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71.
经过多年探索和发展,封闭型植物工厂无论在材料、装置和技术都取得了快速进步,生产产量成数倍增长。在介绍发展封闭型植物工厂必要性的基础上,着重分析了封闭型植物工厂的发展现状、设施分类、栽培形式选择、栽培技术选择,最后指出了存在的问题,并对未来的封闭型植物工厂外部设施及其栽培技术进行了展望。 相似文献
72.
The effects of long-term fertilization of acidic soils on ammonia-oxidizing archaea (AOA) and bacteria (AOB) communities and its ecological implications remain poorly understood. We chose an acidic upland soil site under long-term (27-year) fertilization to investigate ammonia oxidizer communities under four different regimes: mineral N fertilizer (N), mineral NPK fertilizer (NPK), organic manure (OM) and an unfertilized control (CK). Soil net nitrification rates were significantly higher in OM soils than in CK, N or NPK soils. Quantitative analysis of the distribution of amoA genes by DNA-based stable isotope probing revealed that AOA dominate in CK, N and NPK soils, while AOB dominate in OM soils. Denaturing gradient gel electrophoresis and clone library analyses of amoA genes revealed that Group 1.1a-associated AOA (also referred to as Nitrosotalea) were the most dominant active AOA population (>92%), while Nitrosospira Cluster 3 and Cluster 9 were predominant among active AOB communities. The functional diversity of active ammonia oxidizers in acidic soils is affected by long-term fertilization practices, and the responses of active ammonia oxidizers to mineral fertilizer and organic manure are clearly different. Our results provide strong evidence that AOA are more highly adapted to growth at low pH and low substrate availability than AOB, and they suggest that the niche differentiation and metabolic diversity of ammonia oxidizers in acidic soils are more complex than previously thought. 相似文献
73.
以无籽刺梨组培苗根尖为材料,探讨其染色体制片技术。结果表明,无籽刺梨根尖在常温下用0.003mol/L8-羟基喹啉溶液预处理6-8h或0.004mol/L8-羟基喹啉溶液预处理4-6h后,在预冷的卡诺固定液(冰醋酸:无水乙醇=3:1中)0℃下处理15min,经95%乙醇:15% Hcl=1:1的解离液处理5min或无水乙醇:36-38% Hcl=1:1处理6min,然后用卡宝品红染色15或20min,其镜检效果较佳;无籽刺梨的染色体数目为2n=2x=14。无籽刺梨染色体制片技术研究及其染色体数目的确定对其遗传改良工作有着重要的意义。 相似文献
74.
农机与农艺紧密结合,对于农业经济发展具有重要意义,是未来农业发展的必然趋势。阐述农机与农艺结合的重要性,分析农机与农艺结合过程中存在的问题,提出加快农机与农艺结合的有效措施,以期为现代农业的发展提供参考。 相似文献
75.
从育苗、定植前准备、定植、田间管理、病虫害防治、采收等方面对农业观光园番茄树京丹六号栽培技术进行总结。 相似文献
76.
WARM is a model for rice simulation accounting for key biotic and a-biotic factors affecting quantitative and qualitative (e.g., amylose content, chalkiness) aspects of production. Although the model is used in different international contexts for yield forecasts (e.g., the EC monitoring and forecasting system) and climate change studies, it was never explicitly evaluated for transplanting, the most widespread rice establishment method especially in tropical and sub-tropical Asia. In this study, WARM was tested for its ability to reproduce nursery growth and transplanting shock, using data on direct sown and transplanted (both manual and mechanical) rice collected in 24 dedicated field experiments performed at eight sites in Jiangsu in 2011, 2012 and 2013. The agreement between measured and simulated aboveground biomass data was satisfactory for both direct sowing and transplanting: average R2 of the linear regression between observed and simulated values was 0.97 for mechanical transplanting and direct sowing, and 0.99 for manual transplanting. RRMSE values ranged from 5.26% to 30.89%, with Nash and Sutcliffe modelling efficiency always higher than 0.78; no notable differences in the performance achieved for calibration and validation datasets were observed. The new transplanting algorithm – derived by extending the Oryza2000 one – allowed WARM to reproduce rice growth and development for direct sown and transplanted datasets (i) with comparable accuracy and (ii) using the same values for the parameters describing morphological and physiological plant traits. This demonstrates the reliability of the proposed transplanting simulation approach and the suitability of the WARM model for simulating rice biomass production even for production contexts where rice is mainly transplanted. 相似文献
77.
Impact of sampling and storage technique,and duration of storage,on the composition of fresh grass when analysed using near‐infrared reflectance spectroscopy 下载免费PDF全文
The objective of this study was to examine the effect of sampling technique (pluck or cut), storage duration (immediate analysis, 24‐h or 48‐h), storage temperature (ambient or chilled) and storage conditions (air present, air excluded or breathable) on the composition of fresh grass sampled from a sward managed to simulate grazing. Treatments were repeated across four sampling dates, with grass samples stored in grip seal bags prior to analysis using near‐infrared reflectance spectroscopy. Grass sampled by ‘pluck’ had a higher crude protein and ME content, and a lower acid detergent fibre (ADF) content, compared to that sampled by ‘cut’. Grass stored for 48 h had a lower water soluble carbohydrate (WSC) and ME content and a higher ADF content than for immediate analysis. Samples stored for 24 h did not differ from immediate analysis. Grass stored at ambient temperature had a lower WSC and ME content compared to immediate analysis. Grass stored under ‘breathable’ conditions had a lower ME content and higher ADF content than immediate analysis or samples stored with air present or air excluded. It is recommended that grass for analysis should be sampled by cutting, stored chilled (4°C) in a sealed bag to minimize exposure to oxygen and analysed within 24 h of harvest. 相似文献
78.
79.
晚稻机收留高茬紫云英迟播技术的应用效果研究 总被引:2,自引:0,他引:2
通过田间试验,研究了双季稻田晚稻机械收获留高茬后紫云英迟播的应用效果。结果表明,与传统紫云英播种技术相比,晚稻机械收获留高茬紫云英迟播显著缩短了紫云英的生育期,但其盛花期能保持与传统播种技术一致,对下茬早稻作物的种植没有影响;两种播种方法对盛花期鲜草产量、植株养分含量和养分积累量均没有显著影响,说明迟播播种能达到与传统播种一样的肥田目的;迟播对紫云英的种子产量及产量构成因素均没有明显影响,与传统播种技术相比可节约劳动力成本约45元/hm2,且可避免传统播种方法对晚稻植株的伤害。在现代双季稻种植条件下,晚稻机械收获留高茬紫云英迟播技术具有较大的优势和发展前景。 相似文献
80.
圣优996系福建科力种业有限公司与南平市农业科学研究所育成的中籼三系杂交稻新品种,2014年通过福建省品种审定。建阳市引进圣优996种植,观察了其主要特征特性,总结出高产栽培技术要点,为大面积推广应用做好技术储备。 相似文献