耐低钾玉米自交系灌浆至成熟期生理特性研究

研究耐低钾玉米自交系灌浆至成熟期的生理特性,探讨其耐低钾的生理机制,为钾高效玉米育种提供理论依据.以多年筛选出的典型耐低钾玉米自交系90-21-3和典型不耐低钾玉米自交系D937为试材,在天然低钾土壤上进行田间试验,于灌浆至成熟期测定根系形态、叶片持绿性、各器官的钾素积累量、钾利用效率、产量及产量性状.与不耐低钾玉米自...     

Residual effects of potassium placement for conservation-till corn on subsequent no-till soybean

Biannual surface application of potassium (K) fertilizer prior to corn (Zea mays L.) in a corn–soybean (Glycine max (L.) Merr.) rotation has been common in conventional-till crop production in North America; however, whether this traditional K management practice is effective for soybean when both corn and soybean are grown with conservation tillage is largely unknown. This study evaluated the residual effects of spring K fertilizer placement in conservation tillage systems applied to previous corn on subsequent no-till soybean. Experiments involving a corn–soybean rotation were conducted from 1997 to 2000 on a silt loam soil (Albic Luvisol) with 12 years of continuous no-till management near Paris, Ontario, Canada. The fields had low initial soil-test K levels (<61 mg l⁻¹) and evident soil K stratification in the top 20 cm. In the “corn” years from 1997 through 1999, spring K fertilizer placement methods of deep band (76 cm centers), surface broadcast, broadcast plus shallow band, and no K were evaluated for no-till, spring zone-till, and spring mulch-till tillage systems (1997 and 1998) but for no-till alone in 1999. From 1998 to 2000, soybean was no-till planted in 19 cm row widths on the respective previous-year corn treatments without further K fertilizer application. Soybean leaf K concentrations responded more frequently and positively to K application in no-till corn than in zone-till and mulch-till corn. Deep band and surface broadcast K placements were similar in their residual effects on soybean leaf K. Positive soybean yield responses to residual K fertilizer were observed in only 1 out of 3 years despite consistent increases in both soil K and soybean leaf K concentrations where K was applied to previous corn. On long-term no-till fields with low soil K levels, interrupting a continuous no-till corn–soybean system with mulch-till corn production provided residual benefits in soil K availability and leaf K nutrition for subsequent no-till soybean. Furthermore, the residual effects of K fertilizer applied to previous corn on subsequent no-till soybean were not affected by K placement method.     

氮、磷、钾素在土壤中垂直运移研究现状

随着土壤溶质运移理论研究的逐渐深入以及化肥施用后利用率低,环境污染严重等问题日益突出,人们开始越来越多的关注氮、磷、钾素在土壤中的运移情况,并做了大量的研究工作,文章主要对当前氮、磷、钾素在土壤中垂直运移研究现状进行简单概述,以期为我国南方砖红壤上氮、磷、钾素垂直运移研究提供相关的理论依据.     

钾对甜菜产量与质量的影响

甜菜(Beta vulgaris L.var.saccharifera Alef.)是一种需肥量大的喜钾作物。本试验结果表明,在施用充足的氮磷肥基础上,亩施钾肥(硫酸钾)20kg的效果较好,两试点亩增产分别为278kg和740kg,块根含糖率都比对照提高1个百分点以上。     

不同施钾水平对红富士苹果产量和品质的影响

通过施用不同水平钾肥对果树果实品质及产量的影响研究,结果表明,增施钾肥能够有效地改善红富士苹果果实的各项品质指标。但是钾素对果树各个指标的影响只是在一定的范围内效果较为明显,当超过这个范围的时候,增施钾肥表现出对各个指标的抑制。     

烟草钾营养的基因型差异及烤烟育种中应用研究Ⅰ.烟叶钾含量的基因型差异

为探明烟叶含钾量的基因型差异,对104份烟草基因型上、中、下部烟叶含钾量进行了系统测定.结果表明,烟叶含钾量存在明显的基因型差异,不同烟草基因型间上部叶含钾量在1.10%±0.51%～4.46%±0.51%之间,中部叶含钾量在1.50%±0.63%～4.82%±0.63%之间,下部烟叶含钾量在2.14%±0.89%～6.53%±0.89%之间;上、中、下部叶随着部位的升高,烟叶含钾量下降,而烟叶含钾量的变异系数则相反;烟草基因型间烟叶含钾量的分布次数为非对等的、中间多、两端少的分布趋势;YZ99-2,9411,9306,革新3号,中烟98,台烟7号,岩烟97等可作为高钾亲本应用于高钾烤烟新品种的选育.     

茶园土壤钾素容量／强度关系及施用钾镁肥的影响

对我国主要茶区茶园土壤分析结果表明，土壤钾素含量大都处于中等水平以下，且呈地带性分布，即缓效钾的含量由北而南下降，速效钾占缓效钾的比例由北而南增加。对土壤钾素容量／强度（Ｑ／Ｉ）分析表明，茶园土壤钾素的ＡＲｋｅ（强度指标）通常都小于０．０１（ｍｏｌ／ｌ）－１２。施用钾肥能显著提高供钾强度指标ＡＲｋｅ和ΔＫ０（容量指标）。施镁能增加ＡＲｋｅ，但对ΔＫ０和ＰＢＣｋ（缓冲能力）无明显影响。不施钾处理土壤的ＡＲｋｅ和ΔＫ０均趋于下降     

丹参氮磷钾肥效反应模式研究

采用N、P二因素五水平和N、P、K三因素五水平最优设计，在陕西天士力药用植物有限公司丹参基地进行了丹参氮、磷、钾肥效田间试验，结合试验点的土壤肥力水平，求得了丹参N、P、K的肥效反应方程，提出了丹参不同产量水平时的N、P、K合理配比和肥料用量。丹参目标产量在5000-5700kg/hm^2间的N、P量是N115.5-214.3kg/hm^2；P2O5153.4-243.4kg/hm^2。丹参目标产量在8000-9500kg/hm^2间的N、P、K施肥量N133.8-207.5kg/hm^2；P2O568.25-115.8kg/hm^2；K2O80.3-146.5kg/hm^2。分析了N、P、K对丹参生长发育和产量的影响，结果表明N、P、K都促进了丹参产量的提高，但N、P、K的施用过量会造成减产。     

土壤钾素供应状况的研究——Ⅲ.几种不同土壤中钾的固定与释放

本文用一般化学浸提法、盆栽耗竭试验和恒湿培养试验,研究了几种不同土壤中钾的固定与释放规律。结果表明,在恒湿条件下不同土壤固钾能力相差很大,固定钾的绝对量随施钾量的增加而增加。黑麦草连续收割6次后,土壤交换性钾降到最低值,尔后不再下降,该最低值因土壤不同而异。它表示了在作物生长过程中土壤对溶液中钾的缓冲能力的即土壤钾的释放速率。同时也说明了层间钾(非交换性钾)的释放对作物钾素供应起了重要作用。