Impact of Rice Nursery Nutrient Management, Seeding Density and Seedling Age on Yield and Yield Attributes

To help farmers in the mid hills of Nepal improve their crop management and rice yields, we conducted a study testing different nursery management options and their effect on grain yield and yield components under rainfed conditions. The experiment was conducted in a farmer’s field during the cropping season 2009 and 2010 at Sundarbazar, Lamjung, Nepal, using a 3-factor factorial RCB design with 3 replications. The three management factors tested were 1) fertilizer management in the nursery, 2) seeding density, and 3) seedling age at transplanting, using the rainfed lowland rice variety Radha-4. There were eight treatment combinations, consisting of two levels of fertilization (0 and 20:20:0:13 kg NPKS ha-1 at 15 DAS), two levels of seeding density (607 and 303 g·m-2) and two seedling ages (20 and 40 days old). Two years’ results showed that top-dressed fertilizer in the nursery had no consistent effect on grain yield. However, lower seeding density (303 g·m-2) resulted in taller plants, more productive tillers m-2, less sterility and higher grain yield. In addition, older seedlings (40 days) produced taller plants, more productive tillers, more filled grains, and a higher grain and straw yield. The interaction analysis between both factors indicated that 40 days old seedling with a low seeding density produced the highest grain yield, both in the drought season 2009 and the high-yielding season 2010. The economic analysis confirmed that the treatment with low seeding density and 40 days old seedlings produced by far the highest net returns and B:C ratio in both seasons, independent of the fertilizer treatment. The combination of these two management components is therefore economically viable and profitable, and can be recommended to farmers. However, the results need to be confirmed for other varieties used by farmers in the region.

EFFECTS OF SOIL MOISTURE CONTENT ON DRY NURSERY SEEDLING QUALITY OF LATE DOUBLE CROPPING RICE IN SOUTH CHINA

In the present paper, an experiment was conducted to study the effects of soil moisture content on dry nursery seedling quality in Guangzhou in 1995. Through comparing the difference of dry nursery seedlings and wet nursery seedlings, we found a close relationship between soil moisture content and seedling growth. The seedling emergence of dry nursery seedling was more even, tidy and faster, and the survival rate was higher than that of wet nursery seedling. Dry nursery seedlings had small plant stature, slow leaf stretching speed and low individual seedling dry weight, but had high dry/fresh weight ratio. This was abeneficial factor for seedlings to recover from transplanting shock more quickly. As com-pared with the wet nursery seedlings, dry nursery seedlings had poor rooting ability,but had more vigorous white roots and fewer rust roots. It was the possibly important reasonfor dry nursery seedlings to form strong“explosive force”.

EFFECTS OF SEEDING DENSITY AND BASIC MANURE ON THE GROWTH OF DRY NURSERY SEEDLINGS IN LATE DOUBLE CROPPING RICE IN SOUTH CHINA

During the period of dry nursery seedling raising of late double cropping indica rice in South China, both chemical fertilizer and farmyard manure did not show obvious effect on the growth of shoot and root in young seedlings at 4-leaf stage （18-day-old seedling）, but had significant effects on root growth in old seedlings with 6-7 leaves （27-day-old seedling） at suitable seeding densities (65-125g m-2). There were satistically significant differences （at 0.01 or 0.05 levels）between treatments in root number and rooting ability of root-pruned seedlings.

The technology of raising rice seedlings in dry nursery in China

A new technology of raising rice seedlings in dry nursery began to be adopted in early 1980’s inChina. It expanded in Northeast of the Country and spreaded from North to South in the followingyears. In 1995, it was listed as one of the national popularization project during the ’Ninth Five-Year-Plan’ by the Country Government. The total area was up to 9.3 million hm~2 in 1996 (cover-ing 80% paddy field in the northern parts of China). The expected popularized area will be up to15.3 million hm~2 in 2000 according to the Ministry of Agriculture, half of the total rice-growingarea in China.

Growth responses of seedlings produced by parent seeds from specifi caltitudes

Restoration activities in semi-arid Mediterranean areas like Greece face many obstacles,such as summer droughts that are becoming more intense with climate change,that pose limitations to transplanting success.Seedlings for restoration must be of high quality;a vigorous root system is critical to enable seedlings to tolerate adverse conditions.Here we investigated the eff ects of altitude and source parent for seeds on the growth of subsequent seedlings to determine the best seed sources for obtaining highest-quality,most-tolerant seedlings for restoration eff orts.Seeds of Quercus coccifera L.were collected on an altitudinal gradient of 50 m(200,250 and 300 m a.s.l.)and from specifi c parents at each altitude.Subsequent seedlings were grown for 3 months in a greenhouse with controlled irrigation.The results indicated a strong altitudinal and parental seed eff ect on seedling characteristics.As altitude decreased,biomass of the seedlings increased,and they developed more vigorous roots and more photosynthetic leaf tissue.Thus,altitude and parent are critical factors to consider when producing seed-derived seedling.By collecting seeds from a specifi c altitude and parent,more vigorous and stresstolerant seedlings can be obtained to enhance transplanting success.

Synergic Effect of Mucuna pruriens var.Utilis(Fabaceae)and Pontoscolex corethrurus(Oligochaeta,Glossoscolecidae)on the Growth of Quercus insignis(Fagaceae)Seedlings,a Native Species of the Mexican Cloud Forest

Propagation of native species in local nurseries is an important activity in reforestation and forest restoration programs. A requisite for successful plantation is that nursery produced plants are of a size and quality that allows optimal establishment under field conditions. Manipulation of edaphic processes through the combined use of the earthworm Pontoscolex corethrurus, Mucuna pruriens and inorganic fertilizers may promote faster biomass gain. This study assessed the activity of P. corethrurus, its association with M. pruriens (green manure) and inorganic fertilizers, on the growth of Quercus insignis seedlings under greenhouse conditions. Measured variables were basal diameter, height, biomass and foliar nitrogen content. Growth rates of basal diameter (F = 5.33;P F = 2.84;P P. corethrurus-M. pruriens-inorganic fertilizer, relative to the control. Also, leaf biomass and total biomass of the seedlings were greater in the treatment of P. corethrurus-fertilizer (F = 2.32;P F = 3.71;P Foliar nitrogen content <span style="font-family:Verdana;

Effects of phosphorus and potassium addition on growth and nodulation of Dalbergia sissoo in the nursery

A study was conducted to test the influence of different inorganic fertilizers （phosphorous and potassium） on the nodulation and growth of Dalbergia sissoo grown in the nursery. Before seeds sowing, different combinations of P, K fertilizers were incorporated with the nutrient-deficient natural forest soils, and then amended with cowdung （soil： cowdung = 3：1）. Nodulation status （nodule number, shape, fresh weight, dry weight and color） in the roots and the plant growth parameters （length of shoot and root, collar diameter, fresh and dry weight of shoot and root） were recorded 60 days after seeds sowing. Nodulation status and growth of the plants varied significantly （P〈0.05） in the soils amended with fertilizers in comparison to the control. The highest nodule number （62）, fresh （0.50 g） and dry （0.07 g） weights were recorded with the dose of PK at the rate of 160 kg/hm2. Nodule shape and color also varied widely in different treatments. In case of plant growth parameters, shoot and root length, collar diameter, fresh and dry weight of the plants took on a significant difference （P〈0.05） among various combination of fertilizers. From the study, it is revealed that PK at the rate of 160 kg/hm^2 fertilizer with soil and cowdung mixture （soil： eowdung = 3：1） is recommended for optimum growth and nodule formation of D. sissoo in degraded soils at a nursery level.

Functional relationships of nodulation response and biomass production at nursery stages of two fast-growing, leguminous-multipurpose tree species in Bangladesh: Albizia saman and Leucaena leucocephala

This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49).

THE DISCUSSION ON THE MEASURES OF INCREASING NURSERY STOCK QUALITY IN FRIGID REGION OF CHINA

Through several years seedling-growing experiments in nursery in Daxing‘anMountains forest region,the author posed that the seedling cultivated for the region mustpossess the characteristics of being suited to thin and meager soil and having strongresistance to adverse conditions.For this purpose,the cultivation regime ought to bedirectization,standardization and programmatization;seedling growth ought to be promotedby regulating ecological conditions;and the mursery stock quality ought to be tested usingvigor index.

发酵稻壳通过增强氮代谢途径影响烟草幼苗的生长发育

为探究发酵稻壳替代炭化稻壳在烟草(Nicotiana tabacum L.)漂浮育苗中的可行性,以商用基质为对照,用不同比例发酵稻壳(fermented rice husk, FRH)替换湘烟7号栽培基质中的炭化稻壳(carbonized rice husk, CRH),并在温室中漂浮育苗60 d,测定幼苗形态指标;选取长势最好处理组FRH1,测定根系和生理指标,进行转录组测序,并对相关代谢通路和关键基因进行鉴定和分析。结果表明,6个处理间整齐度差异不大,但FRH处理生长势优于CRH处理;综合比较,FRH1处理在株高、根冠比和壮苗指数方面优于其他处理。FRH1处理的一级侧根数量、长度和表面积分别为292条、39.7 mm、4.9 cm^(2),根系脯氨酸含量、CAT和SOD活性分别为7.0μg·g^(-1)、232 U·g^(-1)·min^(-1)和45.7 U·g^(-1)·min^(-1),均显著高于CRH处理;FRH1和CRH处理共有294个显著差异表达基因参与氮代谢、戊糖和葡萄糖醛酸相互转化等20个KEGG代谢通路,并得到了显著富集;共挖掘出12个参与氮代谢的关键基因,并通过qRT-PCR进行了验证,同时发现硝酸盐/亚硝酸盐转运体基因newGene_31743在2个处理(FRH1和CRH处理)中相对表达量都较高。与CRH处理相比,FRH1处理中烟苗根系硝酸还原酶、亚硝酸还原酶活性分别显著提高8%和7%,氮含量上升1.7%(无显著差异)。发酵稻壳替代炭化稻壳进行漂浮育苗可以增强烟草幼苗氮代谢途径,从而改善烟草根系酶活性,提高根系活力,改良根系形态,进而促进烟苗生长。

指数施肥对杉木容器育苗基质真菌群落及功能类群的影响

【目的】进一步探索杉木幼苗基质真菌群落对指数施肥的整体响应特征。【方法】以杉木无性系“洋061”轻型容器育苗基质为研究对象,通过设置4个浓度梯度的施肥处理(EF1,40 mg/株;EF2,80 mg/株;EF3,120 mg/株;EF4,160 mg/株),对照组不施肥,基于(Illumina MiSeq)高通量测序与FUNGuild真菌功能预测技术,研究不同指数施肥梯度对杉木苗基质理化性质、真菌群落结构及功能类群的影响。【结果】短期指数施肥对基质对真菌多样性没有影响,但能显著提高丰富度指数。粗孢孔目(Trechisporales)肉座菌目(Hypocreales)、粪壳目(Sordariales)、Chaetosphaeriales和被孢霉目(Mortierellales)分别是伞菌纲、粪壳菌纲、被孢霉纲三大优势真菌纲下的优势种群。指数施肥显著提高了肉座菌目相对丰度,显著降低了粪壳目、被孢霉目相对丰度。基质真菌营养类型以腐生型为主,木质腐生真菌为优势功能类群,指数施肥后病理腐生共生过渡型、腐生共生过渡型、植物病原真菌相对丰度显著减少,从枝菌根真菌相对丰度显著增加。RDA分析结果表明,AP、TK和TN是影响基质真菌群落结构与功能类群的主要环境因子。指数施肥显著增加了基质中AP、TN含量,推测指数施肥可能会促进对N、P敏感的真菌类群繁殖,这部分真菌属于腐生营养型与共生营养型,随着施肥量增加,腐生营养性真菌类群逐渐占据主导地位,反而抑制了共生营养型真菌类群生长。【结论】指数施肥能有效提高基质养分有效性,调控真菌优势群落结构,增加共生与腐生型真菌比例,降低病菌含量,为杉木幼苗生长发育提供良好条件。

湿润剂对育苗基质水分吸持和黄瓜穴盘苗生长的影响

基质水分吸持特性直接影响基质含水量和蔬菜穴盘苗生长发育。为了探明湿润剂对穴盘育苗基质水分吸持的作用,研究了湿润剂添加后对不同粒径育苗基质的水分吸收量、蒸散速率和黄瓜穴盘苗生长的影响,结果表明:小粒径基质吸水速率和吸水量显著低于大粒径基质,湿润剂更有利于增加小粒径基质吸水量,相对于大粒径基质增加了17.32百分点;添加湿润剂同时提高了穴盘育苗基质吸水速率和蒸散速率,并使基质在1、2、3次吸水-蒸散过程始终保持较高相对含水量;基质添加湿润剂可有效促进小粒径基质条件下黄瓜穴盘苗生长发育,显著提高了黄瓜幼苗根冠比和成坨率。表明基质添加湿润剂可有效改善小粒径育苗基质水分吸持特性,有利于黄瓜穴盘苗壮苗形成。

Design and test of soft-pot-tray automatic embedding system for light-economical pot seedling nursery machine

Most of the commercially-available pot seedling nursery machines are incompatible with soft-pot-trays and are labor-intensive and low in productivity.A soft-pot-tray automatic embedding system was developed in this study to achieve automatic embedding of the soft pot tray into the hard tray following sowing and covering with soil.A control system was constructed using the Arduino program development environment.An embedded-hard-tray automatic lowering mechanism and conveyor-belt-based pot-tray embedding system were designed.Dynamics analysis was conducted to derive an equation to describe the embedding process of the soft pot tray into the embedded hard tray.A prototype of the soft-pot-tray automatic embedding system was manufactured and tested.The analytical equation suggested that a minimum linear velocity of 0.86 m/s was required for a complete embedding process.The experimental results showed that the embedded-hard-tray automatic lowering mechanism was reliable and stable as the tray placement success rate was greater than 99%.The successful tray embedding rate was 100%and the seed exposure rate was less than 1%with a linear velocity of the conveyor belt of 0.92 m/s.The experiment findings agreed well with the analytical results.The proposed soft-pot-tray automatic embedding system satisfied the technical specifications for a light-economical pot seedling nursery machine.

石家庄市苗圃经营现状分析

为探究河北省石家庄市全域苗圃经营现状及其存在的问题,该文通过实地调查,结合政府公开数据等资料对石家庄市苗圃的数量、面积、树种类型、经营方式等进行了分析。结果显示:(1)石家庄市苗圃共555家,总面积6053.33 hm^(2)。国有苗圃7个(1.26%),私营苗圃548个(98.74%);苗木种类有102种,多为乡土树种,落叶与常绿种数比为8:17;(2)苗圃骨干技术人员842人,其中大专学历以上只有180人;(3)苗圃销售渠道多样,多为本地直销,公司、企业订购和经纪人销售(占比67.82%),目标市场以首都北京为中心的地域圈层。针对苗圃经营中存在管理专业化水平低、机械化程度低、经营特色不突出等问题,提出了提高科技水平、发展多功能苗圃和差异化苗木的建议。

不同育秧基质对垦稻12秧苗素质的影响

为明确不同育秧基质对水稻秧苗素质的影响,采取随机区组设计进行试验研究。结果表明,相较于常规营养土育苗,中禾育秧基质下水稻秧苗综合素质更强,尤其是秧苗的根长、百株干重、充实度、发根力根数,与常规营养土间差异均达到了显著水平,育苗优势明显,可替代常规营养土育苗。

刺梨实生苗苗木质量分级研究

在贵州省都匀市以不同地理种源刺梨(Rosa roxburghii Tratt.)种子培育出862株1年生实生苗,逐株测量苗高(H)、地径(D)、主根长(L)、长度≥5 cmⅠ级侧根数(N)与长度≥5 cmⅠ级侧根平均长(R)等生长指标。各指标观测值经离差标准化处理后进行相关性分析,发现各指标间呈极显著(p<0.01)正相关。为便于生产应用,选择苗高与地径为苗木分级指标。采用逐步聚类法进行苗木质量分级,得到的1年生刺梨实生苗分级标准为:Ⅰ级苗H≥80.00 cm、D≥7.52 mm;Ⅱ级苗80.00 cm>H≥59.00 cm、7.52 mm>D≥5.12 mm;Ⅲ级苗H<59.00 cm、D<5.12 mm。

CQ-2000型苗圃振动式起苗机设计

针对现有横切式起苗机起苗时存在被切主根有撕裂、茬口不平齐等问题,设计了一种新型振动式起苗机。该机的起苗刀由两片呈一定角度排布的切刀组成,起苗时可有效解决上述问题和一体式起苗刀生锈腐蚀,起苗质量得不到保障的现象。对CQ-2000型苗圃振动式起苗机的入土角、起苗刀刀宽和斜角进行了设计。为验证起苗机是否达到了预期性能目标,对CQ-2000型苗圃振动式起苗机进行了起苗深度变化范围、入土行程和伤苗丢苗率试验,试验结果表明:CQ-2000型苗圃振动式起苗机起苗深度变化范围、入土行程和伤苗丢苗率均符合LY/T 1430-2013苗圃床作型起苗机设计标准。

浅析大规格楸树圃地苗抚育管理技术——以界首市为例

基于楸树生物学特性,以界首市为例,阐述了大规格楸树圃地苗的抚育管理技术和要点。通过做好松土除草和水肥管理工作、科学定植与施肥、针对性地开展病虫害防治,为培育优质大规格楸树壮苗提供科学依据。

黄泛区苗木现状及优质绿化精品苗培育技术

通过对山东省菏泽市林木老苗圃进行提升改造试验,指出老苗圃存在的密度大、偏冠、质量差、效益低等问题,并从降低密度、整形修剪、改接良种等方面提出了提质增效的措施,以期为促进菏泽市苗木产业发展提供参考。

不同育秧方式和播种量对水稻秧苗素质的影响

为探究不同育秧装备和播种量水平下水稻机插秧育秧秧苗素质各项指标的差异,以W型、S型循环立体苗床和温室地面育秧作为不同育秧方式,设置每盘芽种120、160、200 g共3个播种量水平,展开试验。结果表明,在阴雨天气时,3个播种量水平下,S型装备育出的秧苗素质优于W型,但不及地面育秧;不同育秧方式的最佳播种量也不尽相同,W型和S型育秧装备的最佳播种量范围为芽种160~200 g/盘,而地面育苗方式的最佳播种量范围为芽种120~160 g/盘。本文研究结果为W型和S型循环立体育秧装备技术的推广应用提供了理论指导和实践依据。