栽培方式对粳型巨胚稻结实期剑叶一些生理特性的影响

［目的］ 探索有利于巨胚稻剑叶生长的合理栽培方式。[方法]以常规粳型巨胚稻品种西巨胚1号为试料,以当地推广的常规优质粳稻品种合系22-2为对照,采用淹水、旱种和垄畦3种方式进行栽培,研究不同栽培方式对粳型巨胚稻结实期剑叶一些生理特性的影响。[结果]3种栽培方式中,垄畦栽培方式下水稻结实期剑叶的叶绿素含量较高,叶片衰老缓慢,该栽培方式有利于剑叶渗透调节物质可溶性糖的主动积累和保护性酶SOD酶活性的提高,增强细胞保水能力,维持细胞正常的代谢;旱种栽培方式下水稻剑叶叶绿素含量低,衰老快,渗透调节物质和保护性酶的变化水平对水分胁迫极为敏感。[结论]在生产上建议采用垄畦栽培方式更有利于巨胚稻的剑叶生长。     

枣庄地区煤矿塌陷地综合复垦治理研究

以枣庄地区煤矿塌陷地复垦利用为实例,在对该地区塌陷地实地调查的基础上,分析了塌陷地的危害性及其影响,提出了塌陷地复垦中存在的问题,并从技术的科学性、政策的有效性和资金的充足性等3个角度提出塌陷地复垦治理措施.     

煤矿区土地复垦的影响因素及对策研究

煤炭开采造成了大量土地资源的破坏,作为以整治被破坏土地为目的的土地复垦,是实现矿区土地可持续利用的关键环节。根据资料分析和实地调查,认为目前我国煤矿区存在着影响土地复垦的一系列因素,包括经济、技术、理论、政策和历史因素等。对此,应加强土地复垦理论和技术经济的研究、土地复垦技术的推广相关法律制度的完善,以形成煤矿土地复垦的支撑体系,促进矿区经济社会的可持续发展。     

粉煤灰复垦区杨、柳、榆、刺槐的生物量*

粉煤灰复垦区杨、柳、榆、刺槐的生物量刘雅荣，刘建伟，王世绩，冷国友，周树理，程锦山关键词煤矿复垦区，杨，柳，榆，刺槐，生物量淮北地区煤矿开采后，形成大面积的塌陷区，造成可利用的土地面积减少，生态环境恶化。据统计，类似淮北的情况，全国以每年２万ｈｍ２的...     

Pasture renovation practices of farmers in the neotropical savannahs

Degradation of sown pastures in the neotropics is a well known but poorly documented phenomenon. The paper reports the results of a survey conducted in the eastern savannahs of Colombia to quantify farmers' reactions to perceived pasture degradation. The survey was conducted in an area of 23 644 km². The sample consisted of 46 farms, which had 19 012 ha of Brachiaria decumbens pastures distributed in 374 paddocks. Of these paddocks, 196 had been sown with vegetative seed, and 281 had received modest rates of P fertilization at planting. Pastures sown on flat lands had younger modal ages (three years) and were renovated more frequently than those sown on hilly or dissected savannahs (10 years). These differences were probably a result of variations in infrastructure and relative stage of development of the two topographies, but slight differences in inherent soil fertility may also have played a role. We found no relationship between grazing management and frequency of pasture renovation. Implications for future research on pasture reclamation are discussed. © 1998 John Wiley & Sons, Ltd.     

填海工程对海洋沉积物微生物群落的影响

为了解海域微生物的群落结构和空间差异,探究其与环境的潜在联系,选择大型石化基地浙江舟山市鱼山岛海域,以期为我国海洋工程建设的环境管理提供技术支撑。在基地建设围填海时期,设置10个海域生态监测站,按《海洋监测规范》和《海洋调查规范》对海域沉积物进行取样调查。结果显示,海域环境明显受到长江、钱塘江等入海河流的影响,有机碳(TOC)、石油类(Oil)、砷(As)、镉(Cd)、铜(Cu)和铅(Pb)均在海域西北形成高值区,并逐步向东部海域递减。应用Illumina MiSeq宏基因组高通量测序技术,在海域沉积物中鉴定得到古菌和细菌共39门、260科、431属。从门水平上看,变形菌门(Proteobacteria)在各站位均表现出明显优势,其相对丰度占总数的39%;其它较为丰富的门类包括放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)、绿弯菌(Chloroflexi)、拟杆菌门(Bacteroidetes)和泉古菌(Crenarchaeota)。从属水平上看,Gamma变形菌是最主要的优势菌,其它主要种类还有Deltar变形菌、拟杆菌、放线菌、酸杆菌、浮霉菌(Planctomyces)、Beta变形菌和黏球菌(Myxococcus),Delta变形菌成为微生物群落的主要种类之一,显示海域环境一定程度地受到了沿岸人类活动的影响。微生物与环境因子的相关性分析表明,有机碳、砷和底栖生物对微生物门水平的群落分布具有显著性影响,奇古菌、黏胶球形菌和P-SR1与石油类、砷、铅、镉等重金属呈显著负相关。     

不同草地利用方式对河北坝上天然草地植物群落特征的影响

本研究以坝上天然草地植物群落为研究对象,分析了不同草地利用方式(打草场、冬牧地、公牧地)对植物群落的数量特征、物种组成、功能群特征及物种多样性的影响.结果表明:冬牧地的群落高度、物种数及物种多样性指数均最大,打草场的群落盖度显著大于放牧地(冬牧地和公牧地)且其地上生物量与冬牧地没有显著差异,同时打草场物种多样性指数与冬...     

论发展黑龙江垦区现代化大农业

现代化大农业是一个新的提法。本文在对现代化大农业的相关资料进行深入思考的基础上,从横向、纵向等多个维度对现代化大农业的内涵进行了界定,继而通过对原始农业、现代农业和现代化大农业进行区别分析,提出了现代化大农业的本质特征为绿色发展。最后,从构建垦区绿色农业体系、绿色产业体系和绿色城镇体系三个方面提出了黑龙江垦区现代化大农业发展的战略重点。     

Potential of mine land reclamation for soil organic carbon sequestration in Ohio

Soils are an effective sink for carbon storage and immobilization through biomass productivity and enhancement of soil organic carbon (SOC) pool. The SOC sink capacity depends on land use and management. Degraded lands lose large amounts of C through SOC decomposition, erosion, and leaching. Thus, restoration of disturbed and degraded mine lands can lead to increase in biomass productivity, improved soil quality and SOC enhancement and sequestration. Reclamation of mined lands is an aggrading process and offers significant potential to sequester C. A chronosequence study consisting of 0‐, 5‐, 10‐, 15‐, 20‐ and 25‐year‐old reclaimed mine soils in Ohio was initiated to assess the rate of C sequestration by pasture and forest establishment. Undisturbed pasture and forest were used as controls. The SOC pool of reclaimed pasture sites increased from 15·3 Mg ha⁻¹ to 44·4 Mg ha⁻¹ for 0–15 cm depth and from 10·8 Mg ha⁻¹ to 18·3 Mg ha⁻¹ for 15–30 cm depth over the period of 25 years. The SOC pool of reclaimed forest sites increased from 12·7 Mg ha⁻¹ to 45·3 Mg ha⁻¹ for 0–15 cm depth and from 9·1 Mg ha⁻¹ to 13·6 Mg ha⁻¹ for 15–30 cm depth over the same time period. The SOC pool of the pasture site stabilized earlier than that of the forest site which had not yet attained equilibrium. The SOC sequestered in 0–30 cm depth over 25 years was 36·7 Mg ha⁻¹ for pasture and 37·1 Mg ha⁻¹ for forest. Copyright © 2000 John Wiley & Sons, Ltd.     

冬闲期耕作方式对连作花生叶片衰老和产量的影响

大田连作条件下种植大花生品种"山花108",以冬闲期免耕晾晒土地后整地种植(冬闲免耕露地,MGLD)为对照,设置冬闲免耕覆膜(冬闲期免耕晾晒土地后整地覆膜种植, MGFM)、冬闲翻耕露地(冬闲期翻耕晾晒土地后整地种植,FGLD)、冬闲翻耕覆膜(冬闲期翻耕晾晒土地后整地覆膜种植,FGFM)、冬闲压青露地(前茬花生收获后常规种植冬小麦,于花生种植前粉碎还田后整地种植, YQLD)、冬闲压青覆膜(前茬花生收获后常规种植冬小麦,于花生种植前粉碎还田后整地覆膜种植, YQFM)5种处理,探究对连作花生叶片衰老、光合特性和产量的影响。结果表明,覆膜、冬闲翻耕与压青处理均可提高植株功能叶片光合色素含量、净光合速率、气孔导度及蒸腾速率,降低胞间CO2浓度;同时提高叶片超氧化物歧化酶(SOD)、过氧化氢酶(CAT)及过氧化物酶(POD)活性,降低丙二醛(MDA)含量,延缓叶片衰老,进而增加荚果产量。YQFM、FGFM、MGFM处理的荚果产量较YQLD、FGLD、MGLD处理分别增加5.11%、6.77%、3.70%;与MGFM处理相比, YQFM、FGFM处理分别增产14.83%、8.30%;与MGLD处理相比, YQLD、FGLD处理分别增产13.30%、5.18%,并且增产幅度由高到低依次是YQFM、YQLD、FGFM、FGLD、MGFM处理。冬闲压青覆膜处理的产量和经济效益最佳。