Does the Use of Biodegradable Materials Aid in Plant Growth?

This topic submitted by Lauren Stiebler, Michelle Kirby, Laura Krugh, and Jen Peterson on 10/10/03 .

Natural Systems 1 Syllabus---Western Program---Miami University

Introduction
Does the use of biodegradable materials enhance plant growth? We believe that yes, biodegradable materials will aid in plant growth in many different ways. First, we predict they will help the soil retain water for the plants. This means plants will require less watering and make better use of the water they receive. Second, There will be less runoff and wasted water because the materials will absorb and hold the water for the plant. With this research, we hope to successfully make use of biodegradable materials and to use this knowledge towards promoting better water usage and more efficient ways to grow plants. We think that there should be a more effective method of producing produce. If biodegradable materials help plants grow with less water, this can be helpful not only to American farmers, but also to third world countries where water is less abundant. We are interested in this project not only for our own knowledge, but also for the impact it may have in producing a more adequate food supply for the world.
Background Information
If our conclusions confirm our hypothesis, the implications this would have are huge. Our foundation is the idea that biodegradable materials can be used to aid in plant growth by reducing the amount of water necessary to grow these plants. This would by far have a huge effect on the produce industry. Agriculture is the number one consumer of water, and with our project we could perhaps reduce this consumption. Moreover, as the world becomes more populated, the necessity to produce food more efficiently increases. It is estimated that by the year 2040, the world population would have grown to 10 billion, requiring food production to triple (Groot, J.J.R. 1998. Food Supply Capacity Study at Global Scale. Nutrient Cycling in Agro ecosystems: 181-189). Water stressed countries are especially facing this problem when they realize they have too many people, a fair amount of crops, but not enough water to manage either of them.
Not all countries are as fortunate as the United States to hold large quantities of fresh water. We not only receive a fair amount of water through rain, but also house the largest fresh water aquifer, the Ogallala. The United States receives four cubic miles of rain each day, a lot of which is not put to use (http://www.co2science.rog/journal/2002/v5n3c2.htm) Furthermore, the Ogallala runs from Souh Dakota, Nebraska, Colorado, Wyoming, Kansas, Oklahoma, Texas, and New Mexico and covers a total of 800 miles north to south and 400 miles east to west (http://www.rra.dst.tx.us/gw/Ogallala_1.cfm) Despite how helpful these two facts are in American farming, we are not using these resources in a sustainable manner. For instance, when we use water in our home or in an industry, 90% of the water used is eventually returned to the environment where it then replenishes water sources (http://www.christmas-tree-farm.com/dripgarden.html). However, when water is used for irrigation, only half of it is reusable because the rest is lost through evaporation, transpiration, or is lost in transit (http://www.christmas-tree-farm.com/dripfarden.html). Moreover, about 70% of freshwater resources are globally used in irrigation agriculture (Cruins, Hendrik J.a. 2000. Proactive Contingency Planning vis-ˆ-vis Declining Water Security in the 21st Century. Journal of Contingencies and Crisis Management: 81-82). Obviously we are losing a lot of water when growing produce. This is where our project would step in and absorb a majority of the water lost. Through products such as Soilmoist, to your everyday diaper and sponge, we have chosen these items based on their absorbing abilities. Diapers are made up of super absorbent polymers that retain about 30 times their own weight in liquids (http://jrscience.wcp.muohio.edu/nsfall03/proposalmenu.html). Polymer products have amazing liquid retention, and we wanted to take advantage of this feature. We decided to choose a second polymer-based product to test: Soilmoist, a product on the market specifically used to increase moisture in the soil and aid plant growth (JRM Chemical Inc. 1998. Soilmoist Polymers Commercial Applications. Brochure). Soilmoist reduces plant watering by 50%, so we are looking forward to positive results from this product. Superabsorbants have good absorbency both in water and other liquid solutions. The copolymers (like Soilmoist) enhance the water retention in soil (Raju, K.M. 2003. Synthesis of Superabsorbant Copolymers as Water Manageable Materials. Polymer International: 768-772). The other two materials, corn cob and natural sponges, are organic and in addition to their absorbing qualities, we can discover a new use for these now ÒunusedÓ items. With these materials used as a foundation to our experiment, we are well on our way.
If our project works out, it would help all the third world countries that lack the technology to utilize what little water is available for them. The extended periods of drought that occur in Africa make farming a difficult and tedious process. Not only that but countries in Sub-Saharan Africa have minimal experience in planting and preparing for drought; only Botswana and South Africa have made efforts to develop drought response (Wilhite, D.A.A. 2000. Drought Preparedness and Response in the Context of Sub-Saharan Africa. Journal of Contingencies and Crisis Management: 63-72). Another example of a third world country that needs improvement in their water management is irrigation is India. Their booming population demands a large crop output, which was successfully fulfilled to some extent with the green revolution (Duffy, D. V. 2003. Composition and Method of Enhancing Moisture Content of Plants. Naturally Safe Technologies, Inc: 12-16). However, since they increased their productivity, they also increased their water usage. Thus, good water methods are vital to their ever-expanding population. It then goes without saying that our experiment would aid India in conserving every bit of their vital water and increase the plant productivity even more. Because vegetables are 80 to 95 percent water, their yield and quality suffer very quickly from drought (Sanders, D.C. 1993. Vegetable Crop Irrigation. Department of Horticultural Science at UNC: 1-3).
There exist a huge variety of irrigation methods available today, many of which would utilize water much more effectively. Unfortunately, history has proven that old habits die-hard. Despite the new, more water efficient methods of irrigation available, many farmers still insist on sticking to the older methods. The most effective form out there now is the drip method, yet it is also one of the least used forms of watering. With this method, a system of nozzles is planted near the roots of the produce. Thus, when these nozzles release their water, it is assured to go directly to the source (http://www/water_mgmt.com/en/technologies8.htm) This not only means that more water will be absorbed by the roots than with the conventional spray method, but that plants will need to be watered less often because they will actually be receiving most of the water let out. With our research combined with this drip method of irrigation, the water not absorbed by the plants right away would be held in the soil by our absorbent biodegradable materials. Hence when the plant then needs water again, the soil surrounding their root systems will not be depleted of water. Moreover, without our materials, the water not immediately absorbed would just seep lower and lower into the earth. This gradual infiltration not only dries out the soil, but also brings the soil nutrients down with it (Hagan, R.M. 1952. Effect of Porous Soil Amendments on Water Retention Characteristics of Soils. USGA Journal and Turf Management: 29-31). This is why cropland has to be rotated so often, because soil nutrients are depleted not only by the crops, but also by the unused water dragging them down farther into the earth.
As you can see, if our research proves correct, it could potentially have a huge impact on agriculture and the world in general. To be able to conserve fresh water better in a time when it is becoming less and less abundant is going to prove very vital in the near future. Furthermore, it has the ability to make farming more sustainable in areas where not much water is present in the first place, such as Africa, and the Midwest. This means not as much water would have to be transported unnecessarily from areas of high water content. It is now apparent that the addition of biodegradable materials to soil can be very beneficial in the produce industry.
Specific Research Design
The experimental design for this lab is to test the ability of five biodegradable materials and determine their effect on the growth of a bean plant. To test the ability of the materials to enhance plant growth, we will begin with separating the respective materials of two different varieties of corn cob pellets, Pampers diapers absorbency material, natural sponge bits, and Soilmoist pellets, into 5 different trays, one for each material, with each tray containing eight sections each, and each section having a different percentage of the respective material. We will of course maintain a constant section of a separate tray where the plant will be placed in the same watering and growing conditions as every other plant grown in the five different materials. Each tray again contains eight sections; one section will contain 10% of the ground up material with the other 90% of the mixture being soil. The next will contain 15% material and 85% soil. We will continue changing the proportions of the mixture with the other percentages of material in each section being 25%, 35%, 50%, 65%, 75%, and lastly 85% of the mixture. Our decision to mix the materials together was to gain a more favorable distribution of the substances within the soil and to achieve a balance that will hopefully help boost plant development. This method will allow us to simultaneously test which percentage enhances plant growth most effectively. By measuring the height of each plant in centimeters and making observations to the plantÕs health through its color, new leaf growth, number of new leaves, strength of plant stalk, and overall look of the plant, we can measure the growth of the plant not only through numerical measurement but through its overall health. These observations will effectively measure if any or all of the materials successfully enhance plant growth. Another area we will be measuring will be the materialÕs ability to retain water. We will achieve an effective measurement of the water let through by a specific material or specific percentage of a material by placing a cup under each section of the tray containing a different percentage of the material. The more water let through by the material the less absorbent the material is therefore the less effective the material is at retaining water. We will measure the specific amount of water loss by each section in grams by taking the weight of the cup plus the water lost by that section minus the weight of the cup to give an accurate measurement of water loss. We will be watering the plant once a week on Tuesday mornings between the time of 9:45 and 10:00 to imitate a more stressful situation on the plant than in a normal greenhouse environment. Our attempt at causing a stressful situation on the plant is in no way to mimic the rain patterns of a third world country, but we feel that if this experiment produces a favorable result, the use of these materials could be introduced as a source of aid to their difficulties with drought and concurrently plant growth. No interviews, surveys, or any such materials relating to either of those testing methods will need to be used in this experiment and are therefore not present in this section of the proposal. In the end, the best material for enhancing plant growth and retaining water will be the material and more specifically, the percent of material, which produces the healthiest plant. We believe that this plant will have retained a significant amount of water under the conditions we place it in due to our watering system.
Materials and Methods
Some important materials that we will include in this experiment are: Soilmoist, an acrylic copolymer product sold on the market to assist commercial growers, nurseries, and exterior landscapes; 2 different types of Corn Cob that not only are organic, but a low-cost alternative to enhancing plant growth; Diaper material, which has great absorption properties for obvious reasons; and natural sponges as our final substance. We are going to have five separate trays divided into eight sections each into which each tray will hold a separate material. Each section will have a different percent of the material mixed into the soil: 10%, 15%, 25%, 35%, 50%, 60%, 75%, and 85%. By having various percents included we will find out whether the old saying holds true: ÒYou can never have too much of a good thingÓ. To involve the class, we would like to have them come down to the greenhouse to water and observe our plants. We would also like to inform them about the materials we chose and show them the absorption properties of the substances. We hope that they will have a stronger understanding of our experiment and a new appreciation for the many uses of biodegradable materials.

Data Table for Plants
plants number of new leaves height (cm) amount of water in cup healthiness (coloration, apperance, etc.)
10% corn cob
15% corn cob
25% corn cob
35% corn cob
50% corn cob
60% corn cob
75% corn cob
85% corn cob
10% corn cob #2
15% corn cob #2
25% corn cob #2
35% corn cob #2
50% corn cob #2
60% corn cob #2
75% corn cob #2
85% corn cob #2
10% Soil Moist
15% Soil Moist
25% Soil Moist
35% Soil Moist
50% Soil Moist
60% Soil Moist
75% Soil Moist
85% Soil Moist
10% diaper
15% diaper
25% diaper
35% diaper
50% diaper
60% diaper
75% diaper
85% diaper
10% sponge
15% sponge
25% sponge
35% sponge
50% sponge
60% sponge
75% sponge
85% sponge
constant

Research Time Line
We hope to start our project by the last week in October. We will continue with the process of recording and watering every week on Tuesday mornings between 9:45-10:00. With ample time left before break, we will gather all of our data, analyze it, and determine which biodegradable material worked best. Thus having answered our question, we will conclude our lab report. The best is yet to comeÉ

For Results and Conclusions...To be completed later

Fee Fi Fo Fum! I smell the blood of four girls that are DONE!

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