Agroforestry for healthy ecosystems: constraints,improvement strategies and extension in Pakistan

Agroforestry Systems - Globally, forest ecosystems are shrinking and their health is declining due to a range of biotic and abiotic factors. Forest ecosystems in Pakistan...     

海南尖峰岭地区三种热带复合农林业体系效益研究

对海南岛尖峰岭地区热带珍贵树种母生、海南石梓人工林下种植经济作物益智、咖啡的复合农林业系统的生态和经济效益研究表明：复合系统能显著促进主林层乔木的生长,胸径生长速度比对照地高出４３％～１３４％,材积生长高出１８％～８１％,生物量高出５％～８６％;生物量净积累量９．５３～１５．２３ｔ·ｈｍ－２·ａ－１,为对照地的１．６～５．１倍;系统的光能利用率为０．７８％～１．２６％,为对照样地的１．９４～５．０４倍;同时系统具有较高的经济效益,林下种植益智后的产值可达１．８～３万元·ｈｍ－２·ａ－１,为对照地的５．２６～９．８２倍,投入产出比为１∶２．９３～１∶４．１７。     

Farmer’s Perception of and Factors Influencing Agroforestry Practices in the Indus River Basin,Pakistan

Agroforestry practices of farming communities are investigated in southern Punjab province, Pakistan. It is hypothesized that rural people of this areas are more inclined than elsewhere in the province to practice agroforestry due to greater profitability than cropping. A landholder survey revealed that the majority of farmers are inclined to plant trees on their land. Low accessibility of institutional credit is a constraint for both agroforestry farmers (AF) and non-agroforestry farmers. However, among AF respondents only 24% were found to need credit for agroforestry practice, as against nearly 76% for crop production. Mostly farmers were found to have positive perceptions regarding agroforestry practice, because they understand the multiple benefits from growing trees, compared with cropping where farmers face various constraints, including poor access to credit, natural hazards, and little support from local authorities. Further, effort to sensitize farmers that growing trees has multiple benefits compared to only cultivation of field crops can bring about change in farmer’s perceptions and attitudes in the Indus River basin, resulting in motivation for agroforestry adoption.     

中国可持续农业发展中的农林复合系统评价

中国是一个具有生物地理多样性和复杂社会经济条件的大国，其农林业资源的可持续性正在受到变化的自然和社会经济环境的严峻挑战。分析表明，多样化的农林复合系统（Ａｇｒｏｆｏｒｅｓｔｒｙｓｙｓｔｅｍｓ）在中国各主要区域可持续农业发展中起着十分重要的作用。然而，适用于多样化的农林复合系统综合评价方法的缺陷，使农林复合系统具有的优势难以得到真实的反映。文章从单一目标评价、多目标评价、风险评价和社会经济评价四个方面，分析了其在中国农林复合系统评价中的应用。分析显示中国农林复合系统的评价主要局限于财务效益方法。从农业可持续发展的宏观背景出发，这显然是不够的。文章接着探讨了在人类生态学理论的基本框架中，农业生态系统分析方法、农业系统分析方法及农林复合系统设计与诊断方法在农林复合系统评价中综合运用的可能性。并指出模型方法，特别是多目标规划方法，由于其与农林复合系统多功能特性一致，具有很大应用潜力。文章最后给出了农林复合系统综合评价的理论构架，指出农林复合系统是个特殊的具有多层次、多功能和多效益特征的农业生态系统。农林复合系统的综合评价必须从可持续发展的观点出发，设计和选择包括生态、经济和社会文化方面的多目标标准体系，并在不同层次     

林农复合生态系统评价指标体系探讨

本文以生态经济学理论和系统工程学原理为基础，建立了林农复合生态系统的结构评价，功能评价，效益评价的评价指标体系，并探讨了林农复合生态系统评价指标体系设置的原则和评价方法。     

Soil Classification and Carbon Storage in Cacao Agroforestry Farming Systems of Bahia,Brazil

Information concerning the classification of soils and their properties under cacao agroforestry systems of the Atlantic rain forest biome region in the Southeast of Bahia, Brazil is largely unknown. Soil and climatic conditions in this region are favorable for high soil carbon storage. This study is aimed to classify soils under cacao agroforestry and further, to quantify carbon stocks in these soil profiles. Soil classification was performed, and the amount of C stored was estimated, based on the thickness of the soil horizons, their bulk density, and total organic carbon stored. In the sites studied under cacao, four general classes of soils were identified: Ultisols, Oxisols, Alfisols, and Inceptisols. Carbon stocks in these soil profiles showed wide variation, ranging from 719.24 to 2089.93 Mg ha^?1. Carbon stocks in soil surface and subsurface layers in different agroforestry systems with cacao (cacao cabruca, cacao?×?rubber tree, and cacao?×?erythrina) were comparable; however, total storage of organic C in these soils was higher than expected, compared to values reported for the International Soil Reference and Information Center (ISRIC), based on the FAO-UNESCO database, and were also higher than estimated regional soil data.     

Tree Quality in Agroforestry Systems Managed by Small-Scale Mayan Farmers in Chiapas,Mexico

Increasingly, plantations for food, fiber and wood, are necessary to provide a growing world population. Agroforestry systems become more and more important, however these systems usually develop in marginal conditions, limited land, restricted funding, occasional technical support and above this, there is limited documentation and evaluation of innovated traditional systems in indigenous and small-scale contexts, which challenge forest scientists. The aim of this research was to assess the quality of trees in plots managed by Mayan indigenous farmers who planted agroforestry systems with fine wood species to increase the value of land and labor in localities with highly-marginal social conditions in Northern Chiapas, México. Twenty oldest plots were selected within a group of previously established plots (eight with improved fallow, six with shaded coffee and six with maize crop associated to trees) where forest inventories were carried out in nested 100 and 1000 m²-circular plots. In all plots tree diameter, height, quality indicators and the incidence of the pest Hypsipyla grandella were measured. Trees in the maize-associated-to-trees system are favored by the practices applied to annual crop during the first 3rd–5th years, a period in which they are free from the interference of other trees and benefit from favorable light conditions, weeding and a higher intensive care from the farmer while shaded coffee and improved fallow have higher tree densities and a more closed canopy condition than maize associated to trees. In consequence, maize associated to trees shows 68.1 % stems with good form; shaded coffee and improved fallow averaged 40.5 and 39.7 % of good quality stems, respectively; improved fallow exhibited a greater number of suppressed trees than shaded coffee and maize associated to trees (p < 0.0001). In addition, maize associated to trees showed the highest proportion of trees with commercial value with 56.9 %, followed by improved fallow with 28.2 %, and shaded coffee with 11.8 % (p < 0.0001); the rest were trees with domestic uses. However, maize associated to trees significantly result with high incidence of H. grandella probably due to the crown exposure. Timber volume averaged 92.9 ± 68.9 m³ for improved fallow, 77.3 ± 24.8 m³ for shaded coffee, and 52.5 ± 39.7 m³ for maize associated to trees. The value of the fine wood represents increment in income, variety of products and self-employment for households. Nonetheless, improved fallow and coffee plantations might benefit from the elimination of competitors from larger trees to favor promising immature ones and pruning, while maize crop associated to trees might benefit from opportune pruning for controlling the stem borer as well as tree replacement to achieve long term replacement and harvesting.     

贵州喀斯特地区农林复合系统的分类

在国内外有关农林复合系统分类研究成果的基础上，结合贵州喀斯特地区的自然环境、社会经济状况以及农林复合系统的发展现状等，按功能分类法将贵州喀斯特地区农林复合系统分为4级：功能、结构、复合模式（组分）、经营方式。     

城郊农林复合生态系统建设与管理

本文通过对城郊农林复合生态系统含义、原理、管理技术等方面的论述 ,提出建设农、林、牧、副协调发展 ,集高新技术、现代农林业技术、管理技术于一体的多功能城郊农林复合生态系统 ,成为城市森林生态工程的重要组成部分     

川中浅丘农区坡地林农复合系统的水文效应

本文对坡地林农复合系统水文效应进行的研究结果表明，复合系统中林地土壤非毛管孔隙对降水的有效调蓄能力比荒草坡强；全年除了３月，５月外，复合系统农地土壤含水量均比对应的纯农地略高；采用横坡聚土垄作或土石护坎工程可有效地减少复合系统农地水土养分的流失量。     

复合农林模式中根际与非根际土壤的酶活性动态研究

土壤酶活性能够实质性的反映土地管理和土壤健康状况。为了更好的了解复合农林模式中土壤酶活性的变化规律和功效,本研究对花椒（Zanthoxylum bungenum）模式、桃树（Prunus persica var.nectariana）模式、桑树（Morus alba）模式和梨树（Pyrus pyrifolia）模式根际与非根际土壤酶活性与土壤养分进行了对比分析。结果表明：由于在林下广泛种植多年生黑麦草（Lolium perenne）,使得木本植株根际与非根际土壤酶活性没有显著的差异,但它们的活性都远远高于其对照地。除各模式多酚氧化酶活性的峰值均出现在9月份外,过氧化物酶、蔗糖酶、磷酸酶、脲酶的峰值多出现在7月和8月份。有机质与这5种土壤酶活性都有显著的正相关,而全N仅与磷酸酶和蔗糖酶有显著的正相关,pH值则与它们呈显著的负相关。植物组成可能对土壤酶活性和土壤化学性质有直接的影响。     

定西地区黄土丘陵沟壑区农林复合生态系统分类研究

在总结和参考国内外农林复合经营系统分类体系研究成果的基础上,根据定西地区黄土丘陵沟壑区气候类型、立地条件、社会经济、农林复合经营现状,以及农村经济和区域生态环境建设综合发展的需要,提出了定西地区黄土丘陵沟壑区农林复合生态系统分类原则及分类体系。     

Agroforestry adoption in the Calakmul Biosphere Reserve,Campeche, Mexico

Since farmers engage in a complex, dynamic process of learning-by-doing, evaluating economic incentives, and assessing risks in deciding whether to adopt agroforestry systems, a multi-pronged research approach is required for a complete analysis of adoption potential and to develop effective technological and institutional interventions. A case study is presented for using multiple approaches to analyse the potential for reforestation and improving livelihoods of small farmers through the adoption of agroforestry systems in the Calakmul Biosphere Reserve in Campeche, Mexico. Specifically, the results from a participatory research project are combined with revealed preference analysis of a household survey to analyse past adoption decisions and preferences, identify limitations, test and evaluate alternatives, and evaluate methods for risk reduction. The participatory research trials suggest that continuous intercropping and line cleaning are equally effective for tree growth, while continuous cropping during the first years offers the additional advantage of early returns to investments through crop production. Farmer participation in the research process, planning of production systems, and annual evaluations, assisted farmers and researchers in identifying limitations, testing and evaluating alternatives, and improving the viability and sustainability of systems. The revealed preference analysis provides insights as to which households are most likely to initially adopt agroforestry systems developed through the participatory research trials. In general, households that originated from the Yucatan Peninsula with more education, more experience both in age of the head of household and technical and project experience, higher incomes, and those that had cleared more forestland were more likely to have experimented with agroforestry systems in the past.     

干旱区木本植物盐分积累与其耐旱性的关系

通过对干旱区4种木本植物体内Na+,K+浓度和水分、光合等指标的测定、比较,分析盐分积累与其耐旱性的关系。结果表明:梭梭和柽柳能够吸收、积累较多的Na+,而花棒和沙枣组织Na+浓度相对较低;与花棒和沙枣相比,梭梭和柽柳具有较低的组织水势和渗透势、较小的蒸腾失水量和较大光合作用有效水势范围。表现为植株水势、渗透势和蒸腾失水量与其组织Na+浓度呈负相关,而光合作用有效水势范围大小则与其呈显著正相关。由此可见:盐分积累能够降低组织渗透势和水势、增强水分吸收的动力,同时还可以减少蒸腾耗水,有利于植株在低水势下维持较高的光合作用能力,即干旱地区的植物通过积盐可以增强其抗旱能力。     

川中浅丘农区坡地林农复合系统价值流的研究

本文对川中浅丘农区坡地林农复合系统的价值流进行了研究。结果表明：复合系统与对应的对服农地系统相比，前者具有明显的价值积累效应和罗高价值积累速率，其纯收益、劳动力产值分别增加２４．４６－３７．１１％和２１．０８－２９．００％。     

Agroforestry farming systems in the homesteads of Kerala,southern India

Kerala State on the southwestern coast of India in the tropical humid zone has a predominantly agricultural economy, a very high density of population and therefore high pressure on cultivable land. The farmers there undertake cultivation of an array of crops — tree crops, plantation crops, seasonals and biennials — all in intimate mixtures on the same piece of land around the homesteads. Farm animals and poultry and sometimes fisheries also are essential components of the system. The close association of agricultural crops, tree crops and animals in the homesteads represents an excellent example of sustainable and productive agroforestry homegardens. Optimum utilization of available resources of land, solar energy and technological inputs and an efficient recycling of farm wastes are important characteristics of the systems. This paper attempts to describe and evaluate the systems' stability, productivity and sustainability, and identify its merits and constraints as well as research needs.     

Agroforestry in the arid zones of India

The arid regions of India cover over 300,000 km² and are spread over six States, mostly in the northwestern parts of the country. In spite of the hostile environmental conditions, several indigenous agroforestry practices are being practised in this region. The Central Arid Zone Research Institute (CAZRI) has made considerable progress in improving these indigenous practices and also developing new land use technologies some of which involve agroforestry approaches. Notable among these include sand-dune stabilization, shelterbelt plantations, tree planting techniques in difficult land forms, silvopastoral and agrisilvicultural systems, introduction and improvement of fruit trees and other indigenous trees, etc. Some of these technologies are adopted on a large scale by farmers in the arid zone of India, and have attracted international attention in other arid parts of the world. This paper is a summary of the results of these agroforestry initiatives of CAZRI.     

Agroforestry Impacts on Soil Fertility in the Rima'a Valley,Yemen

Yemen is one of the world's least developed countries and experiences problems of scarcity of natural agricultural resources as well as soil erosion and degradation. Agroforestry systems (AFS) are being promoted as a more appropriate land use system than monocropping systems (MCS) worldwide. Unfortunately, long-term studies on agroforestry and other land use systems (LUS) do not exist in Yemen. Agroforestry in the Rima'a region has started to deteriorate and many farmers turned to (MCS). This study was conducted in the Rima'a Valley, near Alsharq town, Dhamar, Yemen. The study evaluates the soil nutrients, organic matter (OM), and other soil properties such as pH, bulk density, and porosity under AFS and compares it with soil under MCS. Standard procedures for soil sampling and analyzing were used to collect and analyze 36 composite samples from Site 1 and 36 composite samples from Site 2 from six cropping systems (treatments). The results showed that there were significant variations in relation to LUS. Agroforestry practices—mixed trees with coffee (S1), and Cordia africana L. with coffee (S2) have higher nitrogen concentration (0.17–0.26%) as compared to the Ziziphus spina-christi L. with maize (S3) and the monocropping maize (S5), (<0.16% in both Sites 1 and 2). Similar results were seen on the effect of the different LUS on the soil P, K, and OM contents at the two sites (p < .01). While soil N, P, and soil K were higher under agroforestry systems S1, and S2 in both sites, it was the lowest in S5 in both sites. It can be concluded that agroforestry has more favorable effects on soil fertility and other soil properties. The government should establish programs and campaigns to disseminate AFS technology and promote the importance of agroforestry in soil conservation.     

Bringing Agroforestry Technology to Farmers in the Philippines: Identifying Constraints to the Success of Extension Activities Using Systems Modelling

This paper presents a systems modelling approach to evaluating the success of an agroforestry extension program in Leyte, the Philippines. During the program, variables which are intrinsic to farmers’ socio-economic and farming systems were found to have influenced the uptake and acceptance of extension advice. Evaluation of the program therefore depended on identifying the variables and their interdependencies and assessing their relative influence on program outputs. For this purpose, a systems approach which encourages breaking systems into component variables, but also acknowledges the context of problems, assisted construction of models. Using both empirical data collected during program activities and input from stakeholders, Bayesian Belief Network software was used to predict critical success factors for four aspects of the overall extension system, namely recruitment, use of written extension materials, farmers’ self-efficacy and retention of participating farmers throughout the program. A key predicted constraint to program recruitment is farmers’ perception of harvest security and while this variable can be partly addressed through dissemination of information on harvesting legislation, title security cannot. Differing levels of farmers’ education result in differences in predicted reading ability, comprehension of extension literature and possible misconstrual of information. The variable most critical to the development of farmers’ self-efficacy is extended on-farm technical assistance and support.