Feeding soils: Nutrient balance in the northeast of the Iberian Peninsula c. 1920

Abstract

Understanding the replacement of soil nutrients removed by har vests provides insight into human influence on land fertility. The nitrogen (N), phosphorus (P) and potassium (K) content of cropland in the province of Barcelona circa 1920 was examined with the aim of improving the methodology from a previous study of cropland nutrient balance circa 1860 in a municipality located in the same province. The main fertilization differences between the two studies involve the use of more manure per hectare circa 1920 and the occurrence of more N fixation due to leguminous crops. Though slightly negative for K, the data generally exhibited a nutrient input/extraction balance. Also noteworthy is the fact that by the latter date synthetic fertilizers had become available. The methodological limitations that constrain a full comparison of the results of the two studies have been provided. Finally, although we could not disaggregate the data on fertilizer per crop type, the results lead us to consider the relationship between fertility and inequality.