Book excerpt: Wide coverage of soils and perennial cropping systems in the tropicsSynthesis of decades of researchChallenges assumptions on the benefits of plantations for soil fertilityIt is generally assumed that soil fertility decline is widespread in the tropics and that this is largely associated with annual cropping and subsistence farming. In contrast, perennial plant cover (as in plantation agriculture) provides better protection for the soil.This book reviews these concepts, focusing on soil chemical changes under different land-use systems in the tropics. These include perennial crops, annual crops and forest plantations. Two case studies, on sisal plantations in Tanzania and sugar cane in Papua New Guinea, are presented for detailed analysis. The author demonstrates that soil fertility decline is also a problem on plantations.