共查询到20条相似文献，搜索用时 750 毫秒
1.
2.
在驻马店市的新坡村与驻马店农科所农场进行了小麦-玉米轮作制下的控释尿素与普通尿素用量试验,结果表明:小麦田、玉米田均以控释尿素100%处理最好.新坡村与驻马店农科所农场的小麦产量分别为8175 kg/hm2和8272 kg/hm2;比同等用量的普通尿素增产873～860 kg/hm2,增产12.0%～11.6%,增产效果显著;小麦氮素利用率以控释尿素100%处理最高,分别为46.1%和48.6%;氮素用量相同时,小麦田控释尿素氮素利用率高于普通尿素氮素利用率.玉米产量为8715 kg/hm2和8848 kg/hm2,比同等用量的普通尿素增产667～686kg/hm2,增产8.3%～8.4%,增产效果显著;控释尿素用量从70%到100%时,小麦、玉米产量随氮肥用量增加而增加,普通尿素也呈现同样趋势,随尿素用量的增加小麦、玉米产量在增加:70%控释尿素与100%普通尿素处理之间产量差异不大,说明使用控释尿素用量比普通尿素用量减少1/3的纯氮量时,小麦、玉米作物产量并不下降. 相似文献
3.
《农业科技通讯》2016,(8)
为探索常宁市茶叶优质适产施肥技术和增产效应,特进行了茶叶有机肥当量试验,结果表明,有机肥与化肥配合施用茶叶增产效果明显,各试验处理以有机肥提供氮占2/3产量较高,达1 012.5 kg/hm2,比无氮区、全有机肥区和全化肥区分别增产389.5 kg/hm2、177.5 kg/hm2和43.5 kg/hm2,分别增产62.5%、21.3%和4.5%;4个有机肥处理以有机肥提供氮占2/3净收益较高,达82 570.20元/hm2,比有机肥提供氮占1/2、有机肥提供氮占1/3和全有机肥处理分别增加5 205.45元/hm2、8 160.75元/hm2、18 751.95元/hm2。生产中应提倡增施有机肥,合理施用化肥,提高茶叶产量和品质。 相似文献
4.
5.
6.
7.
民勤县食用向日葵配方施肥效应研究 总被引：2，自引：0，他引：2
采用“3414”完全设计试验方案,进行了食用向日葵配方施肥试验.结果表明,氮、磷、钾肥配施对食用向日葵物候期影响不大,以施尿素521.8 kg/hm2、普通过磷酸钙618.8 kg/hm2、硫酸钾272.8 kg/hm2处理的经济性状表现较好,折合产量最高,为5980 kg/hm2,较不施肥处理增产2390 kg/hm2,增产率66.6%. 相似文献
8.
9.
氮钾配施对大蒜产量和品质的试验结果表明:增施钾肥对前期蒜苗、蒜薹的生长发育有明显的促进作用,在同一氮肥条件下,施钾量的增加对后期蒜头产量的增产极为显著。两试验点蒜薹增产幅度分别为9.2%～17.4%和8.8%～19.1%,蒜头增产幅度分别为5.9%～8.8%和3.2%～14.6%。在不同氮钾配比试验中,以施氮375kg/hm2,配合施用氧化钾150kg/hm2,对大蒜增产效应最明显。大蒜施磷不足会影响蒜薹的产量,五氧化二磷用量应在90kg/hm2的基础上才能保证大蒜高产和稳产。 相似文献
10.
[目的]为冬小麦-夏玉米轮作体系高产、稳产,合理施用氮肥提供依据。[方法]研究了连续施氮对冬小麦-夏玉米产量、经济效益、氮肥吸收利用效率和土壤无机氮的影响。[结果]施氮使冬小麦-夏玉米轮作体系显著增产,2个轮作周期分别增产17.76%～30.32%、22.24%～46.63%;施氮量660.0kg/hm2在2个轮作周期的产量均最高,分别为23391.19和23444.35kg/hm2,经济效益和产投比较佳,氮肥利用率分别为22.2%和30.7%,农学效率分别为8.3kg/kg和11.3kg/kg。施氮量540.0和660.0kg/hm2的氮肥利用率和农学效率均无显著差异。2个轮作周期后,施氮量540.0kg/hm2的0～40cm土壤无机氮积累量与试验前基本平衡。[结论]该试验条件下,综合产量、效益、氮肥效率及土壤无机氮平衡考虑,高产冬小麦-夏玉米轮作体系适宜施氮量为625.3～660.0kg/hm2。 相似文献
11.
12.
Segregation of form, color, movement, and depth: anatomy, physiology, and perception 总被引：63，自引：0，他引：63
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
13.
ICP-OES法同时测定果蔬中铅、砷、镉、铬、铜、锡含量 总被引：2，自引：0，他引：2
果蔬样品经混酸消化后,控制一定的酸度,定容后应用等离子体发射光谱法(ICP-OES)对果蔬中铅、砷、镉、铬、铜、锡六种有害重金属进行测定,研究了分析测定条件,方法简单快速。测定结果表明,五种元素的加标平均回收率在91.0%~107%之间。其RSD均小于3.5%。按该方法进行处理及测定铅、砷、镉、铬、铜、锡,在选择的测定条件下最低检出限分别为0.0006 mg/kg、0.0003 mg/kg、0.00003 mg/kg、0.00005 mg/kg、0.00003 mg/kg、0.0006 mg/kg。 相似文献
14.
15.
通过野外调查、标本采集、分类学研究及资料考证,基本摸清了贵州樟科、莲叶桐科、景天科、堇菜科、柳叶菜科、鹿蹄草科、柿科、山矾科、木犀科等9个科药用植物资源的种类与地理分布.结果发现贵州现有樟科药用植物49种4变种,莲叶桐科药用植物5种,景天科药用植物21种,堇菜科药用植物19种1变种,柳叶菜科药用植物20种4变种,鹿蹄草科药用植物7种1变种,柿科药用植物9种1变种,山矾科药用植物12种,木犀科药用植物30种3变种.其中,4种为贵州特有药用植物,40种5变种为贵州药用新资源. 相似文献
16.
WILLIAMS TI 《Science (New York, N.Y.)》1960,132(3436):1296-1297
17.
本试验以菜豆品种先行者为试材,采用32孔、50孔两种规格穴盘,设置10、15、20、25 d等4个苗龄段,通过研究不同穴盘规格和苗龄对菜豆性状及产量的影响,筛选出适合菜豆育苗的穴盘规格和适宜的苗龄。结果表明：穴盘育苗的营养面积增大,菜豆产量随之增加,25 d苗龄条件下,32孔穴盘的前期产量和总产量均显著高于50孔穴盘;随着苗龄的增长,菜豆的前期产量和总产量呈增加趋势,其中25 d苗龄的产量显著高于其他苗龄。综合上述各项指标,菜豆育苗阶段,10 d苗龄可选用32孔、50孔穴盘,15 d以上秧苗选用32孔穴盘为宜。 相似文献
18.
The finding of appreciable quantities of p,p'-DDT after feeding o,p'-DDT to rats led to the proposal of a theory, that an isomeric metabolic conversion occurs. The presence of p,p'-DDT as an impurity in supposedly pure samples of o,p'-DDT is the correct explanation for the appearance of p,p'-DDT. Purified o,p'-DDT and (14)C-labeled o,p'-DDT yielded no data to support the idea that o,p'-DDT is converted to the p,p'-DDT isomer. 相似文献
19.
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
20.
Wood NV 《Science (New York, N.Y.)》1947,105(2733):531-532