景观艺术中花岗石的应用实例分析与建议

结合花岗石的主要特性对花岗石的应用实例进行了分析,结合花岗石的命名、特性的分析,及对花岗石使用实例及所选38种石材的聚类分析,提出了科学的花岗石命名方法及分类使用建议。也希望通过这些分析,为花岗石的景观设计者和施．工人员提供一些更多地选择与思路,丰富设计的材料及手法。     

抚顺县大豆“3414”田间试验结果初报

以大豆为供试作物,采用二次回归3414设计,分析氮磷钾肥对大豆生长发育的影响。试验结果表明:氮磷钾肥对大豆有明显的增产效果。采用回归分析方法,探讨氮磷钾肥的合理施用量,章党镇的最佳施肥量为:N3～3.5kg/667m2、P2O52.7～2.8kg/667m2、K2O4～4.2kg/667m2;兰山乡的最佳施肥量为:N3kg/667m2、P2O54.5kg/667m2、K2O4.5kg/667m2。     

引黄灌区合理补偿农业成本水价对策研究

合理补偿农业成本水价是提高灌区经济收入、保证灌区实现良性运行、促进灌区可持续发展的根本,对于保障国家粮食生产安全,推动农业的可持续发展具有非常重要的现实意义。选择河南省人民胜利渠引黄灌区为试点,开展合理补偿农业成本水价综合对策和措施研究。对人民胜利渠灌区农业水价的成本构成和水费征收方式进行了研究,分析了水费征收中存在的主要问题,在此基础上,提出了合理补偿农业成本水价的综合对策与措施。研究成果对于合理计算农业成本水价、保证灌区正常运行、进一步提高引黄灌溉的社会经济效益具有一定的参考价值。     

Effect of supplementation with grain, hay or straw on the performance of weaner Merino sheep grazing old man (Atriplex nummularia) or river (Atriplex amnicola) saltbush

Old man saltbush ( Atriplex nummularia ) and river saltbush ( A. amnicola ) are widely used in commercial grazing systems on saline land in south-western Australia. Three hypotheses were tested during a 3-year study aimed at understanding the performance of weaner Merino sheep grazing saltbush-based pastures. The first hypothesis, that young Merino sheep grazing river saltbush would be better able to maintain live weight, body condition and would grow more wool than sheep grazing old man saltbush, was not supported by the data. Across the 3 years of the study, sheep grazing old man saltbush lost significantly less live weight and grew more wool (proportionately 0·06) than sheep grazing river saltbush. Differences in animal performance were considered to be associated with differences between the plant species in in vitro digestibility, concentrations of fibre, sulphur and crude protein in the herbage and the architecture of the Atriplex plants. The second and third hypotheses concerned supplementation strategies for sheep grazing saltbush. Three supplements were offered, namely barley grain, cereal straw or cereal hay, at a rate that approximated to one-third of the daily metabolizable energy requirements for maintenance of live weight. The performance of the sheep was higher when the grain supplement was offered but there was no effect of feeding roughage supplements compared to no supplementation. The findings suggested that the practice of feeding saltbush with adjacent crop stubbles is unlikely to be beneficial once any fallen grain has been consumed.     

Effect of altering the grazing interval on growth and utilization of grass herbage and performance of dairy cows under rotational grazing

The effects of short grazing intervals in the early part of the grazing season on the growth and utilization of grass herbage, and the performance of grazing dairy cows, in a rotational grazing system were examined. Seventy-six cows were allocated to two grazing treatments: a normal rotation treatment (20-d rotations for the first 60 d) and a short rotation treatment (12-, 8-, 8-, 8-, 12- and 12-day rotations). Thereafter, both treatments had the same grazing interval and over the season as a whole both treatments received the same amount of nitrogen fertilizer and were stocked at the same rate. The short rotation treatment significantly reduced pre- and post-grazing sward heights and pre-grazing herbage mass in May and June. Total herbage production was significantly lower on the short than the normal rotation treatment as a result of a significant reduction in the growth rate of herbage in May and June. The short rotation treatment had a significantly lower milk output per cow. Grazing shorter swards, as a result of shorter rotations, significantly reduced herbage intake, reflecting reductions in intake per bite, grazing time and total bites per day. Treatment had no significant effect on herbage quality or pre- and post-grazing sward height in August and September, despite the increased grazing severity in May and June with the short rotations. The severity of rotation length in this instance had a detrimental impact on animal performance, whereas a more modest reduction in grazing interval may control herbage production, without reducing animal performance.     

Effect of frequency of application of inorganic nitrogen fertilizer within a rotational paddock-grazing system on the performance of dairy cows and inputs of labour

As herd sizes and labour costs increase, and the availability of skilled labour decreases, efficient use of available labour becomes more important in dairy cow systems. Two experiments were conducted to examine the effect of reducing the frequency of application of inorganic nitrogen (N) fertilizer on inputs of labour and performance of dairy cows. Experiments 1 (duration of 169 d) and 2 (duration of 179 d) involved fifty-eight and forty multiparous Holstein–Friesian dairy cows, respectively, in mid-lactation. In each experiment, in the 'infrequent' treatment fertilizer was applied to all paddocks on a single occasion at the start of each grazing cycle, while in treatment 'frequent', fertilizer was applied on three occasions each week, within 2 or 3 d of each paddock having been grazed. The experimental treatments were started from 30 March and 29 March in Experiments 1 and 2 respectively. Total N application rates were approximately 360 and 250 kg N ha⁻¹ in Experiments 1 and 2 respectively. Concentrate feed (4·0 kg per cow) was offered daily in both experiments. With the 'infrequent' treatment, highest concentrations of crude protein and nitrate in herbage were observed in swards grazed approximately 10 d after N fertilizer was applied. Treatment had no significant effect on milk yield, milk fat and protein concentrations, and final live weight and body condition score of cows in either experiment. Milk urea and plasma urea concentrations were not significantly affected by treatment. Calculated application times of fertilizer for a herd of 100 dairy cows were 107 and 83 min week⁻¹ for the 'frequent' and 'infrequent' treatments respectively.     

春季禁牧对内蒙古草原植被的影响

2002年春季进行禁牧与自由放牧的对比研究。结果表明,春季禁牧对草原植被的群落特征具有十分显著的影响;在禁牧区,植被产草量、盖度、高度和密度等与自由放牧区之间差异显著(P<0.05)。春季禁牧有利于草原植被的可持续利用。同时,禁牧期的长短对草原植被也有一定的影响,但是不显著。     

加入WTO后资源保育与农村新风貌建立之探研

加入WTO之后SARS时代,诸多问题有待调整,有效措施及转型焦点将有新的水准。在此时代是资源合理利用之重新评定,为保育性资源利用之重点契机,农地转化为休闲农业后,农村新风貌应如何建造,为今后共同所关心的问题,惟有一理想是可坚信的,就是凡有合理利用资源,以及拥有清静环境与美丽山川之国土者,必是未来之强国,有待同心协力建造。     

土地利用规划管理信息系统的设计研究

针对土地利用规划工作的需要,土地管理必须走信息化的道路,必须充分利用日益完善的地理信息系统技术,以提高管理的效率。设计的土地利用规划管理信息系统,可以大大地提高榆林地区土地管理工作的现代化和科学化决策水平,改善土地利用中存在的问题,其社会效益和经济效益十分显著,具有广阔的市场推广应用前景。     

Mathematical models of population dynamics of the kelp Laminaria religiosa, with emphasis on temperature dependence

Theoretical and numerical models were developed to investigate the effects of water temperature on the population dynamics of the kelp, Laminaria religiosa . The models describe seasonal changes in the biomass of kelp by calculation of growth and grazing rates of sea urchins, Strongylocentrotus nudus . Using the theoretical model, conditions were obtained to satisfy the statistical analysis of a relationship between water temperature and kelp harvests from a fishery census. The conditions require the negative second derivative of the growth rate with respect to temperatures, or the positive second derivative of the grazing rate. By using the numerical model, harvests of kelp were calculated for a change in water temperature over a given period. The period of a temperature change giving the maximum effects on the harvest was determined primarily by temperature dependence on the growth rate. Grazing by sea urchins had large effects on the harvest of kelp. A value of 10⁴ was obtained for a ratio between harvests at the higher and the lower temperatures differing by ± 1^∘C.