Improved understanding of soil water content at field capacity and estimates from pedotransfer functions Andabili, Samira Jaefarzade Rasoulzadeh, Ali Moghadam, Javad Ramezani Pollacco, Joseph Alexander Paul Fernández Gálvez, Jesús The soil water content at field capacity, θFC, is a fundamental variable for irrigation and agriculture. This study determines the optimal tension ( 33 or 10 kPa) of deriving θFC which best matches the in situ field measurements following the Veihmeyer procedure. The Veihmeyer method refers to a profile water status for which there is a negligible drainage rate of bare soil without evaporation. In addition, we derive a set of linear and nonlinear pedotransfer functions (PTFs) which estimate θFC. θFC was measured in 69 plots in northwestern Iran, which has a cold semi-arid climate. The soil properties used for developing PTFs include texture, bulk density, and organic matter. The results show that θFC cannot be derived at a fixed tension. We therefore developed PTFs with satisfactory performance in reproducing in situ measured θFC. The findings show that PTFs developed at a fixed tension consistently underestimate θFC derived in situ. It was also speculated that tension less than 10 kPa could yield improved predictions of in situ θFC 2024-09-05T08:37:15Z 2024-09-05T08:37:15Z 2024-09-04 journal article https://hdl.handle.net/10481/93978 10.1002/ird.3032 eng open access Wiley