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。     

潼南县红棕紫泥夹泥土小麦“3414”肥效试验初报

2007年在潼南县红棕紫泥夹泥土上进行了小麦“3414”肥效试验,结果初步表明:N是影响小麦产量的主要因素,N、P、K三因素的影响效应为N＞K＞P;随施肥水平的提高,N的影响效果呈现先增大后减小的趋势,而P和K的影响效果呈现减小的趋势.小麦最高经济产量为295.73 kg/667 m2,对应施肥量为N=12.5 kg,P2O5=9kg,K2O=9 kg,即N、P2O5、K2O比例为1∶0.72∶0.72;最佳经济产量为238.40 kg/667m2,对应施肥量为N=10 kg,P2O5=1.5 kg,K2O=0 kg.NP、NK交互作用对小麦产量有促进作用,PK交互作用对小麦产量无促进作用.该地区就小麦而言,土壤养分的丰缺指标为全N极低、速效P低、速效K中.小麦对肥料的利用率为:氮62.90％,磷13.00％,钾27.83％.     

潼南县红棕紫泥夹泥土小麦“3414”肥效试验初报

2007年在潼南县红棕紫泥夹泥土上进行了小麦"3414"肥效试验,结果初步表明:N是影响小麦产量的主要因素,N、P、K三因素的影响效应为N>K>P;随施肥水平的提高,N的影响效果呈现先增大后减小的趋势,而P和K的影响效果呈现减小的趋势。小麦最高经济产量为295.73kg/667m2,对应施肥量为N=12.5kg,P2O5=9kg,K2O=9kg,即N、P2O5、K2O比例为1∶0.72∶0.72;最佳经济产量为238.40kg/667m2,对应施肥量为N=10kg,P2O5=1.5kg,K2O=0kg。NP、NK交互作用对小麦产量有促进作用,PK交互作用对小麦产量无促进作用。该地区就小麦而言,土壤养分的丰缺指标为全N极低、速效P低、速效K中。小麦对肥料的利用率为:氮62.90%,磷13.00%,钾27.83%。     

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.     

新疆南疆核桃肥料效应及推荐施肥量测算

研究新疆南疆核桃施肥效应与最佳效益的推荐施肥量,为肥料的高效利用提供理论依据。以南疆叶城县为研究区,基于“3414+2”试验方案开展核桃肥料效应研究,并利用一元二次、三元二次肥料效应函数进行拟合,进而优化南疆核桃的N、P2O5、K2O施肥量。结果表明,(1)不同施肥量对核桃的产量影响显著,其中N2P2K2处理的产量、品质显著高于其他处理;不同氮肥处理与核桃产量的相关性显著,而磷肥、钾肥对品质的影响更为明显;(2)三元二次回归肥料效应方程的拟合度显著高于一元二次方程,据此测算的核桃推荐施肥量结果为以核桃产量为主要目标情景下,N、P2O5、K2O最佳施用量分别为0.21、0.59和0.58 kg/株,最佳施肥配比为1.0∶2.8∶2.7,预测最佳产量为8.90 kg/株;而以追求核桃品质为目标时,N、P2O5、K2O最佳施用量范围分别是0.55～0.64、1.37～1.50、0.56～0.62 kg/株。基于“3414”肥效试验和三元二次肥效方程回归测算的氮磷钾推荐施肥量及其配比,可为新疆南疆核桃科学施肥提供理论依据。     

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／hm^2N，44．4～75．3kg／hm^P2O5，193．1～245．3kg／hm^2K2O，N：P205：K2O=1：0．26～0．43：1．24～1．41；最佳经济施肥量为140．0～162．0kg／hm^2N，40．8～67．0kg／hm^2P2O5，199．8～227．3kg／hm^2K2O，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。     

燕山早丰板栗密植园施肥-产量模型研究

为了研究N、P、K配合施用对板栗产量的影响,以13年生盛果期的板栗主栽品种燕山早丰(Castanea mollissima‘Yanshanzaofeng’)为研究对象,采用N、P、K三因素二次饱和D-最优设计,在河北省迁西县典型板栗密植园连续两年进行田间试验。通过建立以N、P、K施肥量编码值为变量因子,产量为目标函数的三元二次数学模型,优化施肥量及N、P、K配比。结果表明N、P2O5、K2O对板栗产量有显著影响,并且两两之间存在显著交互效应。三因素对板栗产量影响的次序依次为NP2O5K2O。通过效应函数的频率分析寻优可知,单株目标产量超过4.50 kg,置信区间为95%时,N、P2O5、K2O单株优化施肥方案为:N 0.85~1.04 kg,P2O50.68~0.83 kg,K2O 0.45~0.51 kg。N、P2O5、K2O最佳施肥比例为1:0.65~0.98:0.43~0.60。该研究可为迁西板栗密植园的合理施肥提供理论依据。     

氮磷钾配施对白叶一号茶叶产量、品质及茶花生物量的影响

采用“3414”不完全区组正交设计的氮(N)、磷(P2O5)、钾(K2O)3因子施肥试验(N0P0K0、N0P2K2、N1P2K2、N2P0K2、N2P1K2、N2P2K2、N2P3K2、N2P2K0、N2P2K1、N2P2K3、N3P2K2、N1P1K2、N1P2K1、N2P1K1),通过测定白叶一号茶叶产量、品质、茶花生物量,拟合氮、磷、钾与茶叶产量及茶花生物量的肥料效应方程,结合不同氮磷钾配施条件下茶叶的品质性状确定施肥量。结果表明,N2P1K2施肥处理茶叶产量仅次于N2P2K0、N2P1K1和N2P2K3,茶花生物量仅高于N0P2K2,茶叶产量占茶花生物量百分比为13.5%,高于其他施肥处理。N2P1K1施肥处理茶叶产量占茶花生物量百分比仅次于N2P1K2处理,但其春茶茶多酚、酚氨比、儿茶素含量最低,品质最优,其中茶多酚含量为14.31%、儿茶素含量为6.64%,均显著低于其他施肥处理。通过拟合氮、磷、钾肥和茶叶产量的三元二次方程及一元一次方程,解析推荐施肥量为氮(N)349～526 kg/hm²、磷(P2O5)0～56 kg/hm²、钾(K2O)0～145 kg/hm²,推荐最佳施肥量为氮(N)349 kg/hm²、磷(P2O5)56 kg/hm²、钾(K2O)0 kg/hm²。该茶园土壤氮、磷、钾养分含量较高,综上所述,推荐最佳施肥量为氮(N)349 kg/hm²、磷(P2O5)56 kg/hm²、钾(K2O)0 kg/hm²。     

优化施肥对小麦品质和产量的效应研究

采用正交旋转组合设计,针对N、P、K、Zn 4种肥料对小麦产量和品质的效应进行探讨,结果表明:N、P对产量都达显著正效应,N对湿面筋含量达极显著正效应,P与湿面筋含量呈显著负效应,K、Zn对产量和品质效应微弱。4种肥料对产量的影响顺序为:N>P>Zn>K,对湿面筋含量的影响顺序为:N>P>K>Zn。小麦产量和品质都较理想的施肥区间为N 252.8～294.2 kg/hm2,P 111.0～139.1kg/hm2, K145.8～153.0kg/hm2, Zn 9.8～12.1kg/hm2, 合理的配比为N:P2O5:K2O:ZnSO4=1:0.46:0.55:0.04     

潼南县红棕紫泥夹泥田水稻“3414”肥效试验初报

2007年在重庆市潼南县红棕紫泥夹泥田里进行水稻"3414"肥效试验,结果初步表明:对水稻产量的影响是N>P>K。水稻的最高经济产量为530.04kg/667m2,对应施肥量为N=12.5kg,P2O5=9kg,K2O=4.5kg;最佳经济产量为515.71kg/667m2,对应施肥量为N=10kg、P2O5=3kg、K2O=0kg。NP交互作用对水稻的产量均有促进作用,NK、PK交互作用对水稻的产量均无促进作用。水稻对氮肥的利用率为21.82%,磷肥的利用率为4.04%,钾肥的利用率为16.25%。     

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.     

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.     

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.     

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.     

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.