紫云英营养特性、栽培要点和肥效

本文是在国际紫云英学术讨论会上简介的内容。用同位素~(15)N试验表明:紫云英对氮肥的回收率,返青后施用的为71.1％,高于冬前施用的32.1％;植株的养分和吸收的标记氮肥约3/5分布在茎叶中;dff值表明,在花序、顶心、绿叶生理功能旺盛器官,比茎干和衰老器官低,说明生物固氮或土壤供氮对紫云英功能器官发育的重要性。植株N/P_2O_5比值表明,紫云英对于磷肥的反应不敏感。紫云英北移后的生态环境不同于南方,栽培技术要点归纳为接菌、早播、密植、灌水和施肥。配合施用磷肥能有效地提高绿肥肥效,使每公斤绿肥氮增产稻谷从5.2公斤提高到11.2公斤。     

不同还田条件下稻田紫云英氮素释放规律及效应

[目的]探明不同还田方式下紫云英氮素释放规律,为合理施用紫云英、减少化肥用量提供依据。[方法]采用网袋腐解方法,结合田间水稻试验,定量研究紫云英在不同还田条件下氮素释放规律、效应。[结论]在紫云英腐解的不同时期,翻压量始终是影响紫云英氮素释放的重要因素,而是否施肥、移栽水稻对紫云英氮素的腐解释放也起重要的调节作用。在大田试验中,紫云英供氮处理的肥效在翻压前期弱于纯化肥,中期强于纯化肥,最终对水稻生长发育无显著影响。     

紫云英氮磷钾肥最佳施用量研究

采用"3414"肥料效应试验设计方案进行田间试验,对紫云英氮、磷、钾肥效应以及肥料的交互作用进行了分析,并筛选出适宜的氮、磷、钾肥用量。结果表明:施用氮肥紫云英增产效果最好,鲜草增产量最高达21.1 t/hm2,增产率为158.6%;施用磷肥增产量为10.8 t/hm2,增产率为81.1%;而施用钾肥增产效果不显著。在本试验条件下,中磷、中钾水平最适宜氮肥肥效的发挥,中氮、中钾水平最适宜磷肥肥效的发挥,中氮、中磷水平最适宜钾肥肥效的发挥。通过肥料效应模型拟合,得到本试验条件下种植紫云英的肥料适宜用量为N 60.2 kg/hm2、P2O549.4 kg/hm2和K2O 64.2 kg/hm2。     

跨季节种植紫云英适宜播期的选择

湖南省长沙地区紫云英的播种时间一般为9月上旬至10月中旬,为了探索春、夏季播种紫云英效果,确定适宜播种期,试验设立3月7日、4月8日、5月11日、6月12日、7月13日5个播期,对其主要形态指标、生理指标及产草量进行比较。结果表明:3月7日播种的紫云英能量积累较差,植株矮小,产草量相对较低;4月8日播种的紫云英受温度胁迫作用较小,株高、根长、根重等形态指标较佳,个体发育较好,产草量最高;5月11日、6月12日和7月13日3个播期的紫云英受到不同程度高温胁迫,表现为株高降低,根长缩短,根重减小,在生理指标方面表现为叶绿素含量降低,可溶性糖含量和相对电导率升高,尤其是7月13日播种的紫云英受高温胁迫最大,播种后45d出现干枯、死亡现象。因此,湖南长沙地区跨季节播种紫云英以4月8日为宜。     

化肥减量条件下不同施用方法对土壤养分有效性及水稻产量的影响

大田试验条件下,采用裂区试验研究了翻压紫云英后化肥减量施用条件下不同施肥方法对土壤养分有效性及水稻产量的影响。结果表明:翻压紫云英22500kg/hm2后,配施80%化肥,底肥:分蘖肥:穗肥=5:5:0,与习惯施肥方法相比,早稻和晚稻收获后土壤中有效氮分别平均增加5.6%和9.8%;而底肥:分蘖肥:穗肥=3:4:3更有利于提高有效K含量,分别平均增加8.9%和13.2%;配施60%化肥,按底肥:分蘖肥:穗肥=5:5:0施肥显著增加早稻收获后土壤中有效K含量,增幅为27.1%;肥料全部用作分蘖肥时降低晚稻或早稻收获后土壤有效N、K含量;配施60%～80%化肥,早稻和晚稻产量均以施肥方法底肥:分蘖肥:穗肥=0:7:3最佳。     

不同施肥处理与接种根瘤菌对黄泥田紫云英产量及养分吸收累积的影响

研究了福建黄泥田施用种肥、苗肥和接种根瘤菌及其组合对紫云英产量、有机C及养分吸收累积的影响.结果表明,施肥显著提高了的紫云英枝茎长度与根瘤数量,各施肥处理鲜草产量、干物质产量分别较CK增幅81.2％～162.6％,45.8％～101.1％,分别达极显著与显著增产水平;各施肥处理有机C累积量与养分累积量分别较CK增幅51...     

Oil from Calanus finmarchicus—Composition and Possible Use: A Review

The long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are produced by phytoplankton in the marine food web. Zooplankton acts as an important link between phytoplankton and fish at higher trophic levels and may therefore be a potential source for these fatty acids. The copepod Calanus finmarchicus is a lipid-rich zooplankton present in large amounts in the North Atlantic Ocean. The astaxanthin-rich oil contains 80–90 % wax esters consisting of mainly long-chain monounsaturated fatty alcohols esterified to saturated or unsaturated fatty acids. The long-chain n-3 fatty acids may account for 20–30% of the fatty acids in the wax esters. The wax ester rich oil is well utilized by fish, and the history of utilization, safety, and tolerability of wax esters for humans are being addressed. Recent reports indicate that oil from C. finmarchicus may have beneficial health effects beyond those which may be ascribed to intake of EPA and DHA alone.     

Modelling the dispersal of Calanus finmarchicus on the Newfoundland Shelf: implications for the analysis of population dynamics from a high frequency monitoring site

We investigated the drift of passive particles on the Newfoundland Shelf and western Labrador Sea using numerical simulations to assess the possible sources of plankton collected at a high frequency sampling site (S27; 47.55°N, 52.59°W) located near the coast of Newfoundland, Canada. We also summarized data detailing the seasonal stage succession of Calanus finmarchicus at that site, as well as along three oceanographic sections sampled in the spring, summer and autumn across the adjacent continental shelf. Simulations indicated that the Labrador and Newfoundland Shelves represent the major sources of particles transiting through the S27 site, with relatively minor contributions from the western Labrador Sea which are significant during a few months each year. The latter point may be affected by uncertainty in the representation of cross‐shelf transport associated with seasonal or short‐term variations in atmospheric and oceanic forcing, which may also affect the strength and location of bifurcation of the inner branch of the Labrador Current around the Grand Banks. Nevertheless, our results indicated that drift along the inner shelf is likely to be the primary source of copepods collected at S27 throughout most of the year. This in turn suggested that there may be a higher degree of connectivity between conditions in coastal areas of Newfoundland and those in Baffin Bay and west Greenland than with the southern half of the Labrador Sea.     

绍兴县紫云英品种（系）比较试验

[目的]筛选适宜绍兴县种植的紫云英品种。[方法]以宁波大桥和江西余江为供试品种,设2个播量处理,分别对2个品种物候期、株高和鲜草产量进行比较分析。[结果]宁波大桥为迟熟品种,江西余江为中熟品种;相同播种量宁波大桥株高均高于江西余江,同一品种播种量为22.5 kg/hm2的植株高于播种量30.0 kg/hm2的植株;2个品种盛花期鲜草产量都达到18 000.0kg/hm2以上。[结论]绍兴县南部山区可以迟熟品种宁波大桥为主,北部平原稻田以中熟品种江西余江为主。