To study nitrogen, phosphorus and potassium (NPK) fertilization effects on growth, nutrient uptake, and bioactive compounds of Astragalus membranaceus var. mongholicus and determine optimal fertilization in northern Shaanxi. A field experiment employed a three-factor D-saturated optimal design with five sampling stages. Growth parameters and key active compounds (astragaloside IV, etc.) were measured. Optimal NPK ranges were derived using subordinate function and frequency analysis. (1) Optimal NPK application ranges: N 100.8–118.4 kg‧ha− 1, P 128.0–146.2 kg‧ha− 1, K 126.1–162.3 kg‧ha− 1; ratio N: P:K = 1:1.23–1.27:1.25–1.37. (2) Fertilizer effects ranked N > P > K on growth and astragaloside IV, excluding calycosin-7-O-β-D-glucoside. Combined NPK significantly enhanced growth versus pairwise/single applications, but excessive fertilization (e.g., high-NPK treatments) reduced quality. (3) Nutrient uptake followed N > K > P. Content increased with growth stage (aboveground < underground). NPK promoted nutrient accumulation, yet excessive rates inhibited absorption. Combined NPK fertilization promotes growth, active compound accumulation, and NPK uptake in Astragalus membranaceus var. mongholicus, but excessive application impairs quality. The optimal NPK ratio under experimental conditions is N: P:K = 1:1.23–1.27:1.25–1.37 within the specified ranges.

总结了黄精—玉米生态带状复合套种栽培技术,包含产地条件、品种选择、整地、做畦、土壤处理、根茎种苗处理、栽植时间、栽植方法等栽种技术,加强田间除草、中耕、摘花、追肥、排灌水管理,黑斑病和叶斑病、蛴螬防治,采收时间、方法、繁殖、轮作倒茬等.

为研究氮、磷、钾施肥模式对甘草产量以及甘草苷、甘草酸含量的影响,同时寻找出宝鸡地区甘草种植的最优施肥方案.通过田间试验,采用3因素2次饱和D-最优设计施肥方案,建立起以氮磷钾肥施用量为自变量,甘草产量、甘草苷、甘草酸含量为因变量的数学模型,通过模型寻优获得最适施肥区间.根据对氮、磷、钾的单因素效应分析,施用适宜浓度的氮、磷、钾肥对甘草产量的增加和甘草苷、甘草酸的积累具有促进作用,但施肥浓度过高时促进作用就会逐渐降低甚至抑制.氮、磷、钾三种元素对甘草产量,甘草苷、甘草酸含量影响大小分别为:磷＞钾＞氮;氮＞磷＞钾;磷＞氮＞钾.对各函数进行频率分析法寻优,得到甘草产量超过5300kg·hm-2、甘草苷含量超过1.25％、甘草酸含量超过3.5％时的施肥区间为氮(N)112.36～148.91kg·hm-2、磷(P2O5)26.03～55.50kg·hm-2;钾(K2O)126.64～160.24kg·hm-2,N、P2O5、K2O的最佳比例为:1∶0.18～0.49∶0.85～1.43.

为了探究微量元素缺乏对素花党参幼苗生长及部分生理特性的影响,本试验设置5个处理,分别为全营养(ck)、缺Fe、缺Mn、缺Cu、缺Zn,测定各处理条件下党参幼苗生长、生理及氮、磷、钾元素含量指标.结果表明,缺Fe处理素花党参幼苗的缺素表征明显,株高、根长、叶绿素与可溶性蛋白含量均显著降低,细胞膜脂质过氧化程度最高;缺Zn处理次之.各处理素花党参幼苗地上、地下部位全氮、全磷、全钾的含量差异达到显著水平,地上部分全磷、全钾的含量均升高,地下部分全氮、全磷的含量以缺Fe处理组为最低.研究表明,素花党参幼苗对缺Fe、缺Zn比较敏感,对缺Mn、缺Cu的耐性较高.

近年来宝鸡市各县区在北柴胡栽培管理上不同造成产量效益差异很大,一般亩产50～100 kg.从本试验应用割薹处理产量结果看,3个不同产地的北柴胡割薹后产量均远高于未割薹产量,本试验割薹增产效果达到180％以上.因此,割薹是柴胡生产中不容忽视的重要管理环节,对于不留种的田块,在抽薹开花前进行割薹可降低柴胡高度,防止倒伏,改善田间通风透光,减少病虫害发生,减少抽薹开花对营养物质的消耗,促使根部生长,能达到明显的增产效果.

苍术是常用中药材,近年来野生苍术资源不断减少而市场需求增加,人工种植成为必然.介绍了陕西省旱作区北苍术人工栽培技术,包括地块选择和整地施基肥、繁殖方式及种根茎的选择处理、栽植、栽植后的管理、收获加工、种子采收等.

苍术为菊科苍术属多年生草本植物(北苍术,是《中华人民共和国药典》(2015年版)规定的正品苍术).干燥根茎呈类圆柱形,常分歧或成疙瘩块状,不规则弯曲,长4～10 cm,直径1.5～3 cm,具有燥湿健脾的作用.现将宝鸡地区苍术栽培技术总结如下. 1 选种 尽量选择一级北苍术种子,或上年种植的北苍术健壮、无病虫害、块茎芽头多、无腐根的块茎作种苗进行播种.

[Objective] The chemical composition and antioxidant activities of essential oil from Paeonia lactiflora Pall.flowers collected at different times were determined.[Method] The essential oil was extracted from P.lactiflora flowers by hydro distillation and the chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS).The relative contents were determined by peak area normalization method and the antioxidant activities were evaluated based on scavenging 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical,2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS) radical,and inhibition of lipid peroxidation in linoleic acid.[Result] Thirty-five compounds accounting for 98.85％ of the essential oil were obtained from flowers collected before sunrise,and major components included pentacosane (21.14％),octacosane (10.52％),tricosane (9.30％),palmitic acid (9.14％),linoleic acid(8.43 ％),tetracosane (6.74 ％),3-dodecyl-2,5-furandione (4.13 ％),heneicosane (3.58 ％),farnesyl acetone (3.45％),hexacosane (3.21％),and geranyllinalool (2.78％).Twenty-seven compounds of 98.10％ were obtained from flowers collected after sunrise.The main compounds were pentacosane (22.54％),palmitic acid (11.81％),octacosane (10.27％),tricosane (8.28％),hexahydrofarnesyl acetone (8.80％),farnesyl acetone (7.35％),tetracosane (6.07％),hexacosane (3.96％),heneicosane (3.90％),and β-4,8,13-duvatriene-1,3-diol(3.40％).The essential oil had strong scavenging effects against DPPH free radical and ABTS free radical,and inhibited the lipid peroxidation of linoleic acid.The anti-oxidation ability increased with the increase of essential oil concentration.[Conclusion] The essential oil form P.lactiflora flowers were rich in chemical components and had high antioxidant activities.Thus,it is a natural potential source of preservative for food and other allied industries.

Understanding how concentrations of elements and their stoichiometry change with plant growth and age is critical for predicting plant community responses to environmental change. We used long-term field experiments to explore how the leaf, stem and root carbon (C), nitrogen (N) and phosphorous (P) concentrations and their stoichiometry changed with growth and stand age in a L. principis-rupprechtii Mayr. plantation from 2012-2015 in the Qinling Mountains, China. Our results showed that the C, N and P concentrations and stoichiometric ratios in different tissues of larch stands were affected by stand age, organ type and sampling month and displayed multiple correlations with increased stand age in different growing seasons. Generally, leaf C and N concentrations were greatest in the fast-growing season, but leaf P concentrations were greatest in the early growing season. However, no clear seasonal tendencies in the stem and root C, N and P concentrations were observed with growth. In contrast to N and P, few differences were found in organ-specific C concentrations. Leaf N:P was greatest in the fast-growing season, while C:N and C:P were greatest in the late-growing season. No clear variations were observed in stem and root C:N, C:P and N:P throughout the entire growing season, but leaf N:P was less than 14, suggesting that the growth of larch stands was limited by N in our study region. Compared to global plant element concentrations and stoichiometry, the leaves of larch stands had higher C, P, C:N and C:P but lower N and N:P, and the roots had greater P and C:N but lower N, C:P and N:P. Our study provides baseline information for describing the changes in nutritional elements with plant growth, which will facilitates plantation forest management and restoration, and makes a valuable contribution to the global data pool on leaf nutrition and stoichiometry.

Based on our previous study, cereal crop wheat (Triticum aestivum L.) could be infected by rhizobia Azorhizobium caulinodans ORS571, and form para-nodules with the induction of 2.4-dichlorophenoxyacetic acid, a common plant growth regulator. To enhance this infection and the potential agricultural application, we compared six different infection methods (Direct seed dip; Seed germination dip; Pruned-root dip; Foliar spray; Circum-soil dip; Seed dip and circum-soil dip) for achieving the high efficient infection of A. caulinodans into wheat plants by employing a green fluorescent protein (gfp)-labeled Azorhizobium caulinodans strain ORS571. With proper methods, copious rhizobia could enter the interior and promote the growth of wheat to the hilt. Circum-soil dip was proved to be the most efficient method, seed germination dip and pruned-root dip is the last recommended to infect wheat, seed germination dip and seed dip and circum-soil dip showed better effects on plant growth, pruned-root dip did not show too much effect on plant growth. This study laid the foundation for understanding the interaction between rhizobia and cereal crops and the growth-promoting function of rhizobia.

The concentrations and stoichiometry of certain elements (carbon, nitrogen and phosphorus) are critical to the maintenance of plant functional and environmental adaptation during plant growth. We explore how the concentrations of C, N and P and the ratios of C:N, C:P, and N:P in the leaves of differently aged Larix principis-rupprechtii Mayr. plantations changed with growing season and stand age from 2012 to 2015 in the Qinling Mountains, China. The results showed that the element concentration and stoichiometric ratios in leaves were significantly affected by sampling month, stand age and sampling year; and multiple correlations with stand age were observed in different growing seasons. Compared to global element concentrations and stoichiometry in plants, the leaves of larch stands in the study region had higher C and P concentrations and C:N and C:P ratios but lower N concentrations and N:P ratios than global levels. The leaf N:P ratios of all of the larch stands were generally less than 14, suggesting that the growth of larch stands was limited by N in the study region. Our study facilitates the management and restoration of forest plantation and provides a valuable contribution to the global pool of leaf nutrition and stoichiometry data.

The purpose of this paper is to study the effects of fertilization on growth and internal quality of Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao and provide the optimum fertilization.The results showed that the application of nitrogen fertilizer at an appropriate rate was advantageous to the increase of shoot height,however,excess nitrogen fertilization could decrease the shoot height.The shoot height of N2K2 treatment was highest,which was 51.93％ higher than that of the control.The application of phosphate fertilizer and potassium fertilizer could promote the growth and development of root,and the treatment of N1P3 K3 was the best,its root diameter and root dry mass were 58.42％ and 43.87％ higher than the control.Fertilization significantly increased the mass fraction of saponin and polysaccharide,and the treatment of N3P3K1 was the optimal,which its mass fraction of saponin and polysaccharide were 118.52％ and 13.14％ higher than those of the control.However,the N3 and P3 treatment were not conducive to the accumulation of flavone,and their flavone mass fraction were 7.56％ and 6.46％ lower than control,respectively.Fertilization could promote the accumulation of Mn,and had no much effect on Cu and Zn.Besides,the K3 treatmentresulted in lower Fe mass fraction.Comprehensively considering the principal component analysis of secondary metabolites and trace elements,eventually we determined the optimum fertilizer treatment in the region was that the mass fraction of urea,calcium superphosphate and potassium phosphate were 74.91 kg/hm2,150 kg/hm2 and 225 kg/hm2,respectively.

Azorhizobium caulinodans ORS571, a novel rhizobium, forms endosymbionts with its nature host Sesbania rostrata, a semi-aquatic leguminous tree. Recent studies showed that A. caulinodans ORS571, as endophytic rhizobium, disseminated and colonized inside of cereal plants. However, how this rhizobium infects monocot plants and the regulatory mechanism remains unknown. MicroRNAs (miRNAs) are small, endogenous RNAs that regulate gene expression at the post-transcriptional levels. In this study, we employed laser scanning confocal microscope to monitor the pathway that rhizobium invade wheat; we also investigated the potential role of miRNAs during A. caulinodans ORS571 infecting wheat. Our results showed that gfp-labeled A. caulinodans ORS571 infected wheat root hairs and emerged lateral roots, then disseminated and colonized within roots and migrated to other plant tissues, such as stems and leaves. Endophytic rhizobium induced the aberrant expression of miRNAs in wheat with a tissue- and time-dependent manner with a peak at 12–24 h after rhizobium infection. Some miRNAs, such as miR167 and miR393 responded more in roots than that in shoots. In contrast, miR171 responded higher in shoots than that in roots. These results suggested that miRNAs could be responsive to A. caulinodans ORS571 infection and played important role in plant growth, nutrient metabolisms, and wheat-rhizobium interactions.

The level of soil fertility of different aged(5 -,10-,and 20-year-old)Larix principis-ruppre-chtii plantation was assessed by using the method of principal component analysis,Norm value and membership function of fuzzy mathematic.The study found that the minimum data set of soil assessment comprises organic car-bon,total nitrogen,nitrate nitrogen,ammonium nitrogen,available phosphorus,available potassium,acid phos-phatase,urease and invertase.The value of available phosphorus was the smallest,the number was 0.14,and the ammonium nitrogen and urease took the second place,the number was 0.26.On the contrary,the membership val-ue of available potassium and sucrose were maximal,reach to 0.75 and 0.74,respectively;In different aged Larix principis-rupprechtii plantation,the value of soil comprehensive quality index fall in between 0.43 and 0.57.Soil fertility showed a declining trend with age,the sequence is 5a>10a>20a;The consumption rate of phosphorus was more quickly than that of nitrogen,the rate was 9.94% and 1.1 1% respectively,so the restriction of phos-phorus on the growth of Larix principis-rupprechtii will increasingly prominent.

The chemical composition, antimicrobial and antioxidant activities of the essential oil of Artemisia sieversiana, a traditional medicinal herb in Tibet, China, were investigated. A total of 48 components, representing 95.36% of the total oil, were identified by gas chromatography-mass spectrometry (GC-MS), with the main constituents being α-bisabolol, chamazulene, α-phellandrene, palmitic acid and lavandulol. The antimicrobial activities of the oil were evaluated against five microorganisms, Bacillus subtilis, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus and Crytococcus neofonman, respectively. The results showed that the oil possessed inhibitory activity against B. subtilis, E. faccalis, S. aureusand C. neoformans, amon+g which the best inhibition was observed against C. neoforman with a minimum inhibitory concentration (MIC) of 5.5 μg/mL. The oil revealed a relatively stronger scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+·) and hydroxyl free radicals in a concentration-dependent way.

Upon the employment of a three-factor and D-optimum repercussion layout for the use of N ,P and K fer-tilizers ,a field experiment was carried out to explore the optimal rates of fertilizer application and the responding models for mountain jujube under the condition of straw mulching to the fertilizers in the loess plateau in north Shaanxi province . The results showed that the combined effects of NPK fertilizers on jujube yield followed the order of K > N > P fertilizers . Through the field experiment ,the responding models of mountain jujube under the condition of straw mulching to N ,P and K fertilizers were found out and the effects of N ,P and K fertilizers on mountain jujube under the condition of straw mulching were explored .Based on the responding models of yields to N ,P and K fertilizers ,an optimized fertilization plan on N ,P and K fertilizers was put forward for a high target yield of 18 000 ~ 25 000 kg·hm - 2 ,specific as the fol-lows :N fertilizer rate of 267 .8 ~ 518 .6 kg·hm - 2 ,P2O5 fertilizer rate of 83 .7 ~ 360 .0 kg·hm - 2 ,and K2O fertilizer rate of 438 .0 ~ 491 .0 kg·hm - 2 .NPK fertilizer treatments had increased the contents of titratable acid ,total sugar ,reducing sugar ,and soluble solids by 32 .5% ,0 .82% ,1 .8% ,and 1 .01% ,relatively from no fertilization treatments .But NPK fertilizer treatments relatively decreased date flavonoid content by 40 .4% from no fertilizer treatments .In conclusion , NPK fertilizers resulted in better quality jujube than no fertilizers .

落叶松是我国栽种区域最广的针叶树种.落叶松人工林的发展,对我国人工林的发展至关重要.文中论述了我国落叶松人工林地的土壤物理性状、土壤化学性状和生物学性状,分析了落叶松人工林地力衰退的研究现状并重点对落叶松人工林的施肥时期、施肥方法、施肥种类和用量以及施肥效应进行了归纳总结,旨在为落叶松人工林的可持续发展以及营养管理研究和集约经营研究提供参考.

以秦岭地区幼中龄林(5,10,20年生)华北落叶松Larix principis-rupprechtii人工林地土壤为研究对象,在林木生长季节(5-10月)每月中旬采集表层(0～20 cm)土壤样品,通过测定不同物候期的土壤速效养分质量分数与土壤酶活性,研究分析两者的物候季节动态特征及相互关系,旨在发现华北落叶松人工林地土壤肥力最低的时期并为人工林的合理施肥提供基础理论指导.结果表明:3种林龄人工林(5,10,20年生)土壤速效养分(速效氮、速效磷)质量分数在整个生长季节内变化规律趋于一致,在林木生长旺盛期土壤速效氮和速效磷质量分数最低,土壤速效氮质量分数最低值分别为29.49,19.96和47.32 mg· kg-1;土壤速效磷质量分数最低值分别为2.31,2.79和1.60 mg· kg-1.3种龄林人工林(5,10,20年生)土壤酶(脲酶、转化酶、磷酸酶、过氧化氢酶)活性在整个生长季节内变化规律基本相同,由萌芽展叶初期到落叶末期土壤脲酶活性和转化酶活性呈逐渐上升趋势,土壤脲酶活性最低值分别为0.33,0.25和0.15 mg·g-1;土壤转化酶活性最低值分别为40.82,41.91和22.25 mg·g-1.从生长旺盛初期到落叶期土壤磷酸酶活性呈缓慢下降趋势,土壤磷酸酶活性最低值分别为0.16,0.13和0.22 mg·g-1;在生长旺盛初期土壤过氧化氢酶活性最低,土壤过氧化氢酶活性最低值分别为1.39,1.44和2.68 mL·g-1.与幼龄林(5年生,10年生)相比,中龄林(20年生)土壤速效磷质量分数显著下降(P＜0.05).土壤速效养分与土壤酶相关性密切,说明土壤酶可以较好地反映土壤肥力状况.因此,土壤肥力由萌芽展叶期到生长旺盛期出现下降而到落叶期有上升趋势,且由幼龄林到中龄林土壤肥力有下降趋势,应在生长旺盛期对中龄林林地进行适当施肥.

目的:研究黄芪种子内源抑制物质活性及其存在的部位.方法:采用浸提法对黄芪种子不同部位进行浸提,获得不同溶剂、不同浓度、不同浸提次数的浸提液,以白菜、小麦种子进行生物活性测定.结果:黄芪种子浸提液可显著抑制小麦和白菜种子的萌发及幼苗生长,且抑制物的活性随质量浓度的增大而增强,当质量浓度达到0.20 g/mL时,小麦和白菜种子萌发率均为0.黄芪种子不同溶剂浸提液抑制活性存在较大差异,其中水溶性浸提液大于醇溶性浸提液,且随着浸提次数的增加,浸提液的抑制活性呈现逐渐减弱的趋势.种皮与种仁都含有活性极强的抑制物质,后者强于前者.结论:黄芪种子中存在活性较强的内源抑制物,且多为水溶性成分,其种仁中含量高于种皮.

[Objectives]Carbon (C), nitrogen (N) and phosphorus (P) play an important role in forests growth. The contents and ratios of C, N and P element reflect the nutritional status and healthy growth of forests. The&nbsp;objective of this research was to explore the seasonal variations of C, N, P contents in the leaves in different ages, so to provide a basis for the academic mamgement of the artificial forests. [Methods]Three different ages, namely 5 years old (5 a) , 10 years old (10 a) and 20 years old (20 a) of Larix principis-rupprechtii in Qinling Mountains were chosen as experimental materials. Leaf samples were collected in different growth phases in the middle of a month from May to October in 2012. The C, N, P contents and stoichiometry were monitored. Seasonal dynamics of leaf C, N, P contents and C ∶N, C ∶P, N ∶P mass ratios in different ages of Larix principis-rupprechtii were analyzed. Data were also analyzed by correlation analysis between N content and C ∶N and P content and C ∶P .[Results] 1 ) C content of these three ages increased gradually from growth stage ( May to June ) to the vigorous growth period ( July to August) ,then decreased at growth anaphase ( August to September) , but there had been a slight pick-up in the defoliation (October). 2) The N content of three ages increased first, then decreased and went up again throughout the growing season ( May to October) . The increasing or reducing time among three ages was different. 5 a and 20 a maintained the upward trend basically from June to vigorous growth period, while the N content of 10 a decreased first from June to July, and then increased sharply from July to September. The N content of three ages decreased sharply to the lowest value from early defoliation to defoliation. 3) The P content of three ages kept the same trend throughout the growing season. They all decreased first, then increased and decreased again, finally they kept stable. 4) Seasonal dynamics of leaf C ∶N mass ratios in three ages were different. C ∶N mass ratios in 5 a, 10 a and 20 a varied in the range of 21. 83-56. 42, 18. 43-58. 49 and 22. 54-87. 83, respectively. The values of coefficient of variation ( CV) were 37. 74%, 42. 05% and 68. 42%, respectively. The value of CV increased gradually along with increasing age. 5) C ∶P mass ratios of needles in 5 a, 10 a and 20 a varied in the range of 169. 17-402. 85, 180. 54-395. 01 and 213. 02-398. 75, respectively. The values of CV were 31. 35%, 31. 43% and 22. 88%, respectively. 6) N ∶P mass ratios of leaf in 5 a, 10 a and 20 a varied in the range of 6. 77-15. 42, 6. 38-20. 13 and 4. 44-14. 45, respectively. The values of CV were 39. 65%, 50. 86% and 33. 03%, respectively. 7 ) C, N, P content and stoichiometry had relationships with the age of Larix principis-rupprechtii, but the differences among the ages in average C, N, P content and their ratios were not significant( P>0. 05 ) .[Conclusions] Correlation analysis indicated that C ∶N mass ratio and C ∶P mass ratio were negatively correlated with corresponding N, P content in different ages of Larix principis-rupprechtii. Furthermore, N is a restrictive factor for young and middle-aged Larix principis-rupprechtii of Qinling Mountains during its growth and development. The growth of trees was restricted by the shortage of soil nitrogen. N fertilizer should be timely supplied in this place to meet the nutritional needs of the normal growth of Larix principis rupprechtii.