Use of Mud in Traditional Seed Storage Methods of Tamilnadu
Seed storage was a common practice in Tamilnadu till a few decades back. They were very precious to us, to the extent that they were even stored in the Kalasas of temples.
Excess seeds from harvest, or seeds required for the next farming cycle were stored and used when necessary. These storage methods also help in saving food for emergency situations, famines and droughts.
Seed Storage techniques have been used traditionally for many centuries in Tamilnadu. They need to be stored in the right temperature, Wind movement and humidity for them to last long. The seeds need dry conditions devoid of any moisture, to maintain its sprouting capacity and to prevent insect,bacteria or fungal attacks.
Our ancestors have developed passive methods of climate control to store their precious seeds in the optimum conditions. Let's look at how Mud helped them achieve this.
Mud as a material is living and by itself is a thermal regulatory system capable of doing different things at once. It plays a major role in heat insulation. Mud acts as a battery that stores the Sun's heat in the morning and releases it slowly at night, maintaining favourable temperature dynamically as the day changes. Mud is porous in nature and has the ability to absorb moisture from the air and evaporates it, thereby also cooling the building. In addition to being a thermal regulator, mud can also regulate humidity. Many seed storages made of mud are found to maintain the same inner temperature and humidity throughout the day, creating appropriate conditions for preservation of seeds.
Lets look at some popular Methods of Traditional seeds Storages made of Mud :
Thombai is constructed on a raised platform with minimum or no contact to the ground. It is usually constructed outdoors, for families that cannot accommodate grains inside their house.
The main structure is made with bamboos and covered with mud on top.The bamboos are split and weaved together to form a skeletal structure and mud is daubed on top of it to fill the gaps and maintain the desired conditions. The roof of these small structures are made with thatch grass available locally.
Usually these are constructed fast depending on their preferences starting from 1m tall to even 3m high. Upto 500kg of seeds can be stored in this Thombai.
This is an indoor Seed storing method which is built and plastered, primarily of mud. Built inside the house according to preference, these structures are used for storage of high quantities of Grains. It is usually built about 1.5m in height and lime washed occasionally to prevent any pest attacks.
Kuthir is basically a Seed storage Pot. The size, design and shape of each pot varies among each families and also the climatic zones. This pot is made with mud mixed with Koda(varagu) millet straw. The pots are made as tall as possible, usually reaching upto 6 feet high. This pot is usually made in layers of 1 feet as separate pieces and finally joined together to form a single unit.
The grains are stored from the top at once and sealed with mud. When one needs to take the grains, they access the pot from a hole at the bottom of the pot.
With the size of the pots varying there are different regional names given to them. A large Seed storage pot is called Koon, while a smaller version is Kuthir. These pots are often limewashed or given a coat of thin cow dung plaster.
This is an outdoor storage method done with Straw and mud. The straw from the grain harvests are made into long ropes which are wound around a bamboo skeleton to form a structure. Then it is plastered with mud, cowdung and lime. The roof of this small structure is made with local thatch grass.
Many different leaves and barks, cow dung, camphor, ash, lime, turmeric are used with the seeds, in the preservation and protection from insects, fungi and bacteria.
In Northern parts of India, there are many more methods depending on their climatic conditions that uses mud to preserve the seeds.
Inter-connectedly, the practise of storing seeds got lost with the introduction of modern
construction materials. Seeds cannot be stored in the right conditions in cement silos or plastic
barrels for more than 3 months. If not, artificial dehumidifiers and dryers need to be used to
standardise the conditions. Without any energy-fueled systems, Naturally mud has the potential
to maintain the most favourable conditions passively.