Soil Water Processes Research Group

Our goal is to advance the science of multi-scale soil moisture monitoring and to find innovative applications of soil moisture information in agriculture and hydrology.

Soil moisture at the Konza Prairie

Installing a cosmic-ray neutron detector for soil moisture monitoring at the Konza Prairie. Picture was taken while Pedro Rossini (visiting scholar) and Nathaniel Parker (Phd student) were mounting an air and relative humidity sensor.

Turf responses to drought

A new study supported by the US Golf Association aims at studying how turf canopies respond to soil moisture deficits and how we can use soil moisture information to assist with irrigation decisions.

Visit from Australian soil scientist

Dr. Keith Bristow (CSIRO, Townsville, Australia) visited our lab and interacted with graduate and undergraduate students about their research project. Dr. Bristow was the 2018 Ellis Lecturer in the Department of Agronomy.

Team

Andres Patrignani


Assistant Professor

andrespatrignani@ksu.edu


Team leader

Nathaniel Parker


PhD Student

parkernath32@ksu.edu


Soil physical properties of the Kansas mesonet / Predicting missing rainfall events with soil moisture information

Pedro Rossini


MS Student

prossini@ksu.edu


Field- and landscape-scale soil moisture spatial variability using cosmic-ray neutron detection

Wes Dyer


PhD Student

wesdyer@ksu.edu


Turf responses to soil moisture deficits / Soil water retention curves / Soil moisture and canopy sensors


Summer Graduates

Narmadha Mohankumar


PhD Student (Stats)

meenu@ksu.edu


Research on the spatial configuration of Kansas mesonet

Mohammad Bisheh


PhD Student (Engineering)

mnajjartabar@ksu.edu


Quantifying residue cover from images using machine learning


Undergraduate Research Assistants

Caullen Sasnett


Computer Science


Soil moisture data retrieval

Spring to Summer 2018

Samuel Long


Biology/Philosophy


Soil moisture modeling / Biodegradable polymers to stop soil evaporation

Fall 2016 and Fall 2017 - Spring 2018

Vibhavi Jayasinghe


Computer Science


Soil physical properties

Spring 2017 - Fall 2017

Daphne Lofing


Agronomy


Soil moisture spatial variability / Soil color

Spring 2018 - Summer 2018

Research

List of recent publications

Reference    Data
Patrignani, A. and Ochsner, T.E., 2018. Modeling transient soil moisture dichotomies in landscapes with intermixed land covers. Journal of Hydrology, 566, pp.783-794. Download
Lollato, R.P., Patrignani, A., Ochsner, T.E. and Edwards, J.T., 2016. Prediction of plant available water at sowing for winter wheat in the southern great plains. Agronomy Journal, 108(2), pp.745-757. Download
Patrignani, A. and Ochsner, T.E., 2015. Canopeo: A powerful new tool for measuring fractional green canopy cover. Agronomy Journal, 107(6), pp.2312-2320. Download
Patrignani, A., Lollato, R.P., Ochsner, T.E., Godsey, C.B. and Edwards, J., 2014. Yield gap and production gap of rainfed winter wheat in the southern Great Plains. Agronomy Journal, 106(4), pp.1329-1339.
Patrignani, A., Godsey, C.B., Ochsner, T.E. and Edwards, J.T., 2012. Soil water dynamics of conventional and no-till wheat in the Southern Great Plains. Soil Science Society of America Journal, 76(5), pp.1768-1775.

Lab

The soil water process laboratory combines traditional and state-of-the art instruments and methods for analyzing soil physical properties.


Particle size analisys

The hydrometer method is part of our routine analyses for determining soil texture, particularly when handling dozens to hundreds of samples. We use the method described by Gavlak et al., 2005. The image shows one of our lab becnhes with 24 samples. The method is relatively simple and accurate for many practical applications.


Cosmic-ray neutrons

Our lab has a state-of-the-art roving cosmic-ray neutron detector for collecting soil moisture obsrvations at the hectometer scale while driving. This innovative tool allow us to characterize the soil moisture spatial variability of entire watersheds and to validate remote sensing soil moisture products.


Soil water retention

Hyprop is one of our new favorite instruments. Capable of continuously measuring soil matric potential in the range between saturation and about 100 kPa. We can now create detailed soil moisture release curves using undisturbed soils.


Soil water retention

Tempe cells are part of rouine analyses for measuring soil water retention at soil matric potentials ranging anywhere between 5 kPa and 80 kPa. We used them very often, particularly in combination with our Eijkelkamp kit for taking undisturbed soil samples.


Saturation point

A relevant soil physical property that is straight forward to measure. We usually leave unsaturated samples partially submersed in 5 mM solution of calcium chloride until pores spaces at the soil surface are filled with the solution (distinctive shiny surface). Fine-textured soils that require many days to reach saturation are typically placed into a vacuum vesiccator to speed up the process.


Soil water retention

Pressure plates are one of the most iconic instruments of a soil physics lab. Typically used for measuring soil water content between 1 bar and 15 bar. Although it can take several weeks to months until soil samples reach equilibrium, pressure plates are ideal for processing large batches os samples.


Saturated hydraulic conductivity

A permeameter for up to 10 samples for measuring hydraulic conductivity using either the constant head or falling head method. Rings from our Eijkelkamp sampling kit fit perfectly in this instrument, minimizing the manipulation of undisturbed soil samples.


Suction table

A traditional suction table (also known as sand box) to accurately measure soil water retention in the range between 0.1 and 10 kPa. It can hold up to 40 samples of 5 cm in diameter. We usually include two check samples to ensure our measurements are within known standards.


Water bath

A versatile water bath for experiments that need rigurous temperature control. Cole-Parmer water bath has ample space to accomodate different sensors and their cables.


Drying ovens

Multi-purpose drying ovens used for determination of soil gravimetric water content and dry biomass.


Truck

A four wheel drive Dodge Ram dedicated to our program allow us to travel and collect data at anytime during the different growing seasons. Whether we need to go to the Konza Biological Research Station after a substantial rainfall event or drive many hours with our cosmic-ray neutron detector, the truck is a vital tool for field data collection.


Soil water potential

A dew point potentiameter is sueful when we need to measure the dry end of the soil water retention curve or we just need to know the osmotic potential of the soil solution. We often times pair the WP4C with the hyprop to generate soil water retention curves.