混菌固态发酵生物饲料的研究

[目的]探讨混菌固态发酵生物饲料的最佳工艺条件。[方法]以玉米粉、豆粕、酒糟为主要原料,通过混料设计确定主要原料的最佳配比,通过单因素和响应面法对混合菌种发酵温度、发酵时间、接种量、含水量、红糖添加量等因素进行研究。[结果]玉米粉的量66%、豆粕量11%、酒糟量23%、发酵温度35℃、发酵时间48 h、红糖添加量5%、含水量43%、接种量9%。[结论]在该条件下获得生物饲料中菌体数量最高。     

高羊茅在吹填土混合基质上种植的优化施肥模型研究

[目的]为脱盐后混合基质的培肥及日后科学、有效地对植物进行养护提供依据。[方法]将吹填土、海砂、电石渣按0.55∶0.40∶0.05体积比混合并脱盐后的混合基质进行盆栽试验,应用二次回归正交设计方法,研究过磷酸钙、牛粪、污泥不同用量对高羊茅的主效应和交互效应与生物量的关系,建立生物量与三因素的回归模型。[结果]污泥是影响生物量的第一位因素,因素间交互效应不明显;通过模拟寻优,高羊茅目标生物量在6.40 kg/m2以上时,过磷酸钙、牛粪、污泥用量分别为21.17～29.64、43.97～76.29、159.11～188.13 g/kg。[结论]吹填土混合基质优化施肥方案,可显著提高高羊茅的生物量。     

沼液复配农药对番茄早疫病病原菌的抑制效果

[目的]探讨沼液复配药剂对番茄早疫病病原菌(Alternaria solani Sorauer)的抑制效果。[方法]将沼液与不同浓度的三唑酮、禾康、易保、霜霉威和井冈霉素进行复配,并分别采用菌丝抑制法和孢子萌发法测定了其对番茄早疫病病原菌的抑制效果。[结果]菌丝抑制法研究显示,霜霉威复配农药抑制效果最为显著,其EC50为3 mg/L。孢子萌发法测定过程中由EC50和EC90可知,5种农药对病原菌孢子萌发抑制效果均不显著,其中禾康和井冈霉素复配沼液的抑制效果相对较好。沼液复配农药较以水为溶剂配制农药的抑制效果显著。5类沼液复配农药对番茄早疫病病原菌菌丝的抑制效果较其对孢子的抑制效果更为显著。[结论]为新型农药的研制提供了参考。     

混合农药防治黄瓜枯萎病效果及稳定性试验

以50%速克灵与72%农用链霉素为试材,用"速克灵+农用链霉素"混合农药对黄瓜枯萎病进行防效试验,并对2种农药复配后的稳定性做测试试验。试验结果表明,"速克灵+农用链霉素"混合农药对黄瓜枯萎病的平均防治效果达96.43%,稳定性较好,值得推广,但生产中防治黄瓜枯萎病时,需在结合农业措施的基础上使用药剂。     

大白菜TuMV抗性的主基因+多基因混合遗传分析

以大白菜抗TuMV品种BP8407的高代自交系和感TuMV品种极早春的高代自交系,抗TuMV品种二青的高代自交系和感TuMV品种春大将的高代自交系配制两个F2群体。以F2群体人工摩擦接种TuMV-C4后的ELISA鉴定的P/N值为抗性鉴定指标,应用P1、P2、F1、F2 4个世代的数量性状主基因+多基因混合遗传分析方法,分析了大白菜TuMV抗性的遗传规律。结果表明：大白菜TuMV的抗性由2对主效基因控制,遗传模型分别为E-1、E-0,主基因遗传率分别为86.51%、77.64%。因此,大白菜对TuMV-C4抗性符合2对主基因+多基因的遗传模式,抗性遗传以主基因为主。     

豆科与禾本科绿肥饲草作物混播增肥及改土效果研究

采用四因素单形重心混料设计,对豆科与禾本科绿肥作物混播增肥改土效果及其混播技术进行研究,结果表明:箭筈豌豆、毛苕子、谷子混播为最佳混播方式,其用种量为箭筈豌豆75.0kg/hm2、毛苕子30kg/hm2、谷子20kg/hm2,在小麦扬花期撒播,鲜草产量可达36138kg/hm2,较单播箭筈豌豆、毛苕子、谷子分别增产34.6%、1.9%、156.3%;鲜根量可达3534kg/hm2,较单播箭筈豌豆、毛苕子、谷子分别增加81.4%、67.2%、28.9%。混播区较单播区土壤有机质含量增加0.148～0.43g/kg,全氮增加-0.04～0.11g/kg,碱解氮增加2.1mg/kg,速效磷增加1mg/kg,全磷基本保持平衡,土壤容重减轻0.01～0.02g/cm3,土壤孔隙度提高0.33%～0.66%。     

香格里拉县云南松林遥感辅助识别特征研究

以香格里拉县云南松林为研究对象,分别从云南松林的空间分布特征、植被指数特征和像元亮度特征三个方面,提取和归纳了云南松林的遥感辅助识别特征,旨在为今后的云南松林遥感分类识别提供方法借鉴。     

Determinants of herbaceous plant species composition on a number of ranches in the north‐western Transvaal

Herbaceous plant species composition was measured on ranches in the Thabazimbi district, Transvaal, to obtain veld composition scores and to quantify the relations between such scores and certain determinants considered important in influencing species composition. Determinants investigated were mean annual rainfall and herbivory (stocking rate). The survey was undertaken on seven game and cattle ranches in Combretum apiculatum woodland of the Mixed Bushveld (Acocks 18) of the north‐western Transvaal. Rainfall for the season preceding the vegetation survey and bulk and selective grazer stocking rates had a significant effect on veld composition scores. The recommended agricultural grazer stocking rate for the survey area is 12.5 LSU 100 ha"¹ a"¹. Under the present conditions and in view of the findings of this survey, it is suggested that a grazer stocking rate of 6.25 LSU 100 ha^?1 a^?1 be implemented.     

Mixed Forests as a Part of Sustainable Forestry in Southern Sweden

Abstract

We review and discuss the applicability of mixed stands in the context of sustainable forestry in southern Sweden. This is done from a silvicultural perspective regarding aspects such as regeneration, pre-commer-cial thinnings, production, economy, damage and policy implications. The paper is based on literature reviews and on studies performed in southern Sweden or under comparable conditions. After considering the underlying mechanisms, we find that it is possible to establish a mixed stand in the regeneration phase and sometimes even to a lower cost compared to monocultures. To keep the mixture, or to create it, with pre-commercial thinnings is, however, often more expensive. The reviewed studies, together with a new simulation, show that the effect on productivity of mixed stands compared to monocultures is minor. Some positive effects on damage (i.e., decreased levels) in mixed stands have been found. The economy and the policy implications of mixed stand management were found to be dependent on the specific stand and situations. A general finding was that research and knowledge of managing mixed stands, as compared to monocultures, are limited, which in turn could limit the applicability of mixed stand management.     

江苏里下河地区鸭鱼共养模式研究

[目的]探讨江苏里下河地区半放养情况下鸭鱼共生比例关系。[方法]通过鸭鱼共养试验测定鸭日排粪量和鱼塘中鸭粪的施肥量,并观测正常养鸭情况下河塘水质情况和鱼的生长情况。[结果]每只鸭每天排出153g新鲜粪。鸭粪中干物质含量为44．83％,全氮含量为1．67％,全磷含量为0．92％,全钾含量为1．62％。采用鸭鱼共养模式可以提高江苏里下河地区养殖的综合效益。[结论]鸭鱼共养模式在江苏里下河地区具有较高的推广价值。