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为研究不同生态区施钾量与烤烟生长和钾肥利用率的关系,以不施钾(CK)为对照,分别在气候和土壤差异明显的山东即墨和云南罗平开展了3个钾水平(即墨,T1 123.75 kg/hm2、T2 247.50 kg/hm2、T3 371.25 kg/hm2;罗平,T1 67.50 kg/hm2、T2 135.00 kg/hm2、T3 202.50 kg/hm2)的田间试验。结果表明:(1)施钾肥显著提高即墨烤烟茎、叶的生物量和总生物量,仅显著提高罗平烤烟烟叶生物量;T1、T2和T3显著提高烟叶生物量,即墨分别为7.62%、29.4%和31.5%,罗平分别为12.4%、19.5%和13.1%。(2)施钾肥显著提高即墨烟叶钾积累量和钾总积累量,T3效果最显著;显著提高罗平烤烟钾总积累量,T2效果最显著。(3)即墨施钾量与烤烟烟叶产量、烟叶钾含量和钾总积累量之间呈极显著正相关,而罗平则符合一元二次方程曲线;罗平T2对应施钾量下,烟叶产量、烟叶钾含量和钾总积累量与最大值(6579 kg/hm2、2.19%、230 kg/hm2)接近。(4)T2处理,即墨烟叶含钾量>3%,钾肥表观利用率(RE)和钾肥农学效率(AE)最高,分别为27.8%和2.50 kg/kg,钾肥偏生产力(PEP)降低,土壤钾素盈余显著;罗平RE高达45.3%,AE和PEP较高,分别为8.05 kg/kg和49.3 kg/kg,土壤钾素亏缺显著。综上,T2处理在提高即墨和罗平烟叶产质量和钾肥利用率以及平衡土壤钾素方面效果显著,可推荐为两地烤烟生产的适宜施钾量。 相似文献
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《Food research international (Ottawa, Ont.)》1999,32(6):433-440
Production of Sherry wine vinegar encompasses a variable period of aging in wood. Changes in phenolic compounds during Sherry vinegar aging were studied. Samples were divided according to their aging period in wood (less than 2 years, more than 2 years) and phenolic compounds determined in a total of 38 samples by means of HPLC and Photodiode Array Detection. Results of Multiple Analysis of Variance (MANOVA) confirms that there were significant differences among both groups. Good recalling rates were achieved in both Linear Discriminant Analysis LDA (mean=92.9%) and Artificial Neural Networks trained by Back Propagation (BPANN) (mean=90.4%) whilst prediction abilities are more discrete. Applying the forward selection of variables, six variables were selected according to the Wilks' lambda criterion: gallic acid, 5-hydroxymethylfuraldehyde, coumaroyltartaric acid glycoside, p-hydroxybenzoic acid, caffeic acid and isoquercetrin. Three of these compounds (gallic acid, hydroxymethylfuraldehyde and coumaroyltartaric acid glycoside) were shown to have an increasing trend through most aging systems. 相似文献