Friday, December 24, 2021

GROUND TEMPERATURE --Cultivated vs Uncultivated ground

 I'm redoing a study I did back in 2015-2016 on temperature differences in different ground conditions.  Those earlier findings can be seen by clicking on "tests" in the labels section and scrolling to the bottom to "HOBO Temperature Sensors" posting.

This current study is starting on 12/24/21 in near freezing, snowing conditions. Temperature readings will be taken every 2hrs until we start seeding the spring crop in spring of 2022, around April.  There will be an update to this posting after seeding.  I started this study by spading and working up two areas to replicate a cultivated field with little surface residue.  I'm comparing this with field conditions where there is surface residue left undisturbed.  All the sites are within throwing distances of one another, one in long term CRP ground and the other in ultra low disturbed no-till crop ground.  We have had some variable weather ranging from freezing to thawing, and mixtures of rain and snow for the past week.  The field aspects are similar from one site to the other.  One difference showed immediately.  The worked CRP field had no sign of frost(pic upper left showing a lot of living roots), where the cropped field showed frozen soil about an inch deep (pic lower left showing some non-living roots).
These observed conditions support the idea that there is more biological activity in the CRP field where the grass roots are living, hence a warmer microclimate in the root zone, compared the the cropped field where there has not been living roots to stimulate biological activity for five months.  Biological activity creates heat.
    HOBO temperature/light sensors (model UA-002-08) will be placed on the surface and at the 2" depth in the cropland sites.  This is my primary interest, to see if there is a temperature difference between cultivated and uncultivated ground, both surface and subsurface locations.  The inclusion of CRP ground is to see how ground temperatures differ between cropped ground with it's limited time supporting living roots, and ground that continuously supports living roots. 
     Once put in place, these sensors will stay until recovery in early spring.  They don't support remote monitoring or downloading. 

The pic to the left shows a typical plot from the data collected with the HOBO (UA-002-08) sensor for temperature and light. A (HOBO) sensor and the "reader" is shown above the wireless keyboard and trackpad.