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1.
有机肥与无机肥配施对菜地土壤N2O排放及其来源的影响 总被引：1，自引：1，他引：0
该研究采用同位素自然丰度法,通过室内培养试验研究北京地区菜地有机肥和无机肥配施对土壤释放N2O及同位素位嗜值SP（site preference）的影响,以期获得不同肥料及其配比下土壤N2O的来源及变化规律。结果表明：施用无机肥释放的N2O显著高于有机肥,其累积排放量是有机肥的6.63倍,且无机肥施用比例越高,排放量越大;各肥料组合在施用后7天内均以反硝化作用生成N2O为主,贡献最高达到78.89%,SP为6.97‰,之后硝化作用逐渐增强并成为主要途径,最高占比达76.48%,SP为25.24‰;培养期内施用无机肥可以促进反硝化作用,平均占比52.98%,SP为15.52‰,而有机肥会使硝化作用增强,平均占比71.35%,SP为23.55‰。因此,在北京潮褐土地区菜地土壤施用有机肥对N2O有良好的减排效果,可为蔬菜生产中肥料的合理应用提供科学依据。 相似文献
2.
有机无机肥配施对玉米-豇豆种植系统土壤N2O排放的影响 总被引：1，自引：0，他引：1
在等施氮量条件下,比较有机肥与无机肥施用后旱地玉米-豇豆复种系统土壤硝化与反硝化作用、N_2O排放与作物产量的变化,有助于正确认识肥料施用对N_2O排放的影响,为制定大田合理的丰产减排措施提供理论依据。本研究通过田间试验,利用静态箱技术和BaPS气压过程分离技术研究了不同肥料类型处理(无机肥、有机肥、有机无机肥配施)下玉米-豇豆种植系统土壤N_2O排放、硝化与反硝化作用的变化特征。结果表明:1)相对于单施无机肥或有机肥,有机无机肥配施可显著降低土壤硝化作用速率;在玉米生长季,有机无机肥配施处理平均土壤硝化作用速率分别比化肥和有机肥处理显著降低了28.74%和13.96%,豇豆生长季显著降低了24.66%和13.28%。土壤反硝化作用速率在各施肥处理间差异不显著。2)有机无机肥配施显著降低土壤N_2O排放;在玉米生长季,有机无机肥配施处理分别比无机肥处理和有机肥处理显著降低33.44%和32.29%,在豇豆生长季分别显著降低27.00%和15.14%。3)相关分析表明,土壤N_2O排放与硝化作用速率呈极显著相关,而与反硝化作用速率呈不显著相关。4)有机无机配施处理玉米和豇豆产量最高。因此,有机无机肥配施能有效降低玉米-豇豆系统土壤N_2O排放和提高作物产量,是一项丰产低N_2O排放的施肥技术,但长期有机无机肥配施对土壤N_2O排放和作物产量的影响还需要进一步研究。 相似文献
3.
有机无机肥配施对酸性菜地土壤硝化作用的影响 总被引：5，自引：0，他引：5
通过室内培养和田间试验, 研究了有机无机肥配施对酸性菜地土硝化作用的影响。培养试验条件为60%土壤最大持水量和25 ℃。 结果表明,土壤硝化作用模式为指数方程,延滞期10天。与纯化肥处理（NPK）相比,鲜猪粪配施无机肥（FPM+NPK）和猪粪堆肥配施无机肥（CPM+NPK）均能降低土壤硝化势和氨氧化潜势,猪粪堆肥配施无机肥还能增加土壤微生物量碳、 氮。鲜猪粪配施无机肥和猪粪堆肥配施无机肥处理在硝化培养和田间试验期间N2O释放量均没有差异,但硝化培养期间鲜猪粪配施无机肥的N2O释放量显著低于纯化肥处理,田间试验期间猪粪堆肥配施无机肥的N2O释放量显著低于纯化肥处理。培养试验结束后的土壤pH值与土壤硝化势间,以及硝化培养期间N2O累积释放量与土壤硝化势间均存在显著正相关关系。本研究表明, 有机无机肥配施显著影响土壤硝化作用以及硝化培养期间和田间N2O释放。 相似文献
4.
不同配比有机无机肥料对菜地N2O排放的影响 总被引：3，自引：1，他引：2
5.
施肥与大气环境质量——论施肥对环境的影响(1) 总被引：21，自引：4，他引：21
无机肥和有机肥都是人类可持续发展不可或缺的资源,只要科学使用不会对环境和生态造成负面影响。不良施肥对大气环境的威胁主要来自有机肥,过量使用有机肥可促进土壤中CO2和CH4的排放;有机肥和畜禽粪肥堆放场地有大量氨气污染,有机物的焚烧可直接向大气排放大量的CO2、CH4及固体微粒,使城乡空气严重污染。有机肥和无机N肥的过量使用,都会导致土壤N素积累。土壤中N素的反硝化作用产生N2O, NOx 的排放。避免有机肥和N肥过量,禁止焚烧有机物,覆盖有机肥和畜禽粪肥堆放场,控制反硝化作用,以减少负面效应,保护大气环境质量。 相似文献
6.
有机肥替代部分无机肥对华北农田土壤理化特性、酶活性及作物产量的影响 总被引：9，自引：0，他引：9
以华北平原农田土壤为研究对象,2012~2015年连续4年研究了有机肥替代部分无机肥对土壤中养分含量、土壤酶活性和作物产量的影响。结果表明：1)0.3M处理(70％无机肥＋3000 kg/hm2有机肥)和0.5 M处理(50％无机肥＋6000 kg/hm2有机肥)与NPK处理(单施无机肥)相比都提高了土壤中全氮、有效磷、速效钾含量,且0.5 M高于0.3 M,说明有机肥替代无机肥的比例越高,土壤中全氮、有效磷、速效钾含量就越高。2)土壤中脲酶活性大小顺序NPK>0.3 M>0.5 M>CK,蔗糖酶活性和过氧化氢酶活性为0.5 M>0.3 M>NPK,说明有机肥可以显著提高蔗糖酶和过氧化氢酶活性。3)小麦4年累计产量0.3 M处理比NPK处理提高5.95％,0.5 M处理比NPK处理降低0.94％,;玉米4年累计产量则是0.3 M比NPK处理降低1.27％,0.5 M处理比NPK处理降低2.00％。综上所述,本研究表明,有机肥替代30％无机肥处理能够保证粮食产量,有机肥替代50％无机肥处理更能提高土壤肥力。 相似文献
7.
不同比例有机肥替代化肥对水稻产量和氮素利用率的影响 总被引：9，自引：0，他引：9
在江西双季稻区进行30 a的田间定位试验,比较不施氮肥(CK)、施用化肥(NPK)、等养分条件下70%化肥配合施用30%有机肥(70F+30M)、50%化肥配合施用50%有机肥(50F+50M)、30%化肥配合施用70%有机肥(30F+70M)施肥条件下水稻产量、氮素吸收、氮素利用率的变化。结果表明:与等养分量NPK处理相比,有机无机肥配施处理能显著提高30 a双季稻平均产量(P0.05),增产幅度在2.47%～5.73%,其中30F+70M处理产量最高,且不同比例有机无机肥配施处理之间有显著差异,30F+70M处理显著高于50F+50M处理(P0.05)。在不同时间段,不同有机无机肥配施处理产量表现不同,低量有机肥配施处理在试验前期具有明显的增产优势,高量有机肥配施处理在试验中后期增产效果明显。与等养分量NPK处理相比,有机无机肥配施处理30 a平均吸氮量无显著差异,不同施肥处理每生产1 t籽粒对氮素的需求不同,有机无机肥配施处理(20.57～20.94 kg)低于NPK处理(21.77 kg),其中30F+70M、70F+30M处理具有较高的氮素生产效率。有机无机肥配施处理30 a平均氮肥吸收利用率与等养分条件下NPK处理无显著差异,但氮肥生理利用率显著提高。有机无机肥配施能提高双季稻产量、氮素利用效率,不同肥力水平稻田应选择适合的比例,中低肥力水平稻田以30%有机肥配施较为合适,而高肥力水平稻田宜选择50%、70%有机肥配施较为合适。 相似文献
8.
有机无机氮肥配施对莴苣土壤N2O排放的影响 总被引：1，自引：0，他引：1
采用静态箱–气相色谱法研究不同种类有机无机氮肥配合施用对盆栽莴苣土壤N_2O排放规律及排放量的影响。试验设置不施肥(CK)、不施氮肥(PK)、施纯化肥(NPK)、有机无机肥配施1(20%猪粪氮+80%化肥氮,NPKM1)、有机无机肥配施2(20%沼渣沼液氮+80%化肥氮,NPKM2)和有机无机肥配施3(20%猪粪堆肥氮+80%化肥氮,NPKM3)共6个处理。结果表明:莴苣生育期各处理施肥后土壤N_2O排放出现多个峰值,出峰时间和大小不一;累积排放量随着生育期的进程逐渐增加,处理间差异更为明显。莴苣生育期各处理土壤N_2O平均排放通量及累积排放量范围分别为0.10～0.25 mg/(m2·h)和1.37～3.42 kg/hm2,大小均表现为NPKNPKM2PKNPKM1NPKM3CK。土壤N_2O排放系数范围为0.13%～0.68%,大小表现为NPKNPKM2NPKM1NPKM3。与NPK处理相比,NPKM1、NPKM2和NPKM3处理莴苣土壤N_2O累积排放量均分别降低48.08%、25.75%和48.30%,产量分别增加48.66%、22.13%和53.76%。总之,施用纯化肥会促进菜地土壤N_2O的排放,而不同种类有机无机氮肥配施能有效减少N_2O排放且提高作物产量,以猪粪类配施效果最佳。因此,有机无机配施是菜地N_2O减排、降低蔬菜种植中氮素损失的重要途径。 相似文献
9.
为了探讨水溶性有机肥与传统有机肥、化肥等相比在提高常见蔬菜的产量、品质及土壤速效养分、酶活性等方面的效果,采用土培小白菜试验,施用化肥(NPK)、鸡粪有机肥(M)和水溶性有机肥(WS),设置10个处理:CK(不施肥)、NPK、M、WS1(0.4 mL/kg土)、WS2(2 mL/kg土)、WS3(4 mL/kg土)、WS4(6 mL/kg土)、MNPK(1/2NPK+1/2M)、MWS(1/2M+WS2)、NPKWS(1/2NPK+WS2),分析了收获期小白菜和土壤的相关指标。结果显示,WS用量越大,小白菜地上部鲜重越大,但处理NPK、MNPK、MWS、NPKWS的地上部鲜重均与WS4(8.62 g/株)无显著差异;高剂量WS处理(WS3、WS4)的粗纤维含量平均比CK、NPK处理分别减少62.6%、38.3%,处理M和MNPK对降低粗纤维含量有同等效果。此外,施用WS的剂量越高,土壤碱解氮、有效磷、速效钾含量越高;土壤蔗糖酶活性在处理WS3、WS4中最高(均值10.1 mg/g),处理M次之(8.81 mg/g),在CK和NPK中最低(均值6.41 mg/g)。从经济效益来看,WS3、WS4处理的净收益为负值,而NPK和MNPK处理的净收益最高。因此,从产量、经济效益、土壤肥力可持续性等方面综合考虑,最佳推荐施肥措施是化肥配施鸡粪有机肥,水溶性有机肥在降低成本后可推广作为速效有机肥料来施用。 相似文献
10.
研究不同施肥措施下东北黑土区玉米农田温室气体(CO_2、N_2O和CH_4)的排放量及其增温潜势,将为制定农业温室气体减排措施提供理论依据。本研究以国家(公主岭)黑土长期定位试验为平台,采用静态箱-气相色谱法对不同施肥措施下玉米农田土壤温室气体排放通量进行了监测,并分析了不同施肥处理间玉米田的综合温室效应差异。结果表明:各施肥处理土壤温室气体CO_2和N_2O的排放高峰均出现在玉米拔节期。农家肥和化肥配施(M_2NPK)处理土壤CO_2、N_2O排放通量和CH_4吸收量均显著高于施化肥处理(P0.05);施用化肥处理土壤CO_2、N_2O排放通量高于不施肥处理;撂荒区土壤CO_2排放通量最高,而土壤N_2O排放通量显著低于施肥处理;等施氮量条件下,化肥(NPK)处理土壤N_2O排放通量明显高于秸秆还田(SNPK)处理,而土壤CH4净吸收量结果则截然相反。从土壤综合温室效应和温室气体强度可分析出,与不施肥(CK)比较,偏施化肥N和NPK处理的综合温室效应(GWP)分别增加了142%和32%,SNPK综合温室效应降低了38%;尤其是有机无机配施(M_2NPK)处理的综合温室效应为负值,为净碳汇。平衡施肥NPK和有机无机肥配施(SNPK和M_2NPK)温室气体排放强度(GHGI)较弱,显著低于不施肥(CK)和偏施化肥(N)处理,其中M2NPK为-222 kg CO_2-eq·t~(-1)。因此,为同步实现较高的玉米产量和较低的温室气体排放强度,有机无机肥配施是东北黑土区较为理想的土壤培肥方式。 相似文献
11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响 总被引：2，自引：2，他引：0
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。 相似文献
12.
Kyle Devey Michael Mucalo Gordon Rajendram Joseph Lane 《Communications in Soil Science and Plant Analysis》2015,46(4):72-80
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing. 相似文献
13.
I.L. Boyd 《Biological conservation》2010,143(7):1664-1674
“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options. 相似文献
14.
Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage 总被引：1，自引：0，他引：1
Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate. 相似文献
15.
《中国生态农业学报》2014,(8)
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology, 相似文献
16.
M.A. Callaham Jr. J.M. BlairT.C. Todd D.J. KitchenM.R. Whiles 《Soil biology & biochemistry》2003,35(8):1079-1093
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils. 相似文献
17.
Yoav Bashan Bernardo Salazar Ma. Esther Puente Macario Bacilio Robert Linderman 《Biology and Fertility of Soils》2009,45(6):585-594
To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse
trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus
were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB;
the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons
reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened
later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons
growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants,
no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi,
enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant.
In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after
30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination
only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity
to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as
compost or PGPB can either amplify the effect or else attenuate it. 相似文献
18.
Grete Skrede Berit Karoline Martinsen Anne-Berit Wold Stein-Erik Birkeland Kjersti Aaby 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):193-208
Abstract A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species. 相似文献
19.
Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value. 相似文献
20.
Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation. 相似文献