Pk Ramachandran Nair

University of Florida | UF · School of Forest Resources and Conservation

During the past few decades, commercial silvopastoral systems (SPS) with exotic Eucalyptus (hybrid) trees have become popular in the Brazilian Cerrado (savanna). With the increasing awareness about the role of carbon (C) storage in soils as a climate-change mitigation strategy and the relationship between the nature of soil aggregates and the soil’...

This chapter discusses the significant role agroforestry systems (AFS) play in realizing ecosystem services other than soil productivity improvement, climate change mitigation, and biodiversity conservation. Such “other” services include the improvement of hydrological characteristics and water quality, socio-cultural and recreational services, and...

Agroforestry homegardens consist of multispecies combinations of a variety of economically useful plants including trees, shrubs, vines, and herbaceous species, often grown in association with livestock, in small landholdings around or adjacent to the home. These unique farming systems founded on generations of experience and traditional knowledge...

This chapter briefly explains the fundamental processes that support plant production on Earth and clarifies the several terms and methods used for measuring and expressing plant productivity. Photosynthesis is the process by which green plants and some other organisms use sunlight (solar energy) to synthesize carbohydrates (chemical energy) from c...

The multipurpose tree (MPT) is a term that is used almost exclusively in tropical agroforestry. In a general sense, the perennial and taller plant components of agroforestry systems (AFS) are referred to as trees, but the MPTs are woody species that are deliberately kept and managed for more than one preferred use, product, or service. Such species...

Silvopasture is a broad term encompassing different forms of integrating trees, forage, and domesticated animals on the same unit of land. The practice ranges from the traditional, extensive animal grazing under woodlots and forests to modernized intensive forms of tree–animal integration. These can broadly be grouped under two categories: grazing...

Recognized for long as the kingpin of agricultural soil management, soil organic matter (SOM) has attained added importance lately because of its significant role as a carbon sink. This chapter will focus on the issues related to SOM in soil productivity enhancement, which is of special relevance to the nutrient-depleted tropical soils; issues rela...

Since its modest beginning in the late 1970s, agroforestry has become widely recognized and accepted as a sustainable approach to land management the world over. Although the international investments in agroforestry research and development have been comparatively meager, those investments have paid off extremely well. The role and potential of ag...

The term agroforestry was coined in 1977 as part of the early international efforts to initiate research on integrated production systems involving crops and trees. Numerous discussions and arguments were held during those early days to define and characterize agroforestry, and several definitions were proposed. This chapter reviews the development...

This chapter examines the role of agroforestry in carbon sequestration (CS) and climate-change mitigation (CCM) based on the scientific hypotheses, research results, and observations accumulated so far. Since the emergence of climate change (CC) as a prominent global issue in the late twentieth century, agroforestry has received immense attention a...

This introductory chapter traces the historical evolution and development of agriculture and forestry as separate disciplines and chronicles how the demands and challenges of the post-World War II era led to the emergence of agroforestry as an interface between the two. The Green Revolution technologies of the late 1900s paved the way for increasin...

The main purpose of a classification scheme is to provide a practical framework for the synthesis and analysis of the information about existing agroforestry systems (AFS) and the development of new and promising ones. During the early stages of AF development in the tropics, a substantial database was generated from a global inventory of tropical...

Biological Diversity, or biodiversity, refers to all living things and the interactions among them, including the diversity within species, between species, and of ecosystems. Agricultural biodiversity or agrobiodiversity is a subset of biodiversity including all crops and livestock and all interacting species of pollinators, symbionts, pests, para...

Biological nitrogen fixation (BNF) refers to the process by which the nitrogen that is present abundantly in the atmosphere as non-reactive molecular dinitrogen (N2) is converted into reactive forms that become available to plants and thereby to all life forms. The key process of BNF is the conversion of N2 to ammonia (NH3) catalyzed by the enzyme...

The shaded perennial systems, also called plantation-crop combinations, include managed multistrata tree-crop associations predominantly in the tropics, in which the main crops are perennials that are harvested periodically like arable crops. These tree crops are economically and socially very important to the countries where they are cultivated be...

This chapter examines the role of agroforestry systems (AFS) in fulfilling the demands and expectations of food security and the related United Nations Sustainable Development Goals (SDGs). These issues are particularly focused on developing countries, where the predominance of small farms is a distinguishing feature. The definition of a small farm...

Plant component interactions refer to the effect of one plant (component) on another or the whole system. In agroforestry systems (AFS), since the woody perennials are dominant components, these interactions are usually referred to as tree–crop interactions or tree-animal interactions. Early assessments of the potential interaction effects in agrof...

Proper management of soils has been central to the welfare of human society since very early times. An understanding of the nature and properties of soils is, indeed, critical to the success of any land-use system. Since the beginning of agricultural research in the mid-1800s, soils and soil-related aspects including plant nutrition were dominant t...

In land-use parlance, the terms tropical and temperate are used loosely as approximate synonyms for developing countries and industrialized regions, respectively. From the agroforestry perspective, the arid and semiarid lands, and the subhumid and humid lowlands and highlands recognized in the FAO reports are considered as tropical developing regio...

Shifting Cultivation or swidden farming is considered the oldest form of agriculture. It refers to the traditional, centuries-old farming system, in which land under natural vegetation is cleared, cropped – usually with food crops – for a few years, and then left untended allowing the natural vegetation to regenerate; a few years later, the farmer...

The concept of soil conservation has evolved over several decades to include both the prevention of soil loss and reduction of its productive capacity. Land degradation, an allied term, refers to any change or disturbance to the land perceived to be deleterious or undesirable. Both these terms are prominent components of soil health, a term that ha...

The temperate countries/regions considered in this chapter include the USA and Canada, Europe, southern Australia and New Zealand, parts of China, and the southern regions of South America, with the primary focus on North America and Europe where agroforestry has made significant strides. Historically, natural forests and woodlands were used for gr...

Alley cropping is an agroforestry practice of growing an arable crop between rows of trees or perennial shrubs. In tropical alley cropping, the perennial species, usually leguminous trees or shrubs, are planted and managed as hedgerows less than 10 m apart with the crop planted in the interspaces or alleys between the hedgerows. The trees are prune...

Agroforestry – the practice of growing trees and crops in interacting combinations – is recognized the world over as an integrated approach to sustainable land-use. Agroforestry systems, being multifunctional, facilitate not only the production of food and wood products but also provide a variety of ecosystem services such as climate-change mitigat...

Ecosystem services (ES) are the benefits that people obtain from ecosystems. The term became popular in both scientific literature and common parlance around the turn of the century. The concept of ecosystems as the organisms and the non-living environment with which they interact has been popular for a long time, but it was not until the latter pa...

This chapter deals with a vast array of complex and diverse systems and practices that are little known outside the limited regions where they are practiced but are revered by the local inhabitants for their multiple products, outputs, and services. The term Cinderella agroforestry systems is used to refer to such “downtrodden” or little-explored s...

Planting and managing native fodder trees and shrubs on degraded lands offers a promising approach to establishing resilient silvopastoral systems (SPS) in the semiarid Caatinga region of Brazil (Pinheiro & Nair, 2018). Although several examples of such successful smallholder initiatives are available, their experience is seldom known or recognized...

In Brazil, silvopastoral systems (SPS) are practiced in about 2 million hectares with Eucalyptus hybrids as the main tree species, and the area is increasing because of governmental incentives. To understand the influence of such systems on soil organic carbon (SOC) storage, we studied C content in three aggregate size classes in four land-use syst...

Although several studies on carbon sequestration under agroforestry systems (AFS) are reported in the literature, they are highly variable in the study procedures as well as the nature of systems and study locations. This makes it difficult to extrapolate the results to broader contexts of systems and locations outside the specific locations of the...

Agricultural production systems have become highly dependent on chemical products and technological inputs resulting in ecosystem degradation on a massive scale. To minimize external fertilizer inputs, use of biochar that can be obtained from locally available farm materials could substitute or complement the use of synthetic products. Wide differe...

The underlying principles and traditional knowledge concerning indigenous agroforestry systems (AFS) around the world have been used successfully in the design of improved systems; but lately there has been a slow-down in that effort. Recognizing that Cinderella, by analogy, refers to an individual whose attributes were unrecognized or one who unex...

Biochar as a soil amendment in land-use systems has attained prominence recently; numerous studies in different parts of the world have reported a variety of beneficial effects of biochar. Considering that several soil constraints limit agricultural production in Brazil and that biochar occurs naturally in the Brazilian Amazon (locally known as “Te...

Properties of biochar are thought to determine whether phosphorus (P) sorption or increased P availability occur following biochar application to sandy acidic soil; the effect of soil properties on P retention in biochar-amended acid soils remains largely unexplored. Our objective was to determine effects of hardwood biochar and poultry litter bioc...

http://www.agroforestry.eu/conferences/III_EURAFConference#Programme

Forage legumes are known for their capacity to fix atmospheric N2 and to improve nutritive value of livestock diets by providing higher levels of crude protein (Sollenberger et al., 2014). Benefits from tree legumes also include ecosystem services such as C sequestration, nutrient recycling from deep soil layers, provision of shade for livestock, a...

This paper introduces the work and diversity of the Council for Frontiers of Knowledge (CFK). In a series of vignettes relating to the intellectual interests of some of the leading academics working with the CFK, both the mission and the trans- disciplinary oversight of the agency are explored.

The perception that agroforestry systems have higher potential to sequester carbon than comparable single-species crop systems or pasture systems is based on solid scientific foundation. However, the estimates of carbon stock of agroforestry systems in Africa — reported to range from 1.0 to 18.0 Mg C ha−1 in aboveground biomass and up to 200 Mg C h...

Writing and publishing a paper always takes more time than originally estimated. Definite instructions are not available on when and in what order the different sections of a paper should be written. The most recommended strategy is to formulate a plan for the paper and start assembling its essential parts as the research progresses and develop a s...

A poster presentation is a visual communication tool and hence presents a different set of challenges than that of an oral presentation. Proper writing tools such as the format for tables and figures that are used for oral presentations and manuscripts are applicable to poster presentations as well. A poster should focus on presenting a single idea...

The most widely accepted criterion for journal quality is its Impact Factor (IF); the higher the value the better the rating. Nowadays all journals require that the manuscripts be uploaded online following the menu-driven instructions. All journals follow the “blind” peer-review procedure for getting an objective assessment of the scientific qualit...

Tables and figures are used to present quantitative data and clear illustrations of trends or comparisons. Although not essential in a paper, they are often an integral part of most scientific papers. Tables are for presenting exact numbers; figures show trends and features. Tables are used to summarize numerical values to facilitate their interpre...

Most scientific papers are prepared according to a format called IMRAD. The term represents the first letters of the words Introduction, Materials and Methods, Results, And, Discussion. It indicates a pattern or format rather than a complete list of headings or components of research papers; the missing parts of a paper are: Title, Authors, Keyword...

Good scientific writing involves use of simple terms and sentences to communicate even a complicated subject. Complex, hard-to-understand sentences are rarely good, and repeated use of unnecessarily difficult words and phrases makes the subject hard to understand. Some important issues of this nature considered in this chapter are: active vs. passi...

While scientific writing provides an opportunity for disseminating the knowledge gained in research findings to others, another means of communicating new research results is through oral and poster presentations at meetings and conferences. This is the most likely form of scientific communication among peers, especially for early results. Oral pre...

Choice of appropriate words enhances the presentation quality of a research paper. Common issues of use and misuse of words include: gender bias, modifiers, idioms, jargon, verb-based noun, collectives, spelling (US vs. UK forms), specialized words, and similar words with different meanings. Examples of each category are provided to illustrate the...

Writing a good scientific paper involves skillful assembly of the various components of the paper. For accomplishing that, well established guidelines and procedures need to be followed in the use of numbers, units, abbreviations, and such other features. The common norms and rules for the use of these “nuts and bolts” are described in this chapter...

The purpose of this book is to help early career professionals in agriculture and natural resources write their research papers for high-quality journals and present their results properly at professional meetings. Different fields have different conventions for writing style such that the authors of the book have found it difficult to recommend to...

The conversion of natural habitats to unsustainable land use practices that continues in many developing countries can further degrade the agricultural landscape and hinder the development of rural areas. Agroforestry is one of the approaches being used to addressing this problem. Acquiring the information pertaining to such sustainable practices a...

Agroforestry refers to the growing of trees and crops, sometime with animals, in interacting combinations on the same unit of land. Although such practices were prevalent for many centuries in different parts of the world, scientific efforts to understand and utilize their sustainability attributes and production benefits started only in the late 1...

Agroforestry practices, such as Shaded Coffee and Homegardens, may provide habitat for forest butterflies and contribute to their conservation in fragmented agricultural landscapes. To determine the influence of agroforestry practices in an agricultural mosaic, the distribution of fruit-feeding butterflies was studied using a systematic approach th...

Current and comprehensive textbooks that portray the latest developments in a subject are the key to successful transfer of knowledge in the subject. In the field of agroforestry, we have witnessed a proliferation of publications during the past two decades, consisting of peer-reviewed articles in a number of world’s leading scientific and thematic...

Agroforestry systems (AFS) have attracted special attention in climate change mitigation and adaptation (M&A) discussions. Various reports on carbon (C) sequestration (and therefore climate change mitigation) potential of different AFSs have been reported from different ecological regions. However, the site-specific nature of AFS and lack of unifor...

Given the recognized role of agroforestry systems (AFS) in climate change mitigation through carbon sequestration, it is important to have rigorous and consistent procedures to measure the extent of C sequestration. The methods used currently vary widely and the estimations entail several assumptions, some of which are erroneous. Large-scale global...

Agroforestry systems (AFS) based on cacao (Theobroma cacao L.) may play an important role in capturing carbon (C) aboveground and storing it belowground (soil) through continuous deposition of plant residues. Cacao AFS in Bahia, Brazil, are comprised of cacao planted either with woody species such as Erythrina spp. and Gliricidia spp. or under tree...

While the biological and ecological role of agroforestry (AF) on climate change mitigation has received considerable research attention lately, the role of socio-psychological factors in this context has been left largely unexplored. Socio-psychological variables such as culture, demography, economy, and social values play important roles in farmer...

The methods used to estimate carbon sequestration in agroforestry systems (AFS) vary widely. Consequently, there is enormous inconsistency in the available datasets. Moreover, the estimations entail several assumptions, some of which are erroneous. A serious one is that C in the biomass and soil are equated to sequestered C. The amount of C stored...

The Brazilian savanna, known as the Cerrado, extending over 200 million ha, is the largest neotropical savanna in the Americas. With its ongoing conversion to intensive agriculture since the 1960s, of which cultivated pastures for beef cattle production is a major form, this unique ecosystem is now considered threatened. Given the recognized role o...

Consequent to the interest in converting degraded lands for cultivation of biofuel crops, concerns have been expressed about greenhouse gas (GHG) emissions resulting from changes in soil-carbon (C) stock following land conversions. A literature-based study was undertaken for estimating the magnitude of emission of GHGs, particularly carbon dioxide...

The extent of carbon (C) stored in soils depends on a number of factors including soil characteristics, climatic and other environmental conditions, and management practices. Such information, however, is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths (0-25, 25-50, 50-75, and 75-100...

Investments in agroforestry research during the past three decades-albeit modest-have yielded significant gains in understanding the role of trees on farmlands, and the ecological and economic advantages of integrated farming systems. While early research focused mostly on farm or local levels, broader-level ecosystem services of agroforestry syste...

Soil particle size and land management practices are known to have considerable influence on carbon (C) storage in soils, but such information is lacking for silvopastoral systems in Spain. This study quantified the amounts of soil C stored at various depths to 100 cm under silvopastoral plots of radiata pine ( D. Don) and birch ( Roth) in comparis...

Silvopastoral management of fast-growing tree plantations is becoming popular in the Brazilian Cerrado (savanna). To understand the influence of such systems on soil carbon (C) storage, we studied C content in three aggregate size classes in six land-use systems (LUS) on Oxisols in Minas Gerais, Brazil. The systems were a native forest, a treeless...

A study was conducted on a Red Bay sandy loam soil (Rhodic Paleudult) in Jay, Florida, USA, to investigate how interspecific interactions between pecan (Carya illinoensis K. Koch) and cotton (Gossypium hirsutum L.) would affect cotton leaf morphology and gas exchange and thereby biomass and lint yield. We quantified specific leaf area (SLA), specif...

Agroforestry—the practice of growing trees and crops in interacting combinations—is recognized worldwide as an integrated approach to sustainable land-use. It is estimated to be practiced over 1 billion hectares in developing countries, and to a lesser extent in the industrialized countries. Agroforestry systems (AFSs) are believed to have a higher...

The extent of carbon (C) sequestration in soils under agroforestry systems in relation to soil types (fraction sizes) and vegetation structure remains largely unexplored. This study examined soil C storage, an indicator of C sequestration potential, in homegardens (HGs), natural forest, and single-species stands of coconut (Cocos nucifera), rice (O...

Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection of soil organic C (SOC). The main objective of this study was to characterize SOC storage in re...

Silvopastoral systems that integrate trees in pasture production systems are likely to enhance soil carbon (C) storage in lower soil layers due to the presence of deep tree roots. To quantify the relative soil C contribution from trees (C3 plants) and warm season grasses (C4 plants) in silvopastoral systems, soil samples were collected and analyzed...

Soil organic matter (SOM), which contains more reactive organic carbon (C) than any other single terrestrial pool, plays a major role in determining C storage in ecosystems and regulating atmospheric concentrations of carbon dioxide (CO2)^1^. Agroforestry, the practice of growing trees and crops in interacting combinations on the same unit of land^...

Agroforestry is recognized as a strategy for soil carbon sequestration (SCS) under the afforestation/reforestation activities, but our understanding of soil carbon (C) dynamics under agroforestry systems (AFS) is not adequate. Although some SCS estimates are available, many of them lack scientific rigor. Several interrelated and site-specific facto...

Conservation of biodiversity in protected areas will be more challenging if local communities are heavily dependent on them for various products and subsistence needs. This study estimated forest dependency and identified factors influencing dependency for households living around Kasané Forest Reserve (KFR Data collected from 237 households were a...

Consequent to recent recognition of agricultural soils as carbon (C) sinks, agroforestry practices in the West African Sahel (WAS) region have received attention for their C sequestration potential. This study was undertaken in the Ségou region of Mali that represents the WAS, to examine the extent of C sequestration, especially in soils, in agrofo...

Conservation of biodiversity and mitigation of global warming are two major environmental challenges today. In this context, the relationship between biodiversity (especially plant diversity) and soil carbon (C) sequestration (as a means of mitigating global warming) has become a subject of considerable scientific interest. This relationship was te...

During the past three decades, agroforestry has become recognized the world over as an integrated approach to sustainable land use because of its production and environmental benefits. Its recent recognition as a greenhouse gas–mitigation strategy under the Kyoto Protocol has earned it added attention as a strategy for biological carbon (C) sequest...

AE443, a 7-page fact sheet by Solomon G. Haile, Clyde W. Fraisse, P.K. Ramachandran Nair, and Vimala D. Nair, is part of the Greenhouse Gas Mitigation in Forest and Agricultural Lands series. It provides basic information about greenhouse gases (GHGs), the greenhouse effect, and global warming, and sources of GHG emissions from forest and agricultu...

Compared with open (treeless) pasture systems, silvopastoral agroforestry systems that integrate trees into pasture production systems are likely to enhance soil carbon (C) sequestration in deeper soil layers. To test this hypothesis, total soil C contents at six soil depths (0-5, 5-15, 15-30, 30-50, 50-75, and 75-125 cm) were determined in silvopa...

The recognition of agroforestry as a greenhouse-gas mitigation strategy under the Kyoto Protocol to the United Nations Framework Convention on Climate Change (UNFCCC) offers an opportunity to agroforestry practitioners to benefit from the global Carbon (C) credit market. Our knowledge on this important topic from the semiarid regions such as the We...

Multiple Land-Use SystemsAgro ForestryPlant Species for AgroforestryThe Systems Perspective of AgroforestryWhither Agroforestry?ReferencesDiscussionReferences

Worldwide, fruit-tree-based agroforestry systems have been only modestly studied, although they are common on smallholder farms. Such systems based on apple (Malus spp.), peach (Prunus spp.), and pear (Pyrus spp.) are common in northwest Guatemala as low intensity homegardens and are known to increase total farm productivity in communities where fa...