河西灌漠土地区加工型甜椒配方施肥研究

采用3因素二次回归通用旋转组合设计,研究了氮肥、磷肥、钾肥对加工型甜椒产量的影响,得到了相应的回归数学模型。结果表明:三因素影响加工型甜椒产量的顺序为氮肥>钾肥>磷肥。各因素间存在交互作用。经过计算机模拟,得到加工型甜椒产量达到最高值时,其相对应N、P、K肥用量分别为N600kg hm-2、P2O597kg hm-2、K2O273kghm-2。对试验结果进行的验证表明,模型选优所得氮肥、磷肥和钾肥配比的产量最高,施肥成本、施肥利润、肥料投资效率分别为0.34万元hm-2、0.65万元hm-2和1.91万元,栽培效果明显优于其它配比。证明构建的模型准确可靠。     

保山市冬早大棚辣椒氮磷钾肥料优化施用

针对保山区域冬早大棚辣椒氮磷钾肥料效应缺乏系统研究,存在偏施氮肥、盲目施肥和过量施肥的现象,采用三因素五水平二次正交旋转组合设计,通过田间小区试验,研究氮磷钾肥料效应模型,通过频率分析研究高产优化施肥组合方案。保山大棚辣椒氮磷钾肥料效应回归模型Y=38 180.4+19.865 7N+16.102 7P+16.150 1K+0.026 6NP+0.012 4NK-0.006 8PK-0.025 8N2-0.038 5P2-0.014 1K2,目标产量大于53 000 kg/hm2的优化施肥组合方案为N 568.9～631.9 kg/hm2,P2O5 242.7～321.3 kg/hm2,K2O 684.6～794.8 kg/hm2,氮磷钾比例为1∶0.47∶1.23,与当地施肥量水平相比,温暖区氮肥用量平均降低36.3%,温热区氮肥用量平均降低23.1%。氮磷钾肥配合施用能显著提高大棚辣椒产量,氮肥效应达极显著水平,磷肥和钾肥效应达显著水平,效应排序为氮肥＞钾肥＞磷肥;氮磷和氮钾的交互效应为显著正效应,N用量在175～425 kg/hm2时,辣椒产量随着P2O5用量的增加呈先增后降趋势,增幅随着磷肥用量的增加而减小,N用量在175～573.7 kg/hm2时,钾肥效应趋势与磷肥一致,在高氮情况下,辣椒产量随着磷肥（或钾肥）用量的增加而增加。     

氮磷钾用量对宁南旱地马铃薯产量及水肥利用效率的影响

在宁南旱地上利用田间试验研究了氮、磷、钾各4个施肥水平对马铃薯(庄薯3号)产量及水肥利用效率的影响。结果表明,增施氮、磷、钾肥马铃薯产量均呈抛物线型增长,其中氮肥增产幅度最高,其次为磷肥,钾肥最低且与对照无显著差异。施用氮对马铃薯产量构成有显著影响,钾肥有利于块茎膨大。马铃薯氮、磷、钾养分累积量随着施肥量的增加而增加,当季氮、磷肥利用率都随着施肥量的增加先升高后降低,钾肥利用率随施肥量增加而降低。氮、磷、钾肥偏生产力均随着施肥量增加而显著降低(P0.05)。施用氮、磷、钾肥显著提高马铃薯水分利用效率,当氮肥施用量大于240 kg/hm2、钾肥施用量大于135 kg/hm2时水分利用效率降低。不同氮、磷、钾肥水分利用效率增幅分别为19.6%~31.2%、11.2%~12.6%、1.3%~9.5%。本试验条件下,从经济施肥与水分高效利用角度宁南旱地马铃薯氮、磷、钾肥推荐量分别为174.0~189.7、92.2~94.6、113.0~113.7kg/hm2。     

施肥对湖北麦冬产量的影响

试验采用了正交区组二次回归设计 ,以氮、磷、钾配方施肥为研究对象 ,系统地进行了湖北麦冬产量的分析 ,建立的施肥与产量之间的回归模型表明 :氮肥、钾肥对产量有显著的影响 ,磷肥则不明显。氮肥与磷肥的互作效应对产量的影响呈互补关系 ,在较低磷肥时随施氮肥的增加而产量增加 ,反之则下降。高氮、高钾、低磷配方施用能达最高产量点 ,施用N 4 5 5 7～ 4 95 4kg/hm2 、P2 O52 5 9 5～ 312 2kg/hm2 、K2 O 6 95 1～ 75 7 3kg/hm2 ,产量为 75 0 0kg/hm2 以上的概率为 99%。     

优质稻肥料效应试验

为取得有关施肥参数,建立优质稻施肥模型,选择高、中、低肥力田块,应用3因素4水平设计方案对优质稻进行田间肥效试验。结果表明,在一定范围内氮、磷、钾肥的施用对优质稻的增产作用是氮肥大于磷肥,磷肥大于钾肥,建议梁河县优质稻高肥力田块氮、磷、钾施用量分别为N 73 kg/hm2、P2O535.6 kg/hm2、K2O87.8 kg/hm2,应施好氮、磷肥,增施钾肥。中肥力、低肥力田块氮、磷、钾施用量分别为N 87.48～103.7 kg/hm2、P2O559～63 kg/hm2、K2O 47.6～52 kg/hm2,应增施氮肥、磷肥,适量钾肥。     

平衡施肥对马铃薯产量和品质的影响试验初报

2012年,在重庆市彭水县进行了马铃薯平衡施肥试验。结果初步表明,最佳施肥(N300kg/hm2,P2O5120kg/hm2,K2O240kg/hm2)条件下,马铃薯单产为28766.7kg/hm2,达到当地的高产水平,每kg养分生产马铃薯18.4kg;在此基础上,继续增加氮肥或磷肥或钾肥的用量,其产量都没有继续增加。足量的磷肥和钾肥对于提高马铃薯的商品性具有重要作用。在供试土壤条件下,要获得马铃薯高产必须施用足够的肥料。     

内蒙古阴山丘陵地区马铃薯施肥现状与评价

为了解内蒙古马铃薯主产区阴山丘陵地区施肥状况,2008、2009年进行了农户抽样调查。结果表明:(1)内蒙古阴山丘陵地区马铃薯化肥投入总量为160.0～292.0 kg/hm2,氮、磷、钾投入量分别为101.8～195.7kg/hm2、57.2～79.4 kg/hm2、5.9～6.9 kg/hm2。(2)水浇马铃薯地氮肥投入量偏高,旱地马铃薯氮肥投入量低。(3)有机肥是氮、磷肥的次要来源,是钾肥的主要来源,其为马铃薯提供的钾肥占全部钾肥的72.2%。     

温室茄子水肥耦合数学模型及其优化方案研究

采用3因素二次回归通用旋转组合设计,研究了灌水量、钾肥、磷肥的耦合效应对茄子的影响,得到茄子产量对3因素的回归数学模型.结果表明①在本试验条件下,3因素影响茄子产量的顺序为施钾量>灌水量>施磷量.②各因素间存在交互作用,水与钾、水与磷、钾与磷在低于1.132和2.312, 0.714和0.431,-4.289和4.092水平时对产量存在正相关关系,在分别高于以上水平时又会呈负相关关系.经过计算机模拟,得到茄子最高产量达 76 459.34 kg/hm2时,相对应的灌水量、施钾量、施磷量分别为2 904.6 m3/hm2、78.6 kg/hm2、15.5 kg/hm2.对试验结果进行的验证表明,构建的模型准确可靠.     

宁南山区施肥对马铃薯生长发育、产量及品质的影响

为探讨在宁南山区不同施肥处理下马铃薯生长发育和产量最佳施肥方式,采取随机区组设计进行田间试验,开展对马铃薯产量和品质影响的研究.结果表明,在当地条件下,处理10收获期干物质积累总量平均比对照增加30.97%,各施肥处理收获期的干物质累积量比对照增加7.35%～73.31%.马铃薯生长发育最佳施肥方式是N 300 kg/hm2、P2O5 200 kg/hm2、K2O 200 kg/hm2、M 17.5 t/hm2,(氮肥基施和追肥各一半,磷肥和钾肥以及有机肥全部基施),能增加马铃薯产量并能增加淀粉含量,从而提高马铃薯产品品质.在宁南山区马铃薯生产中可以推广应用这种肥料组配方案.     

氮磷钾肥配比对马铃薯费乌瑞它品质及耐贮性的影响初探

以马铃薯品种费乌瑞它为指示品种,采用OPT配方施肥方法,研究了氮、磷和钾肥配比对马铃薯产后品质及其耐贮性的影响。结果表明,当施N 180 kg/hm2、P2O5 135 kg/hm2、K2O 0～135 kg/hm2时,马铃薯块茎中氮、磷、钾、钙、铁、锌含量达到最高;氮肥施用量对块茎中干物质、粗淀粉、还原糖、维生素C含量的影响较大,而磷肥、钾肥施用量的影响较小。当施N 180 kg/hm2、P2O5 135 kg/hm2、K2O 135 kg/hm2,马铃薯贮藏260 d时,贮藏损失率最低,为4.37%,其营养品质保持最好,该施肥配比与当地常规的施肥配比相一致。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【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。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

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.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“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.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

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.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

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.