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To capture the overall dynamics of urbanisation in the research space of FOR2432, this study tracks the land cover changes within the two transects across the rural–urban interface of Bengaluru. It covers a retrospective period of almost three decades, with observations in 1992, 2000, 2011, and 2016, based on Landsat and Sentinel satellite images, and aims at unravelling the dynamics of land use change as a prelude to deeper explorations of its drives. The spatio-temporal analysis of broad land cover classes relates it to the agricultural activities described in subsequent chapters of this volume, while for built-up land cover the focus lies on urban sprawl and the evolution of the Survey Stratification Index (SSI). The results underpin that the loss of vegetated and agricultural area increases both, along a spatial gradient towards the city, and over time. The spatial urbanisation pattern described by the SSI remains rather stable if data are aggregated over rural, transitional, and urban regions, or over six predefined strata, while individual villages show pronounced shifts in the SSI, that characterise them as nuclei of urbanisation. Characteristics of the “urban fringe” are highly variable between successive land cover classifications and have high dynamics of change.

Field margins are areas of natural or semi-natural vegetation located adjacent to agricultural fields. They form the interface between different crops and to other land use and land cover types. In most analyses of cropping patterns field margin vegetation (FMV) is neither accounted for nor is it a part of so-called natural ecosystems. Nevertheless, FMV provides important ecosystem services, is integrated in the farming practices of traditional smallholder agriculture, and contributes to farmers’ income. The area, composition and functions of FMV change as agroecosystems are transformed under progressing urbanisation, as encountered in the periphery of Bengaluru, India. This study is a first attempt to systematically assess FMV in such a context. It focuses on different characteristics of FMV along a spatial rural–urban gradient, and its interrelation with changes in crop and farm management.

Urbanisation is a global trend and a major challenge to human societies as well as to the planetary environment and resource pools, and the research landscape related to these issues is accordingly large and diverse. The collaborative Indo-German research project FOR2432 tackles urbanisation-related transformations by an interdisciplinary approach focused on the South Indian metropolitan area of Bengaluru. This editorial sketches the overarching research design, to which most of the book chapters refer, and describes some baseline characteristics of the research space. It thus illustrates the common background for the specific topics and targets of the subsequent studies collated in this volume.

Rural–urban transformation has major implications on agricultural land use. This is also the case in the southern Indian city of Bengaluru, where farmers shift from low intensity subsistence agriculture under rainfed conditions to irrigated, market-oriented production of crops and vegetables. As little is known about the effects of this intensification on water use, nutrient leaching, losses of carbon and nitrogen, and soil quality, a long-term experiment was established under well-defined on-station conditions to generate a typical intensity gradient in an in situ laboratory of change. Measurements of key agronomic, soil-related, and meteorological parameters at high temporal and spatial resolution allow to assess externalities and efficiencies of resource use and to predict long-term consequences of intensification on agricultural sustainability. The two long-term rotation experiments established under rainfed and irrigated conditions also allow to collect and calibrate ground-based multi- and hyperspectral crop reflectance data needed for upscaling to high resolution satellite images that cover a North–South research transect across the rural–urban interface of Bengaluru.

This editorial concludes the volume by reviewing the key findings of the contributions and putting them in context to each other. It highlights the challenges and merits of interdisciplinary approaches and sketches an outlook for future research.