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1.
将不同种类氮肥与微肥匹配施用,探索其对白肋烟产量、质量的影响.结果表明：白肋烟施用碳铵产量、产值显著高于施用硝铵和尿素,不同的氮肥与不同的微肥间存在显著的相互作用.施用碳铵或尿素处理再喷施硼肥有利于提高烟叶产量、产值和评吸质量;施用硝铵处理再喷硼肥有利于提高烟叶产量、产值;施用镁肥或锌肥有利于提高烟叶评吸质量.  相似文献   

2.
The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO2-N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/(g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).  相似文献   

3.
Cadmium (Cd) contamination in soil is an increasingly serious problem. Management of plant nutrients has been proposed as a potentially promising strategy for minimizing Cd accumulation in crops grown in contaminated soil. This study investigated the effects of split applications of nitrogen (N) fertilizers on the Cd concentration in Chinese cabbage (Brassica chinensis L.) plants grown in Cd-contaminated soil. Compared with single applications, split applications of ammonium or urea resulted in significantly lower Cd concentrations, and higher biomass production and antioxidant-associated nutritional quality in the edible plant parts. However, when nitrate was used as the N fertilizer, there were no significant differences between the split and single applications for the same parameters. We conclude that a split application could be more beneficial than a single application method when ammonium or urea is used as the N fertilizer for vegetable cultivation in Cd-contaminated soil.  相似文献   

4.
Experiments were carried out with citrus （Citrus reticulate） and tea （Podocarpus fleuryi Hickel.） to study the effects of compound fertilizers on their yields and quality. In the citrus experiment, application of compound fertilizers increased available P K and Mg contents in soil but decreased alkali-hydrolyzable N contents in soil and N, P and K contents in leaves. In the tea experiment, application of compound fertilizers increased available P, K and Mg contents in soil and N, P, K and Mg contents in leaves but decreased alkali-hydrolyzable N in soil compared with the urea treatment. Application of compound fertilizers could improve the quality of citrus and tea, increase their yields and enhance their economical profits significantly. Compared with the control, application of compound fertilizers increased citrus yields by 6.31, 12.94 and 17.69 t/ha, and those of tea by 0.51,0.86 and 1.30 t/ha, respectively. Correspondingly, profits were increased by 21.4% to 61.1% for citrus and by 10.0% to 15.7% for tea. Optimal rates of compound fertilizers were recommended for both crops.  相似文献   

5.
基于国产环境减灾卫星遥感数据的油菜冻害评估   总被引：1，自引：0，他引：1  
目的：以2011年1月发生在合肥地区的油菜冻害为案例,利用国产环境减灾卫星数据监测其灾情分布,探究自然环境条件及植被长势与灾情之间的关系。
　　创新点：基于遥感手段监测越冬期油菜冻害的研究鲜见报道。鉴于受灾年份的花期影像难以准确呈现油菜的实际空间分布,本文提出了一套适用于灾害年越冬时期的油菜种植区域遥感提取方法,探索了地形条件、越冬前长势、土壤湿度和最冷日期地表温度对于灾情程度的影响。
　　方法：以正常年份的油菜种植区域为基准,利用越冬作物在越冬前生长的特性来提取受灾年份越冬时期的油菜种植区域;利用灾后相对于灾前的归一化植被指数（NDVI）百分比变化量作为冻害监测指标来监测灾情分布;采用随机样本点抽取的灾情与各影响因素数据集,运用相关分析方法来探讨二者之间的联系,采用统计分析方法探讨灾情与坡向之间的关系,采用灰色相关分析方法考查各影响因素对于灾情的影响程度。
　　结论：基于国产环境减灾卫星数据可以有效地监测油菜冻害灾情,展现不同冻害等级的空间分布;在地势低洼、土壤墒情差、植株长势旺盛条件下,油菜冻害趋于严重,南坡向和西坡向生长的油菜受冻相对更为严重;各影响因素对冻害灾情的影响程度由高到低依次为：最冷日期的地表温度、土壤湿度、灾前长势、海拔高度。  相似文献   

6.
为纯化紫苏籽油中的α-亚麻酸,将传统的低温冷冻结晶法和尿素包合法有机结合,对纯化工艺进行优化．结果表明：紫苏籽油在y（无水乙醇）：Ｖ（丙酮）=1：1混合溶剂,粗品：尿素：混合溶剂=2：1：10,冷藏时间为36h时,析出的晶体最长、用时最短．采用筛选的溶剂和优化的工艺条件可大大提高晶体析出量、缩短晶体的析出时间,使纯化后紫苏籽油中的α-亚麻酸从原来的304mg／mL提高到644mg／mL．  相似文献   

7.
本文在一定条件下研究Briot—Bouquet型微分方程的解析解及其在λ——螺形函数中的应用。  相似文献   

8.
在田间试验条件下研究了施肥对“秦油二号”杂交油菜氮、磷、钾营养及其产量的影响,结果表明:单施氮肥,增加植株氮、磷、钾吸收强度和植株含氮浓度,但对植株磷、钾浓度无明显影响。氮磷配施既能显著提高植株氮、磷、钾吸收强度,也能增加植株氮、磷、钾浓度。在施用氮、磷肥料基础上配施氯化钾肥,降低了植株氮、磷吸收强度和氮浓度。施肥使油菜氮,磷营养吸收高峰推迟。吸氮高峰期在油菜苔期,吸磷高峰期在油菜花角期。在本试验条件下,氮肥与磷肥配合施用油菜产量和经济效益最高,比单施氮肥增产23.2％,比氮磷钾配施增产11.4％,每亩增收三十无以上。  相似文献   

9.
Objective:To evaluate the effect of chitosan(CH) and hydrogen peroxide(H2O2) seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology,the H2O2 presence,the catalase(CAT) activity,and the protein quantity.Methods:Seven groups of ten seeds for each maize variety were treated with CH(2%(20 g/L) and 0.2%(2 g/L)) or H2O2(8 mmol/L) by coating,sprinkling,or both.Germination and seedling growth were measured.One month after germination,the presence of H2O2 in seedlings in the coated seed treatments was evaluated.Protein content and CAT activity were determined under all treatments.Results:H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize(QPM) variety.Seedlings had a higher emergence velocity under this treatment in both varieties.CH and H2O2 sprinklings did not have an effect on seedling phenology.Exogenous application of H2O2 promoted an increase of endogenous H2O2.CH and H2O2 seedling sprinkling increased the protein content in both maize varieties,while there was no significant effect on the CAT activity of treated seeds and seedlings.Conclusions:CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.  相似文献   

10.
采用盆栽试验,研究了饱和铵贮库施肥法(NDSA-Nitrogendepotwithsaturatedammonium)对菠菜(SpinaciaoleraceaL.)产量和品质的影响。结果表明,与常规施肥法相比,NDSA施肥法和DCD(双氰胺)两者配施(NDSA2处理)则可显著提高菠菜产量。NDSA施肥法可大幅降低菠菜的硝酸盐含量,而DCD的效果并不明显。施氮可明显增加菠菜的Vc含量,其中以NDSA施肥法配施DCD效果最好。菠菜叶片Vc含量很高,相当于叶柄中的3倍。施氮和NDSA施肥法对菠菜可溶性糖影响不大,但DCD可明显增加菠菜的可溶性糖含量,同时降低了菠菜草酸的含量。  相似文献   

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