Scientists have recently come up with a seed carrier made of wood capable of burying itself into the ground when it comes in contact with water. It is seen as something of high utility to make forest replantation projects successful by throwing these seed carriers on the ground using aerial drones. A seed casing produced using treated wood is stronger than other natural self-burying seeds and is also quite versatile as such seed casings are capable of making seed sowing process from planes or aerial drones very articulate.
SEEKING INSPIRATION FROM THE “ELODIUM” PLANT GENUS
Multiple species of plants produce seeds with such parts which effectively respond to alterations in the environmental humidity patterns to assist the seed in its protection and to bury it in the soil. Such kind of behaviour is exhibited by plants belonging to the genus Elodium. Plants which are members of the Elodium family produce seeds having coiled tails around them. These coiled tails on getting wet uncoil themselves and thus twist the seed into the deeper layers of the soil. In view, Lining Yao, who is a renowned professor at The Carnegie Mellon University of Pennsylvania describes this behaviour of Elodium plants as being developed through long processes of evolution from generation to generation.
Lining Yao with the help of her colleagues observed the behaviour exhibited by Elodium plants and getting inspired by such plants possessing self-burying seeds, designed a seed carrier capable of carrying variable sizes of seeds onto it and then twisting them into the deeper layers of soil. Such seed carriers are being designed to work efficiently in different types of environments.
CHOOSING WOOD FOR SEED CASINGS
The researchers underwent screening of many materials to choose an appropriate material for seed casings. Screening of both natural as well as synthetic materials was conducted and finally, wood from white oak was finalised to make seed casings. Wood was chosen as it would easily respond to any changes in the moisture level of surroundings. While responding, the wood would remain tough and inflexible and thus would be able to screw seeds into the soil. Another significance of utilizing wood is its biodegradable property which will pose no harm to our precious environment. The researchers also came up with a chemical treatment to make wood tightly coil itself. With this chemical treatment, the wood could be bent forty-five times more firmly than any other substitute for wooden components. This would enable the wood to exert more torque while screwing the seed into the soil. Lining Yao explains here that thrust force is proportional to the firmness of the coiled body.
The researchers have also come up with a coil possessing three tails rather than Elodium seeds having a single tail. The reasoning for the three tails given by the researchers is to make the coil end up located at a good angle to enable the seed pod to drive into the ground when it uncoils itself. These three tails would be of great advantage when seed pods are to be screwed into the flat ground.
RESULTS OF FIELD TESTS
The researchers conducted field tests on the flat ground utilising arugula seeds. These seeds were placed in 136 carriers. Around 66% of carriers successfully drove into the soil and 39% of the seeds germinated. In the field tests, it was discovered that weather plays a very crucial role. In one test, more than half of the seeds were dislodged due to heavy rains. Lining Yao opines that a good carrier would assist in making aerial seeding more efficient. Such aerial seeding could be carried out using drones or planes. Aerial seeding finds its utility when extra-large areas of land are to be planted swiftly or when the areas to be planted are arduous to access.
There is still much work to be shown by researchers that seed carriers can effectively be used in the plantations and that there is a need to manufacture them at a large scale to successfully engage in a real-time plantation programme. It is said that novel wooden materials open new possibilities for soft wooden robots capable of responding to changes in the moisture level of surroundings. Such a capability according to researchers is far ahead of what they were able to achieve before.