稀植大穗型玉米品种的品比试验

通过对13个稀植大穗品种的品比试验研究,得出了在山西北中部不同生态区如何选择、推广稀植大穗品种的结论:山西北中部平川区高水肥地宜推广种植忻玉106、晋单48号、新45、天塔1号;丘陵旱作区宜推广种植晋单48号、大丰2号、农大364、强盛12号、泽玉4号;在利用秸秆贮青的养殖区宜选用天塔1号、新45,可以粮饲兼顾,收益更高;生产玉米用于加工淀粉可选用晋单48号;连续种植玉米的地块慎选沈单16号、大丰2号、强盛17号、晋单45号、泽玉4号,避免感染丝黑穗病而造成减产。     

日光温室塑料棚膜透光率比较

试验通过对阿拉尔地区普遍使用的塑料棚膜透光率的测定,分析比较了不同棚膜透光率及其在不同光照条件下的季节变化规律,旨在为日光温室冬季生产合理选择塑料棚膜提供参考依据。     

武汉市彩色马铃薯品种比较试验

为了筛选出适应武汉市种植的彩色马铃薯品种(系),对11个马铃薯品种(系)进行了田间种植和主要农艺性状的鉴定。试验结果表明,08CA0847表皮和薯肉均为红色,颜色鲜艳,产量高,抗虫性强;华薯4号的芽眼为紫色,产量高,植株生长势强,抗虫性中等;华薯5号薯肉深黄,植株生长势强,产量高,抗虫性中等。这3个品种(系)在表皮或者薯肉颜色上富有特色,观赏价值高,综合性状优良,适合在武汉地区种植推广。     

红掌组培苗两种生根培养方法的比较研究

对红掌组培中组培苗两种生根法(传统的瓶内生根与瓶外直接生根法)进行了比较研究。结果表明:两种生根法各有优劣。传统的瓶内生根技术有利于组培苗的生根,提高了苗的生根率、长势和移栽成活率及苗的质量;瓶外直接生根则有利于降低红掌组培的生产成本,提高组培苗的产量和缩短苗的生产周期。     

甘肃张家川阴湿地区紫花苜蓿品比试验研究

通过对12个紫花苜蓿品种的产量、生长速度、越冬性、鲜干比、抗病虫害等方面的比较试验,结果表明阿尔冈金鲜草产量最高达41.57 t/hm2,其次为THG-1,兼用型FD3,天水苜蓿鲜草产量最低,仅为30.37 t/hm2;生长速度,越冬率,鲜干比等指标,筛选出的品种表现较好,且与对照天水苜蓿差异显著(P<0.05),因此,适宜于在当地种植的紫花苜蓿品种依次为THG-1,兼用型FD3,阿尔冈金,金皇后,多叶。     

A comparison between multivariate Slash, Student's t and probit threshold models for analysis of clinical mastitis in first lactation cows

Robust threshold models with multivariate Student's t or multivariate Slash link functions were employed to infer genetic parameters of clinical mastitis at different stages of lactation, with each cow defining a cluster of records. The robust fits were compared with that from a multivariate probit model via a pseudo‐Bayes factor and an analysis of residuals. Clinical mastitis records on 36 178 first‐lactation Norwegian Red cows from 5286 herds, daughters of 245 sires, were analysed. The opportunity for infection interval, going from 30 days pre‐calving to 300 days postpartum, was divided into four periods: (i) ?30 to 0 days pre‐calving; (ii) 1–30 days; (iii) 31–120 days; and (iv) 121–300 days of lactation. Within each period, absence or presence of clinical mastitis was scored as 0 or 1 respectively. Markov chain Monte Carlo methods were used to draw samples from posterior distributions of interest. Pseudo‐Bayes factors strongly favoured the multivariate Slash and Student's t models over the probit model. The posterior mean of the degrees of freedom parameter for the Slash model was 2.2, indicating heavy tails of the liability distribution. The posterior mean of the degrees of freedom for the Student's t model was 8.5, also pointing away from a normal liability for clinical mastitis. A residual was the observed phenotype (0 or 1) minus the posterior mean of the probability of mastitis. The Slash and Student's t models tended to have smaller residuals than the probit model in cows that contracted mastitis. Heritability of liability to clinical mastitis was 0.13–0.14 before calving, and ranged from 0.05 to 0.08 after calving in the robust models. Genetic correlations were between 0.50 and 0.73, suggesting that clinical mastitis resistance is not the same trait across periods, corroborating earlier findings with probit models.     

商丘地区彩色马铃薯引种试验

通过对9个彩色马铃薯品种进行品种比较试验,筛选出适合商丘地区种植的彩色马铃薯品种。结果表明,紫罗兰、诺兰、中薯6号和黑美人4个品种薯形好,品质优,产量高,较抗病,适宜商丘地区种植。特别是紫罗兰、诺兰产量分别比对照增产10.30%和2.65%,均达极显著水平,可作为主推品种。中联红、花云2号、紫云1号、云3458和夏LX-70不适宜商丘地区种植。     

8个西瓜品种在海南地区棚栽的适应性比较

[目的]通过8个西瓜品种的品比试验,筛选出适合海南省种植、推广的棚栽西瓜品种。[方法]以主栽品种＂早佳＂为对照,对比参试品种的生物学性状、产量、质量及综合抗（耐）性等基本属性。[结果]无籽西瓜品种帅童、蜜童表现较好,各方面极显著或显著地优于对照和其他供试品种,适合在海南省大面积推广;小玉红、神武4号则表现一般,有待于进一步试验、重估;而甜童、小贵、神武1号和神武2号表现最劣,不适于在海南省推广种植。[结论]筛选出了帅童和蜜童2个优良品种。     

Comparison of Soil Clean-up Standards for Trace Elements Between Countries: Why do they differ? (9 pages)

Goal, Scope and Background

In the nineteen nineties most European countries issued legislation on soil protection, including soil contamination. In the case of a presumed contamination, soil investigation mostly follows a stepwise approach starting with a preliminary investigation, then an in-depth investigation and, finally, remediation. Soil clean-up standards are often foreseen as trigger criteria to determine the need for an in-depth soil investigation or for remediation. There are however large differences in soil clean-up standards. This is partly because of the different roles of soil clean-up standards in each legislative framework and partly because of differences in the soil clean-up standard (SCS) derivation procedures. Despites these differences there are large similarities in the concepts of the derivation procedures for clean-up standards. A better understanding of the differences in clean-up standards is needed. In order to clarify the variation, the background of the clean-up standards for a selected number of countries was investigated. The objective of this paper is to investigate the underlying reason why country-wide generic soil and groundwater clean-up standards of eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) differ between the selected countries.

Main Features

To avoid misinterpretation of the differences in application of the clean-up standards, a short overview of the legislative role of clean-up standards is given first. Differences in model concepts and parameter values are discussed, followed by a comparison of the generic soil and groundwater clean-up standards for trace elements and a discussion on the sources of variation. The influence of the use of ecotoxicological criteria and data for the derivation of soil clean-up standards will be discussed in more detail. Selected countries were Canada, the Flemish Region (Belgium), France, Germany, Great-Britain, the Netherlands, Norway, Sweden, Switzerland and United States of America (USA).

Results and Discussion

When soil clean-up standards for eight trace elements (cadmium, chromium (III), copper, mercury, lead, nickel, zinc and arsenic) were compared between the selected countries differences of more than a factor 1000 arose. Notwithstanding the use of similar derivation procedures, differences were caused by the use of different software models with their specific input data, boundary conditions and applied protection criteria for humans and the ecology. Ecotoxicological criteria tend to lower the soil clean-up standard for the selected trace elements.

Conclusions

In the countries that are included in this study, clean-up standards are used is different ways, this is for the determination of the necessity for remediation or for the need for further soil investigation. This paper shows a wide variation in the clean-up standards, which has further implication on the decision for remediation or further investigation and, hence, the financial costs of soil management. All the clean-up standards have as primary goal the protection of human health. A number of countries also include the protection of the ecological function of the soil. Differences in selected software model, (standard) parameters values, selected human toxicological and ecotoxicological criteria, are reason for a substantial variation in the clean-up standards for trace elements.

Recommendations and Perspective

. Is this variation justified? The derivation of soil clean-up standards involves - besides scientific elements - political elements, like differentiation in landuse types (agricultural, residential, recreational, industrial), receptor at risk or protection level. It is obvious that harmonization of these elements will be complicated. However, a European action programme, like the thematic strategy for soil protection, could initiate this process of harmonization. Nevertheless, soil-clean-up standards could never be uniform over the whole of Europe because they include country specific elements (geographical, ethnological) and political decisions.     

海峡两岸粮食政策与制度比较

海峡两岸尽管政治制度和经济发展模式不同，但由于粮食问题在国计民生中所处的特殊地位，几十年来两岸始终将粮食问题置于社会与经济发展的首位。大陆地区的粮食政策与制度在近半个世纪的历程中走过了艰难曲折的发展道路，取得了显著的成绩，也有明显的失误。同样，台湾地区的粮食政策与制度也经历了反复的波折与探索，有丰富的经验和教训。两者在一些方面有很大的相似性，而在某些方面却有很大的差异，有许多做法是可以相互学习和借鉴的。