江苏南通棉花水浮育苗与营养钵育苗比较试验

棉花水浮育苗技术是采用多孔聚乙烯泡沫育苗盘为载体，以混配基质为支撑，以营养液水体为苗床，进行漂浮育苗的综合技术，是棉花栽培中一项育苗新技术。2009年江苏省南通市如东县丰利镇农业技术服务站进行了该技术的试验。现将试验小结如下：     

棉花漂浮育苗技术探讨

在阐述棉花漂浮育苗方法的基础上,分析了棉花漂浮育苗的优点,包括省工时、省种子及育苗操作简单等,并提出了育苗过程中易出现的问题及预防措施。     

棉花漂浮育苗技术的优势及注意事项

棉花漂浮育苗技术是一种全新的棉花育苗方法,采用多孔聚乙烯泡沫育苗盘为载体,以混配基质为支撑,以营养液水体为苗床进行漂浮育苗的一种新技术.     

烤烟漂浮育苗技术研究现状及展望

从育苗基质、育苗盘、营养液及控苗技术等方面综述了烤烟漂浮育苗技术的研究成果及现状,提出了烤烟漂浮育苗技术需要继续研究改进的问题。     

江苏大豫镇棉花大棚穴盘育苗技术与实践

棉花塑膜大棚穴盘育苗技术是一种轻便、省工、省力的新型棉花育苗方式，顺应了当前棉花生产向轻简化方向发展的要求，解决了棉花营养钵育苗费时、费力的问题。本文具体介绍了棉花塑膜大棚穴盘育苗技术的操作方法，发展前景以及在实际生产中出现的一些问题，并提出了解决办法。     

棉花对营养液漂浮育苗适应能力的评价方法研究

 研究比较了29个棉花品种营养液漂浮育苗的适应能力。对棉苗素质的分析结果表明,在12个形态指标中,根系干重的变异系数最大,根系平均直径的变异系数值最小,根系干重可作为评价不同基因型品种漂浮育苗适应性的重要指标。主成分分析表明,第一主成分为根重因子;第二主成分为棉苗地上部鲜重和苗高因子;第三主成分为根长因子;第四主成分为根粗因子。上述4个主成分的累积方差贡献率达到84.5%,反映了营养液漂浮育苗适应能力相关性状的绝大部分变异信息。通过聚类分析,将不同基因型品种营养液漂浮环境适应能力分为3类。     

石河子地区棉花水浮育苗移栽技术

棉花水浮育苗技术是湖南农业大学陈金湘教授研究发明的棉花育苗新技术。是以营养液水体为苗床进行的漂浮育苗技术．是棉花耕作栽培的一项新技术。在一定的光热条件下用常规栽培模式已经很难使棉花的产量得到较大提高．棉花育苗移栽技术可以使棉花在特定环境下的光热资源得到充分利用．延长棉花有效铃期,避开棉苗受开春低温、霜冻、冰雹等天气影响．从而提高棉花品质与产量．     

赣北棉区两种棉花育苗方式的比较试验

通过在赣北棉区设置棉花小拱棚基质穴盘育苗与营养钵育苗移栽方法的比较试验，分析其移栽质量和效益的差异，旨在探索适用赣北丘陵地区种植棉花的最简育苗方法。结果表明，小拱棚基质穴盘育苗方法虽然比营养钵育苗方法省工、省力、效率高，但相对棉农分散种植育苗来说，并不是一种简单经济的育苗方法，而结合工厂化育苗，实行产业发展，才能降低成本，实现其应有的经济效益。     

漂浮育苗盘孔数和微生物菌剂对长叶龄烟苗生长的影响

为明确漂浮育苗盘孔数和微生物菌剂对长叶龄烟苗生长发育的影响,以云烟87为材料,采用双因素试验,设计136孔和200孔2种规格育苗盘和添加微生物菌剂、不添加微生物菌剂2种基质处理,比较分析不同处理烟苗的根系性状指标、根系活力、地上部生长和干物质积累量,并采用η²值对育苗盘孔数、微生物菌剂及其互作对烟苗生长的影响进行评价。结果表明：采用136孔育苗盘和基质中添加微生物菌剂有利于烟苗根系和地上部生长,促进烟苗干物质积累;136孔育苗盘可促进烟苗主根伸长,提高根系活力,增加烟苗茎粗以及地下部分干物质积累;添加微生物菌剂可促进烟苗根尖数增加,促进烟叶生长以及干物质积累。育苗盘孔数、微生物菌剂及其互作对烟苗根系生长的贡献率分别为48.47%、33.37%、18.16%,对烟苗根系活力的贡献率分别为44.07%、40.88%、15.05%,对烟苗地上部生长的贡献率分别为42.50%、49.25%、8.26%,对干物质积累的贡献率分别为43.84%、44.61%、11.57%。因此,采用136孔漂浮育苗盘配合添加微生物菌剂的基质可促进烟苗的生长发育,有利于培育8～10叶龄的长叶龄...     

5种棉花育苗移栽方法的比较研究

试验采用应用较广、影响较大、代表性较强的5种棉花育苗移栽技术进行比较研究。结果表明：棉花种子发芽率和出苗率,以疏松透气的无土基质育苗最高,有土育苗较差,水浮育苗最差;棉苗生长速度以水浮育苗最快,次为有土育苗,但无土基质育苗较慢;棉苗素质以有土育苗较好,无土基质育苗较差。棉苗的移栽效果上,无土基质穴盘育苗的成活率最高,缓苗期最短,营养钵育苗次之,3种无土（裸根）移栽的较差。从技术的稳定性和可靠性看,营养钵和穴盘育苗较好。     

转基因作物基因流及其基因污染的研究进展

本文综述了转基因作物以及转基因作物带来的基因流及其基因污染的研究现状，并讨论了转基因作物基因流和基因污染所带来的问题，提出了一些建设性的对策与建议。     

糖厂新型糖浆上浮提高白砂糖质量的应用研究

本文介绍了新型糖浆上浮工艺特点及自控原理,结合英茂糖业有限公司景真糖厂的应用实践,对糖浆的色值、混浊度、纯度以及产品质量等指标的改善情况进行了分析,并针对新型糖浆上浮工艺与产糖率的关系问题进行了浅析.     

Effect of swaying motion of floating vegetation on wind-induced entrainment phenomenon in closed water body

When floating vegetation grows on the water surface in a closed water body, the vegetation counteracts the magnitude of the wind acting on the water surface, and affects the fluid flow and the water quality variation in it. In this study, in order to investigate the counteraction effect of the luxuriant growth of floating vegetation on the fluid flow and water quality in the closed water body, we conducted hydraulic experiments on wind-induced flow with density stratification using a wind tunnel test tank and imitated vegetation. We used imitated vegetation made from polystyrene foam plates instead of using real floating vegetation. And we experimentally considered the effect of the vegetation using the concept of the wind-induced entrainment phenomenon. In particular, we focused the effect of the occupation rate and the swaying motion of vegetation. The results indicated that the swaying motion of imitated floating vegetation had an effect on the scale of entrainment. In addition the results had the same tendency as the previous study on the wind-induced entrainment phenomenon.     

Effects of physiological age and floating plastic film on tuber dry-matter percentage of potatoes,cv. Record

Summary Two experiments investigated the effects of five physilogical ages with and without a floating plastic film on the growth, yield and tuber dry-matter percentage of cv. Record. Samples were taken over a period that represented the early range of harvest dates used in crops destined for crisp manufacture. Plastic film increased final tuber numbers in one experiment but otherwise tuber numbers were not affected by treatments. Tuber yield was incrased by plastic film until August and by advancing physiological age until early July. Within each experiment, tuber drymatter percentage was largely a function of yield. During the main period of tuber bulking, there was a linear relationship between tuber dry-matter percentage and the mean fresh weight of tubers >30 mm when the data from both experiments were combined.     

Controlled-release fertilizer,floating duckweed,and biochar affect ammonia volatilization and nitrous oxide emission from rice paddy fields irrigated with nitrogen-rich wastewater

It is of great concern that nitrogen-rich (N-rich) wastewater irrigation increases ammonia (NH₃) volatilization from rice (Oryza sativa L.) paddy fields. A pilot-scale field trial was conducted to study the impact of different management practices on reducing NH₃ volatilization and their subsequent impacts on nitrous oxide (N₂O) emission from a paddy field irrigated with N-rich wastewater generated by livestock production and supplemented with urea N fertilizer. A total of 225 kg N ha^?1 combined with urea and N-rich wastewater was split into basal, the first, and second supplementary applications for the following five treatments: urea N mixed with controlled-release N fertilizer (BBF), floating duckweed (FDW), biochar alone (BC), biochar mixed with calcium superphosphate (BCP), and control with no amendment (CK). Results showed that each treatment had similar pattern of NH₃ volatilization and N₂O emission after N application. Treatments of BBF, FDW, and BCP effectively reduced NH₃ losses by 22.8, 55.2, and 39.2 %, respectively, compared with the CK. BBF treatment decreased NH₃ volatilization after the first supplementary N fertilization; BCP treatment reduced NH₃ volatilization after the basal fertilization; and FDW treatment reduced NH₃ volatilization after both the basal and first supplementary fertilization. Besides controlling the NH₃ volatilization, BCP treatment also reduced 19.5 % of N₂O loss. However, BC alone suppressed N₂O emission by 24.3 %, but did not reduce NH₃ loss. The findings can practically guide farmers to choose the appropriate management practices in improving N use efficiency and minimizing the impact of fertilization on environmental quality.     

The effect of floating vegetation on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from subtropical paddy fields in China

Duckweed (Lemna minor), a floating macrophyte belonging to the Lemnaceae family, is commonly found in subtropical paddy fields. This plant rapidly takes up nutrients from water and forms dense floating mats over the water surface that may impact the biogeochemical processes and greenhouse gas production in paddy fields. In this study, we measured CH₄ and N₂O emissions from duckweed and non-duckweed plots in a subtropical paddy field in China during the period of rice growth using static chamber and gas chromatography methods. Our results showed that CH₄ emission rate ranged from 0.19 to 26.50 mg m^?2 h^?1 in the duckweed plots, and from 1.02 to 28.02 mg m^?2 h^?1 in the non-duckweed plots. The CH₄ emission peak occurred about 1 week earlier in the duckweed plots compared to the non-duckweed counterparts. The mean CH₄ emission rate in the duckweed plots (9.28 mg m^?2 h^?1) was significantly lower than that in non-duckweed plots (11.66 mg m^?2 h^?1) (p < 0.05), which might be attributed to the higher water and soil Eh in the former. N₂O emission rates varied between ?50.11 and 201.82 µg m^?2 h^?1, and between ?28.93 and 54.42 µg m^?2 h^?1 in the duckweed and non-duckweed plots, respectively. The average N₂O emission rate was significantly higher in the duckweed plots than in the non-duckweed plots (40.29 vs. 11.93 µg m^?2 h^?1) (p < 0.05). Our results suggest that the presence of duckweed will reduce CH₄ emission, but increase N₂O flux simultaneously. Taking into account the combined global warming potentials of CH₄ and N₂O, we found that growing duckweed could reduce the overall greenhouse effect of subtropical paddy fields by about 17 %.     

豫北优质大豆产业发展策略

针对豫北地区的大豆生产现状，从气候、土壤、品种、生态因素及市场需求等方面提出了优质大豆的发展策略与途径。     

吉林省平安农业科学院大豆所大豆研究工作报告

1　吉林省平安农业科学院大豆研究工作简介吉林省平安农业科学院大豆研究所 ,设在吉林省长春市西安大路种子大厦内。现有科技人员 6人 ,其中研究员 2人 ,农艺师 2人 ,技术员 2人 ,定向培养研究生 2人。大豆研究所的主要任务是选育稳产、高产、优质及抗病虫大豆新品种 ;同时密切     

Comparisons of methods of scheduling irrigations of potatoes

Irrigation of Netted Gem potatoes was scheduled during three growing seasons by three methods: (a) when plants displayed first visual symptoms of moisture stress, (b) when indicated by a soil moisture budget involving estimated evapotranspiration, and (c) on the basis of tensiometer readings of soil moisture suction. When the tensiometer method of scheduling was used, the mean yields of tubers were 55.0 and 25.8 cwt/acre (6160 and 2890 kg/ha) higher than those obtained with the other two scheduling methods. Methods did not affect the specific gravity of potatoes. Method (a) scheduled irrigations least frequently. Scheduling by the budget method was not always adequate because it was based on the assumption that the crop extracted water from a constant 4 ft (1.2 m) profile from planting to full vegetative growth. In one year the budget method scheduled the first irrigation earlier than necessary and delayed the second irrigation during a critical period of crop growth. From full vegetative cover to harvest the irrigation schedules were alike for both the budget and tensiometer methods.