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81.
Barley (Hordeum vulgare L. cv Doriru) leaf samples were collected from a field comprising three plots, plot F chemical fertilizer treated, plot S receiving sewage sludge and sawdust mixed compost, and plot H receiving sewage sludge and rice husk mixed compost. Relative concentrations of selected elements, potassium (K), calcium (Ca), and chloride (Cl) of young, mature, and old barley leaves were determined by microscopic energy dispersing X‐ray fluorescence (EDXRF). The objective of this investigation was to verify the applicability of EDXRF for rapid nutrient element diagnosis of plants. Typically whole leaves were washed in deionized‐distilled water and dried by ironing for analysis. Intact dried barley leaf sample irradiation was accomplished with X‐rays obtained from an X‐ray tube focused on an area <100 μm of the respective sample specimen surface. The EDXRF provided sufficient sensitivity for relative concentrations of K, Ca, and Cl. Element content data of all the elements investigated, specifically K, resulted in adequate plant nutrient element values to diagnose K insufficiency in barley leaves taken from plants in the sewage sludge receiving plots. Potassium was more densely accumulated in the new leaf than in mature and old leaves in case of plants from the S and H plots. In contrast, such K accumulation was more dense in old and mature leaves than young leaves in case of plants from the F plot. However, Cl and Ca coupling in barley leaves from all of the F, S, and H plots had shown the similar pattern of distribution and followed the order: old > mature > young. Therefore, EDXRF can be an easy, rapid, and practical method for diagnosing the elemental content of plant tissues and thereby help to aid plant growth and development through timely supplements of the required element(s). 相似文献
82.
Abstract Green manure legumes are often used to compare biomass production as well as nitrogen-fixing capacity. Mineral deficiency often limits the symbiotic nitrogen fixation of many legumes, thus limiting their productivity despite their high yielding potential (O’Hara et al. 1988; Flis et al. 1993). Leguminous species require large amounts of P for growth, nodulation, and nitrogen fixation. Consequently, they are often unable to grow in acid soils with low available P. The low P availability in tropical acid soils often arises from fixation of P by Al and Fe in soil. Generally, Al and Fe-phosphates are relatively unavailable to plants (McLachlan 1976; Ae et al. 1990). 相似文献
83.
Koji Wada Yasutaka Tsumori Yoshikazu Nitawaki Kazuhiko Egashira 《Soil Science and Plant Nutrition》2013,59(3):313-322
Flocculation tests and permeability measurements were carried out for silt and clay fractions separated from surface and subsurface horizons of four paddy soils. There was not much difference in the flocculating power between A1(OH)2.2C10.8 and CaSO4. Their flocculation value, 0.3 to 3 mM, was attained by adding the reagents at the rate of 0.24 to 2.4 mmol/100 g of the silt and clay. The flocculation with A1(OH)2.2C10.8 or CaSO4 did not affect the sediment volume of the silt and clay. This sediment volume was smaller for the surface than for the subsurface horizons of each soil, suggesting that soil organic matter and repetition of wetting and drying contribute to the stable aggregation of the silt and clay in the surface horizon. The permeability was higher for the silt and clay fractions separated from the surface horizon than that from the subsurface horizon, and the addition of 2.5 to 4.2 mmol of A1(OH)2.2C10.8 or CaSO4/100g of the silt and clay increased its permeability by 1.5 to 4 times. The effect of A1(OH)2.2C10.8 was more lasting than that of CaSO4 and was recognized even after 200 ml of water passed through 1 g of the silt and clay. The effect of the flocculating reagent on the permeability was more or less enhanced by air-drying the treated silt and clay. 相似文献
84.
渠道边坡粘性土渗透系数的变化规律 总被引:1,自引:0,他引:1
就单向渗透固结过程中渗透系数的变化规律进行了探讨,通过对试验所测得的指标进行统计分析,得出了渗透系数k随孔隙比e变化的关系式,并对其精度进行分析。该关系式为水工建筑设计与施工提供了可参考的依据。 相似文献
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86.
木材可压缩流体渗透中滑流的研究 总被引:1,自引:0,他引:1
在气体平均压力倒数为1.4-48atm~(-1)范围内测定了长白鱼鳞云杉和红松木材可压缩流休渗透中滑流效应及影响滑流的因素,论述了木材中流体流动形态和机理。研究表明,两种木材可压缩流体渗透中均产生滑流,但长白鱼鳞云杉中滑流高于红松。前者滑流渗透性与真渗透性百分比、比名义渗透性与真渗透性比、滑流因素分别为69.39%、1.69、0.356atm;后者分别为37.64%、1.376、0.197atm。滑流的大小与木材有效毛细管半径、真渗透性和气体平均压力有高度紧密相关。木材有效毛细管半径愈小,真渗透性愈低,或气体平均压力愈低,则滑流效应愈大。 相似文献
87.
几种重金属离子对高羊茅种子萌发及生理活性的响应 总被引:5,自引:3,他引:2
试验以高羊茅Festuca arundinacea"凌志1号"种子为材料,研究了镉(Cd2 )、铜(Cu2 )、汞(Hg2 )对种子萌发和幼芽细胞膜透性以及其体内过氧化氢酶(CAT)活性的影响.结果表明,0.5和5mg/L Hg2 极显著地促进萌发(P<0.01),50mg/L Cu2 极显著地抑制萌发(P<0.01),500mg/L各离子均显著抑制种子萌发(P<0.05).随处理的质量浓度逐渐增加,幼芽细胞膜透性逐渐增加.0.5mg/L的质量浓度下,Cu2 和Hg2 处理幼芽细胞膜透性显著低于对照(P<0.05);5和50mg/L的质量浓度下,Hg2 处理细胞膜透性最大;500mg/L的质量浓度下,Cu2 处理细胞膜透性最高.幼芽CAT的影响均表现为随质量浓度增加而逐渐升高,在0.5mg/L的质量浓度下,Cu2 处理CAT活性相对较高;在5mg/L的质量浓度下,Hg2 处理CAT活性相对较高;在50mg/L的质量浓度下,Cu2 和Hg2 处理CAT活性相对高于Cd2 处理;在500mg/L的质量的浓度下,Cu2 处理CAT活性相对较高.发芽率与细胞膜透性间存在较强的相关关系,发芽率和细胞膜透性与CAT呈负相关.综合分析几种重金属离子对高羊茅种子萌发的影响,Cd2 对高羊茅的毒害作用最大,Cu2 最小. 相似文献
88.
89.
90.
The current study was conducted to investigate the effect of stocking density (SD) on oxidative stress status and mammary gland permeability in early lactating dairy cows. Thirty‐two dairy cows were allocated into 16 blocks, basing on parity, previous milk yield, and body weight, and were then randomly assigned into one of the two treatments as follows: 75% (75SD) and 100% (100SD) SD. The cows were fed with same diet throughout the 8‐week experimental period. The milk yield and milk sample were collected on two consecutive days during the 8‐week experimental period weekly. Plasma samples were collected on fourth and eighth experimental weeks. Raw, energy‐corrected, and 4% fat‐corrected milk yield were significantly higher in 75SD‐cows than that of 100SD‐animals, respectively. The milk somatic cell count was lower in 75SD‐cows than that of 100SD‐animals. The levels of Na+, Na+/K+, bovine serum albumin and plasmin were lower in 75SD‐cows than those of 100SD‐cattle, respectively. The 75SD‐cows had reduced insulin and insulin/glucagon levels but higher prolactin and growth hormone concentrations, compared with those of 100SD‐animals, respectively. In conclusion, compared with low SD‐animals, early lactating cows with higher SD had higher oxidative stress status, which further led to a greater mammary gland permeability. 相似文献