科尔沁沙地灌溉与施肥对退化草地生产力的影响

在科尔沁沙地典型退化草地上开展了裂区组合设计的灌溉与施肥二因素试验。结果表明,科尔沁沙地退化草地土壤储水量受降水量的影响强烈。由于受到干旱气候和灌溉量的影响,灌水仅对地表0~30 cm的土壤含水量变化有作用,对深层土壤的含水量没有作用。灌溉和施肥对沙地退化草地的植物生物量有着明显的促进作用。灌溉处理中,灌溉90 mm试验区的植被生物量为最高(128.3 g/m2),施肥处理中,每hm2施600 kg氮肥试验区的植被生物量为最高(147.3 g/m2)。灌溉90,60,30 mm和对照试验区的植被耗水量分别为379.00,349.90,313.20和293.50 mm。与其相应的水分利用率分别为0.28,0.38,0.34和0.35 kg/(mm.hm2)。综合分析认为科尔沁沙地退化草地的基本耗水量为294 mm。     

差不嘎蒿茎叶解剖特征及其与气候因子的关系

差不嘎蒿(Artemisia halodendron)是我国东北部重要的防风固沙植物,本研究利用石蜡切片法观察内蒙古不同地区差不嘎蒿的叶片和茎解剖结构,运用方差分析方法比较不同地区差不嘎蒿解剖结构间的差异性,以逐步回归得出影响解剖数量特征的主导气候因子.结果表明:差不嘎蒿叶为等面叶,表皮细胞为1层,栅栏组织呈环栅型,排...     

应用灰色系统理论评价草地质量初探

以草地优良牧草产量、可食牧草产量、载畜量、牧草利用率和覆盖度为主要指标，应用灰色系统理论中关联工分析的方法，对武威地区３２个类型草地质量进行了评价。结果表明，质量最好的草地是山地草甸，质量最关的是干荒漠和荒漠摹。根据分析结果，提出了武威地区草地质量分级的方案。     

Collective management on communal grazing lands: Its impact on vegetation attributes and soil erosion in the upper Blue Nile basin,northwestern Ethiopia

Collective action, on communal grazing land, has evolved in the highlands of northwestern Ethiopia to mitigate the problems of feed shortage and land degradation due to overgrazing. The exercise is liked by farmers for improving the availability of natural pasture during the long dry season when other feed sources get depleted. However, large portions of the communal grazing lands are still managed under free grazing throughout the year. This study was undertaken in Maynet village in the upper Blue Nile basin, northwestern Ethiopia, to assess the impacts of three different types of grazing land management (GLM) and two slope gradients (<10%; 15–25%) on aboveground herbaceous biomass yield, ground cover, species richness, runoff, soil loss and soil bulk density of grazing lands. The GLMs include (a) freely open communal GLM, (b) restricted communal GLM – collective management of communal grazing land locally named as ‘yebere sar’ and (c) private holding GLM. Stocking density was more than carrying capacity of grazing lands across all GLMs. However, the extent of overstocking problem was exceptionally severe in freely open communal GLM. The interaction between GLM and slope was significant (P<0.05) for runoff, soil loss and runoff coefficient. The average runoff coefficient was close to 50% in freely open communal GLM on steeper slopes (15–25%). Freely open communal GLM on steeper slopes resulted in consistently highest cumulative runoff and soil loss amounting to 491 mm and 32 t/ha per year, respectively. Polynomial regression analysis showed that quadratic relationship (r²=0.87) existed between soil loss and runoff. But, soil loss was close to nil when runoff did not exceed 2 mm per rainfall event. As expected, restricted communal GLM appeared to reduce surface runoff by more than 40% and curb the rate of soil erosion by more than 50% compared to freely open communal GLM. Its vegetation cover persisted above 70% throughout the year, meeting the threshold level recommended to keep surface runoff and soil loss to minimum. Reducing the problem of overstocking and pasture resting in August–November are important components to improve ground cover and aboveground herbaceous biomass yield, which in turn reduce land degradation on grazing lands.     

黄河源区"黑土滩"退化草地群落类型多样性及其群落结构研究

调查了黄河源区高寒草甸极度退化产物“黑土滩”植被群落类型多样性及其群落结构特征。结果表明,分布在黄河源区高寒草甸上的“黑土滩”草地植被可分为7个类型,分别为:黄帚橐吾 铁棒棰群落、白苞筋骨草群落、铁棒棰群落、西伯利亚蓼 鹅绒委陵菜群落、摩苓草群落、甘青微孔草群落和甘肃马先蒿群落。从群落结构和已有的研究结果看,黄河源区所有类型的“黑土滩”草地都完全失去了牧用价值,短期内自然恢复的物质基础也已丧失,该类草地的恢复治理必须通过人工植被的重建来实现。     

青岛市畜禽粪污土地承载力及粪便资源化利用策略

根据青岛市畜牧业和种植业实际情况,测算了该市畜禽粪污土地承载力,分析了青岛市畜禽粪便资源化利用存在的主要问题,提出了合理规划产业布局、发展种养结合、完善财政投入和补贴机制、发展专业化服务组织、加快技术研发和示范推广及完善信息化监管手段等方面的对策建议,以期为优化调整畜牧业布局、促进种养结合、推进畜禽粪污资源化利用、引导畜牧业绿色发展提供理论依据。     

基于粮食安全的重庆市耕地保护

耕地资源关系到一个国家或地区经济发展、社会稳定和粮食安全。文中通过对1997-2005年重庆市粮食产量和耕地面积的统计数据进行分析,发现耕地面积不断减少、粮食产量以2001年为分界点出现逐年减产和增产的现象,并提出基于粮食安全的重庆市耕地保护对策。     

云南干热河谷旱坡地南洋樱植物篱水土保持效益研究

对云南元谋干热河谷旱坡地水土流失和土壤退化严重的地区,引进豆科速生树种南洋樱,以30 cm×40 cm株行距、品字形双行等高栽植快速形成植物围篱。结果表明,南洋樱植物篱在元谋干热河谷旱坡地生长良好,并且在种植3年间,治理区径流发生次数明显减少,年径流模数减少了29.13×104m3/km2,减少率76.90%;土壤年退化减少12 986.8 t/km2,减少率76.02%。研究区降水量与径流量间者的相关系数由建植篱前的显著相关变为不显著;有机质和钾流失减少量高达3 111.64 kg/hm2和3276.57 kg/hm2。南洋樱植物篱在控制旱坡地水土流失、减少土壤侵蚀和改善土壤养分等效益显著。     

鲁梅克斯K-1杂交酸模在盐渍化土地适应性栽培效果分析

对临泽盐渍化土地栽培的鲁梅克斯K－1杂交酸模，进行了植物学特征、耐盐碱、抗寒性、营养价值，根系及土壤含盐量等性状的分析，发现鲁梅克斯K－1杂交酸模在含盐量1．15％土壤环境生长良好，其根组织能耐盐碱，且0－5cm土层含盐量可下降37．05％－50．58％，年可收获优质干草12．4t/hm^2，开发利用潜力巨大。