly from the soil surface to the tips of the leaves. After 73 d, the plants were harvested, the roots washed from the soil and shoots and roots dried and weighed. Plants fertilised with vermicompost enriched with rock powder were taller and heavier than plants fertilised with non-enriched vermicompost. Plants grown on soil fertilised with rock powder but not with vermicompost were larger than plants grown on unfertilised soil. Vermicompost enriched with steatite powder resulted in a larger effect on plant growth than the mere sum of applying vermicompost of non-enriched manure and steatite alone to the soil. A similar, but non-significant effect was also observed for gneiss. The different effects between gneiss and steatite may be associated with the lower resistance to chemical weathering of steatite minerals compared to gneiss minerals, as well as the former being softer than the latter. The effect of vermicompost on the optimisation of nutrient release from silicate rocks seems to depend on the rock type.