Experience in preserving rice after harvest.

(Baonghean)During the summer-autumn rainy season, prolonged flooding has significantly impacted rice harvesting and grain preservation. If farmers harvest prematurely due to flooding and fail to properly preserve the rice, the quality of the grains will be severely degraded, and the nutritional content and commercial value will decrease considerably. To overcome these challenges and minimize losses during harvesting, farmers need to apply the following basic techniques:

Dry

In rainy conditions, with low temperatures and no modern drying systems, farmers have to dry rice using ventilation fans and electric lights to reduce the moisture content of the grains. They spread the rice in rows on a dry surface, each row about 10-15cm high and 40-50cm wide, and turn the rice over every half hour to prevent the grains from overheating.

In addition, rice can be dried using artificial methods such as: drying rice with hot air, convection drying, radiation drying, etc. These methods have the advantage that rice can be dried at any time and are not dependent on sunny or rainy weather, the moisture content of the grains can be reasonably controlled within a limited time, and during milling, the rice recovery efficiency is higher compared to natural drying.

Under favorable weather conditions, rice is usually dried using the following methods:

Fast drying: Rice is dried in direct sunlight, with air temperatures reaching 40°C. Temperatures on cement or brick surfaces can reach 60-70°C, meaning the rice grains can exceed 50°C. This method requires continuous drying from 8-9 AM to 4-5 PM for 2-3 sunny days before milling is complete. The rice is dried in rows, each row about 10-15 cm high and 40-50 cm wide, and is turned over every half hour. However, this method results in cracked grains during milling, and a high percentage of broken rice due to insufficient time for water to evaporate.

Longer drying: This method requires more time and labor, but the rice is less likely to be broken. The rice is spread out in rows as described above, but on the first day, it is only dried in the sun for 2 hours, on the second day for 3 hours, and on the third day for 4 hours. It is raked and turned every 15 minutes. For the first 3 days, after drying in the sun, the rice is moved to a shady place, the more ventilated the better. On subsequent days, the rice is continued to be dried for 5-6 hours/day until it reaches the appropriate moisture level for milling or storage. If the sun is good, by the fourth day, the moisture level of the rice will be sufficient for milling and storage.

Tran Thi Hoai Phuong