共查询到20条相似文献，搜索用时 62 毫秒
1.
国家甘蔗品种生产示范试验初报 总被引：5，自引：0，他引：5
本文报道了来自福建、广西、广东、云南四省（区）１０个甘蔗品种在广西的生产试验结果。试验结果表明：桂糖８０、闽糖８６／０５两品种的蔗茎产量,甘蔗蔗糖分含火糖量表现突出。桂糖８９／５蔗茎产量为９２．９ｔ／ｈｍ＾２,分别为ＣＫ１、ＣＫ２的１２４．８％和１３８．５％;含糖量达１４．４１ｔ／ｈｍ＾２;分别为ＣＫ１、ＣＫ２的１２７．５％和１３８．４％。闽糖８６／０５新宿根蔗茎平均产量为８３．９ｔ／ｈｍ＾２,分 相似文献
2.
在旱地中采用周年覆盖一年两熟栽培技术，地期降蒸发的抑制率可达３０－５０％，比春覆膜（对照）多保蓄２００ｍｍ以上的降水；秋覆膜的硅民麦沟形成微型集雨区，不易向沟内径流，可多聚水１００ｍｍ以上。两项合计３００ｍｍ以上。科春两季１０ｃｍ地积温，垄上与垄底分别增加约４００℃．ｄ和２００℃ｄ。土壤中各种微生物增加０．６６－１．２倍，土壤总孔隙度提高４．５１％，速效氮（Ｎ）、磷（Ｐ２Ｏ５）、钾（Ｋ２Ｏ）含量分 相似文献
3.
本试验应用农业生态学原理和现代农业技术，在我国广西岩溶山区低产水稻田应用稻＋蔗＋鱼＋菇＋菜复合生态农业模式，实现了每公顷稻田年产稻谷４．６５吨，甘蔗２４．６５吨，鱼０．７７吨，平菇１５．５吨，蔬菜２．３３吨，总产值５４４１１元，纯收入３４９３５元，奖金产投比２．７９：１，比对照（仅种双季稻）的产值增加８．４倍，纯收入增加１０．１倍，取得了显著的经济效益和生态效益。 相似文献
4.
坡耕地果粮间作聚流与覆盖相结合改造利用技术研究 总被引：1，自引：0，他引：1
针对坡耕地水土流失、干旱问题和粮食产量效益低等现状，提出了聚流与覆盖相结合、治理和开发并重、生态效益和经济效益同步提高的坡改技术。明确了果粮间作冠下区、近冠区、远冠区的合理立体植被覆盖结构和不同坡度隔坡水平沟聚流工程模式。果粮间作结合隔坡水平沟技术降低坡耕地径流量９８．６％￣９９．１％，土壤侵蚀模数减少９３．１％￣９５．８％；亩纯收益比单种粮食提高３１．３％￣６４．２％，比果树提高８１．０％。在平 相似文献
5.
PGR—08对小麦种子萌发与幼苗生长的影响 总被引：1，自引：0，他引：1
ＰＧＲ—０８是一种新的植物生长物质．通过５～５０ｍｇ／Ｌ浸种处理，在（２５±１）℃条件下，使小麦种子发芽率４８ｈ内比对照增加９．３％～１９．３％，同时使种于中淀粉酶的活性比对照增加１０６．３％～１６２．５％．育苗６ｄ后，使苗高与根长都相当于对照的２～４倍，２５ｄ后，麦苗的一级分蘖相当于对照的１．６～２．３倍，而且有１／４～１／２的植株出现二级分蘖．同样条件下，对照却无二级分蘖。 相似文献
6.
几蔬菜的养分需求与钾素增产效果 总被引：7，自引：0，他引：7
通过对９种蔬菜研究表明，蔬菜各器官养分含量高而转移率低，属营养非完全转移型作物；蔬菜需肥量大，比谷类作物约高出１／３；蔬菜的钾氮吸收比高（大于１￣１．５），而磷氮吸收比低（小于０．３）；每公顷产４５￣７５ｔ蔬菜，约需Ｎ３００￣４５０ｋｇ，Ｐ２Ｏ５ １０５￣２２５ｋｇ，Ｋ２Ｏ１０５￣２１０ｋｇ，１ｋｇＫ２Ｏ可增产番茄２６．１￣１４１．３ｋｇ，甘蓝１１．２￣５３．１ｋｇ，黄瓜５．８￣８６．９ｋｇ，甜菜 相似文献
7.
晋中东山地区褐土土壤水分特征的测定与应用 总被引：7，自引：0，他引：7
利用压力膜方法测定晋中东山地区褐土的土壤水分，并分析了土壤水分及其能态特征。结果表明：本区土壤水吸力与土壤含水量之间呈明显的幂函数关系，可以用幂函数方程模拟；土壤的当量孔径分布大致随土壤水吸力的增加而减小；土壤的结构性能良好，通气孔隙、毛管孔隙、无效孔隙的当量孔径分布分别占土壤总孔隙度的１８．３％、５１．２％和３０．５％，尤其是毛管孔隙的分布占土壤总孔隙度的一半以上；土壤的比水容量随吸力的增大而迅速减小．当吸力为０．１×１０￣５～０．３×１０￣５ｐａ时，其比水容量的量级为１０￣（－１）［ｍ１／（１０￣５ｐａ·ｇ）］，而当吸力达３×１０￣５～１５×１０￣５ｐａ时，其比水容量的量级下降了１００倍，为１０￣（－３）［ｍｌ／（１０￣５Ｐａ·ｇ）］。表层土壤水分对于作物吸收利用比心土层和底土层更为有效，但深层土壤的持水性能比表层士壤要好。为此，必须提高作物对土壤深层储水的利用。 相似文献
8.
在高温夏季（１９９３年７月１日～９月３０日，合肥地区，开放式鸡舍，舍温２７．９～３８．７℃，平均３２．３℃），用６种不同配方的日粮饲喂处于相同生境的６组２３～３６周龄罗曼蛋鸡。按罗曼公司推荐的饲养标准配制第１组日粮；对第２～６组日粮养分浓度作适当调整。饲养结果表明：各组间罗曼蛋鸡产蛋率、饲料转化率和产蛋饲料成本有显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）差异。其中，第５组鸡产蛋率（８３．９３％）和饲料转化率（４３．６４％）均为最高（Ｐ＜０．０１），比第１组鸡产蛋率（７８．９１％）和饲料转化率（４１．２６％）分别提高６．３６％（Ｐ＜０．０５）和５．７７％（Ｐ＜０．０５）；第５组鸡产蛋饲料成本（２．５５元／ｋｇ）比第１组鸡产蛋饲料成本（２．９２元／ｋｇ）降低１４．５１％（Ｐ＜０．０１）。第５组日粮配方（％）为：玉米６１．０、小麦麸３．０、大豆粕１７．０、鱼粉４．０、菜籽饼４．３、蛋氨酸０．１４、赖氨酸０．０５、骨粉０．８、石粉８．５、磷酸氢钙０．８、食盐０．３１、禽用微量元素添加剂０．１２、罗曼多维素０．０１８。 相似文献
9.
胚胎的冷冻是用二步降温法，将胚胎降至－２５℃，并直接投入液氮。试验Ⅰ，将６～８日龄的牛胚胎置于显微镜下，按发育期把胚胎分成桑椹胚、早期囊胚、囊胚、扩展囊胚四个阶段，然后分别平衡在１．５ｍｏｌ／Ｌ甘油＋０．２５ｍｏｌ／Ｌ蔗糖ＰＢＳ液中，２０ｍｉｎ后进行冷冻。解冻后，各阶段的胚胎孵化率分别为：２９．０％，７３．２％，７４．６％，６１．２％。桑椹胚的孵化率极显著（Ｐ＜０．０１）地低于其它三个阶段的胚胎，其它三个阶段之间无显著差异（（Ｐ＞０．０５）。试验Ⅱ，将７日龄的囊胚，在显微镜下鉴定质量并分为１～５级，仅１，２级胚胎用于冷冻。试验结果表明：每管装２枚胚胎时，有１枚胚胎以上孵化的细管数，１级的有９３．８％（４５／４８），２级的有７７．４％（２４／３１），它们之间差异显著（Ｐ＜０．０５）。每管装３枚胚胎时，有２枚胚胎以上孵化的细管数，１级的有８７．５％（４２／４８），２级的有６８．０％（１７／２５），二者间差异显著（Ｐ＜０．０５）。本研究结果表明：不同阶段和质量的牛体外培养胚胎冷冻后对存活率有显著的影响。 相似文献
10.
利用缺体回交法选育小黑麦异代换系的研究 总被引：3，自引：0，他引：3
以４Ｄ缺体为母本，黑麦为父本进行杂交，授粉后１６￣１８ｄ进行幼胚培养，培养的试管苗用０．０５％秋水仙素处理，加倍后的植株再用缺体回交１￣２次，就可获得小黑麦异代换系。在第二次回交的Ｆ１（Ｂ１Ｆ１）代理，单体代换植株占１８．５％，双单体代换占２４％，这两种类型经自交后都获得了４Ｄ／４Ｒ异代换系，有的异代换系已直接用于生产。 相似文献
11.
In order to identify key adaptive traits which affect productivity in Mediterranean grain and forage legumes and simultaneously determine the agricultural potential of a wide range of Vicia species, germplasm collected from the wild throughout the eastern Mediterranean was grown under semi-arid conditions in Tel Hadya, Syria (313 mm growing season rainfall). These included species currently in use in Mediterranean agriculture, such as V. sativa L., as well as those more widely used in the past-such as V. ervilia L., but also a broad selection from Section Narbonensis (B. Fedtsch. ex Radzhi) Maxted, including V. narbonensis L, V. johannis Tamamsch., V. hyaeniscyamus Mout., V. serratifolia Jacq., and V. kalakhensis Khattab et al. V. faba, a near relative of the taxa in Section Narbonensis, was included as a domesticated control. Where applicable, a representative range of subspecies was used. Accessions were chosen from a wide range of habitats in terms of latitude (31.02–40.72 decimalo), longitude (27.1–43.17 decimalo), altitude (20–1510 m), rainfall (180–1700 mm/yr) and soil depth (5–50 cm) in order to maximise diversity within species. Agricultural potential was determined by measuring seed, hay and biological yield, as well as agronomic traits such as harvest index, standing crop height, and seed size. The comparative influence of phenology and key agronomic traits such as plant habit and seed size on productivity varied tremendously between species, depending on their reproductive strategies. In V. sativa and V. ervilia, the smaller seed species which rely on long vegetative phases and growing seasons to accumulate sufficient biomass to set seed, and in which there was comparatively little agronomic variation, phenology had a large impact on yield. In early emerging taxa such as V. ervilia and V. s. subsp. sativa, with built-in long vegetative phases and growing seasons, seed yield was negatively correlated with flower ing (r = –0.86 to –0.88), whereas the opposite was the case for later emerging taxa such as V. s. subsp. nigra (L.) Ehrh. (r = 0.95). Within V. narbonensis and relatives, the larger seeded Vicia species which rely on more conservative reproductive strategies where high seedling vigour associated with large seeds enables the species to enter reproductive phases relatively early, phenology had a much smaller impact on yield than did variation of key traits such as seed weight, plant habit and pod shattering. Among the undomesticated germplasm harvest indices ranged from 0.09–0.31, hay yields from 0.1–3.4 t/ha, seed yield from 0–2.0 t/ha, and dry matter at maturity from 1.6–6.5 t/ha. Sub-specific taxonomy was crucial in determining agronomic potential. V. narbonensis var. aegyptiaca Kornhuber ex Asch. et Schweinf. showed the most potential, combining an upright habit, large seeds (212 mg) and tendency to retain intact pods after maturity, with the highest yield, harvest index and crop height of all the wild Vicia species. V. sativa subsp. sativa, V. ervilia and V. narbonensis var. narbonensis were less productive, but still showed agricultural potential. The smaller seeded V. narbonensis, var. affinis, var. jordanica H. Schäf. and var. salmonea (Mout.) H. Schäf., and their close relatives V. johannis, V. hyaeniscyamus, V. serratifolia and V. kalakhensis have little to offer Mediterranean agriculture on the basis of poor agronomy. 相似文献
12.
13.
14.
J. K. Leary N. V. Hue P. W. Singleton D. Borthakur 《Biology and Fertility of Soils》2006,42(3):215-223
Gorse (Ulex europaeus) infestation occupies over 4,000 ha of agriculture and conservation lands on the southeastern slope of Mauna Kea on the Island
of Hawaii. The aim of this investigation is to identify ecological features associated with this weed invasion by comparing
the gorse-infested areas to the surrounding uninfested areas of this landscape. The soils within the gorse infestation are
more acidic, resulting in higher levels of KCl-extractable Al and lower levels of Mehlich III-extractable Ca, Mg, Mn, and
Zn. Yet, gorse accumulates higher concentrations of Ca, Zn and, Cu than the kikuyu grass (Pennesitum clandestinum), which is ubiquitous throughout the site. The Ca:Al and Mg:Al molar charge ratios of the soils are lowest within the epicenter
of the gorse infestation, while the molar ratios are highest in the gorse apical stem tissues. All gorse plants are nodulated
and have higher nitrogen contents than the surrounding kikuyu grass. Furthermore, the δ15N of the gorse stem tissues approaches 0‰, suggesting that nitrogen is being symbiotically fixed from the atmosphere. Characterization
of the Bradyrhizobium isolated from gorse nodules shows similarities and distinctions to Bradyrhizobium isolated from the endemic legume koa (Acacia koa) within the same location. Population densities of the indigenous Bradyrhizobium are higher within the gorse rhizosphere than the kikuyu grass. Soil acidification, nutrient depletion, and symbiotic nitrogen
fixation distinguish gorse-infested areas from the surrounding uninfested areas. These observations suggest that gorse has
a competitive advantage over kikuyu grass under conditions of soil nutrient deficiency. 相似文献
15.
Ten leguminous trees, four exotic species (Australian Acacia) and six indigenous species (three Sahelian Acacia spp. and three Sesbania spp.), were grown for 4 months in a natural Sahelian soil inoculated with or without the endomycorrhizal fungus, Glomus intraradices. In control trials, the determinant factor structuring the soil nematode fauna was the plant species, related plants having a similar influence on the nematode community in the soil. Soil nematode abundance increased from exotic acacias (3.3 g-1 dry soil) to native acacias (11.5 g-1 dry soil) and Sesbania species (17.6 g-1 dry soil). Plant feeding nematodes (mainly Scutellonema and Tylenchorhynchus) were significantly less abundant under exotic acacias (1.4 g-1 dry soil) than under native acacias (7.2 g-1 dry soil) or Sesbania species (7.3 g-1 dry soil). Bacterial feeding nematode density increased from exotic acacias (1.2 g-1 dry soil) to native acacias (3.0 g-1 dry soil) and Sesbania species (7.7 g-1 dry soil) as total densities. However, the differences in the structure of the nematode communities between plant groups were suppressed in the presence of the mycorrhizal fungus. In fact, no difference in nematode densities remained between plant groups when G. intraradices developed in several dominant taxa belonging to different trophic groups, particularly: Tylenchorhynchus, Apelenchina, Cephalobus and Dorylaimoidea. This study clearly indicated that inoculation with the arbuscular mycorrhizal fungus G. intraradices diminished the plant-specific effect on the structure of the soil nematode community. 相似文献
16.
Sofie E. De Meyer Koenraad Van Hoorde Bram Vekeman Tamara Braeckman Anne Willems 《Soil biology & biochemistry》2011,43(12):2384-2396
We investigated the diversity of rhizobia isolated from different indigenous legumes in Flanders (Belgium). A total of 3810 bacterial strains were analysed originating from 43 plant species. Based on rep-PCR clustering, 16S rRNA gene and recA gene sequence analysis, these isolates belonged to Bradyrhizobium, Ensifer (Sinorhizobium), Mesorhizobium and Rhizobium. Of the genera encountered, Rhizobium was the most abundant (62%) and especially the species Rhizobiumleguminosarum, followed by Ensifer (19%), Bradyrhizobium (14%) and finally Mesorhizobium (5%). For two rep-clusters only low similarity values with other genera were found for both the 16S rRNA and recA genes, suggesting that these may represent a new genus with close relationship to Rhodopseudomonas and Bradyrhizobium. Primers for the symbiotic genes nodC and nifH were optimized and a phylogenetic sequence analysis revealed the presence of different symbiovars including genistearum, glycinearum, loti, meliloti, officinalis, trifolii and viciae. Moreover, three new nodC types were assigned to strains originating from Ononis, Robinia and Wisteria, respectively. Discriminant and MANOVA analysis confirmed the correlation of symbiosis genes with certain bacterial genera and less with the host plant. Multiple symbiovars can be present within the same host plant, suggesting the promiscuity of these plants. Moreover, the ecoregion did not contribute to the separation of the bacterial endosymbionts. Our results reveal a large diversity of rhizobia associated with indigenous legumes in Flanders. Most of the legumes harboured more than one rhizobial endosymbiont in their root nodules indicating the importance of including sufficient isolates per plant in diversity studies. 相似文献
17.
One hundred and forty-seven Chinese barley varieties maintained at the Gene Bank of the National Barley Improvement Centre,
Zhejiang, and 84 progenies from these varieties were tested at the seedling stage for their reaction to 32 selected pathotypes
of Blumeria graminis f. sp. hordei. Eighteen resistance spectra were identified comprising single or combined resistances from eight known (Ml(Bw), Ml(Ch), Mla7, Mla8, Mla9, Mla13, MlaRu4 and Mlg) and six unknown resistance genes. The most frequent gene was Ml(Bw), which was found in 69 varieties and previously detected in only a few European winter barley varieties. The genes Mla8 and Ml(Ch) were also often present, but other resistance genes were rare. After inoculation, considerably fewer pathogen colonies were
observed in ‘Aiganqi’ and one line of ‘Tong5’. Twenty varieties were composed of lines with different resistance genes. China
is likely to be a region of origin of the genes Ml(Bw), Mla7, as well as three unknown genes found in original landraces and perhaps another three unknown genes detected in cultivars
bred in China. The resistances of varieties from the Zhejiang province and those originating from 11 other Chinese provinces
were quite different. Unfortunately, none of the varieties are promising sources of resistance to powdery mildew and China
does not seem to be a region suitable for identifying such sources. 相似文献
18.
Summary Feeding by the isopod, Oniscus asellus, produced changes in the sulfur constituents of leaf litter substrates (Acer negundo, A. saccharum, Fagus grandifolia, Picea rubens, and Tsuga canadensis). Isopod consumption of leaf litter generally accelerated the mineralization of carbon-bonded S and increased the formation of ester sulfate in all substrates. After the isopod egestion of A. negundo leaves, fecal decomposition over 6 weeks increased total S concentration from 68 to 120 mol S/g due to the catabolism of organic carbon. During the same period sulfate decreased from 34 to 20 mol S/g and carbon-bonded S increased from 34 to 100 mol S/g. Thus the total S pool in aged feces became enriched with organic S (83% of total S). Macroinvertebrate consumption accelerated the transformation of S constituents and the carbon-bonded S concentration approached that of the Oa organic horizon of a northern hardwood forest.Dedicated to the late Prof. Dr. M.S. Ghilarov 相似文献
19.
The effects of five agroforestry woody species (Dactyladenia barteri, Gliricidia sepium, Leucaena leucocephala, Senna siamea andTreculia africana) on the surface aasting activity ofHyperiodrilus africanus were studied in an Alfisol (Oxic Paleustalf) in southwestern Nigeria. Casting activity under the woody species decreased in the following order:Dactyladenia sp. (26.4 Mg ha-1 year-1)>Gliricidia sp. (24.4 Mg ha-1 year-1)>Treculia sp. (22.9 Mg ha-1 year-1)>Leucaena sp. (18.6 Mg ha-1 year-1)>Senna sp. (18.3 Mg ha-1 year-1). These differences in casting activity were partly explained by microclimatic effects. Irrespective of the woody species, the worm casts were higher in clay and silt contents, bulk density, water-stable aggregates, pH, organic C, exchangeable cations, effective cation exchange capacity, and extractable P levels than the corresponding surface soils. The woody species did affect the physicochemical properties and P sorption of the worm casts. The content of water-stable aggregates of worm casts decreased in the following order:Dactyladenia sp.>Treculia sp.>Senna sp.>Leucaena sp.>Gliricidia sp. Large differences in extractable P levels were observed.Senna sp. was associated with the highest extractable P level (11.5 mg kg-1) andTreculia sp. the lowest (4.9 mg kg-1). P sorption was highest on worm casts underDactyladenia sp. and lowest on those underTreculia sp. Without fertilizer application, there were no significant differences in the dry weight of maize grown in the different worm casts. With NPK applications, the dry weight of maize grown in worm casts associated withTreculia sp. was significantly lower than that of maize grown in the other worm casts, mainly due to the low extractable P level. Despite a high organic C and exchangeable K status, maize grown in the worm casts still responded significantly to N and K applications. The N uptake by maize grown in worm casts associated withTreculia sp. was lower than that in the other treatments. 相似文献
20.
I. V. Rodushkin T. I. Moiseenko L. P. Kudryavtseva 《Water, air, and soil pollution》1995,85(2):731-736
The powerful mass-flow of melt water during the brief period of spring thaw provides a surge of pollutants and causes extremely toxic short term conditions. Together with the increase in total metal concentrations during this period, a redistribution in metal speciation occurs that increases the proportion of more toxic forms. Concentrations of ion-exchangeable fractions of nickel (Ni), copper (Cu), aluminium (Al), and manganese (Mn) show strong negative correlations with pH. The sum of complex metal species shows a strong positive correlation with total organic carbon (TOC). A data analysis model based on relationships observed between key parameters and metal behaviour together with gidrological data allowed an assessmrnt of the metal impact on waterbodies from accumulated airborne pollution (Ni, Cu) as well as from accelerated leaching from watersheds (Al, Mn). 相似文献