Soil Systems

low-cost, biodegradable and chemical free SAP made out of orange peels and avocado skin, it has a better water absorbing ability, yields moist soil and supports the greatest plant growth.

All experiments were performed at 21 degrees Celsius. Each pot received a constant 500 lumens of artificial sunlight.The boiling liquid of three oranges served as the ‘Orange peel Solution.’ The cut up sun dried orange peels and avocado skins baked with previous boiling liquid then crushed, served as the ‘Orange peel powder.’ The crushed powder mixed with the sun dried orange and avocado peels served as the ‘Orange peel mixture. 5g of Orange Peel Solution, Orange Peel Powder and Orange Peel Mixture variables were placed into 3 separate glass beakers 200ml of distilled water was added to each beaker. Each beaker was left for ten mins .The amount of retained water was calculated as follows;

(Gs-Gi)/Gi

where Gs is the weight of the swollen sample .Gi is the initial weight of the sample.Four planting containers were filled with 1 kg of top soil. Each pot received a different sample or variable.25g of Orange peel powder, 25g of orange peel solution and 25g of orange peel mixture served as the experimental group; and one planting container containing no sample served as the control. Each sample was mixed with the soil and saturated with 100ml of water on day 0.

It can be safely assumed that a shortfall of 20% of regular rainfall will cause crop and water shortfalls in any region accompanied by social and economic hardship. Currently effects on agriculture can be seen in summer crops,  crop plantings were severely damaged by the drought and heat experienced. Summer crops have also been affected, which has negatively impacted Zimbabweans food security. Zimbabwe usually exports maize; however Zimbabwe will be required to import 5 to 6 million tons of maize to meet the country’s demand. This  also resulted in an increase in food prices in Zimbabwe. SAPs have great water absorption capacity relative to its own weight which improves soil moisture. Most commercially found SAPs are prepared from acrylic acid and cross-linked by solution or suspension polymerization.However, post consequences of commercial SAP absorbed by the root of the plant, ultimately penetrate into the roots of crops and may cause noxious effects on the consumers. Current manufacture of SAPs involve toxic residual by-products which have the ability to heavily pollute the environment. I sought to create a product that can improve soil quality,preserve water and resist drought therefore producing a better environment for crops to grow. It mustbe harmless and non-polluting with super water absorbing ability and water preserving ability. The SAP makes use of naturally found polysaccharide in orange peels, naturally occurring oils in avocado skins and is thermally cross-linked. The product is fully biodegradable, low-cost and has better water retaining properties than commercial SAPs.

Zimbabwe is presently experiencing one of the worst droughts in 30 years, with the lowest ever rainfall since 1991. In 2020, Zimbabwe received only an average of 550mm, which is merely 61% of the annual average rainfall. This matter has to be urgently addressed, with food sources under severe strain and still household food security being a major concern. However, a clear solution would be Superabsorbent Polymers (SAPs). SAPs absorb and carry about 300 times its weight in liquid relative to their own mass. When a SAP is cross-linked with polymerization, the product is water retaining hydrogels that act as a reservoir of collected water in soil. However, these SAPs are not biodegradable, costly and full of acrylic acid, sodium hydroxide and other chemicals. During more research in the topic, I found that natural occurring polymers exist in most citrus fruits. Orange peels contain over 64% of polysaccharide making it a candidate for biodegradable polymer. However, the polymer has to be cross-linked usually requiring chemicals such as Sulphur and Hydrochloric acid. I have explored an organic cross-linking method using UV light and heat. Emulsion polymerization was then conducted by using natural oil found in avocado peels and adding it to boiled orange peels. The product is then left in the sun, utilizing photo polymerization. The product should be able to retain large amounts of water and combat the effects of drought on crops by retaining soil moisture, whilst still recycling waste products of the juice manufacturing industry.

It can be safely assumed that a shortfall of 20% of regular rainfall will cause crop and water shortfalls in any region accompanied by social and economic hardship. Agricultural drought is defined by a lack of soil water to support the growth of crops, caused by too little rainfall. Currently effects on agriculture can be seen in summer crops, especially maize, could not be planted in many areas and crop plantings were severely damaged by the drought and heat experienced. Soya, sorghum, groundnuts and sunflower crops have also been affected, which has negatively impacted Zimbabweans food security. Zimbabwe usually exports maize; however Zimbabwe will be required to import 5 to 6 million tons of maize to meet the country’s demand. This will also resulted in an increase in food prices in Zimbabwe. Dry weather conditions and lack of regular rainfall encourages water conservative technology of Superabsorbent polymers (SAPs). My experiment was conducted independently and I carried out the investigation at my house. Throughout the course my experiment great care was taken when creating and measuring the various superabsorbent polymers. 

I selected this stage because I have tested the product I made in my community. I have tested the product using the crops and my house and haven't engaged individuals in my community. I would like to experiment further with my orange peels SAP in experiment testing water filtration and oil removal from water. I would also like to make larger amounts of orange peels SAP and apply it to crops such as maize and wheat in poorer communities in Zimbabwe. In conclusion, I am delighted with the result that I have created, a Superarbsorbent polymer with no chemicals and entirely made out of waste products. With the use of the orange peel SAP, in agricultural drought disaster areas food security could increase by 73%.

I used agricultural and farming technology which was already there. For example in my case I produced a low cost biodegradable polymer which was not produced up to date. Using the knowledge of SAPS that was already there but used alternative ways to solve and alternative techniques to solve the problem.

The project is currently not serving any one but I plan to serve more than half of the population in Zimbabwe in order to minimise drought in Zimbabwe.

I plan to experiment further with my orange peels SAP and experiment testing water filtration and oil removal from water. I would also like to make larger amounts of the polymer and apply it in farms. With the production of larger amounts of the SAP, food security could increase by 73%.

Monitoring Soil Moisture of plain topsoil

 Soil Sample Preparations

Four planting containers were filled with 1 kg of top soil. Each pot received a different sample or variable. 25g of Orange peel powder, 25g of orange peel solution and 25g of orange peel mixture served as the experimental group; and one planting container containing no sample served as the control. Each sample was mixed with the soil and saturated with 100ml of water on day 0. No additional watering was performed during the experimental period, which lasted 21 days.

 Monitoring Soil Moisture and Growth of Vegetables (Covo)

The next experiment was performed to observe the effect of the ‘Orange peel mixture’ on the growth of plants, applying the results of the soil experiment in a real-life situation. Planting pots were used again to store the vegetables used in this experiment. 1 kg of topsoil was used as the control; 25 g of ‘Orange peel mixture’ was used as an experiment group. The plants used in this experiment were vegetables and they were all of the same size as of Day 0. To saturate each pot, 100 ml of water was used on Day 0. As in the soil experiment, no additional watering was done after Day 0. The soil moisture, number of growing flowers and plant height in cm were measured and recorded each day for 20 days.

In order to greatly reduce the effects of little rainfall in my country and many, large amounts of Superabsorbent polymers should be produced. Since the polymers are made from biodegradable substances it means less cost compared to those made in industries but for us to produce as many polymers it needs money so as to apply it in our farms but as of now I can easily say that the barrier I have is research because I have to keep on researching on how I will further experiment with my project.

Delivering the product will be selling to individuals so they can apply in their farms.

I am not working with any organisation

I think this will be an opportunity to showcase my potential and advance. I would like to further experiment my project by testing water filtration and oil removal from water using this same project. 

I think this will be an opportunity to showcase my potential and advance. I would like to further experiment my project by testing water filtration and oil removal from water using this same project.