带状种植系统养分供给与利用研究进展

带状种植是1种以固N植物篱为核心、农作物与植物篱相间种植的农林复合经营模式，植物篱通过修剪避免对农作物遮光，其枝叶作为覆盖物和有机肥，可提高土壤肥力。阐述了植物篱枝叶N素矿化和利用、枝叶有机碳矿化及其对土壤有机质的影响以及固N植物篱对土壤P素和其他矿质元素的供给状况，并评价了该模式下土壤养分和有机质动态。     

等高植物篱模式下土壤物理性质变化与水土保持效果研究进展

等高植物篱模式就是在坡耕地上每隔4~8m的距离沿等高线将植物篱与作物种植带相间分布的一种农林复合经营模式,用于坡耕地的水土保持。已有的研究结果表明,等高植物篱技术用于坡耕地可有效地改善土壤物理性质和土壤水分状况,防治坡耕地水土流失效果显著,土壤水分的季节性再分配也有利于农作物的生长。但是该系统内植物篱和农作物相互之间的水分和养分关系有待深入研究。     

密云水库库区不同植物篱模式下的氮磷阻控效应

筛选拦截效果最佳、经济效益最佳的植物篱模式,为密云水库水源保护区控制坡耕地氮磷流失提供技术参考。设置“桔梗+狗牙根”“丹参+狗牙根”“桑树+野牛草”“黄芩+野牛草”4种不同的植物篱模式,监测2020年天然降水条件下的地表径流、泥沙以及养分情况,分析不同植物篱模式下径流小区的产流和产沙情况,探讨不同植物篱对坡耕地地表径流、泥沙和养分的拦截效率及其影响因素。结果表明：4种植物篱种植模式都能够起到截流减沙,减轻水环境富营养化的作用,从而避免对下游水体的污染。其中“桑树+野牛草”植物篱效果最为显著,大雨雨强下可以减流57.96%,减沙96.64%,暴雨雨强下可以减流64.63%,减沙97.17%;对氮的相对拦截量为93.14 mg,相对拦截率约88.27%;对磷的相对拦截量为25.17 mg,相对拦截率约80.72%,能有效减少地表径流中的氮、磷含量。在考虑经济效益、社会效益和生态效益下,开展植物篱防控面源污染工作中,最佳的物种选择为“桑树+野牛草”,其次为“黄芩+野牛草”。野牛草在防控水土流失与面源污染方面效果十分显著,可以作为水土保持的先锋植物推广。     

西南丘陵山区坡耕地植物篱水土保持效益研究进展[1]

从植物篱拦截径流、减缓坡度、改善土壤理化性质、提高土壤酶及微生物活性、保护生物多样性等方面综述了植物篱控制水土流失的机理,总结了西南丘陵山区不同植物篱模式的水土保持效果及坡度和平衡施肥对其的影响。西南丘陵山区植物篱研究以草本类的香根草、黄花菜以及乔木类的新银合欢等居多,其中黄花菜多与果树配合。最后从加强植物篱土壤生物学特性和植物篱带间距方面的研究进行了展望,以期为西南丘陵山区植物篱水土保持研究与应用提供参考,促进该区域化肥减量增效目标的实现。     

Agroforestry in the management of sloping lands in Asia and the Pacific

Steeply sloping lands are widespread in the tropics. An estimated 500 million people practice subsistence agriculture in these marginal areas. Continued population growth has led to the intensified cultivation of large areas of the sloping lands, exacerbating the problem of soil erosion. Although research shows that alley cropping and other contour agroforestry systems can stabilize the sloping lands, these systems have not been widely adopted by farmers. The Framework for Evaluating Sustainable Land Management (FESLM) has been tested in sloping land areas in the Philippines. Sustainable land management must be productive, stable, viable, and acceptable to farmers, while protecting soil and water resources. Farms on which contour hedgerow intercropping has been adopted meet the multifaceted requirements of FESLM, whereas the farmers' current practice does not. Appropriate land management measures for particular locations depend on a complex suite of social, economic, and biophysical factors, and need to be developed in participation with farmers. The role of agroforestry in sustainable management of sloping lands is the subject of networks coordinated by the International Board for Soil Research and Management (IBSRAM) in seven countries in Asia (ASIALAND) and four countries in the Pacific (PACIFICLAND). We review selected outcomes from a wealth of network data. From these results the following conclusions about the sustainability of various agroforestry systems for sloping lands can be drawn: • In the Pacific, soil loss from sloping lands due to water erosion under farmers' current practices is episodic, unpredictable, and possibly not severe; • Agroforestry systems that utilize legume shrubs, fruit trees, coffee (Coffea spp.) or rubber (Hevea brasiliensis) provide useful economic returns, but are not an essential component in terms of soil protection because grass or pineapple (Ananas comosus) planted on the contour are equally effective in reducing erosion; • Agricultural intensification will lead to nutrient mining, reduction of aboveground biomass, declining yields, and less soil protection unless external sources of nutrients are used; • nitrogen can be effectively supplied using legumes; • Cash derived from hedgerow trees and/or shrubs may providean incentive for their adoption by farmers, as well as funds to purchase external inputs such as fertilizers; • Labor may be a major constraint to the adoption of complex agroforestry systems. We also discuss the information management systems required to effectively manage and utilize the extensive sets of experimental and indigenous data being accumulated. We believe such information systems can facilitate technology transfer across and between regions, and improve the efficiency of research into agroforestry and other land-management approaches. This revised version was published online in June 2006 with corrections to the Cover Date.     

The potential of alley farming in humid West Africa — a re-evaluation

Previously published hypothesis concerning the potential impact of alley farming on maize yields are re-examined relative to the humid regions of West Africa. When more realistic assumptions regarding the availability of organic nitrogen are used, it is concluded that alley farming may have potential in a wider range of maize yield environments in West Africa than previously proposed. A pragmatic approach to alley farming research is proposed, and the importance of on-farm research in the development of ‘farmer friendly’ alley farming is stressed. (Former Agronomist, International Livestock Centre for Africa, P.M.B. 5320, Ibadan, Nigeria)     

Alley cropping of sorghum with Leucaena during the post-rainy season on Vertisols in semi-arid India

A field experiment was conducted for two years (1989– 1991) on a Vertisol in Bijapur, India in a split-plot design, replicated four times, to evaluate the potential of alley cropping post-rainy season sorghum between Leucaena hedgerows. Leucaena produced on average 2.74 t per ha of prunings and 1.57 t per ha of wood annually. Alley cropping decreased sorghum yields by 28 to 45% when all Leucaena prunings were removed from the system and by 21 to 24%, when on average 1.92 t per ha prunings were applied to the soil annually. The reduction of sorghum yield increased as higher rates of N were applied to sorghum. Although alley cropping increased organic carbon by 21% and available N by 19% at the time of crop sowing, it did not result in increased crop yields because of competition for water between hedgerows and crops. Calculation of land equivalent ratios based on total Leucaena biomass indicated that alley cropping was more productive than sole cropping of sorghum only in one year, and that, too, when no N was applied to sorghum. Therefore, alley cropping of Vertisols with post-rainy season sorghum is not likely to have any advantage in the short term. This revised version was published online in June 2006 with corrections to the Cover Date.     

黄土丘陵区牧草篱对坡耕地土壤抗侵蚀性的影响

以苜蓿、红豆草2种牧草篱为研究对象,对黄土丘陵区坡耕地布设牧草篱前后及牧草篱形成初期草带内、带间坡耕地土壤物理性质、抗蚀性、抗冲性、抗剪性的差异及各相关性进行了研究.结果表明:1)牧草篱可以明显改善土壤容重、总孔隙度、饱和含水量、水稳性团聚体含量等物理性质;2)牧草篱影响下土壤抗蚀性、抗冲性提高,牧草篱带内土壤抗剪强度小于带间坡耕地;3)牧草篱系统内土壤抗冲系数与土壤容重呈负相关关系,与总孔隙度、饱和含水量、水稳性团聚体含量呈正相关;崩解速率与土壤容重成正相关,与总孔隙度、饱和含水量、水稳性团聚体含量呈负相关;土壤抗剪强度与土壤容重呈正相关(p＜0.05),与总孔隙度、饱和含水量、水稳性团聚体呈负相关.     

5种绿篱植物挥发性有机化合物成分分析

为了探讨不同植物释放挥发性有机物(VOCs)组分和含量的差异,采用动态顶空采集法和热脱附-气相色谱-质谱(TDS-GC-MS)联用技术,分析了近自然状态下杭州地区常用绿篱植物金叶女贞Ligustrum quihoui var.aureaphylla,红花檵木Loropetalum chinese var.rubrum,瓜子黄杨Buxus sinica,龟甲冬青Ilex crenata‘Convexa’和无刺枸骨lles cornuta var.fortunei释放VOCs的种类和相对含量.结果表明:瓜子黄杨释放的VOCs主要有乙酸-3-己烯酯(相对含量为27.10％),芳樟醇(19.70％),2-辛烯(7.20％);红花檵木释放的挥发性物质主要有乙酸-3-己烯酯(26.10％),α-蒎烯(6.70％),苯甲醛(6.50％);金叶女贞主要有乙酸-3-己烯酯(16.30％),苯甲醛(8.30％),壬醛(5.50％)和对甲基苯乙烯(5.10％);无刺枸骨主要有β-蒎烯(12.10％),癸醛(9.50％),2-壬烯醇(7.40％),月桂烯(7.20％),苎烯(6.50％),2-辛烯(6.10％)和6-甲基-5-庚烯-2-酮(6.01％);龟甲冬青主要有癸醛(21.60％),壬醛(13.60％),已内酰胺(6.80％)和苯甲醛(5.60％).     

等高植物篱种植模式及其应用中存在的问题

等高植物篱技术是一种坡耕地上低投入、高收益的保护性耕作和持续利用技术。坡耕地采用植物篱种植模式进行水土保持和生态环境治理,能达到明显的保水保土效果,同时能产生显著的经济效益和社会效益。但其推广应用效果不理想,这是因为实施前期收益不明显,作物产量提高滞后,农户管理水平低等因素阻碍了这项水土保持措施的实施。因此,要实施该项技术,应筛选经济价值高的植物篱品种,科学规划篱笆带间距和种植密度,立足山区实际开展技术培训,多渠道筹措资金等。