1. Using VIS-NIR spectroscopy to predict Water-Extractable Soil Phosphorus content in Texas Vertisols

  Phosphorus (P) is an essential nutrient for plant growth. However, excessive P application can result in P accumulation in agricultural soils, increasing the risk of P losses to water sources. Water-extractable P (Pw) data are essential for assessing the risk of environmental P losses. Investigating field-scale variability of Pw using visible–near infrared spectroscopy (VIS–NIR) remains limited. This study aimed to develop an empirical relationship between Pw, soil chemical...