蜂胶复合制剂对心脏活动的影响

利用蜂胶乙醇提取液与中药甘草、芍药配伍的复合制剂为实验材料,以牛蛙为实验对象,通过在体蛙心运动描记法和离体蛙心灌注(斯氏法),探讨了蜂胶对蛙心活动的影响〔1〕。实验结果表明:两者均能使心肌收缩力加大,而心律变化不大,从而增加心输出量。这一作用以复合蜂胶制剂更为明显,而且这一作用在一定浓度范围内呈量效正相关,即随着浓度升高而作用增强。通过本制剂与经典递质乙酰胆碱(Ach)、肾上腺素(E)和受体阻断剂心得安、阿托品等作用对照,提示本制剂的强心作用不是通过激动β1受体,而可能是通过抑制M受体起作用,也可能是肌源性的。     

不同灌溉和施肥方式对杂交稻生长和根际环境的影响

对杂交稻中优218不同灌溉方式和氮肥管理下水稻生长和根际环境的变化进行研究,结果表明,水稻好气灌溉条件下各施肥处理产量均高于传统灌溉处理,产量比淹水灌溉增产10.5%~11.3%,主要表现在每穗粒数增加而提高产量。好气灌溉与淹水灌溉比较各生育期地上部干物重和叶面积指数均增加,土壤氧化还原电位提高,放线菌数量显著增加。增加有机肥降低土壤氧化还原电位和提高放线菌数量,在好气灌溉条件下施相同氮素有机肥放线菌数多于化肥。     

灌溉模式对烤烟不同生育期光合特性的影响

为探寻烤烟节水灌溉优化模式,采用避雨控水试验研究9种灌溉模式对烤烟不同生育期光合特性的影响。结果表明,伸根期灌溉控制下限为60%田持能显著提高该期烤烟净光合速率,并能显著促进烤烟旺长期净光合速率提高;成熟期灌溉控制下限为60%田持较70%田持更有利于提高该期烤烟净光合速率和叶片水分利用效率;推断"伸根期-旺长期-成熟期"灌溉下限为"60%-70%-60%"田持的灌溉模式在9种模式中为提高烤烟全生育期净光合速率的最优模式。     

光照强度对光伏抽水灌溉系统性能的影响

为掌握光照变化对无蓄电池光伏灌溉系统运行特性的影响,搭建光伏灌溉系统开式试验台,试验测量了不同光照强度下的系统性能.试验结果表明:较低光照强度下喷头工作压力、射程随光照强度增大而增大,较高光照强度下随光照强度上下波动,射程变化趋势与工作压力变化趋势一致,但旋转周期变化趋势与工作压力呈相反规律;喷头工作压力变化趋势与光伏水泵出口压力、光伏组件输出功率变化趋势一致;光照强度1 000 W/m²附近系统运行参数达到阈值,喷头射程与工作压力最大值分别为9.8 m和0.44 MPa,水泵流量与出口压力最大值分别为1.68 m³/h和0.45 MPa;未达到阈值前,影响水泵与喷头运行的主要因素是光照强度,运行参数变化幅度较大,达到阈值后影响因素主要为光照强度和温度,运行参数变化幅度较小;较低光照强度下,组合平均喷灌强度随着光照强度增大而增大;较高光照强度下,组合平均喷灌强度随着光照强度上下变化,与光伏组件输出功率的变化趋势一致;随着光照强度增大,喷头喷灌均匀系数和分布均匀系数逐渐趋近最高值,喷灌均匀系数最高达到88%.     

引黄灌区不同肥料类型和施肥技术对稻田氮磷流失的影响

为减少引黄灌区稻田退水导致的农业面源污染,寻找水稻稳产和环境友好的最佳结合点,研究了大田示范条件下不同肥料类型和施肥技术对稻田田面水和排水沟退水氮磷变化特征的影响。结果表明,与常规施肥处理比较,优化施肥和侧条施肥均可以显著降低稻田田面水和排水沟中TN质量浓度,其中以侧条施肥处理效果最好,田面水和排水沟中TN质量浓度仅为常规施肥的47.4%和34.3%,各施肥处理间田面水和排水沟中TP质量浓度变化差异不显著。优化施肥和侧条施肥处理在肥料减量的条件下水稻产量并没有降低,其中有机种植处理产量最低,相对产量仅为常规处理的73.5%。综合考虑水稻产量和环境因素,优化施肥和侧条施肥技术可以作为环境友好型施肥技术在引黄灌区进行推广。     

棉花调亏灌溉的生态生理效应

在人工控制试验条件下 ,采用子母盆栽土培法 ,以棉花为试验材料进行了调亏灌溉试验研究。结果表明 ,棉花调亏灌溉是可行的 ,可以实现节水、高产和高效的目标。适时适度的水分调亏显著抑制蒸腾速率 ,而光合速率下降不明显 ,复水后光合速率又具有超补偿效应 ,光合产物具有超补偿积累 ,且有利于向棉铃运转与分配 ;抑制营养生长 ,促进生殖生长。棉花调亏灌溉的适宜指标是 :苗期轻、中度调亏 ,0～ 40 cm土层湿度控制下限为田间持水量的6 0 %或 5 0 %;蕾期轻度调亏 ,0～ 40 cm土层湿度控制下限为 6 0 %;花铃期不宜调亏 ,应保证充足供水 ,0～ 40 cm土层湿度应不低于 75 %;吐絮期可中度调亏 ,0～ 40 cm土层湿度可控制在 5 0 %～ 5 5 %。     

Water Requirements of Safflower Entries in Middle Egypt

Two promising selected land races of safflower ( Carthamns tinctorious L.) designated as line 11 and line 13, together with the local variety Giza 1 , were examined under three levels of moisture depletions, i.e. 40, 60 and 80 % ASMD at Fayoum, Middle Egypt during 1986/87 and 1987/88 seasons. In both growing seasons, the second irrigation treatment i.e. 60 % ASMD gave the highest means for growth characters as well as seed yield and most of its components. Seed oil content per cent exhibited an increased as soil moisture depletion increased with no significant difference between entries. Safflower entries showed clear differences in some yield components which compensate each other and resulted in no significant difference in seed yield per hectar.
Consumptive use of water by safflower plants increased as the available soil moisture around the root zone increased. No significant differences were found in water consumed by safflower entries used in all experiments.
In the two experimental seasons, the best water use efficiency (WUE) for seed production was obtained also from the second treatment (60 % ASMD). The line 11 gave the best WUE.     

中国中温带农区种养结合型农业科技园区模式研究

根据区域特点和农业科技园区发展要求,研究概述了我国中温带地区种养结合型农业科技园区模式的生成、特征、类型及实施,为区域农业科技园区发展提供了依据和借鉴。     

农业灌溉用水价格改革探讨

目前我国农业用水存在诸多问题，水资源供需矛盾十分突出。为此，通过我国水价变革情况、水价实施种类的分析，提出了农业灌溉用水价格调整的原则，以促进水资源的可持续开发和利用。     

Economic feasibility of growing capsicum crop under drip irrigation in West Bengal, India

Drip irrigation system has been one of the technical means to improve water use efficiency. In India, this system is gaining popularity among fruit growers and in water scarced area but a substantial area is being covered annually under vegetables crops. One of the major concerns raised by farmers about this system is its economic viability. In present study, the economic viability of drip irrigation system for growing capsicum crop based on discounted cash flow technique (Net present worth and Benefit cost ratio) was explored. Eight irrigation treatments were laid under drip with and without plastic mulch. The irrigation levels were taken as 1, 0.8 and 0.6 of the crop evapotranspiration. The pan evaporation method was used for estimation of reference evapotranspiration and Water Balance Approach was used for irrigation scheduling. The average amount of water supplied under treatment VD (100% irrigation requirement supplied with drip) was found to be 415 mm for whole growing season of the crop. Similarly the amount of water was found to be 332 mm and 249 mm for the treatment 0.8VD (80% irrigation requirement supplied with drip) and 0.6VD (60% irrigation requirement supplied with drip) respectively. Highest yield was recorded in case of treatment VD + PM (100% irrigation requirement supplied with drip plus plastic mulch) followed by VD. Yield under treatments 0.8VD, 0.6VD, 0.8VD + PM and 0.6VD + PM were significant while treatments VD, VF and VF + PM were at par with the treatment VD + PM. Net Present Worth (NPW) was found to be positive for all the treatments. The highest NPW was obtained under treatment VD as Rs. 309,734.90 and lowest was in case of 0.6VD + PM as Rs. 144,172.24. The yield per mm of water used was reported to be at higher side as 35 in both the treatments VD and VD + PM. But the yield per mm of water used was found to be lowest as 18.07 and 19 in case of VF and VF + PM respectively.