共查询到20条相似文献，搜索用时 78 毫秒
1.
2.
3.
氮磷钾养分对板栗产量的影响 总被引：1，自引：0，他引：1
以板栗为研究对象,通过氮、磷、钾三因素三水平肥料试验,建立了三元二次关于板栗产量的施肥模型。结果表明:氮、磷、钾肥对板栗均有增产效应。单一元素施肥时,施肥上限:氮肥1.61kg/株、磷肥1.56kg/株、钾肥1.66kg/株。板栗施肥存在NK、NP、PK互作效应。二元施肥时,氮钾肥配合使用N∶K2O=0.8∶1.0,氮磷配合施用N∶P2O5=0.8∶1.0,最大用量为1.8kg/株;磷钾配合使用P2O5∶K2O=0.35∶0.4,最大用量为0.75kg/株。N、P、K最大施肥量为每株N 1.543kg、P2O51.349kg、K2O 1.288kg,目标产量4.61kg。 相似文献
4.
以籽用南瓜为试材,设置不同施肥量梯度处理,明确施肥对籽用南瓜养分吸收特征及品质的影响规律。结果表明:各处理白瓜籽产量均高于不施肥对照(CK)处理,其中最佳(OPT)处理(N 55kg/hm2、P2O582.5kg/hm2、K2O 67.5kg/hm2)的产量最高。不施氮、磷、钾肥分别减产了23.1%、19.3%和11.1%,CK减产32.2%。不施氮、磷、钾肥收入平均减少了3 583、2 681、1 411元/hm2;不施肥收入减少了3 666元/hm2。在最佳处理的基础上,不施氮肥(O-N)除了会影响籽用南瓜对氮素的吸收外,还会影响其对磷钾肥的吸收;在最佳处理的基础上,分别不施磷肥(O-P)和钾肥(O-K),会影响籽用南瓜对氮、钾和氮、磷的吸收,进一步说明平衡施肥可以有利于籽用南瓜对养分的均衡吸收。氮肥的农学效率最高,其次为磷、钾肥。氮肥的肥料利用率最高,其次为钾、磷肥。适量的氮肥用量可以提高籽用南瓜的整体品质,磷肥可以提高粗蛋白、粗脂肪含量,钾肥可以提高可溶性糖、淀粉含量。 相似文献
5.
莴苣测土配方施肥试验研究 总被引：1，自引：0，他引：1
试验结果表明，不施氮肥、不施磷肥、不施钾肥均会影响作物产量，不施磷肥对作物产量影响不大；磷肥与钾肥增产作用相差不大，在增产作用中氮肥〉钾肥〉磷肥。缺磷区和缺钾区相对产量和土壤有效磷、速效钾测定值分析结果与施木田编著的《园艺植物营养与施肥技术》的“蔬菜土壤养分分级标准”中土壤有效磷、速效钾分级标准无差异；缺氮区相对产量和碱解氮测定值分析结果与施木田编著的《园艺植物营养与施肥技术》的“蔬菜土壤养分分级标准”土壤碱解氮分级标准有较大差异。因此，蔬菜土壤养分分级标准中土壤碱解氮丰缺指标有待进一步研究探讨。肥料利用率分析结果认为该试验区在近年来化肥年使用量普遍较高的状况下，特别是磷、钾肥普遍过量使用，且土壤有效磷、速效钾含量高的状况下，氮、磷、钾肥利用率较低，磷、钾肥利用率更低，有下降趋势。 相似文献
6.
7.
陕西渭北红富士苹果园土壤有效养分及长期施肥对产量的影响 总被引：11，自引：0，他引：11
调查了陕西渭北地区915 个盛产期红富士苹果园的土壤有效养分、全年施肥和产量情况,
并在合阳县1 个果园通过8 年定位试验研究了长期施用氮、磷、钾肥对苹果产量、单果质量的影响及肥
料农学效率和肥料贡献率的变化。结果表明,土壤碱解氮、速效磷、速效钾含量的平均值分别为60.1
mg · kg-1、17.7 mg · kg-1 和173.0 mg · kg-1,有机质含量为12.6 g · kg-1,最高分布频率的土壤养分分布范围
分别为碱解氮40 ~ 60 mg · kg-1,速效磷10 ~ 20 mg · kg-1,速效钾150 ~ 200 mg · kg-1,有机质10 ~ 15 g · kg-1。
碱解氮和速效磷含量与苹果产量的相关性分别达到极显著和显著水平,土壤速效钾和有机质含量与产量
的相关性不显著。果园氮、磷、钾肥平均用量分别为纯N 454.5 kg · hm-2、P2O5 327.7 kg · hm-2、K2O 313.2
kg · hm-2,有机肥平均用量4.7 t · hm-2;纯N、P2O5 和K2O 用量均为200 ~ 400 kg · hm-2 的分布频率最高,
仅26.6%的果园施用有机肥。氮、磷、钾肥用量与苹果产量和土壤速效氮、磷、钾含量具有极显著或显著
相关性。在高产年份、中产年份和低产年份,氮肥对苹果产量、单果质量的影响效果及其农学效率和肥
料贡献率均大于磷和钾肥。对苹果产量的影响,高产年份磷肥显著大于钾肥,中、低产年则无显著差异。
对单果质量的影响效果,高产和中产年份磷肥和钾肥无显著差异,低产年份钾肥显著大于磷肥。氮、磷、
钾肥的农学效率和肥料贡献率,在高、中产年份为氮 > 磷 > 钾,低产年份为氮 > 钾 > 磷。 相似文献
8.
以薄皮甜瓜‘博洋61’为试材，采用3因素5水平二次正交旋转组合设计，研究了氮肥(尿素)、磷肥(过磷酸钙)、钾肥(硫酸钾)用量对塑料大棚薄皮甜瓜产量和品质的影响，分别建立了以产量和果实可溶性固形物为目标效应方程，以期为甜瓜科学施肥提供参考依据。结果表明：甜瓜产量和果实可溶性固形物含量均先随氮肥、磷肥、钾肥施用量的增加而增加，达到极大值后又随施用量的增加而降低。氮肥、磷肥、钾肥对甜瓜产量和品质的单因子效应均为钾>磷>氮，磷肥与钾肥存在交互效应。结合模型优化分析结果，筛选出该试验条件下甜瓜既高产又优质的施肥方案为氮肥513.16～543.38 kg·hm-2,磷肥1 317.23～1 391.93 kg·hm-2,钾肥319.20～353.78 kg·hm-2,即N 236.05～249.95 kg·hm-2,P2O5 210.76～222.71 kg·hm-2,K2O 159.60～176.89 kg·h... 相似文献
9.
10.
11.
氮磷钾硼肥配施对青花菜养分吸收分配及产量和品质的影响 总被引：4，自引：0，他引：4
研究了不施肥处理,氮磷钾配施和增施硼肥对青花菜养分吸收分配及产量和品质的影响。结果表明,现蕾期至花球膨大期,青花菜对氮、磷、钾的吸收量最大,整个生长期对钾的吸收最多,氮次之,磷最少。氮磷钾主要分配在叶片中,现蕾后逐渐向花球转移,从现蕾到采收时,叶片中氮、磷、钾分配率分别降低了19.6%、10%和9.0%,花球中氮磷钾分配率分别提高了23.1%、15.9%和11.1%。不施氮、磷、钾肥显著降低了花球产量、维生素C含量和成品率,增施硼肥处理的花球成品率较氮磷钾肥处理提高了4.8%,不施氮肥和钾硫肥(K2SO4)显著降低了花球中的硫代葡萄糖苷含量。相关性分析表明,青花菜产量与植株内氮、钾积累量显著正相关,成品率与植株内磷营养显著正相关。 相似文献
12.
江汉平原是国家优质粮食、优质棉花和双低油菜重要生产基地,也是湖北省西瓜主产区。种植西瓜对增加农民收入、丰富市场、发展农村经济、提高土地利用率具有重要作用。江汉平原西瓜生产的突出特点是间作套种,早在20世纪70年代就推广了“麦／／瓜-稻”这种水旱、粮经作物配套种植的优化模式．并获得原荆州地区科技进步二等奖。由于西瓜间作套种提高了单位面积的经济效益、 相似文献
13.
AIM: To detect the treatment of K562 leukemia cells with bortezomib altering the expression of genes fas, bcl-2, bcl2l12, bim, bax, caspase-9 and caspase-3.METHODS: MTT assay was used to detect the inhibition of proliferation. Apoptosis was detected by Annexin-V staining and mitochondrial transmembrane potential (Δψm). RT-PCR was used to analyze the mRNA expressions of fas, bcl-2, bcl2l12, bim, bax, caspase-3 and caspase-9.RESULTS: Bortezomib caused a time- and dose-dependent inhibition of cell proliferation and IC50 of 24 h and 48 h were 161.41 nmol/L and 96.33 nmol/L, respectively. At the concentration of 104 nmol/L, bortezomib induced apoptosis in a time-dependent manner, including increasing annexin-V positivity and decreasing the Δψm. RT-PCR showed that bortezomib up-regulated the mRNA expression of fas, bcl2l12, caspase-9 and caspase-3, but mRNA expressions of bcl-2, bim and bax did not changed obviously.CONCLUSION: Bortezomib inhibits the proliferation of K562 and induces apoptosis, in which fas, bcl2l12, caspase-9 or caspase-3 gene is one of the main genes taking part in. 相似文献
14.
Omid Khalifezadeh Koureh Mohammadreza Pourghayoumi Majid Majidian 《International Journal of Fruit Science》2019,19(1):1-12
The aim of this research was to determine the effect of three different fertilizing systems, including organic, conventional, and integrated ones, on the yield, fruit quality, antioxidant activity, and some phenolic compounds of white seedless grape. The study was carried out on several 6-year-old white seedless grapevine located in the Urmia Province (North-West Iran). The results showed that the fruit physical characteristics and yield were affected significantly by different fertilization systems. The highest yield was observed in the conventional fertilization, followed by organic and integrated systems. The leaf mineral contents were obviously dependent on the different fertilization used, whereas pH and titratable acidity were not affected. Based on our results, the highest values of antioxidant activity and total flavonoid were found in the organic and integrated fertilization systems, respectively. Also, the highest contents of total phenolic, catechin, and quercetin-3-galactoside were observed in the organic fertilization system. Overall, the highest nutritional quality and biochemical characteristics of white seedless grape were obtained in organic fertilization system, which improved antioxidant capacity by enhancing total phenolics, total flavonoids and valuable phenolic compounds. 相似文献
15.
Geographical perspectives of space,time, and scale 总被引：24，自引：0，他引：24
Vernon Meentemeyer 《Landscape Ecology》1989,3(3-4):163-173
16.
Harold S. J. Zald Thomas A. Spies Manuela Huso Demetrios Gatziolis 《Landscape Ecology》2012,27(8):1197-1212
Tree invasions have been documented throughout Northern Hemisphere high elevation meadows, as well as globally in many grass and forb-dominated ecosystems. Tree invasions are often associated with large-scale changes in climate or disturbance regimes, but are fundamentally driven by regeneration processes influenced by interactions between climatic, topographic, and biotic factors at multiple spatial scales. The purpose of this research was to quantify spatiotemporal patterns of meadow invasion; and how climate, larger landforms, topography, and overstory trees have interactively influenced tree invasion. We combined airborne Light Detection and Ranging (LiDAR) characterizations of landforms, topography, and overstory vegetation with historical climate, field measurements of snow depth, tree abundance, and tree ages to reconstruct spatial and temporal patterns of tree invasion over five decades in a subalpine meadow complex in the Oregon Cascade Range, USA. Proportion of meadow occupied by trees increased from 8?% in 1950 to 35?% in 2007. Larger landforms, topography, and tree canopies interactively mediated regional climatic controls of tree invasion by modifying depth and persistence of snow pack, while tree canopies also influenced seed source availability. Landscape context played an important role mediating snow depth and tree invasion; on glacial landforms tree invasion was negatively associated with spring snowfall, but on debris flows tree invasion was not associated with snow fall. The importance of snow, uncertain climate change impacts on snow, and mediation of snow by interacting and context dependent factors in complex mountain terrain poses substantial hurdles for understanding how these ecotones may respond to future climate conditions. 相似文献
17.
中国''''99昆明世界园艺博览会蔬菜瓜果园 总被引：1，自引：0，他引：1
蔬菜瓜果园作为中国’99昆明世界园艺博览会六大专题展园之一 ,占地 4 90 0ｍ2 。园内以农舍草屋为中心 ,通过瓜架、篱笆、草亭及蔬菜瓜果栽培 ,构出一幅农家乐园式的田园风光。另外 ,通过集中展示中国蔬菜瓜果的科技生产水平 ,丰富的资源优势 ,色彩缤纷、新奇别致的蔬菜瓜果品种 ,来突出本次世博会的主题“人与自然 ,和谐发展———迈向 2 1世纪” ,从而展现“蔬菜瓜果园艺是人类赖以生存的重要食源和艺术”为主题思想的蔬菜瓜果园内涵。 蔬菜瓜果园位于世博园主入口世博大道南侧 ,与盆景园、药草园相邻。在总体布局、栽培上充分运用园… 相似文献
18.
P. Adams C. J. Graves G. W. Winsor 《The Journal of Horticultural Science and Biotechnology》2013,88(6):877-884
Two levels of N and four levels of K, applied to beds of sphagnum peat before planting (Experiment A), were tested in factorial combination with three concentrations of N (50, 175 and 300 mg 1-1) and two of K (50 and 250 mg T1) in the liquid feed. In three cucumber crops grown, Mg was supplied or omitted before planting as a split plot factor (96 subplots). In two further crops (Experiment B), grown in fresh peat, six concentrations of N (20-320 mg 1-1) were tested in the liquid feed, all other nutrient levels being constant. In Experiment A, the early yield was reduced by low and high levels of N. The main effect of N on the final yield was not significant, but maximum yield was achieved with 175-300 mg 1-1 N in the liquid feed where the peat received a small amount of ureaformaldehyde (15 g m“2) and Mg fertilizer. The N x Mg interaction became increasingly marked with successive crops; the loss in yield due to Mg deficiency (<31%) increased with the amount of N applied. K deficiency reduced the yield by up to 66%, and very high levels of K also tended to decrease the yield. The K x Mg interaction became more marked with time and the loss in yield due to Mg deficiency (<23%) increased with the amount of K applied. Leaves from N, K and Mg deficient plants contained <2.5% N, <1.0% K and <0.28% Mg respectively. In Experiment B, where N was supplied only in the liquid feed, the highest yield was obtained at 220 mg 1-1. The relation between yield and the total amount of N supplied in the feed was defined by a quadratic regression. 相似文献
19.
盆景果树集"艺术欣赏与果实享用"于一身。文章重点阐述盆景果树的定义、发展史与现状、分类与特点、文化和经济的双重价值等内容。 相似文献