富钾硅复合物的农业化学行为研究

富钾硅复合物中硅、钾、钙、镁养分的可溶性含量很高,但其有效态的养分含量却相对较低,故其养分只能缓慢地释放出来。在5个月的贮存过程中,多元复合物的水分含量对其养分的有效性没有明显的影响,但其养分含量却经历了一个明显的变化过程,其中可以用Freundlich方程拟合钾、镁的变化规律。多元复合物中硅、钾、钙、镁4种养分元素的释放速率随时间的延长而逐渐下降。     

Rekonstruktion des Paläomilieus und der Geo‐Pedogenese kalkfreier Marschböden Niedersachsens

Reconstruction of the paleo‐environment and geopedogenesis of non‐calcarous marshland soils (Eutric Gleysols) of Lower Saxony The genesis of non‐calcarous marshland soils is still controversially. For clarification, the paleo‐environments of two Eutric Gleysols were reconstructed by using X‐ray fluorescence spectroscopy, light microscopy, and scanning electron microscopy. Profile 1 shows seven facies. The diatom composition reveals paleo‐environments variable in time with lacustrine, brackish, and marine conditions. Pyrite was found at the transition of clastic material and peat and within the peat, indicating together with frequently found small Zr:Al and Si:Al ratios and small Ca:Sr ratios calm, brackish, and lagoonal sedimentation conditions with reed‐peat formation. Profile 2 shows two facies; their transition is very sharp and characterized by a sudden change in diatom composition, geochemical quality, and carbonate contents. The diatom flora and Ca:Sr ratios of the lower facies reveal a tidal creek habitat with a connection to the sea and exceptional small Si:Al and Zr:Al ratios. The results, particularly for many facies of profile 1, suggest a decalcification during geopedogenesis. Two genetic phases of this decalcification are therefore likely for today non‐calcarous marshland soils, either during early geopedogenesis or during later terrestrial development.     

山区半山区稻瘟病流行区硅肥的抗病增产效果研究

 在山区半山区缺硅多病(稻瘟病)水田进行了施硅肥效果的研究。7年间多点试验结果,施硅使稻瘟病病情指数下降54.6%.平均增产21.5%.亩增稻谷45.8公斤;试验还表明,在这类水田.因受低洼制约,增氮效果难以期望.但以增硅为基础,增氮效果则可正常发挥,所以提高这类水田供硅能力,是实现增肥(N)增产的基础。据此认为,施用硅肥是提高山区半山区多病水田生产力的一项基本措施。     

Silicon fractions in Histosols and Gleysols of a temperate grassland site

The importance of silicon (Si) in nutrition is currently being recognized by its beneficial effects on many crops. Therefore, it is important to determine the soil Si status and to examine different extractants for testing plant‐available Si. Little information is available about the Si status of Histosols and C_org‐rich Gleysols in temperate climate. This study was undertaken (1) to characterize different Si pools in C_org‐rich groundwater soils of an experimental site and (2) to study the influences of small‐scale variability on element distribution. At the experimental site, the thickness of the C_org‐rich layer ranges between 4 and 5 dm overlying fine‐sandy fluvial sediments. Four extractants were evaluated: 0.01 M CaCl₂, 0.5 M acetic acid, 0.1 M sodium pyrophosphate, and 0.1 M Tiron (C₆H₄Na₂O₈S₂ · H₂O). Further, total element content was determined following HNO₃/HF digestion. Calcium chloride–soluble Si shows no significant relations to other parameters analyzed. On the basis of published data, the soils investigated could be classified as Si‐deficient. The Si fraction extracted with acetic acid displays relations to C_org content of the soil and a weak correlation to CaCl₂‐soluble Si, indicating that both solutions extract overlapping but not the same fractions. Sodium pyrophosphate extracts mainly organo‐mineral Fe and Al complexes in the soils studied, which is reflected in a highly positive correlation to C_org. Pyrophosphate‐soluble Si showed a negative relationship to C_org, which means a closer relation of this Si fraction to mineral matter than to C_org. The Tiron solution extracted most Si of all extractants, but this amounts only 1% of the total Si content. Taking into account the element‐specific relationship between pyrophosphate and Tiron‐extractable Fe, Al, and Si, it can be concluded that Tiron dissolves mainly the opaline silica present in Histosols and C_org‐rich Gleysols. The distribution of C_org and ash content shows clear spatial trend at the experimental site, which is correlated to pyrophosphate‐extractable as well as total Si. This small‐scale variability of soil parameters itself is related to a distinct microrelief.     

Effects of water and exogenous Si on element concentrations and ecological stoichiometry of plantain (Plantago lanceolata L.)

Silicon (Si) is widely distributed in nature and can promote plant growth under various biotic and abiotic stresses. Drought stress seriously affects plant growth and the concentration and ecological stoichiometry of nutrients. Integrated nutrient management effectively protects plants from stresses. However, the role of water and Si availability on element concentrations and stoichiometry in plantain (Plantago lanceolata L.) are unclear. Accordingly, this study observed changes in the concentration and stoichiometry of macro- and micro-elements in plantain leaves supplied with various levels of Si under variable water availabilities through a greenhouse experiment. Supplemental Si increased Si concentration of leaves under both well-watered and drought conditions. Without supplemental Si, drought conditions decreased concentrations of carbon (C), C: nitrogen (N), C: phosphorus (P), silicon (Si):N, Si:P and increased concentrations of N, P, N:P, Si:C, calcium (Ca²⁺), magnesium (Mg²⁺), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). Increased Si under water stress increased concentrations of C, C:N, C:P, Si:C, Si:N, and Si:P, and decreased concentrations of Ca²⁺, sodium (Na⁺), and Mg²⁺. These results suggested that exogenous Si changed the concentrations and ecological stoichiometry of macro- and micro-elements.     

Silicon Effect on Nutrient Acquisition of Peanut (Arachis hypogaea L.) Under Aluminum Stress

Aluminum (Al) toxicity represents one of the main yield-limiting factors for crops in acid soils. Silicon (Si) is known to increase tolerance in higher plants. This study was conducted to determine whether treatment with Si could improve nutrient uptake by peanut under Al stress. Peanut (Arachis hypogaea L. cv Zhonghua 4) was raised with or without Si (1.5 mM) in the growth chamber under 0 and toxic Al (0.3 mM) levels. Aluminum stress significantly decreased the root- and total-dry weight by 52.4% and 32.0%, respectively. The content of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) was significantly decreased, but that of Al increased markedly in shoots and roots after Al exposure at seedling, flower-needle, and pod-setting stage. Silicon alleviates Al toxicity in peanut plants in relation to Al distribution and allocation of tissue P, K, Ca, and Mg by favoring the partitioning of dry mass to roots.     

六盘水市烟田土壤有效硅含量与空间分布特征

要 ：[目的] 分析六盘水市烟田土壤有效硅含量与空间分布,指导硅肥合理施用。[方法] 2020年烤烟移栽和施肥前,在六盘水市钟山、盘州和水城三个烟区分别采集100、220和180个烟田耕层土壤(0~20 cm),测定有效硅含量,评价其丰缺情况；绘制有效硅含量空间分布图,分析其空间分布特征。[结果] 三个烟区烟田土壤有效硅含量介于18.86~754.71 mg/kg,平均含量介于260.88~403.80 mg/kg,均属高级别(≥150 mg/kg)；三个烟区高硅烟田占比介于83.33%~99.09%；有效硅含量由西向东呈降低趋势,低硅烟田(<100 mg/kg,仅占1.4%)集中分布于水城烟区的中部。有效硅含量与pH(p<0.01)、有机质含量(p<0.05)和粘粒含量(p<0.05)之间均呈显著正相关,与粉粒含量(p<0.05)之间呈显著负相关。[结论] 六盘水市绝大部分烟田不需施用硅肥,缺硅烟田可考虑施用硅肥或通过改酸和提升土壤有机质等措施间接提升土壤硅素的有效性。     

不同盐分条件下硅对两个高羊茅品种生物量分配和营养元素氮、磷、钾吸收利用的影响

频繁的灌溉，使人工草地的高羊茅生长在盐渍化或潜在盐渍化环境中。硅可以抑制植物对Na⁺的吸收，增加对N、P和K⁺的吸收，从而提高植物的耐盐性，且这种影响因植物种类和品种的不同而不同。本研究采用盆栽试验，研究了不同程度盐生境下施硅对两个高羊茅品种（抗性弱的K31和抗性强的XD）生物量和植株N、P、K⁺、Na⁺含量的影响。结果表明，随着盐浓度的增加，两个高羊茅品种地上和地下生物量、N、P、K⁺含量降低，Na⁺含量增加。施硅对地上和地下生物量、N、P、K⁺、Na⁺含量的影响与盐浓度有关，在中低盐浓度下，施硅增加了高羊茅的地上、地下生物量、根冠比、N、P、K⁺ 含量、K⁺/ Na⁺ 值，降低了Na⁺含量。高盐浓度时，施硅对高羊茅的生物量和N、P、K⁺、Na⁺含量没有影响。施硅对两个高羊茅品种地上和地下生物量、Na⁺、P含量的影响相似，对K⁺、N含量的影响不同，硅对耐盐性较强的XD地上部K⁺及N含量的有利影响优于耐盐性较弱的K31。结果表明，在低中盐浓度条件下，施硅可以促进高羊茅的生长，并且对耐盐性较强的高羊茅品种XD更为有利。