Estimating Chemical Properties of Florida Soils Using Spectral Reflectance

Abstract

This study was conducted to develop fundamental relationships between soil properties from three representative Florida soil orders and their spectral characteristics. The ultimate goal of this work is to develop a real-time soil property sensor for use in effective farm management. A total of 270 samples collected from the three representative soil orders (Alfisol, Entisol, and Ultisol) in Florida were used for analysis. Soil samples were obtained from 0 to 15 cm depth at 15 sampling points within three specific fields of 2.0 ha each of the three soil orders at six different times of the year, assuring a wide range of sample variability in sampling times and locations. Reflectance of the soil samples was measured in the range of 400 to 2498 nm with a 2 nm increment, and the corresponding nutrient content (P, K, Ca, and Mg) along with pH and soil organic matter content was measured for each of the samples. Partial least squares analysis was used to build prediction models with a calibration data set of 180 randomly chosen samples. The remaining 90 samples were used to validate the models. The prediction models for measured soil chemical properties for the three soil orders yielded R 2 values of 0.24 to 0.88. This result could be useful in the development of a soil nutrient sensor for site-specific crop management.

Impacts of residential fertilizer ordinances on Florida lacustrine water quality

“…The state averages 134 cm of rain each year and has wet (summer) and dry (winter) seasons, with statewide precipitation averaging 89 cm during the wet season and 45 cm during the dry season (Irizarry-Ortiz et al 2013;Data Collection Bureau 2021). The state also has a shallow groundwater table which is intimately connected to surface waters (Katz et al 1997;Sutton et al 2015) through karst topography and highly permeable sandy soils, leading to relatively rapid surface water and groundwater movement throughout a nutrient rich landscape (Obeysekera et al 1999;Lee et al 2003). Florida has 2173 km of coastline which is home to approximately 77% of the state's 19.6 million residents (National Oceanic and Atmospheric Administration n.d.;Beaver 2006).…”

Predictive Analysis of Soil Organic Matter and Moisture Content Using Image-Based Modeling

“…Many reasons contribute to the decision about the value of the SMC threshold. Few researchers also observed soil reflectance as a change in the visible region only until SMC reaches 20% [44][45][46][47]. A study suggested a critical SMC of 15% [14].…”

Pure Iodide Multication Wide Bandgap Perovskites by Vacuum Deposition

“…In a simplified view, this observation can be explained by the impact of the ionic radii of the additional cations: being smaller (217 pm), MA + would reduce the perovskite tolerance factor, slightly widening the bandgap, while FA + (253 pm) would have the opposite effect. 46 The triple-cation perovskite films were tested in n-i-p devices with the structure reported in Figure 3d. The solar cells based on the perovskites obtained with FAI showed lower performance, reaching an average PCE of 10.7%.…”