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1.
[目的]提高泸州烟区施肥方式与烟株对营养元素吸收量相匹配,满足烟株生长需求。[方法]在泸州烟区烤烟生产过程中,间隔一定时间采集田间烟株不同器官样品,测定养分含量及干物质积累变化,根据养分积累规律,提出相应施肥措施。[结果]泸州烟区的烤烟根、茎、叶不同器官干物质积累均呈“S”型规律变化;根、茎、叶分别从移栽后41、31和21 d至移栽后70 d干重迅速增加,分布达到相应器官总干重的71.45%、73.69%和81.97%。根、茎干物质积累强度最大时期为打顶后10 d内,分别为35.06和45.27 kg/(hm2·d),叶干物质积累强度最大时期为移栽后41~50 d,达54.92 kg/(hm2·d)。烟株氮、磷、钾积累量均呈“S”型规律变化,氮、磷、钾积累量分别从移栽后10~50、10~70、10~50 d迅速增加,栽后50 d时氮、磷、钾积累量分别为总含量的77.17%、51.13%和84.64%;氮、钾吸收高峰均出现在移栽后31~40 d,分别达2.61和3.96kg/(hm2·d),磷吸收高峰出现在移栽后51~60...  相似文献   

2.
不同硫酸钾用量对烤烟氮、钾、硫吸收的影响   总被引:2,自引:0,他引:2  
采用大田试验研究不同硫酸钾施用量对烤烟干物质及氮、钾、硫等元素吸收的影响。结果表明,与不施肥相比较,施肥显著增加了烤烟干物质积累以及氮、钾、硫元素的积累;在烤烟生长发育进程中,提高硫酸钾施用量并没有明显增加烟叶干质量;氮在烟株中的分配比例为叶>茎>根;在团棵期和旺长期,钾和硫在烟株中分配比例为叶>茎>根,在成熟期则为茎>叶>根;在烤烟生长进程中,硫酸钾施用量对烟根氮、钾、硫的积累量影响不明显,硫酸钾施用量对烟叶氮、钾、硫积累量的影响大于对根和茎;提高硫酸钾用量显著增加了烟叶钾和硫的含量。  相似文献   

3.
花生干物质积累、养分吸收及分配规律   总被引:3,自引:0,他引:3  
王秀娟  李波  何志刚  汪仁 《湖北农业科学》2014,(13):2992-2994,3065
采用田间小区试验的方法,研究了花生不同生育时期干物质积累量、氮磷钾养分吸收量及在不同器官的分配规律。结果表明,干物质积累量在苗期最少,至结荚期积累量达到生育期总干物质量的57.70%。根系和叶片干物质积累主要在生育前期,茎干物质积累主要在生育中期,结荚期是荚果干物质积累的关键时期。花生对氮磷钾养分吸收量为氮>钾>磷,形成100 kg荚果产量需要N 4.01 kg、P2O51.56 kg、K2O2.65 kg。随着生育期的推进,根、茎、叶的氮磷钾养分吸收量所占比例逐渐降低,荚果的吸收量所占比例逐渐增加,结荚期是养分吸收的关键时期。生产中应结合花生的生理需肥特性和肥料性质合理施肥。  相似文献   

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为给黄河三角洲地区冬枣钾施肥提供理论参考,以10年生冬枣为试材,研究了黄河三角洲冬枣在不同生育期内对钾肥的吸收及分配规律。结果表明,冬枣萌芽期生长较缓慢,干物质积累较少,对钾肥的吸收速率较低,吸收量仅占全生育期的5.33%,所吸收钾的88.25%分配到叶片中;花期枣树生长速率加快,干物质积累明显增加,吸收速率达到0.42g/(株·d),吸收量占全生育期的19.57%;果实膨大期干物质积累略有增加,钾吸收量占全生育期的34.46%;果实成熟期干物质积累达到高峰,吸收速率达到0.49g/(株·d),吸收量占全生育期的40.64%,所吸收钾的14.20%被分配到果实中。综合分析认为,萌芽前应少量施钾,花期适当提高钾肥的施用量,果实膨大期和成熟期应以钾肥为主,增加钾肥施用量。  相似文献   

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用分期取样、化验分析、模型拟合的方法对杂交茎瘤芥干物质积累和氮、磷、钾的吸收特性进行了研究。结果表明,杂交茎瘤芥干物质积累和氮、磷、钾的吸收均符合Logistic生长曲线,干物质的旺盛积累期在13~18叶龄,磷、钾的旺盛吸收期与干物质的旺盛积累期同步,氮的旺盛吸期在11~16叶龄。在旺盛生长期干物质积累量占87%,氮、磷、钾在旺盛吸收期的吸收量占大田营养生长阶段吸收总量的68.9%,70.3%,72.7%。在此基础上,讨论了杂交笨瘤芥施肥量、施肥时期和追肥次数.  相似文献   

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不同施肥水平对杂交水稻氮、磷、钾吸收积累的影响   总被引:1,自引:0,他引:1  
为探索不同施肥量下2个杂交水稻植株氮、磷、钾的吸收积累特性,采用田间小区试验研究了两个杂交稻品种抽穗期和成熟期的植株氮、磷、钾吸收积累。结果表明,2个杂交水稻品种在不同施肥水平下,抽穗期和成熟期茎+叶鞘、叶、穗各器官内的氮、磷、钾的含量无显著差异;抽穗期,叶的氮含量最高,茎+叶鞘的磷、钾含量最高;成熟期,叶的氮含量、茎+叶鞘的磷含量、穗的钾含量均下降。抽穗期,氮、钾吸收量及干物质量红泰优996高于粤优589,磷吸收量粤优589高于红泰优996;成熟期,氮、钾吸收量及干物质量粤优589高于红泰优996,磷吸收量2品种差异不明显。2个杂交水稻品种地上部植株对氮、磷、钾积累量比例的变幅范围均在高产水稻积累变幅范围内。  相似文献   

7.
棉花芦管育苗新技术研究   总被引:1,自引:1,他引:0  
供试棉种为苏棉8号,芦管育苗与传统营养钵育苗移栽棉对比试验结果表明:在1叶、3叶期,芦管育苗移栽棉全株及其根、茎、叶氮、磷、钾含量低于营养钵育苗移栽棉,现蕾期两者基本一致;在苗期阶段,芦管育苗移栽棉氮、磷、钾含量均于营养钵育苗移栽棉;随着生育进程的推进,两者的氮、磷、钾吸收量差异逐渐缩小,3叶期至现蕾期芦管育苗移栽棉氮、磷、钾吸收量接近或略超过营养钵育苗移栽棉;棉株各器官中氮、磷、钾分配及其比例两  相似文献   

8.
在相同的水、肥供应条件下,研究了4个品种烤烟干物质积累和氮、磷、钾积累的变化动态。结果表明,4个品种烤烟的不同器官及整株干物质及氮、磷、钾积累量随生育期延长而持续增加,变化规律均呈"S"型曲线。NC 71叶片和整株对干物质及氮素的积累表现出前期积累速率慢、后期快的变化趋势,最终的干物质和氮素积累量最大。中烟100烟株和不同器官对钾素的积累速率均最大,钾素积累最多。中烟205烟株和不同器官对干物质、氮、磷、钾的积累速率和积累量均最小。不同烤烟品种对干物质和氮、磷、钾的积累速率大小均表现为干物质氮钾磷,积累速率在不同器官间表现为叶茎根。烟株对氮、磷、钾最大积累速率出现的时间,氮稍早于钾,磷最晚;氮又早于干物质最大积累速率出现时间。干物质和氮、磷、钾最大积累速率出现时间及最大积累速率在不同品种、同一品种的不同器官间存在一定的差异。  相似文献   

9.
宁夏向日葵不同生育期吸收氮、磷、钾养分的特点   总被引:10,自引:0,他引:10  
在宁夏不同地区进行了向日葵肥料田间试验,测试了其不同生育期和不同器官NPK养分含量及其干物质累积量,分析了宁夏食用葵和油用葵不同生育期氮、磷、钾养分的吸收特点.结果表明:在供试土壤条件下,施肥可明显提高向日葵干物质累积量、体内氮、磷、钾含量及其累积量.不论施肥与否,食用葵和油用葵干物质累积量随生育期均呈"S型"曲线增长,其干物质累积高峰期均在现蕾期至开花期.植株体内氮、磷、钾含量在不同生育期变化较大,但总体趋势是生育前期高于后期,随生育期延长其含量呈下降趋势.食用葵和油用葵各器官吸收氮、磷、钾的量有一定差别,食用葵整个生育期各器官中总吸氮量依次为:叶>茎>籽>盘;磷为:籽>叶>茎>盘;钾为:茎>叶>盘>籽;油用葵各器官中总吸氮量依次为:叶>籽>茎>盘;各器官中总吸磷、钾量的大小与食用葵一致.食用葵吸氮高峰期为现蕾期至开花期,吸磷、钾的高峰期在开花期;油用葵吸氮、钾高峰期在现蕾期、吸磷高峰期在开花至成熟期.在供试条件下,食用葵每形成100 kg籽粒约需吸收氮(N)3.8~4.9 kg,磷(P2O5)1.5~2.1 kg,钾(K2O)8.9~10.3 kg;油用葵约需吸收氮(N)3.5~4.6 kg,磷(P2O5)1.6~2.1 kg,钾(K2O)6.9~9.2 kg.  相似文献   

10.
烤烟干物质和氮磷钾吸收积累规律研究   总被引:5,自引:1,他引:5  
烟株干物质和养分吸收积累结果表明 :烟苗在移栽后 3 0~ 75d干物质的积累量占总积累量的 70 %左右 ,是烟株干物质的主要积累时期。烟株干物质累积强度以移栽后 60~ 75d最大。干物质在烟苗移栽 75d以后在根、茎、叶中的分配趋于相对稳定 ,根、茎、叶的干物质重分别约占全株干重的 16%~ 19%、3 2 %和 5 2 %~ 49%。烟株移栽后 3 0~ 75d是烟株养分的主要吸收时期。在目前烟草生产水平下 ,水田需施用的磷 (P2 O5)、钾 (K2 O)分别为 13 5 .0 0~ 173 .5 5、3 5 9.2 5~ 5 2 1.5 5kg/hm2 ;旱地需施用的磷 (P2 O5)、钾 (K2 O)分别为 10 4.1~ 13 3 .95、2 49~ 3 61.5kg/hm2 ,氮肥的利用率和施用量有待于进一步研究。  相似文献   

11.
Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.  相似文献   

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The aim of this paper is to make possible dialogue between those who claim that technologies are coded with social, political, or ethical values and those who argue that they are value-neutral. To demonstrate the relevance of this bridge-building project, the controversy regarding agrifood biotechnology will be used as a case study. Drawing on work by L. H. Nelson about the nature of human knowledge-building enterprises and E. F. Kittay’s account of the relationally-constituted self, the argument will be made that all technologies embody the values of the communities that created them. Zahra Meghani is an assistant professor in the Department of Philosophy at the University of Rhode Island. Her research interests are philosophy of technology, feminist theory (especially feminist epistemology and feminist philosophy of science), normative ethics, practical ethics (especially health care ethics), disability issues, and political theory.  相似文献   

15.
R & D, through its effects on the rate of productivity increase, can significantly restrain the rate of inflation in the medium and long run. High rates of inflation damage the workings of the price system and impair the efficiency of practically all economic activities, including R & D. Findings suggest that the percentage increase between 1969 and 1979, in total real R & D expenditures, has been exaggerated due to the inadequacy of the gross national product deflator as applied to R & D.  相似文献   

16.
The primary rocks are a sequence of titanium-rich basic volcanics, composed of clinopyroxene, plagioclase, and ilmenite with minor olivine, troilite, and native iron. The soil and microbreccias are respectively loose and compacted mixtures of fragments and aggregates of similar rocks, minerals, and glassy fragments and spheres. Impact events are reflected by the presence of shock metamorphosed rock fragments, breccias, and glasses and their resulting compaction to form complex breccias, glass-spattered surfaces, and numerous glass-lined craters. Chemistry of the glasses formed by the impact events is highly variable, and the high iron and nickel content of a few moundlike features suggests that at least some of the projectiles are iron and nickel-rich meteorites.  相似文献   

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Maslansky R 《Science (New York, N.Y.)》2003,301(5639):1479-82; author reply 1479-82
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