共查询到10条相似文献，搜索用时 46 毫秒
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聚乙烯醇对香料烟产量、质量及土壤结构的影响 总被引：7，自引：1，他引：6
盆栽和田间试验结果表明,聚乙烯醇（PVA）对香料烟生长具有一定的生理效应,使叶绿素、水溶性糖含量增加,NR酶活性、光合效率及烟株根系活力增强。PVA能增加烟株株高和节距,促进烟株早发和提早成熟;增产作用虽未达到显著水准,但对香料烟中上等烟率、均价、产值有明显效果。PVA使晾制后香料烟叶内全钾含量、还原糖量、醚提取物量增加,而烟碱含量减少。用扫描电镜和显微光密度仪观察PVA对土壤结构的影响发现,施用PVA后土壤微结构中出现明显的微团聚体,激团聚体内及体间有较多的孔隙;90％以上颗粒粒径在9～15m之间。未施PVA的土壤,90％以上颗粒粒径在4～10m之间,单粒平均直径比处理土壤的小4～5m,少有微团,孔隙较小,因而紧实。PVA不仅促进了烟株体内代谢和其生长发育,而且改良了土壤结构,良化了作物生长环境。 相似文献
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水分和温度对土壤钾素释放、固定影响的初步研究 总被引：7，自引：1，他引：7
钾是植物的重要养分之一。由于土壤中存在着不同的矿物,因而产生钾的释放和固定,但这一过程受到很多因素的影响,其中水分状况是重要因素之一。多年来水分状况对钾素释放、固定影响的问题,受到了土壤研究者的注意,但是,到目前为止仍无一致的结论,例如Omuetiand[1]等认为。用风干土测定的交换性钾能很好反映土壤供钾状况,而Luebs等[2]则认为,以用新鲜潮湿土测定为好。为了更好的反映土壤当季的供钾水平,合理使用钾肥,以及发挥土壤钾素的潜力,因此这一问题的研究是有实践意义的,现将研究结果报告如下。 相似文献
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氯和钾营养对烤烟产量和品质的影响 总被引：22，自引：1，他引：22
在四川中性紫色土上研究烤烟的氯钾营养及其与产量品质的关系。结果表明,施氯量80-240mgCl/kg土,可提高烟叶的光合强度,增强POD、PPO、SOD、NR等抗逆酶的活性,增大叶面积。烟叶含氯量随施氯量的增加而增加,烤烟烟叶产量比对照提高5.5-21.5％。以烟叶含氯1％,K2O/Cl比4为标准确定的该地区烤烟耐氯临界值为139-165mgCl/kg土(土壤水溶性氯),可使烟叶中糖和烟碱含量和比例协调。从烤烟营养和品质看,植烟土壤含氯(水溶性氯)以不超过160mg/kg土为宜。试验还表明施氯促进了烤烟对氯、钾的吸收,提高烟叶水溶性总糖含量,但不利于烟株对磷的吸收。因此合理配置烤烟氮、磷、钾、氯的比例对烤烟品质至关重要。本试验结果初步表明在中性紫色土植烟区,以部分氯化钾代替硫酸钾是可能的。 相似文献
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《Journal of plant nutrition》2013,36(9):1445-1455
The larval stage of the spotted cucumber beetle (Diabrotica vigifera zeae), the Mexican corn rootworm, is a highly devastating pest of cornfields in Texas and the Southwest. A systemic organophosphate insecticide, standard release terbufos (ST), applied in row with the corn seed at planting, has been termed effective in reducing crop damage from the Mexican corn rootworm. However, recent field observations have indicated possible association of micronutrient deficiency symptoms with use of terbufos and over-the-top sulfonyl urea herbicides (nicosulfuron, primisulfuron) on crops such as corn. This experiment was conducted to determine if this systemic soil insecticide would affect plant metabolic activities as measured by nutrient deficiency chlorosis and plant growth. The study also involved testing a controlled release terbufos (CR) version of the same insecticide. Each soil insecticide was compared with and without foliar treatments with one of the sulfonyl urea herbicides (nicosulfuron) used in controlling grass-type weeds in corn. The greenhouse study was conducted on a Monteola sandy clay loam (Typic Pellusterts), which is a typical soil used in corn production in southern Texas. Standard release (ST) and CR forms of terbufos were compared at the label recommended rate (1.1 kg a.i./ha) and also at 2 kg a.i./ha. All materials were banded in the seed row at planting. Treatments were arranged in a randomized block design with three replications. Early visual chlorosis ratings (7 days) and chlorophyll readings at 28 days indicated increased interveinal chlorosis with soil insecticide applications. Plants overcame these early effects with time and showed higher chlorophyll than untreated plants at 42 days. Depressed early plant growth and reduced tissue levels of certain micronutrients indicated these systemic insecticides both with and without over-the-top herbicide could be injurious during early stages of plant growth. However, the affected plants were able to overcome most of the effects later in the growing season. Tissue iron (Fe) concentrations were slightly reduced by terbufos alone and reduced further when nicosulfuron was applied. Zinc was reduced substantially by terbufos but appeared to not change when the over-the-top herbicide was included. 相似文献
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Maryam Safdarian Jamashid Razmjoo M. Movahhedi Dehnavi 《Journal of plant nutrition》2014,37(4):611-617
The objective of this study was to determine the effect of nitrogen (N) application source and rate on silage corn (Zea mays L.). Urea, ammonium nitrate, and ammonium sulfate were compared at 50, 100, 150, and 200 kg N ha?1. The application of ammonium sulfate produced the highest plant height, leaf area index (LAI), total yield, and stem, leaf, and ear dry matter, followed by ammonium nitrate and urea. However, nitrogen sources had no marked effects on the content of protein, ash, oil, soluble carbohydrates, acid detergent fiber (ADF) and neutral detergent fiber (NDF). As the rate of nitrogen increased plant height, LAI, total yield, and stem, leaf, tassel, and ear dry matters, and protein, ash and oil contents increased while soluble carbohydrates, ADF, and NDF contents decreased. Ammonium sulfate was the most effective N source on production and 200 kg N ha?1 was the most effective N rate on corn yield and quality. 相似文献
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乙草胺和异丙甲草胺在土壤中吸附的研究 总被引：29，自引：1，他引：28
本文研究比较了乙草胺和异丙甲草胺在６种土壤中的吸附,采用Ｆｒｅｕｎｄｌｉｃｈ方程对其吸附等温线进行描述,对Ｆｒｅｕｎｄｌｉｃｈ方程吸附常数Ｋａｔ和Γ／ｎ的乘积与土壤理化性质的相关性进行了分析,并探讨乙草胺和异丙甲草胺在腐殖酸上的吸附机理。结果表明,乙草胺和异丙甲草胺在土壤中吸附主要受土壤有机质支配,有机质含含量越高越有利于这两种除草剂在土壤上的吸附。异丙甲草胺在土壤中的吸附明显弱于乙草胺。氢键是乙 相似文献
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改良剂对玉米和大豆间作植株锌铬积累的影响 总被引：1，自引：0，他引：1
通过盆栽试验,研究改良剂石灰和过磷酸钙对玉米、大豆间作植株各器官锌铬积累的影响。结果表明,不同改良剂处理后,能显著降低土壤中锌、铬有效态含量,植株各器官锌含量为:对照>低浓度石灰>高浓度石灰;铬含量为:对照>高浓度过磷酸钙>低浓度过磷酸钙,单作>间作。在间作下施用低浓度过磷酸钙改良效果最优,其中玉米根、茎、叶的锌、铬含量分别比只施用低浓度过磷酸钙单作降低30.72%、35.96%和29.51%,69.98%、64.21%和51.56%;比不施加改良剂的对照间作玉米降低55.57%、59.68%和66.57%,64.10%、76.79%和80.75%;大豆根、茎、叶的锌、铬含量分别比其只施用低浓度过磷酸钙单作降低0.26%、4.91%和16.42%,14.25%、8.16%和23.33%,比不施加改良剂的对照间作降低63.95%、69.54%和65.49%,54.15%、57.14%和57.14%。间作条件下,低浓度过磷酸钙处理在不增加大豆对锌铬吸收的前提下,大幅降低玉米对重金属的吸收,显著增加玉米产量。 相似文献
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除草剂草甘膦在几种土壤和矿物上的吸附研究 总被引：5，自引：0，他引：5
通过批平衡实验考察了草甘膦在几种性质不同土壤和矿物上的吸附行为。研究发现土壤对草甘膦有较强的吸附能力，草甘膦在土壤上吸附量的大小与土壤理化性质密切相关。草甘膦在土壤和矿物上的吸附符合Freundlich吸附方程，其在土壤上的吸附常数K与土壤粘粒含量呈正相关，并随土壤氧化铁和氧化铝含量增加而增加，而与土壤的pH呈显著负相关。草甘膦在高岭石上的吸附量要比在蒙脱石上大，而草甘膦在金属离子饱和的蒙脱石和高岭石上的吸附研究结果表明，草甘膦在钠、钙、铁离子饱和的矿物上的吸附能力依次为Fe-蒙脱石〉Ca-蒙脱石〉Na-蒙脱石和Fe-高岭石〉Ca-高岭石〉Na-高岭石。 相似文献