Soil Microarthropods as Indicators of Soil Health Under Agricultural Waste Treatments

Jacob Stover Author

07/15/2021 Added

25 Plays

Description

Soil quality can be analyzed in many new and different ways. An emerging soil quality indicator is the analysis of soil microarthropods. This indicator was used to analyze soil conditions upon various forms of agricultural waste application.

Searchable Transcript

Search:

[00:00:01.410]Hello everyone. My name is Jacob Stover.
[00:00:03.600]I'm a junior agricultural engineering major.
[00:00:05.920]This summer I've been working with Schmidt labs on a project using soil
[00:00:09.250]microarthropods as indicators of soil health under agricultural waste.
[00:00:12.700]So basically I've just been looking at these guys quite a bit in a lot of
[00:00:15.900]different ways. On this project have been me, Karla, Mara, and Dr.
[00:00:20.010]Schmidt. Let's get started.
[00:00:23.097]This summer we furthered our research
[00:00:24.780]into the application of agricultural waste and how to
[00:00:27.120]analyze its effects.
[00:00:28.091]Some brief background here.
[00:00:29.760]Manure is a very common byproduct and waste of agriculture.
[00:00:32.910]Another common waste of agriculture,
[00:00:35.190]especially here in the great plains, is the eastern red cedar tree.
[00:00:38.470]These trees are a harmful tree species in Nebraska that have grown out of control
[00:00:42.290]on valuable prairie and range land due to a lack of grass fires.
[00:00:45.420]Both manure and red
[00:00:46.470]cedar are composed of plentiful organic matter and nutrients. At Schmidt labs,
[00:00:50.390]we have been researching to see if grinding up eastern red cedar trees into
[00:00:53.520]woodchips,
[00:00:54.540]mixing it with various forms of manure, and applying it on corn fields will make
[00:00:58.200]a difference in soul quality. This summer,
[00:01:00.210]we decided to do something we haven't done before and look into soil
[00:01:03.160]microarthropods. Arthropods include anything that is an insect,
[00:01:07.140]crustacean, arachnid, myriapod, or scorpion.
[00:01:09.810]What we are mostly interested in is the fact that arthropods,
[00:01:12.320]especially soil arthropods, are very sensitive to changes in the environment.
[00:01:15.760]There are certain arthropods that will only really be found within soil that is
[00:01:18.840]healthier and higher in quality, making these little guys great indicators for
[00:01:22.350]soil health. This led to the creation of the EMI rating system.
[00:01:25.980]EMI is short for eco morphological index.
[00:01:28.610]This system rates arthropods from one to 20,
[00:01:30.750]with one being the lowest indicator of soil health
[00:01:33.050]and 20 being an indicator of great soil health.
[00:01:35.240]It isn't bad to have a one rated arthropod in your soil.
[00:01:37.880]The arthropod is just more likely to be found in soils that aren't as healthy as
[00:01:41.680]well or they can be found above ground as well too.
[00:01:45.470]If it's a 20 rated arthropod that arthropod reserves
[00:01:47.920]itself to higher quality soil only.
[00:01:50.160]In other words,
[00:01:51.090]it's basically a ranking for how picky an arthropod is.
[00:01:54.000]As you can see in table one here,
[00:01:56.150]many different orders are shown of different arthropods with their
[00:01:59.310]corresponding EMI rating.
[00:02:00.740]It's important to notice that there's even EMI variance within each order of
[00:02:04.190]arthropod due to different species and different adaptations within species that
[00:02:07.570]make an arthropod more soil bound.
[00:02:09.390]So now the main goal of our project is to see how woodchip and manure
[00:02:12.750]application will impact the soil arthropod diversity and abundance within
[00:02:16.260]agricultural soils, according to the EMI system. Let's get into how we did it.
[00:02:21.600]The first place to start is our research site.
[00:02:24.060]We are researching a cornfield that is nearby the village of Julian, Nebraska.
[00:02:28.420]As you can see by figure one, we use three different treatment types: control,
[00:02:32.130]which has no manure or wood chips, slurry,
[00:02:34.200]which is a manure that is anywhere from 5 to 10 percent solid matter.
[00:02:37.440]applied at 3,530 gallons per acre, and slurry plus woodchips,
[00:02:42.120]which has a 3,530 gallons per acre slurry along with 10 tons per acre of red
[00:02:47.010]cedar wood chips.
[00:02:49.228]After all the plots were set up and treated in may,
[00:02:51.550]it was time to start collecting samples. Once monthly,
[00:02:54.090]we would take 10 soil core samples from the first 8" of soil in each
[00:02:57.630]plot. This was then put into a Burlese funnel,
[00:03:00.310]which you can see here in figure two.
[00:03:02.170]The funnel has a wire grating near its bottom, which keeps the soil inside.
[00:03:05.710]A heat lamp is left over the top,
[00:03:07.820]driving the vast majority of the mobile arthropods down through the grating into
[00:03:11.500]a jar full of ethanol on the bottom. This ethanol preserves arthropods
[00:03:15.430]and gives us a medium to identify and quantify the arthropods in the microscope.
[00:03:19.540]The EMI score of each sample is found by taking the number of each type of
[00:03:23.140]arthropod and multiplying it by its corresponding EMI score,
[00:03:26.260]and then summing all these values together. For example,
[00:03:29.520]if a sample had two Acari and a Diptera, the EMI score for that
[00:03:34.500]sample would be 2 times 20.
[00:03:36.270]As you can see right there, 20, plus 1 times 10. So then,
[00:03:41.100]the score will be 50 for that sample. Then by using statistical methods,
[00:03:45.180]the three treatments were compared according to their impact on total EMI,
[00:03:48.690]as well as the correlation of total EMI to important soil quality environmental
[00:03:52.440]factors measured in this study. Let's move on to data and results.
[00:03:56.730]Overall our data shows an increase in total EMI with the application of manure
[00:04:00.750]and the manure plus wood chips mix. This is shown on figure three right here.
[00:04:05.820]So these values were obtained by averaging the sum of EMI scores for each plot.
[00:04:10.200]As you could see the control, which didn't have anything applied on,
[00:04:13.560]placed the lowest out of the three with an average score of 944.
[00:04:17.940]Next was manure at 1,194.
[00:04:21.210]And the highest placing out of the three was the manure plus woodchip
[00:04:24.420]application at 1,483. This is significantly higher than the control.
[00:04:29.910]We also wanted to see what soil quality and environmental factors have the
[00:04:33.450]greatest and least effects on the sum of the EMI.
[00:04:36.470]We analyzed this using a scale called the Pearson R Value.
[00:04:39.330]The closer the value is to one, the closer it correlates, or the closer the R
[00:04:42.990]value is to negative one,
[00:04:44.300]the more inversely correlates.
[00:04:45.991]The organic matter applied,
[00:04:47.610]which is the mass of wood chips and manure, yielded an R of 0.23.
[00:04:51.570]The soil moisture measured on a wet basis, yielded an R of 0.34.
[00:04:56.400]The soil pH, however,
[00:04:58.210]yielded a negative value of -0.085.
[00:05:02.870]This could very well be such a small number due to there not being quite enough
[00:05:06.480]time for the soil to change pH yet.
[00:05:08.250]This will continue to be analyzed in the future as well.
[00:05:11.240]Out of the four factors,
[00:05:12.490]the soil temperature was the highest correlating value with a
[00:05:17.410]correlation of 0.58. This means that the higher the temperature of the soil,
[00:05:21.580]the more arthropods will be present.
[00:05:24.260]Let's sum things up here.
[00:05:25.519]This is the key takeaway from this whole presentation.
[00:05:28.120]The manure and wood chip mix showed the highest value of arthropod diversity and
[00:05:32.170]quantity of arthropods that are good indicators of soil health.
[00:05:35.380]So according to arthropod analysis,
[00:05:37.570]the manure and wood chip application creates the healthiest soil
[00:05:40.350]out of the three applications.
[00:05:41.890]The total EMI also correlates to other soil quality indicators that were measured,
[00:05:45.793]which demonstrates EMI value as a strong soil quality indicator.
[00:05:50.220]This project is not going to be done here. Further work on this project should
[00:05:53.890]incorporate an examination of different application ratios of
[00:05:57.160]manure and eastern red cedar wood chips to determine optimal conditions
[00:06:00.490]for arthropod populations.
[00:06:02.110]After this ratio is found, testing this ratio in different soil types and
[00:06:05.540]conditions is necessary to see if this ratio can be a standard around Nebraska or
[00:06:09.680]if specialized ratios are going to have to be found in varying soil types and
[00:06:12.890]conditions. Another important element is to look at crop yield.
[00:06:16.340]If this is positively correlated with higher crop yields,
[00:06:19.190]if the arthropods are positively correlated with higher crop yields,
[00:06:22.400]this would contribute to much support for this project and further awareness
[00:06:25.970]of soil microarthropods.
[00:06:27.690]The last current thought for further advances would be
[00:06:30.000]incorporating more sensor technology to
[00:06:32.080]analyze additional environmental factors and soil nutrients in
[00:06:35.120]their impacts on soil arthropods.
[00:06:37.100]We did use some sensor technology in this project,
[00:06:39.470]but we definitely could use a lot more.
[00:06:41.340]We want to continue to be advancing
[00:06:42.740]in this as well.
[00:06:44.240]So now I would like to extend my gratitude to the Nebraska UCARE summer 2021
[00:06:48.800]program, as well as the
[00:06:50.101]Nebraska environmental trust project 18-203 fund.
[00:06:53.770]Thank you very much. This project was a lot of fun to be working on.
[00:06:56.990]I'm very grateful. So we wish to extend our gratitude to Juan Carlos,
[00:07:00.320]as well as Nancy Sibo for their assistance in sample collection, preparation and analysis.
[00:07:04.730]This research is also a continuation of a larger series of projects on manure
[00:07:08.360]and wood chips led by Linda Schott, Augustin Olivo, and Karla Melgar as well.
[00:07:12.070]Thank you all very much and have a great day.

The screen size you are trying to search captions on is too small!

You can always jump over to MediaHub and check it out there.

Comments

0 Comments

Soil Microarthropods as Indicators of Soil Health Under Agricultural Waste Treatments

Description

Searchable Transcript

Comments icon comment

Related Channels

Comments