European colonial expansion significantly altered human-environment interactions, impacting land use, biodiversity, and climate. The 19th and 20th centuries saw accelerated landscape changes in tropical regions due to burgeoning global trade. The Philippines, with its diverse islands and successive colonial regimes (Spanish and U.S.), exemplifies the varied ecological outcomes of these transformations. This study aims to quantitatively characterize these changes by analyzing colonial censuses and datasets to assess land use, production, and agricultural yields from approximately 1870 to 1925. Understanding the localized ecological consequences of commodity production in the tropics requires multidisciplinary collaboration integrating archival research with ecological sciences. The Philippines, with its over 7100 islands and two distinct colonial periods, presents a unique case study for this type of research. Both the Spanish and U.S. administrations actively sought to integrate the Philippines into global agricultural markets, promoting the production of various commodities. While significant agricultural changes occurred, their pace and consequences varied across regions. The early U.S. period was particularly transformative, partly due to increased funding and explicit efforts to "improve" Philippine agriculture through infrastructure development, land redistribution, and the promotion of "scientific agriculture". The late Spanish period also saw policies aimed at agricultural expansion, although less well-funded. Both regimes shared a common goal: increasing the profitability of Philippine agricultural products. This concept of "agricultural improvement" was linked to emerging sciences like agronomy and the rise of statistical accounting by states. The use of censuses to measure "agricultural improvement" became prevalent, particularly under the U.S. regime. The availability of digitized census data and open-access geo-analytical tools now allows for novel quantitative analysis of these historical datasets.

Existing literature highlights the large-scale impacts of European colonialism on tropical environments, including species substitution, deforestation, and the replacement of Indigenous land use practices. However, the localized ecological consequences of commodity production in the tropics remain less well-documented due to the geographical and chronological variability of these changes. Studies have emphasized the interplay between local factors (topography, agricultural practices, population, political status) and global market forces in shaping these outcomes. The need for multidisciplinary research integrating historical data with ecological sciences has been recognized. Previous work on Philippine agriculture has suggested unprecedented changes during the Spanish and U.S. colonial periods, but the non-uniformity of these changes across provinces remains a key challenge. Existing scholarship has documented the policies and interventions of both colonial regimes but lacks comprehensive quantitative analysis of their impact on land use, production, and yields at multiple spatial scales.

This study uses data from the 1903 and 1918 Philippine Censuses and the Joseph Ralston Hayden Papers (JRH Papers), which contain national land use and production data for numerous crops from 1903, 1910, 1915, and 1920–1925, including provincial data for 1925. Data transcription and preparation involved converting various units of measurement to kilograms and addressing discrepancies between datasets. Several crops were excluded from analysis due to incomplete data or inconsistent reporting across time points. Adjustments were made to account for changes in provincial boundaries between 1903 and 1918. The analysis calculated productive yields (kg/ha) at national and provincial scales and determined the average annual growth rate of land use and production for each crop. In addition to quantitative data, the study examines non-quantitative publications and reports, such as farmers’ bulletins and agricultural manuals from both colonial periods, to understand the context of agricultural policies and best practices. The analysis focuses on thematic and structural similarities and differences in these documents to understand how knowledge was produced and disseminated. Map-making involved georeferencing a historical map of the Philippines in QGIS. The study compares the U.S. census data and JRH Papers to better understand the changes between 1903 and 1925, and uses Spanish-era agricultural manuals and export data to understand the earlier period. The qualitative analysis focuses on the goals, rationale, and underlying assumptions present in colonial agricultural publications.

At the national scale, Philippine agricultural land increased from approximately 1.2 million hectares to 3.6 million hectares between 1903 and 1925. Six crops (rice, sugarcane, corn, coconut trees, abaca plants, and tobacco) accounted for the vast majority of cultivated land. Land use for all these crops increased substantially, with the most significant growth in abaca and corn. Production of eight major agricultural products (palay, granulated sugar, abaca, tobacco, corn, copra, cacao, and coffee) also increased considerably, with the largest gains in copra, corn and palay. However, productive yields (kg/ha) for most products remained relatively constant or showed only modest increases. The year 1918 showed exceptionally high yields for some products, potentially due to factors like market conditions or data collection differences. When data from 1918 is excluded, a clearer pattern emerges: while some products like coffee, cacao, and copra exhibited yield increases, others, including sugar, abaca, corn, and tobacco, did not show significant changes. The provincial-scale analysis revealed uneven distribution of land use and production growth across regions. Mindanao experienced the fastest growth in land use, while Luzon, Panay, and Cebu had the largest total land use but slower growth rates. Provincial-level variations in production influenced national-scale trends. Figures plotting provincial-level production against land use for different crops show a strong linear relationship for most provinces, with only modest increases in yields overall. Data from the late Spanish period was less reliable and could not be directly compared to U.S. data. However, export data and historical research suggest that increased production during this period was primarily driven by land expansion, with modest gains in yields. Analysis of farmers' manuals from both periods revealed similar recommendations for agricultural practices, suggesting minimal changes in cultivation techniques between 1870 and 1925. Both emphasized the importance of soil selection, weeding, and fertilizer application, while criticizing traditional shifting cultivation practices. The study reveals increases in palay yields may be attributed to irrigation expansion.

The findings challenge the narrative of successful "agricultural improvement" during the Spanish and U.S. colonial periods in the Philippines. While both colonial administrations aimed to increase yields through "scientific agriculture," this goal was largely unachieved. The substantial increases in agricultural land and production were primarily the result of extensive expansion, rather than improvements in efficiency. The failure to increase yields in both periods raises questions about the effectiveness of colonial agricultural policies, highlighting potential confounding factors like diseases, pests, and natural hazards. The study's provincial-scale data emphasizes the importance of considering local factors such as labor practices, land ownership patterns, and regional geography to understand the varied ecological transformations. The study also indicates that the impact of colonial policies was not uniform across the archipelago. The differences in ecological outcomes between regions with diverse cropping systems and labor practices reflect the complex interplay of various factors. The findings generally support the theory of capitalist ecology, suggesting that environmental degradation is a potential outcome of capitalist-oriented market systems. The results call for future research on the local ecological impacts of agricultural expansion and the interplay of various factors in shaping these outcomes.

This study provides a quantitative assessment of agricultural changes in the Philippines during the late Spanish and early U.S. colonial periods. It demonstrates that while agricultural production and land use expanded significantly, efforts to improve yields were largely unsuccessful. The uneven distribution of change across provinces highlights the importance of considering local contexts. Future research should focus on detailed historical-ecological analyses at the local level, comparing the Philippines with other regions to better understand the diverse ecological legacies of colonial agricultural policies. The study contributes to the growing body of work on the Anthropocene, emphasizing the need for nuanced understanding of regional variation in human impacts on the Earth System.

Data limitations from the late Spanish period prevented direct comparison with the more extensive U.S. data. Some discrepancies in data reporting across the different sources were encountered and addressed to the best extent possible. The study primarily focuses on major agricultural products, potentially overlooking the impacts on less prominent crops and other aspects of land use. Changes in provincial boundaries between census years introduced challenges to data analysis and interpretation.