Nitrate leaching losses under Miscanthus grass planted on a silty clay loam soil

Abstract. Nitrate leaching under newly planted Miscanthus grass was measured for three years. The crop received either no fertilizer-N or an annual spring application of 60 kg or 120 kg N ha^-1. During three winters soil water was collected from porous cup probes installed 90 cm deep. Nitrate leaching was calculated from the mean drain flow recorded in two drain gauges multiplied by the mean nitrate-N concentration in the soil water solutions collected. In the first year soil water nitrate concentrations were high on all treatments and N losses were 154, 187 and 228 kg ha^-1 respectively on the unfertilized treatment and those that received 60 or 120 kg N ha^-1. Leaching losses in the second and third years were, in turn, 8, 24 and 87 kg ha^-1 and 3, 11 and 30 kg ha^-1 for the unfertilized treatment and for the 60 and 120 kg N ha^-1 treatments respectively. Leaching losses were closer to those recorded under extensively managed grassland than arable land. The large losses in the first year were probably due to the previous agricultural management at the site and excessive inputs of N on the fertilized plots. In the second and third year, lower drainage volumes may also have influenced losses. The results show that Miscanthus , once established, can lead to low levels of nitrate leaching and improved groundwater quality compared with growing arable crops.     

Effects of amendments on soil structural development in a clay soil-forming material used as a cap for landfill restoration

Abstract. Restoration of landfill sites to a vegetated after-use is severely compromised if soil-forming materials (SFMs) have to be used as substitute growing media for the restoration cap, owing partly to their poorly-developed structure. The effects of crushed brick material (brick), composted green-waste organic matter (OM) and potassium chloride salt (KCl) in a clay SFM were assessed at the Brogborough Landfill Site (Shank Group plc) in the county of Bedfordshire, UK. Soil structure was characterized three times in a two-year experimental period through measuring drainage water release and aggregate stability and size distribution. Crushed brick and composted OM at 100 t ha⁻¹ improved the ability of the clay to release water by drainage. In addition, the composted OM was associated with an increase in the size of stable aggregates, whereas the brick amendment reduced the overall aggregate stability. The KCl amendment had no consistent effect. Some beneficial structural improvements were thus associated with the brick and OM amendments, although these were rarely significant at the 5% level and the effects declined over time in the absence of vegetation and re-application. Nevertheless, incorporation of crushed brick and organic amendments may offer a potential structure-improving option in clay SFMs prior to vegetation establishment.     

绿竹滩涂栽培试验

通过对绿竹在沿海滩涂上的耐盐力、抗力表现、生产力水平、笋体品质，经济价值等方面的综合试验分析，揭示出绿竹可承耐土壤含量盐量０．４１％以下，是沿海滩涂有发展遂叙的经济防护林树种。     

鱼油挥发性成分分析和脱除方法

采用改进的动态顶空技术捕集、浓缩鱼油挥发性成分，并通过GCMS分析鉴定其中45个成分，结果表明。其中14个为饱和、不饱和醛类，8个为饱和、不饱和酮类。这些物质被认为是形成鱼油异味的主要成分。通过GC分析评价鱼油储藏过程中的感观变化和氧化，结果表明，GC分析的总峰面积能够指示鱼油的气味强度和氧化程度，并和感官检验结果一致。凹凸棒黏土处理鱼油取得较好脱色脱臭效果，其脱色脱臭效率分别为86．2％和84．1％。     

“曼生壶”的艺术表现及其影响

陈鸿寿作为清朝乾嘉时期才华横溢的西泠八家之一,他将诗词铭文书刻在紫砂壶上,既显现美学形态造诣之高深,又展示紫砂壶设计创新之独特,开辟了清朝文人雅士对紫砂壶研究收藏之先河。     

花生-萝卜轮作体系下红黏土红壤对猪粪安全消纳能力研究

为减少养猪场废弃物排放和化肥使用,降低环境污染,最大限度将猪粪肥料化,采用盆栽试验方法,在自然降雨条件下模拟研究了亚热带红壤丘陵区花生-萝卜轮作体系下红黏土红壤对猪粪的安全消纳能力。试验设在江西鹰潭中国科学院红壤生态试验站,供试土壤肥力水平中等(有机碳5.16g·kg-1,Olsen-P28.34mg·kg-1)。试验以3组化肥水平为基础(不施化肥,常规化肥减半,常规化肥用量),常规化肥年施肥量为:N100 kg·hm-2,P50kg·hm-2,K100kg·hm-2。每个化肥用量基础上分别设置7个猪粪施肥梯度(以P计):0、25、50、100、200、400、800kgP·hm-2。通过监测两年土壤渗漏水中铵态氮、硝态氮和总磷浓度变化,结合作物产量和土壤养分含量变化,初步确定了花生-萝卜轮作体系下红黏土红壤对猪粪的安全消纳量。结果表明:(1)从地下水和土壤环境角度分析,在不施化肥情况下,猪粪施用量应低于200kgP·hm-2,常用化肥用量减半时,猪粪安全用量为不高于100 kg P·hm-2;常规化肥用量下,即使不施猪粪,渗漏水硝态氮浓度已经有引起污染的风险。(2)从作物产量角度考虑,猪粪和化肥配合施用时猪粪用量超过100 kg P·hm-2时不能使作物显著增产。因此,在保证经济效益和环境生态效益的同时,确定年化肥用量为常规用量减半水平,花生-萝卜轮作体系下红黏土红壤猪粪最大安全消纳量为100kgP·hm-2,相当于每年施用鲜猪粪24000kg·hm-2。