浅谈混农林业的设计

混农林业在农业生产中占有相当大的比例,其科学的规划和设计是农业和林业取得双赢的基础,设计内容主要包括:社会需求和基本情况调查、可行性分析、优化生产组合(技术设计),最后提出适合于当地社会经济和自然条件的混农林业综合生产体系方案。混农林业结构设计内容包括垂直结构、水平结构、时间结构、食物链结构和技术结构的设计。     

混农林业在云南山区经济可持续发展中的作用

混农林业经过多年的探索,已得到较全面的发展,并经实践证明是一种可供选择的具有良好生态效益的高效种植模式.通过描述云南山区的特点,总结分析混农林业在云南山区发展的现状及在云南山区经济可持续发展中的作用,并针对现状,提出了今后发展方向.     

石漠化环境水土综合整治与山地混农林业前沿理论与对策

石漠化环境水土综合整治走向产业化,其技术体系与山地混农林业模式及技术研发耦合。通过对158篇相关文献的统计分析,结果表明:(1)时间序列的文献发表数量呈现峰丛状曲线分布,说明该研究有进一步加强的需要;(2)研究内容主要针对试验监测研究、运用技术研究、理论与机理研究、模式构建、示范推广和效益分析6个方面进行,其中以试验监测为主,监测混农林业对土壤理化性质的改良作用以及对生态效益、经济效益和社会效益的影响;(3)研究区域主要分布在中国的北方地区和南方喀斯特地区,说明水土综合整治与山地混农林业相结合的研究主要在干旱半干旱地区和工程性干旱的喀斯特地区。还从理论研究、技术研发、模式构建、试验示范、监测评价5个方面揭示石漠化环境水土综合整治与山地混农林业的前沿理论。最后发现石漠化水土综合整治与山地混农林业耦合的综合性理论研究和重大关键技术研发显得滞后,应该加强五水赋存动力转化、地表地下空间水土资源联合调配、坡面水土漏失阻控技术、节水增值产业技术、林—粮—草立体空间优化配置技术等方面的研究,以综合性水土整治技术发展混农林业,实现石漠化地区生态修复并带动区域经济产业的发展。     

生物多样性与我国的农林业复合经营

对节白蜡繁殖方面的问题迄今未见报道。经大量调查研究试验，结果表明；对节白蜡有其自身的繁殖规律和独特的繁殖能力，在正常情况下，能通过有性繁殖和无性繁殖的方式，完成其生活史，使其种质资源得以保存，稳定其生物的多样性，并世代繁衍下去。     

吸水剂的研发及在农林业中的应用进展

吸水剂(保水剂)是一类具有高吸水特性的功能性高分子交联物,由于其具有高吸水性、水不溶性和绿色环保性等显著特点,在多个领域得到广泛应用。着重介绍20世纪60年代以来世界吸水剂的研发成果以及在农林业和生态环境建设中的作用,同时对应用前景进行展望。     

低丘红壤开发与复合农林业对土壤侵蚀的影响

在低丘红壤的开发利用中,通过复合农林业技术达到植树种草、增加地面覆盖率、发展当地经济植物促进畜牧业发展,探索低丘红壤开发利用的新模式,科学合理地开发红壤资源,实现开发中保护。经过2年的试验表明:选择适宜的植物种类对于有效地发挥生物措施与复合农林技术的功效是极其重要的,各试验块的植被覆盖度分别是湿地松18%,茶叶23%,柑橘34.6%;覆盖度大小顺序依次为柑橘>茶叶>湿地松;低丘红壤开发的第1年土壤侵蚀量一般都超过土壤允许侵蚀量500t/km2.a,第2年就减小到350t/km2.a左右,各类型的土壤平均侵蚀量次序为柑橘>湿地松>茶叶;各处理的平均N素流失量为湿地松138.8 kg/km2,茶叶450.1 kg/km2,柑橘182.4 kg/km2;N素流失大小顺序为茶叶>柑柑橘>湿地松。在试验区采样分析结果表明:随着土壤侵蚀的逐步升级,土壤容重、田间持水量、土壤粉粒、土壤团聚体、土壤pH、土壤盐基饱和度、土壤盐基交换量均相应降低,而土壤交换性酸对应增加。验证了水土流失直接导致土壤结构、土壤物理性状退化、变差的结果。     

外来入侵生物对我国热带农林业的影响及防控对策

综述了热区外来有害生物入侵现状,从国际贸易、生态安全、经济发展和人类健康安全方面分析了外来有害生物入侵对热区农林业发展的影响,并提出了相关的防控对策。     

混农杨树林根系分布与生长量关系的研究

本文研究了杨树单行混农林、双行混农林、速生丰产林及“小老树”的生长量及根系分布规律，结果表明，混农林年均生长量最大，混农林根系分布更合理、更均匀、更有利于土壤空间，水分、养分的利用。     

农林业的概念、发展与研究

农林业是近十余年来,国际新发展起来的一门实践性和综合性很强的新兴学科,它是运用生态学和经济学为原理,把林木与作物有机结合成完全或部分相互依存的整体、达到充分发挥不同成分之间正作用,如对光、热、水、肥、空间、时间的合理互补与优化使用,因此,它是一种低投入、高产出的农林复合经营体系,尤其在地少人多的发展中国家,已把农林业作为农林发展的产业核心。为此,本文就国内外农林业的发展、原理和研究现状作一简介,以推动农林业在我国的发展。     

不同核桃农林复合经营模式对土壤肥力的影响

为了解复合经营对核桃园土壤肥力的影响,在贵州省威宁县核桃主产区选取了3种具有代表性核桃复合经营模式,即核桃-白三叶(J+T)、核桃-大豆(J+S)和核桃-玉米(J+M),以核桃清耕为对照(CK),4年后对4种核桃经营模式0~20 cm,20~40 cm,40~60 cm土层土壤肥力进行分析。结果表明:与核桃清耕模式相比,三种核桃复合经营模式均降低了土壤p H值,提高了土壤有机质、全氮、有效氮、全磷、有效磷、全钾和有效钾等;四种核桃经营模式土壤p H值均随土层深度增加而增大,土壤有机质、全氮、有效氮、全磷、有效磷、全钾和有效钾等均随深度增加而减少;三种复合经营模式土壤p H值大小依次是核桃-大豆模式核桃-白三叶模式核桃-玉米模式;三种复合经营模式土壤有机质、全氮、有效氮、全磷、有效磷、全钾和有效钾等含量高低均表现为核桃-玉米模式核桃-白三叶模式核桃-大豆模式。说明复合经营可以改善核桃园土壤肥力,且四种模式间的土壤肥力差异主要是由不同施肥量引起的。     

红壤丘陵区农林复合生态系统研究与展望

本文针对红壤丘陵区农林复合生态系统存在的问题,分析了红壤农林复合生态系统现状、结构功能与结构演替规律;提出了红壤农林复合生态系统的五级分类系统;初步建立了红壤地区农林复合生态系统评价指标体系框架,并对典型县域复合生态系统进行了评价;在此基础上,提出了红壤丘陵区农林复合生态系统的优化调控措施以及资源持续利用对策,并对该区农林复合生态系统的后继研究进行了展望。     

Agronomic Potentials of Rarely Used Agroforestry Species for Smallholder Agriculture in Sub-Saharan Africa: An Exploratory Study

Despite significant evidence that green manures from agroforestry species can improve soil fertility, green biomasses from many agroforestry species have not been sufficiently explored. In this study, we determined the suitability of green manures of Tithonia diversifolia, Gliricidia sepium, and Senna spectabilis for smallholder agriculture in Africa. Field trials were established to compare them with mineral fertilizer. The results showed that green manures of the three species were of high quality based on their macronutrient compositions. The effect of the green manures (particularly Tithonia) on both the biomass and fruit yield of okro were comparable and in some cases greater than fertilizer treatments. Total yield response in Tithonia treatment was 61% and 20% greater than the control and fertilizer treatments, respectively. In addition, the okro plants recovered a greater percentage of the nitrogen (N), phosphorus (P), and potassium (K) added as green manure compared to fertilizer-treated plots, which received the greatest N, P, and K inputs.     

Preliminary Assessment of the Riverine Nitrogen Concentration and Load in an Agroforestry Basin in NW Spain

In this study, the concentrations and loads of different forms of nitrogen [nitrate nitrogen (NO₃-N), total Kjeldahl nitrogen (TKN), and total nitrogen (TN)] in the headwater catchment of the Mero River (NW Spain) were analyzed. The TN concentrations were relatively low (mean: 2.57 mg L^?1). Nitrate was the predominant form of N in the Mero catchment, accounting for 76.65 percent of the TN concentration. Measured NO₃-N concentrations were always lower than the maximum allowed drinking water concentration. An annual TN load of 61.2 Mg was computed, representing an export of 0.94 Mg km^?2 y^?1, whereas annual exports NO₃-N and TKN were of 0.79 and 0.15 Mg km^?2 y^?1, respectively.     

Temporal Oscillations of Calcium,Magnesium, Potassium,and Sodium Dissolved Contents in an Agroforestry Catchment from the Atlantic Galicia

There is an increasing awareness worldwide of the conveyance of sediment-associated nutrients across eroding soil surfaces into receiving waters. The objective of this study was to analyze the temporal oscillations of concentrations as well as the exportation of calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) at the outlet of an agroforestry catchment. These macronutrients were measured in the drainage waters of a 36.3-km² catchment located at the Valiñas River (Coruña, northwest Spain), where 560 samples were taken from 2003 to 2007. The water collection strategy was a stratified point sampling involving more frequent collections when flow was high. Element contents in the water were analyzed by inductively coupled argon plasma–mass spectrometry (ICP-MS). The dissolved content ranges were as follows: Ca between 4.47 and 20.7 mg L^–1, Mg between 2.4 and 7.3 mg L^–1, K between 1.13 and 8.6 mg L^–1, and Na between 8.9 and 27.2 mg L^–1. Significant correlations among all the analyzed elements were observed during the entire study period. Mostly, nutrient losses were related to degradation induced by soil erosion on the cultivated land portion of the catchment.     

Agroforestry techniques for the rehabilitation of degraded salt-affected lands in India

The development of appropriate technologies for the judicious use of India's 8.11 million ha of salt-affected lands would give increased food, fodder and fuelwood production. A sizeable portion of the salt-affected lands of the Indo-Gangetic plain have been reclaimed through chemical amendments and are being commercially used for arable farming. However, large areas of salt-affected common lands, village and government lands and waste lands near cities, along railway tracks and roads do not have any productive use. Owing to their sparse vegetative cover such lands are vulnerable to further degradation and can be a source of runoff causing floods, especially where cows congregate. Research at the Central Soil Salinity Research Institute, Karnal has generated agroforestry techniques which could enable the economic exploitation of such marginal lands. This paper deals with various aspects of these techniques, which have been applied to over 50 000 ha by 1994. Based on eight to ten years of growth and biomass figures, the most salt-tolerant woody species identified were: Prosopis juliflora, Acacia nilotica, Casuarina equisetifolia, Tamarix articulata, Leptochloa fusca (a palatable forage grass which was found to be a promising primary colonizer of salt lands). Agronomic practices for the successful establishment of trees such as planting methods, amendment use, irrigation, spacing and lopping schedules are discussed. A Prosopis juliflora-leptochloa fusca silvipastoral model was found to be excellent for fuelwood and forage production and for the amelioration of high pH soils. This system, when followed for little more than four years, reclaims alkali soils to such an extent that normal agriculture crops such as Trifolium alexandrinum and T. resupinatum can be grown successfully. A ridge-trench system of tree planting was found to be helpful in alkali soils, the in situ rainwater conservation it led to assisting biomass production. Eucalyptus tereticornis, Populus deltoides and Tectona grandis based agroforestry were promising for reclaimed salt-affected lands. The short- and long-term effects of various tree plantations on the physicochemical properties of the soil and on soil-water relations are also discussed. Agroforestry options for the development of salt-affected lands found in various agroclimatic zones of India are explored.     

Oscillation of Three Phosphorus Forms and Suspended Solids Content from 1999 to 2007 in a Spanish Agroforestry Catchment under Atlantic Climate

Phosphorus (P) transfers may accelerate water eutrophication to waters. Increasing awareness of the role of diffuse P sources motivates land managers in different regions of Europe to undertake conservation programs that place emphasis not only on soil conservation but also on water quality and eutrophication risk. Fertilizer applications and wastes are the main sources of dissolved P in Galicia and in the Atlantic regions of Spain. The aim of this study was to assess the temporal changes in concentration of total P (TP), sedimentary P (SP), and total dissolved P (TDP) and suspended solids at the outlet of an agroforestry catchment located in northwestern Spain. The study datasets range from January 1999 to December 2007, with 992 water samples collected. The water-collection strategy was a stratified point sampling involving more frequent collections when flow was high. Phosphorus contents were assessed by inductively coupled plasma (ICP)–mass spectroscopy (MS), and suspended solids were measured by filtration. The content ranges of the different studied P forms and suspended solids were as follows: TDP between 1 and 672 mg L^?1, SP between 1 and 1064 mg L^?1, TP between 1 and 1111 mg L^?1, and suspended solids between 1 and 1044 mg L^?1. A few events of intense precipitation with peaks of TP greater than 200 mg L^?1 and in some cases even more than 1000 mg L^?1 were responsible for most of the P losses in the catchment studied. TP and SP, TP and suspended solids, and SP and suspended solids showed highly significant correlations during the entire study period, evidencing the erosive origin of P in this catchment.     

低丘红壤南酸枣一花生复合系统物种问水肥光竞争的研究—Ⅱ．南酸枣与花生利用光能分析

试验研究结果表明低丘红壤南酸枣遮荫使复合系统花生光合有效辐射减弱以及花生产量和生物量明显下降 ,与单作花生相比间作各行花生相对光合有效辐射值日变化主要与距南酸枣树行远近有关 ,与复合系统花生产量和生物量中间行高而两侧行低的趋势相一致 ,两者呈显著正相关。     

三峡库区砾石坡耕地农林复合经营效益研究

在三峡库区砾石坡耕地采用水平阶整地方式 ,布设等高植物篱 ,实施农林复合经营技术。通过近 1年的实地观测 ,对此项技术在防治水土流失、改土方面的效益作了初步研究 ,结果发现 :农林复合经营技术可以增加土壤总孔隙度和非毛管孔隙度 ,降低土壤容重 ;有效减少水土流失量 ,复合经营小区的土壤流失量仅是对照 (CK)的1 1 .4 2 %。因此 ,在三峡库区值得推广此项技术     

黄灌沙区农田耕层土壤性状空间异质性分析

用地统计学的方法,研究了黄灌沙区农田耕作层(030 cm)土壤的有机质、全氮、碱解氮、速效磷、速效钾、pH和电导率的空间变异规律。结果表明,农田耕作层土壤养分的空间异质性主要由随机性因子如土壤耕作措施,包括施肥、灌溉和作物轮作等造成,这与该区农田耕作层土壤是引黄灌溉改良的结果有关。土壤养分含量的变异函数均可很好地拟合成线性模型,块金值和基台值之比(C0/C0 C)均为1,说明随机性因子是导致该区土壤性状空间变异的主要因素,在整个尺度上具有恒定的变异,造成了土壤性状的相对均一。pH的变异函数为指数模型,其空间异质性组成中随机性和结构性因子各占50%。电导率的变异函数为球状模型,空间变异主要由结构性因子导致,结构性因子引起的空间异质性占总空间异质性的67%。分维数也表明耕层土壤性状空间依赖性较小,随机因子如农业活动是引起黄灌沙区土壤性状空间异质性的关键原因。Moran s I系数表现为除了pH和电导率受结构性和随机性因子共同作用外,其余土壤性状均呈较弱的相关关系。因此,干旱沙区通过人为措施改良的土壤性状空间上的变异主要受人为活动如灌溉、施肥和耕作等影响,在农业活动中更应该注重施肥和灌溉方式、灌溉水源等问题,以避免因土壤性状的变异导致的肥料利用效率降低。