苗期不同营养液处理对草莓产量形成的影响

在ＤＦＴ栽培条件下，研究了草莓苗期不同营养液处理对定植后草莓产量形成的影响。试验结果表明，苗斯断肥处理能增加草莓前期产量和总产量，苗期营养液浓度１．０ｍＳ／ｃｍ较０．５ｍＳ／ｃｍ有利于草莓产量形成。试验结果还表明，不同草莓品种对苗期营养液具有相同的适应性，草莓品种春香宜作为水培草莓品种。     

镉处理对绿豆种子萌发及蛋白质含量的影响

采用室内试验方法，研究了不同浓度的Cd^2＋溶液对绿豆种子萌发及蛋白质含量的影响。结果表明，当Cd^2＋溶液浓度低于20mg/L时，种子的发芽率不受Cd^2＋溶液浓度的影响；当Cd^2＋溶液浓度低于10mg／L时，种子的发芽指数不受Cd^2＋溶液浓度的影响；与对照相比。种子的活力指数与发芽势随着Cd^2＋浓度的增加而下降。种子内的蛋白质含量随着Cd^2＋溶液浓度的提高而升高，而蛋白酶活性和自由氨基酸的含量均下降。     

洪泽县主要作物施肥动态及对策

通过调查10年来洪泽县小麦、油菜和水稻3种主要作物的施肥动态，寻求提高3种作物生产水平的合理施肥结构和用量。     

刚体平面运动的矢量导数解和矩阵解

一般而言,在理论力学的运动学中,平面运动刚体的平面图形上各点的速度与加速度的主要求解方法与计算公式,是应用运动的分解与合成─Ｃｈａｓｌｅ运动叠加定理导出的。本文作者应用矢量导数直接导出上述公式,并且在矢量导数的定型公式基础上建立相应的定型矩阵公式,使此类问题的求解简明便捷,又能应用矩阵的ＦＯＲＴＲＡＮ程序,使用日趋普及的现代化电脑进行运算。     

日本的营养液栽培现状及其新技术

该文从营养液栽培的发展规模、投资费用、营养液栽培方式等方面介绍了日本营养液栽培的现状、存在的问题及发展方向。在营养液管理方面，已发现单纯依靠检测电导率EC值控制营养液浓度的弊端，提出应针对各种离子的营养液浓度进行管理；各种废液的处理方法和营养液循环利用中去除病原菌和生长阻害物质的方法。分析了各种方法的利弊。最后该文详细介绍了日本营养液栽培的新技术——移动栽培和营养液土耕的基本原理，主要方法和效果。     

绿肥轮作还田对稻田土壤溶液氮素变化及水稻产量的影响

通过研究利用绿肥等改变轮作制度及N素管理后稻田土壤溶液中溶解性N素的动态变化及水稻产量的变化,评价了利用绿肥参与水稻轮作系统,减少无机N肥的施用量,促进水稻生长的同时降低环境负荷的可行性。研究表明,在总N量相当的情况下,冬绿肥还田或冬季休闲稻季土壤溶液中NH4 -N浓度均比稻麦轮作单施化肥的处理低。溶液NO3--N浓度随还田有机物料的C/N增加显著降低。利用豆科紫云英轮作还田,可降低44％的无机N肥用量,溶解性N浓度显著降低,是减小稻季N肥流失环境风险的有效途径。     

Molybdenum reserves of seed,and growth and N2 fixation by Phaseolus vulgaris L.

Summary Plants grown from seed with high (1.5–7.3 g Mo seed^-1) and low (0.07–1.4 g Mo seed^-1) Mo contents were grown in the presence and absence of Mo in growth media (perlite) or in a flowing-solution culture, in a controlled environment. Neither the high (1.5 g Mo seed^-1) nor the low (0.1 g Mo seed^-1) Mo content in seed from a small-seeded genotype (BAT 1297) was able to prevent Mo deficiency (reduced shoot, root and nodule dry weight, N₂ fixation and seed production) in growth media without an external supply of Mo, whereas both the high (7.3 g Mo seed^-1) and the low (0.07 g Mo seed^-1) contents in seed were able to prevent Mo deficiency in a large-seeded genotype (Canadian Wonder). Responses to Mo treatment by the Two genotypes were inconsistent between the growth media and solution culture experiments. Seed with a large Mo content (3.5 g Mo seed^-1) from the Canadian Wonder genotype was unable to prevent Mo deficiency (reduced shoot and nodule dry weight and N₂-fixation) in a solution culture without an external source of Mo, whereas both the large (1.7 g Mo seed^-1) and the small (0.13 g Mo seed^-1) contents in seed prevented a deficiency in BAT 1297. Growing plants from seed with a small Mo content, without additional Mo, reduced the seed Mo content by 83–85% and seed production by up to 38% in both genotypes. Changes in seed size and increases in shoot, root and nodule dry weight occurred, but varied with the genotype and growth conditions. These effects were also observed in some cases where plants were grown with additional Mo, demonstrating that the amount of Mo in the seed sown can influence plant nutrition irrespective of the external Mo supply. Nodule dry weight, total N content of shoots and seed production were improved by using seed with a small Mo content (1.64–3.57 g Mo seed^-1) on acid tropical soils in Northern Zambia. Plants of both the large- and small-seeded genotypes grown from seed with a small Mo content (<1.41 g Mo seed^-1) had a smaller nodule weight, accumulated less N and produced less seed. The viability of seed with a small Mo content was lower (germination up to 50% less) than that of seed with a large Mo content.     

基于水量平衡原理的畦灌水流推进简化解析模型研究

畦灌水流推进过程计算模型对确定灌水技术要素、田间平均入渗率和糙率有十分重要的作用。该文依据水量平衡模型，分析畦灌下渗水形状系数、地表储水形状系数的变化规律，结果表明下渗水形状系数受地表水推进过程中的推进距离和时间的幂指数影响很小，可用一个稳定值代替，由此建立了基于水量平衡原理的畦灌水流推进简化解析模型。结合已有文献资料和田间试验对模型进行检验，表明该模型具有计算求解方便、精度较高的优点，可用于畦灌合理灌水技术指标的确定。     

Irrigation with plant extracts in ecofarming increases biomass production and mineral and organic nitrogen content of plants

Seedlings of alfalfa, rape, spinach, and wheat, potted on sandy soil, were irrigated with an aqueous extract of pea shoot (PE, 9.84 g dry weight l^–1) or a solution of Ca, K, Mg, P, and NO₃‐N salts (SS) in a concentration similar to that in PE, for 31–48 days. In comparison to water‐irrigated controls, both SS and PE treated plants showed nearly equal increases in shoot dry weight (29–40 %), whereas PE‐treated plants had higher fresh weights (38–84 %) due to increased succulence. Treatment with SS did not enhance, but sometimes even reduce, the concentrations of Ca, K, Mg, and several trace elements in shoot tissues. In contrast, PE‐treated plants had higher Ca, K, Mg, and organic N, but lower As and Ni contents and were thus of higher nutritive value. Reduced contents of metals in plant tissue correlated with their reduced solubility in the soil solution, which was not due to changes in pH. Fertilizer components such as K and Mg (metals of lower exchange intensity) were incorporated into the soil to release Ca, Sr, and Ba (metals of higher exchange intensity) and reduce the solubility of most trace elements and metal‐complexing humic substances. In addition, application of Ca precipitated heavy metals and humic complexes directly from the soil solution. This effect was partially overcome by PE. Its carboxylic acids could act as phytochelators of metal ions and as mobilizers of the highly diffusible humic substances which carry metals to roots. It is concluded that continuous PE application replaces the quantities of Ca, K, Mg, P, and organic N, but not of NO₃‐N consumed during plant growth. Using PE does not add any relevant quantities of toxic metals to the plant‐soil system.