日光温室连作黄瓜根际微生物区系的变化

[目的]研究黄瓜再植病害的发生机理。[方法]选择种植年限分别为13、、5、7和8年的日光温室,采集0~20 cm根区耕层土壤,测定微生物类群和数量。[结果]连续种植5年的土壤中微生物数量最多,达2.2×108cfu/g（干土）;8年的最少,为2.7×107cfu/g（干土）。细菌占微生物总量的97%以上。随连作年限的增加,细菌和放线菌数量表现出先增加后减少的趋势,第5年达到最大值,分别为2.17×108和1.92×106cfu/g（干土）;真菌数量随连作年限的增加呈增长趋势。随连作年限的增加,氨化细菌、固氮菌和纤维素分解菌数量呈现先增加后降低的趋势,分别在连作5、3和3年达到最大值,而硝化细菌数量随连作年限的增加急剧下降。[结论]黄瓜连作显著地改变了根际微生物区系。     

GRP新型温室覆盖膜温热特性的研究

为解决现有温室塑料覆盖膜使用寿命短、变光性能差、造价高的问题, 研制成功了经济耐用、变光性能优的GRP新型覆盖材料。在实验基础上, 运用现代数理统计方法, 初步分析了GRP温室覆盖材料的温热特性, 防雾和防滴性能及对栽培作物产量的影响。结果证明, GRP膜具有良好的温热性与保温性, 在最低气温条件下, 试验温室室内最低气温比对照温室室内气温高2℃, 而最高气温均为32℃; 在阴天, GRP膜的增温效果较EVA膜好,最好时比对照温室内气温高3 30℃。另外, 在实验期间, 试验温室从未见过起雾, 滴水也很少, 说明新材料具有良好的防雾、防滴性能。因此, GRP膜对作物生产具有明显的增产效应, 与对照温室相比, 增产幅度高达16 2%。     

Dense planting with less basal nitrogen fertilization might benefit rice cropping for high yield with less environmental impacts

Dense planting and less basal nitrogen (N) fertilization have been recommended to further increase rice (Oryza sativa L.) grain yield and N use efficiency (NUE), respectively. The objective of this study was to evaluate the integrative impacts of dense planting with reduced basal N application (DR) on rice yield, NUE and greenhouse gas (GHG) emissions. Field experiments with one conventional sparse planting (CK) and four treatments of dense planting (increased seedlings per hill) with less basal N application were conducted in northeast China from 2012 to 2013. In addition, a two-factor experiment was conducted to isolate the effect of planting density and basal N rate on CH₄ emission in 2013. Our results show that an increase in planting density by about 50% with a correspondingly reduction in basal N rate by about 30% (DR1 and DR2) enhanced NUE by 14.3–50.6% and rice grain yield by 0.5–7.4% over CK. Meanwhile, DR1 and DR2 reduced GWP by 6.4–12.6% and yield-scaled GWP by 7.0–17.0% over CK. According to the two-factor experiment, soil CH₄ production and oxidation and CH₄ emission were not affected by planting density. However, reduced basal N rate decreased CH₄ emission due to it significantly reduced soil CH₄ production with a smaller reduction in soil CH₄ oxidation. The above results indicate that moderate dense planting with less basal N application might be an environment friendly mode for rice cropping for high yield and NUE with less GHG emissions.     

不同蜂授粉对设施草莓产量和品质的影响

通过比较熊蜂和蜜蜂对大棚栽培草莓的授粉效果试验得出,与蜜蜂相比,熊蜂的出巢时间早,工作时间长,趋光性差,撞棚膜现象发生少,且饲喂简单,饲料投入量少。采用熊蜂授粉的草莓平均产量可达16708.5kg/hm2,比采用蜜蜂授粉的棚增产35.0%;熊蜂授粉草莓单果质量为8.28g,比采用蜜蜂授粉的增加58.6%,差异显著;熊蜂授粉的草莓糖度为11.68%,蜜蜂授粉的草莓糖度为11.29%,差异不显著;熊蜂授粉的草莓畸形果率平均比蜜蜂授粉的低67.9%,差异显著。试验结果进一步说明了熊蜂比蜜蜂更适合用来进行设施草莓授粉。     

晨雨生物有机肥对大棚黄瓜的增产效应研究

通过温室大棚试验,研究了晨雨生物有机肥在黄瓜上的应用效果。结果表明:在同等价格下,合理施用晨雨生物有机肥作基肥,大棚黄瓜公顷产量可达到93831kg,与等基质发酵肥料和有机无机配施相比,增产率分别为27.71%和17.47%,且黄瓜品质、植物学性状以及土壤理化性状均有不同程度的改善和提高。由此可见,晨雨生物有机肥作为一种优质高效肥料可以大面积推广使用,有着良好的经济效益和生态效益。     

套袋·反光膜和棚膜对桃果实大小的影响研究进展

在参考大量文献的基础上,综述了套袋、反光膜和棚膜对桃果实大小的影响,以期为进一步开展相关研究和生产较大果实提供依据.重点对不同类型果袋对果实大小的影响进行了分析,讨论了套袋后果实单果重变化的几种情况及原因分析、不同类型果袋对果实大小的影响及棚膜对果实大小影响的复杂性,并建议进一步系统开展套袋对果实大小影响的研究.     

施肥对日光温室土壤微生物与酶活性变化的影响

在日光温室内,采用田间试验的方法,研究不同施肥处理对西红柿土壤酶活性和土壤微生物数量的影响。结果表明:施有机肥、化肥、有机肥 叶面肥处理土壤磷酸酶活性增加,施化肥 叶面肥处理比施化肥处理土壤磷酸酶活性增加;施有机肥处理土壤脲酶活性增强;施化肥 叶面肥处理土壤磷酸酶活性比施有机肥 叶面肥处理降低;施肥对蔗糖酶和过氧化氢酶活性的影响较小。施有机肥处理土壤细菌、真菌和放线菌数量增加,施化肥处理土壤细菌数量降低,土壤真菌和放线菌数量增加。     

Modeling and implementing the use of aeration to increase water temperature and dissolved oxygen in greenhouse aquaculture cages

In this study, an unique bamboo floating cage was built in order to heat the water used for rearing Nile tilapia (Oreochromis mossambicus x O. niloticus) and climbing perch (Anabas testudineus, Bloch) in Northern Thailand during the colder rainy and winter seasons. This special greenhouse fish cage (SGFC) was covered with polyethylene to heat the surface air with solar energy, and insulated to prevent heat loss. The water temperature at depths of 0.1, 0.3 and 0.8 m was modeled and measured. In various trials, the cages were aerated with and without heated air from the surface. It was found that the thermal efficiency of the SGFC integrated with hot air aeration at a water depth of 0.80 m was 32.65 %. Throughout the day, the average water temperature was 31.82 ± 0.68 °C, which was 0.76 °C higher than the water temperature outside the experiment, and the amount of oxygen in the water of 11.35 ± 0.13 mg/l. The SGFC can produce one extra fish harvest per year when compared with regular fish cages. Development equations to describe the thermal model were used for predicting the water temperature in the SGFC and thus validating the model. Moreover, the economic analysis of the SGFC found that the payback period was one year, seven months and fourteen days.     

Energy and resource consumption of land-based Atlantic salmon smolt hatcheries in the Pacific Northwest (USA)

This paper evaluates the resource and energy requirements of six different types of land-based, hatchery production systems located in the U.S. Pacific Northwest: flow-through with a gravity water supply, flow-through with a pumped water supply, flow-through with pure oxygen, partial reuse system, partial reuse with heating, and a reuse system for the production of Atlantic salmon (Salmo salar) smolts. Key parameters used in the evaluation include direct energy, indirect energy, transportation energy, greenhouse gas emissions, and pollutant discharges.Power (electricity and natural gas) and feed energy accounted for the majority of the required energy for all the rearing option evaluated. The sum of the fixed capital and chemicals components accounted for less than 2–12% of the total energy budget for any rearing option. The energy efficiency (energy output/energy input) of the six options ranges from 0.97% for flow-through with pumped supply to 3.49% for the flow-through with gravity supply. The rearing options with the three highest energy efficiencies were flow-through with gravity supply (3.49%), partial reuse (2.75%), and reuse (2.64%).On a kg of smolt produced basis, the six rearing options showed a wide range in performance. The reuse system had the lowest water (2 m³ kg^− 1) and land (0.13 m² kg^− 1) requirements and the third lowest total energy requirement (288 MJ kg^− 1). The partial reuse system had the second lowest total power requirement (276 MJ kg^− 1), a low land requirement (0.21 m² kg^− 1), and moderate water requirements (33 m³ kg^− 1). The partial reuse with temperature control had the second highest total power requirement (657 MJ kg^− 1) and land and water requirements similar to the partial reuse system without temperature control. The flow-through system with pumped water supply had the highest water (289 m³ kg^− 1), land (2.19 m² kg^− 1), and energy requirements (786 MJ kg^− 1) of any of the rearing options. By comparison, the flow-through system with gravity water supply had the lowest energy requirement (218 MJ kg^− 1), a moderate land requirement (0.78 m² kg^− 1), and a high water requirement (214 m³ kg^− 1). The ranking of the six rearing options based capital and operating costs are likely to be quite different from those based on energy, water, and greenhouse gas emissions.