Although oil palm is an economically important crop, widespread establishment of oil palm plantations has been an environmental disaster for tropical developing-world countries, accounting for 2.3% of global deforestation and large habitat loss, land degradation and loss of ecosystem services, among others. Increasing regulations preventing the clearing of forests in the major producing countries of Malaysia and Indonesia, and consumer-driven regulatory pressures are encouraging large Asian companies to diversify their production areas and to invest in Central Africa, including Cameroon. Cameroon was one of the first countries in the world to start large scale industrial oil palm cultivation. However, due to very low and declining yields, Cameroon remained a major importer of crude palm oil during the past three decades. Dr. Georges K. Kome and Prof. Fritz O. Tabi decided to investigate the underlying factors responsible for low and variable oil palm yields and to develop an oil palm intensification guide for increased and sustainable production.
This book analyzes factors responsible for low and variable yields in the oil palm belt of Cameroon, with a focus on pedological, climatic and management factors. Attention is paid to soil fertility and other soil-related attributes, which are missing in most studies, thereby limiting agro-technology transfer. Chapter 2 presents the situation of oil palm cultivation in Cameroon from the 1960s to 2023 alongside a review on factors causing low oil palm yields. Chapter 3 gives detailed biophysical characteristics of the oil palm belt of Southwest Cameroon with focus on climate, landscape and drainage. In chapters 4 – 7, quantitative results on factors explaining oil palm yield variations in Cameroon are presented based on primary and secondary-related data. Emphasis is on the influence of plantation age and soil parent material (chapter 4), influence of soil variability (chapter 5), soil fertility constraints (chapter 6), and the influence of plantation management (chapter 7). Chapter 8 is a synthesis of techniques most suitable for oil palm intensification with a focus on oil palm replanting, site-specific nutrient management, estimation of fertilizer rates, oil palm nutrition and nutrient sources, and methods of fertilizer placement - key factors which are indispensable for efficient plantation management and increased yields. This book is a valuable tool for investors in the oil palm sector, field assistants, estate managers, practical planters, agronomists, and anyone interested in oil palm cultivation in Cameroon and similar tropical environments and where there exist vast potentials for sustainable intensification. 
Kenneth R. Olson,
Professor Emeritus of Soil Science,
NRES, ACES, University of Illinois at Champaign.
Urbana, Illinois, USA.

As Editor-in-Chief of this book series, I welcome this volume as a contribution to a task that deserves sustained attention: building a body of agricultural knowledge grounded in the conditions, observations and research priorities of Cameroon. Its authors examine oil palm production through the soils, landscapes, plantations and farming practices of their own country. They bring local evidence into a discussion in which comparisons with better-documented production systems elsewhere can too easily take the place of investigating what happens in a particular African region.
The subject has immediate practical significance. Oil palm production raises questions about agricultural income, the use of land, the maintenance of soil fertility and the protection of forests. Decisions about plantation renewal, drainage and nutrient management have consequences that extend well beyond a single harvest. This book approaches those decisions through an examination of the coastal lowlands of Southwest Cameroon. Its value lies in the effort to make those landscapes more legible to the people who cultivate, manage and study them.
One of the book’s clearest strengths is its geographical specificity. Mon-doni, Debundscha, Bota, Mungo, Idenau and Illoani-Boa appear as places with different histories and production conditions. The authors compare plantation records, describe variations in rainfall and relief, and examine the significance of volcanic and sedimentary parent materials. Maps and climatic tables help the reader locate these differences. Such detail gives a practical meaning to the often repeated recommendation that agricultural management should be adapted to local conditions. A recommendation becomes useful when we can identify where it applies, which constraint it addresses and what evidence supports it.
The investigation of plantation age is a further valuable contribution. Chapter Four draws on yield records from six estates for the period 2005–2017 and relates them to the age of the palms. This directs attention to a management question that can remain hidden behind an apparently favourable natural environment: whether an ageing plantation can continue to justify its use of land and resources. The authors make plantation renewal an explicit subject for analysis. Their work provides a basis for further comparisons of replacement schedules, production losses during renewal and the economic circumstances of different producers. The proposed timing of replanting should be understood within the conditions studied and developed through continued agronomic and economic assessment.
The soil investigations give the book another substantial foundation. The authors examine differences between surface and subsurface soils, analyse the variability of important soil properties and assess constraints at thirteen sites. Their treatment of parent material, acidity, exchangeable bases, organic matter and drainage shows why a coastal plain that appears relatively uniform can contain very different agricultural environments. The attention paid to potassium status and its relationship with magnesium is particularly useful as a direction for subsequent field research. These findings help formulate questions that can be tested through locally designed fertilizer trials, soil and leaf analysis, and repeated observations of crop response.
The soil descriptions and analytical tables also have value beyond the immediate arguments of individual chapters. They preserve information about identifiable locations, soil characteristics and the conditions under which cultivation takes place. For later researchers, such material can provide a point of comparison when fields are revisited or management practices change. Publishing detailed observations makes it possible for other specialists to examine the interpretations, refine them and ask new questions. The usefulness of a scientific book includes the evidence it leaves available for work that has yet to be undertaken.
I also welcome the attention given to smallholders. The study of 127 producers brings farming practices and farmers’ perceptions into the discussion of yield variation. Plantation age, planting density, the choice of planting material, fertilizer use and harvesting practices are considered alongside the conditions in which households make decisions. The discussion of fertilizer costs is especially relevant. A technically plausible recommendation still has to be examined in relation to what a farmer can obtain, afford and apply. By bringing these questions together, the book creates opportunities for cooperation among soil scientists, agronomists, agricultural advisers and researchers studying rural livelihoods.
The environmental direction of the work deserves recognition. The authors repeatedly return to improving production on land already under cultivation and to the need to conserve remaining forests and wetlands. They ask how plantation renewal, residue management, more precise nutrient application and attention to drainage might contribute to this task. This is a useful way to frame a research programme: identify the causes of low productivity in existing plantations, investigate the feasible remedies and assess their wider consequences. The environmental performance of each intervention will require examination in its own setting, but the emphasis on understanding and improving existing agricultural systems is a constructive starting point.
The final chapters connect diagnosis with possible action. They discuss replanting, nutrient recycling, soil and plant analysis, fertilizer management and the financial constraints that affect implementation. The concluding discussion identifies work still to be done, including field trials on different soils and the development of recommendations appropriate to Cameroon. I regard this as one of the volume’s important achievements. It helps turn a broad concern about declining and variable yields into a set of researchable questions. Those questions can guide student projects, repeated field measurements and longer collaborations among research institutions and producers.
For me, the significance of this book also concerns who undertakes this work and who determines its priorities. African specialists should have the opportunity and the confidence to initiate investigations of the problems they know through sustained professional engagement. They should be able to formulate the questions, assemble the evidence, publish their findings and lead the programmes that follow. Knowledge of a place develops through access to its fields and records, communication with its producers, and the ability to return and observe change. Researchers working within those settings have much to contribute to the design and continuity of scientific inquiry.
There is no reason to postpone such work until an outside institution identifies the problem or supplies a complete research framework. Useful investigations can begin with existing plantation records, carefully documented field observations, targeted soil sampling and questions developed with farmers. Their scale can grow as methods are refined, institutions cooperate and resources become available. The task is to make each stage sufficiently clear and well documented that the next investigation can build on it. This book demonstrates the value of assembling locally relevant evidence and placing it in the public scientific record.
International cooperation has an important role in that process. Shared laboratory facilities, methodological expertise, comparative datasets and research funding can extend what a locally initiated programme achieves. The most productive partnerships give African researchers a substantial role in setting objectives, interpreting findings and deciding how knowledge will be used. Scientific independence is strengthened by the capacity to participate in such cooperation as an author and investigator with a defined contribution. It also requires rigorous methods, transparent reporting and a willingness to test and revise interpretations. These are conditions for durable scientific authority in every country.
Cameroon’s agricultural environments deserve continuing observation and research designed around their diversity. A future programme could connect georeferenced soil information with plantation age, yield histories, management records and the costs of proposed interventions. Repeated sampling and field trials would allow the relationships identified here to be examined over time. Work with smallholders could help determine which improvements are feasible in practice and what forms of advice or support they require. The present volume offers material from which such a programme can be developed; its continuation will depend on sustained local leadership and effective collaboration.I thank the authors for undertaking this work and for making their findings available to a wider readership. I hope the book will encourage researchers in Cameroon and elsewhere in Africa to document the environments they know, examine the problems they consider important and publish the results of their investigations. Their contribution deserves careful reading and active scientific engagement. The observations assembled here should generate further measurements, discussion and experiments. That is the future I wish for this book: to become a useful reference in an expanding programme of research led by people with a lasting interest in the land and communities concerned.
Dmitry NikolaenkoPhD, Dr. Habil.Editor-in-Chief Pollution and DiseasesEditor-in-Chief of the PD Book Series