We often see scenes like this (photo above) of padi spread on the roadway in the countryside. At times, the scene will show persons with back-mounted motor blowers or using their feet to spread the padi. How many of us understand the purpose of spreading the padi on the roadway and the process that that is taking place?
Farmers use this process to dry the padi using the heat from the sun. At the time of harvest (see photos below) the padi grains are usually ‘wet”, approximate ranges being about 80% dry material and 20% water.
Botanically, padi is considered ‘live’ material. It respires like human beings, the products of respiration are heat and carbon dioxide. The greater the water content in the padi, the greater the amount of heat and carbon dioxide produced. In the wet stage the initial heat and carbon dioxide serve to produce an even greater amount of heat and carbon dioxide, resulting in padi spoilage setting in as early as 6 hours after harvest. Farmers obtain a lower grade and income from the millers for padi with a high moisture content.
The millers incur the added expenditure of using hot air, derived from burning fossil fuels such as kerosene, dieselene, natural gas etc., to dry the padi and preserve it from further spoilage. In effect, therefore, farmers spread the padi on the roadway, as an intermediate step, to dry it to about 15% moisture content and so obtain a better grade and more income prior to taking it to the millers or use for their own purposes.
Contributed by Abraham David: The writer is a retired agricultural engineer, residing in Region #5.
