湖北省荆门市水稻土配方施肥的效果研究

选定荆门市水稻土进行效应函数法配方试验，以找出不同N、P、K用量与水稻产量的关系，明确最高施肥量和最佳施肥量，提供水稻专用配方肥的参数。试验发现，N、P、K配合后有利于促进杂交中稻的个体发育，建立良好的群体结构。在供试土壤和“汕优63”水稻上，氮是控制产量的首要因子。建议供试土壤上施肥配方为：N150∽180kg／hm^2，P20530∽45kg／hm^2，K20105∽120kg／hm^2。     

南安市丘陵旱地甘薯氮磷钾适宜配比的研究

通过在南安市丘陵旱地三种不同类型土壤上布置"3417"设计的平衡施肥田间肥料试验,验证NPK肥的施用效果,建立甘薯产量和施肥利润与N、P、K施用量的数学模型,得出在该条件下的甘薯适宜施肥量和比例。结果表明,甘薯施用NPK肥料均获得一定幅度的增产增值效果。获得最高产量的施肥量为154 3～173 6kg/hm2N,44 4～75 3kg/hm2P2O5,193 1～245 3kg/hm2K2O,N P2O5 K2O=1 0 26～0 43 1 24～1 41;最佳经济施肥量为140 0～162 0kg/hm2N,40 8～67 0kg/hm2P2O5,199 8～227 3kg/hm2K2O,N P2O5 K2O=1 0 25～0 41 1 23～1 64。低产田土壤适当增施N肥,P、K比例可以低些,中高产田土壤P、K比例要高些。     

施肥对中长绒陆地棉产量和品质的影响

通过对供试棉田土壤主要养分限制因子及中长绒陆地棉最佳施肥量研究表明,氮素是供试土壤的第一养分限制因子,其次是磷素和钾素,对中长绒棉产量影响的养分限制因子顺序为氮>磷>钾。平衡施肥的N、P2O5、K2O施肥量分别为207、138、75 kg/hm2时能显著提高中长绒陆地棉的产量。不施肥CK处理相对OPT(氮磷钾最佳施肥处理)减产达33%。通过氮磷钾肥料效应方程得到N、P2O5、K2O最佳经济施肥量分别为203.3、141.7、46 kg/hm2,N∶P2O5∶K2O为1∶0.70∶0.23,最佳经济皮棉产量分别为1474、1550和1516 kg/hm2。     

2008年绩溪县水稻“3414”肥料效应田间试验报告

通过"3414"回归最优设计原理设置的水稻肥效试验,获得了肥料效应函数方程,由此数学模型得出:理论N、P、K最佳施肥量为纯N 144.38 kg/hm2、P2O5 38.38 kg/hm2、K2O 67.02 kg/hm2,N∶P2O5∶K2O为1∶0.27∶0.46时,最佳经济产量为9146.63 kg/hm2.综合分析不同推荐施肥方法的推荐施肥量,结合当地实际,建议推荐施肥量分别为尿素(N,460 g/kg)总量322.34 kg/hm2、过磷酸钙(P2O5,120 g/kg)314.84 kg/hm2、氯化钾(K2O,600 g/kg)112.44 kg/hm2.     

配方施肥对党参产量性状的影响

为了确定党参合理施肥量,在陇西县进行了“3414”施肥配方试验。结果表明,当施N 208.8 kg/hm2、K2O 57.0 kg/hm2时,党参籽粒产量最高,为174.7 kg/hm2;当施N 104.4 kg/hm2、P2O5 108.0 kg/hm2、K2O 57.0 kg/hm2时,党参根产量为3 104.8 kg/hm2。施肥量为N 104.4 kg/hm2、P2O5 108.0 kg/hm2、K2O 57.0 kg/hm2时,党参单根干重和鲜重最高,分别为3.55、12.75 g;施肥量为P2O5 108.0 kg/hm2、K2O 57.0 kg/hm2时,干鲜比最高,达30.19%。不同氮、磷、钾配方对党参根长有显著差异,对根粗的影响差异不显著,在不施化肥的情况下党参的根长和根粗最大。在生产实践中应根据收获的不同经济产量选择合理的配方施肥。     

配方施肥对水稻养分吸收动态及产量的影响

本文主要研究配方施肥与常规施肥对水稻养分吸收和产量的效应,检验大配方的区域适宜性和合理性。以水稻品种晚稻187为材料,采用大小区随机区组设计,在安徽省怀宁县进行了大配方小调整田间试验,结果表明,整个生育期内,水稻对氮素的总吸收量以小调整配方T4处理 （施肥量为N150 kg/hm2、 P2O5 120 kg/hm2、 K2O 105 kg/hm2）最高,为N 1.25 g/plant;对磷、 钾的吸收总量配方施肥均高于常规施肥,也以小调整配方T4处理最高（P2O5 0.18 g/plant、 K2O 0.95 g/plant）。配方施肥的产量均高于常规施肥,以大配方2（T3, 施肥量为N 232.5 kg/hm2、 P2O5 120 kg/hm2、 K2O 120 kg/hm2）的产量最高,达到了11129 kg/hm2,但小调整配方（T4）的产投比优于大配方。总体而言,配方施肥的施肥配比与肥料运筹较之常规施肥更为科学合理,大配方适宜该地区的水稻生产。     

南安县域甘薯的土壤养分丰缺指标研究

应用"3414"田间肥料试验设计的试验结果,旨在了解南安甘薯产区的N、P、K肥料施用效果,建立县域土壤的甘薯养分丰缺指标,并通过多元二次肥料效应函数寻求甘薯最高产量和最佳经济施肥量。甘薯施用N、P、K肥增产增效较为显著,其增产增收效果NPKNKP,单位肥料效益PNK。南安县域内甘薯的土壤养分丰缺等级指标划分为3级,即当土壤碱解氮、有效磷、速效钾养分含量分别为75 m g/kg、20 m g/kg、65 m g/kg时为低,在75~177 m g/kg、20~40 m g/kg、65~135 m g/kg时为中,177 m g/kg、40 m g/kg、135 m g/kg为高。甘薯推荐施肥量随土壤碱解氮、有效磷、速效钾含量的提高而减少。全市平均,甘薯最高产量施肥量为N 197.43 kg/hm2,P2O563.84 kg/hm2,K2O 226.32 kg/hm2;最佳经济施肥量N 179.74 kg/hm2,P2O561.10 kg/hm2,K2O 212.50 kg/hm2。     

高产夏玉米的种植密度和肥料效应研究

应用电子计算机和二次通用旋转组合设计法,以玉米种植密度和N、P、K施肥量为供试因子,玉米籽粒产量和经济效益为目标,得出了夏玉米产量分别为≥10500kg/hm2,11250kg/hm2和12000kg/hm2的高产高效益的种植密度和N、P、K施肥方案.种植密度为97200株/hm2,施纯N 332.4kg/hm2,施P2O5 111.8kg/hm2和K2O 150.0kg/hm2,籽粒产量≥10500 kg;种植密度105000株/hm2,施纯N 367.2kg/hm2,施P2O5 110.0kg/hm2和K2O 150kg/hm22,籽粒产量≥11250kg/hm2;种植密度105000株/hm2,施纯N 439.4kg/hm2,施P2O5 120.0kg/hm2和K2O 150kg/hm2,籽粒产量≥12000kg/hm2.籽粒产量从10500 kg/hm2增加到12000kg/hm2,扣除成本每hm2纯收益增加603.5元.     

桔梗氮、磷、钾施肥效应与施肥模式研究

采用氮、磷、钾三因素2次D-饱和最优设计(310),通过大田试验建立了氮、磷、钾施肥量与桔梗产量和总皂苷含量的效应函数。结果表明,氮、磷、钾肥对桔梗产量的影响大小依次为氮肥 钾肥 磷肥;氮、磷、钾肥对桔梗总皂苷含量的影响大小依次为氮肥 磷肥 钾肥。对各效应函数进行频率分析法寻优结果表明,桔梗目标产量在4200～4800 kg/hm2,95%置信区间的优化施肥量为N 83.72～119.41 kg/hm2、P2O5 64.10～134.39 kg/hm2、K2O 78.80～147.20 kg/hm2;桔梗总皂苷含量在5.5%以上,95%置信区间的优化施肥量为N 113.37～140.12 kg/hm2、P2O5 85.96～153.44 kg/hm2、K2O 76.86～136.38 kg/hm2;桔梗高产优质高效栽培最优施肥量为N 113.37～119.41 kg/hm2、P2O5 85.96～134.39 kg/hm2、K2O 78.80～136.38 kg/hm2,N、P2O5、K2O的最优施用量配比为1︰0.72～1.18︰0.66～1.20。     

设施栽培黄瓜的氮磷钾肥料效应研究

采用"3414"肥料试验方案开展了设施栽培黄瓜的N、P、K肥料效应研究。结果表明,随着N、K肥施用量增加,黄瓜产量呈先增后减的趋势;随P肥施用量增加,黄瓜产量呈下降趋势;N、K肥配施为正交互作用,N、P肥和P、K肥配施均为负交互作用。在中等P、K肥配施水平下,黄瓜硝酸盐含量随施N量的增加而降低。施N量与黄瓜亚硝酸盐含量间存在显著的函数关系,P、K肥的影响较小。不同施肥处理黄瓜蛋白质和Vc含量差异均不显著,且与N、P、K施肥量间的函数关系拟合度较低。每生产100 kg黄瓜需要吸收的养分量为N 0.296kg、P2O50.166 kg、K2O 0.517 kg。供试条件下黄瓜最佳经济施肥量为N 150.0 kg/hm2、K2O 409.5 kg/hm2,不施或少施磷肥。     

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。     

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.     

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.     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

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.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.     

Electron donor and pH relationships for biologically enhanced dissolution of chlorinated solvent DNAPL in groundwater

Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.     

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.     

Responses of native legume desert trees used for reforestation in the Sonoran Desert to plant growth-promoting microorganisms in screen house

Three slow-growing legume trees used for desert reforestation and urban gardening in the Sonoran Desert of Northwestern Mexico and the Southwestern USA were evaluated whether their growth can be promoted by inoculation with plant growth-promoting bacteria (Azospirillum brasilense and Bacillus pumilus), unidentified arbuscular mycorrhizal (AM) fungi (mainly Glomus sp.), and supplementation with common compost under regular screenhouse cultivation common to these trees in nurseries. Mesquite amargo (Prosopis articulata) and yellow palo verde (Parkinsonia microphylla) had different positive responses to several of the parameters tested while blue palo verde (Parkinsonia florida) did not respond. Survival of all tree species was over 80% and survival of mesquite was almost 100% after 10 months of cultivation. Inoculation with growth-promoting microorganisms induced significant effects on the leaf gas exchange of these trees, measured as transpiration and diffusive resistance, when these trees were cultivated without water restrictions.     

Increase in auxiliary photoprotective photosynthetic pigments in wheat seedlings induced by Azospirillum brasilense

Inoculation of wheat seedlings with the plant growth-promoting bacterium Azospirillum brasilense Cd was immobilized in alginate microbeads and, without applying any stress, significantly increased the quantity of several photosynthetic pigments, such as chlorophyll a, chlorophyll b, and the auxiliary photoprotective pigments violaxanthin, zeaxanthin, antheroxanthin, lutein, neoxanthin, and β-carotene. This resulted in greener plants with no apparent visible stress. After monitoring the quantity of photosynthetic pigments for 4 weeks, we observed that inoculated plants had higher quantities of pigments in shoot and stem. The greatest difference in the quantity of all pigments between inoculated and noninoculated plants occurred in the first week of growth. Regardless of treatment, the quantity of pigments in stems was three to four times less than the quantity of these pigments in shoots. Application of Azospirillum, either as liquid inoculant or as alginate microbeads, did not alter the positive effect of the bacteria on pigment production or the positive response of the plants towards A. brasilense Cd inoculation.