土壤速效磷对烟草生长发育及干物质积累与分配的影响

作物的磷素营养丰缺状况会严重影响其生长发育与干物质的积累与分配,为探明土壤速效磷含量对烟草生长发育及干物质积累与分配的影响,为湖南烟区磷肥的合理施用提供科学依据,以湖南省8个不同速效磷含量的植烟土壤为研究对象,采用盆栽试验,研究在不施磷肥的情况下土壤速效磷含量对烟草生长和干物质积累与分配的影响。结果表明,当土壤速效磷含量大于50mg/kg时,烟草生长发育良好,而小于30mg/kg时,则明显影响了烟草的生长发育,表现为烟株矮小,有效叶片数减少,干物质量明显降低。速效磷含量较低的土壤与含量较高的土壤相比,烟株的干物质积累量减少27%~31%,当土壤速效磷含量很低时,烟株的干物质积累量仅为速效磷含量较高土壤烟株干物积累量的3.6%。土壤速效磷含量低不仅明显限制烟草茎和叶的生长,还会导致烟叶的长宽比由2.2增大到2.7,使烟叶呈狭长形。烟草移栽后76~90d是烟株干物质积累最快的时期,当土壤速效磷含量较低时,该时期的干物质积累比例为55.2%~69.2%,明显高于速效磷含量高的土壤,即当土壤速效磷含量较低时,烟株不仅生长缓慢,而且干物质的积累还明显滞后。     

玉米杆好氧发酵后沼液营养成分的变化

以玉米杆废弃物为研究对象,利用好氧发酵堆肥方式,对其处理前后沼液营养成分进行分析。结果表明,与空白对照相比,处理后发酵沼液营养成分丰富,其中腐植酸增幅达123.7%,五氧化二磷降幅达63.3%;处理后腐殖酸含量显著增加,同时好氧发酵过程消耗大量的磷。     

Effect of cutting,phosphorus and potassium fertilization on guar plant (Cyamoposis tetragonoloba) in newly reclaimed soil in Egypt

A two year experiment was carried out in newly reclaimed soils (sandy soils) to investigate the effect of cutting and phosphorus and potassium fertilization on the growth, yield, seed mucilage content and seed protein content of guar plant. The results revealed that different cutting treatments significantly decreased the plant weight, seed yield, seed mucilage content and seed protein content. Phosphorus fertilization up to 350 kg super-phosphate (15% P₂O₅)/feddan significantly increased plant weight, seed yield, seed mucilage content and seed protein content. Fertilization with 150 kg potassium sulfate (48% K₂O)/feddan was quite capable to meet guar plant potassium demands in this kind of soil. Without cutting plants, fertilization with 350 kg superphosphate and 150 kg potassium sulfate/feddan resulted in the highest seed yield, seed muculage content and seed protein content.     

大豆对磷素吸收规律的研究

以北丰-14为供试品种,采用五因素三水平实施方案,系统的研究了大豆在不同密度、施肥量处理下,各器官磷素含量和对磷素的吸收规律.结果表明:随着生长发育进程的推进,大豆各器官磷素浓度大小因器官而异,均呈下降趋势;大豆对磷素最高吸收速率出现在结荚至鼓粒期,最高吸收速率为5.28mg/株·d,吸收量约占全生育期总吸收量的30%～50%左右;适宜密度和氮磷钾适量配施,可显著提高大豆磷素的吸收量与吸收速度,并能显著提高大豆的经济产量.     

春小麦品种磷营养效率研究Ⅲ.磷高效品种的特征特性

通过对不同磷效率类型品种（系）性状表现的方差分析，阐明了春小麦磷高效品种的性状特征。当受到同一缺磷胁迫时，耐缺磷的品种具有较高的的化和结实能力，品种耐缺磷能力越强，对加磷反应越不敏感；品种的磷利用效率同耐缺磷能力和对加磷反应敏感性无关。具有发达根系的品种吸磷能力强、耐缺磷程度高。     

野生油菜种子氮磷含量及其超氧化物歧化酶活性初探

１８１份野生油菜种子的全氮全磷含量和超氧化物歧化酶（ＳＯＤ）活性及其同工酶的测定结果表明；野生油菜种子粗蛋白含量变相为２５．１１％—３７．６７％，平均含量为３１．２６％；全磷含量变幅为０．２３％—０．５７％，平均含量为０．３９５％。野生油菜种子ＳＯＤ活性变幅为１６０７．５—１８０５．５酶单位／克干重，平均为１７０６．１。萌发过程中野生油菜ＳＯＤ活性的变化大于栽培油菜品种，ＳＯＤ同工酶谱带多１—２条。     

维生素A联合铁剂治疗学龄期青少年缺铁性贫血临床观察

目的 探讨维生素A缺乏(VAD)在学龄期青少年缺铁性贫血（IDA）发病中的意义,观察维生素A联合铁剂治疗青少年IDA的疗效。方法 将88例缺铁性贫血青少年随机分为观察组与对照组各44例,观察组予以琥珀酸亚铁+维生素A治疗,对照组则单用琥珀酸亚铁治疗,疗程2个月。观察比较两组的临床疗效,并分析血清维生素A水平与贫血程度的关系。结果 （1）随着贫血程度的加重,VAD发生率显著增加(P＜0.05);（2）观察组治疗后的Hb、SF、SI、TIBC升高幅度明显大于对照组(P＜0.05)。结论 青少年缺铁性贫血常合并VAD存在,维生素A 联合铁剂治疗青少年IDA效果明显优于单纯铁剂治疗。     

Influence of Potassium Substitution by Rubidium and Sodium on Growth,Ion Accumulation,and Ion Partitioning in Bean under High Alkalinity

ABSTRACT

The effects of partial and complete substitution of potassium (K⁺) by rubidium (Rb⁺) and sodium (Na⁺) on plant growth and ion accumulation and partitioning was studied in bean young plants cultivated in nutrient solution with or without bicarbonate (HCO₃ ^?)-induced alkalinity. Plant growth was significantly decreased due to alkalinity and the substitution of K⁺, being leaves more affected than roots. Rubidium caused a severe toxicity reflected in a reduction in root dry mass and total chlorophyll concentration. Ion partitioning was markedly altered by alkalinity. Content of nitrogen (N), calcium (Ca), magnesium (Mg), iron (Fe), K, and Na were more accumulated in the roots in HCO₃ ^?-treated plants, while decreased in the shoot. Iron (Fe) was accumulated at similar extent in plants with and without high alkalinity, except in plants grown in Rb⁺ solutions. However, Fe was more accumulated in the roots, suggesting that chlorophyll synthesis was impaired by reduced translocation or internal inactivation of Fe. Zinc total uptake was severely reduced under high alkalinity in plants grown in Na⁺ solutions, maybe due to decreased Zn activity. Calcium was translocated more actively to the leaves and Mg was accumulated more in the roots of plants in Na⁺solutions. Despite the severe decrease in plant dry mass caused by Rb⁺, there was a higher translocation of N, phosphorus (P), Ca, Mg, Fe, zinc (Zn), copper (Cu), and manganese (Mn) from the roots to the leaves.     

COMPARISON OF ZINC EFFICIENCY AMONG WINTER WHEAT GENOTYPES CULTURED HYDROPONICALLY IN CHELATOR-BUFFERED SOLUTIONS

Zinc (Zn) efficient genotypes grow and yield well in Zn deficient environments. The objective of this study was to compare Zn efficiency and seed Zn content among nine winter wheat (Triticum aestivum L.) genotypes grown in chelator-buffered nutrient solutions containing 0 μmol Zn L^?1 (?Zn treatment) or 3 μmol Zn L^?1 (+Zn treatment). The Zn efficiency of the genotypes ranged from 24% to 46%. Zinc efficiency was positively correlated with shoot dry weight, shoot Zn content, but there was no significant correlation between Zn efficiency and shoot Zn concentration, seed Zn concentration, or seed Zn content. The results suggested that variation in Zn efficiency among these nine wheat genotypes is genetically inherent. Differences in Zn efficiency among these wheat genotypes, which are widely grown in northern China, indicate the potential to breed for wheat genotypes with increased tolerance to soil Zn deficiency.