Experience in soaking, sowing, and caring for rice seedlings in the spring crop.

(Baonghean)Soaking and germinating seeds may seem like a simple task, but every production season sees numerous cases of seed soaking and germination failure due to various reasons. Besides poor seed quality, common causes include: insufficient watering (not enough soaking time), preventing the seeds from absorbing enough water to convert starch into sugars for germination. Conversely, soaking seeds for too long causes the endosperm to rot, the starch to ferment, and the entire seed to rot.

There are also many cases where seeds are soaked in enough water, but are severely damaged during germination. These include cases where the seeds don't sprout at all, or if they do sprout, the percentage of germinating seeds is very low. This often happens in the spring, because the seeds weren't properly covered during germination, and the outside air temperature was too low (16°C or below), resulting in insufficient warmth for the sprouts to develop into seedlings.

Additionally, there are cases where seeds after germination exhibit short roots and long sprouts, or long roots and short sprouts. This is because the seeds were not saturated with water before germination (lack of water), resulting in long sprouts and short roots. Alternatively, the seeds may have been compressed too tightly during germination and not properly mixed, depriving the sprouts of air to breathe, leading to short sprouts and long roots.

To overcome the aforementioned shortcomings, we suggest that farmers implement the following measures:

- Before soaking, seeds should be dried in gentle sunlight for 1-2 hours to increase their water absorption capacity.

- Soaking seeds: In the spring planting season, the weather is often very cold, with air temperatures below 17-18°C. Therefore, the seeds' ability to absorb water is very slow. So, spring seeds should be soaked in warm water at 54°C (3 parts boiling water + 2 parts cold water) to help them absorb water quickly and also to kill fungi and bacteria parasitic on the rice husk. The average amount of water for soaking is 1.5 liters per 1 kg of seeds.

- Soaking time and technique: Soak the seeds in warm water at 54°C (3 parts boiling water + 2 parts cold water) for 5-6 hours. Then, remove the seeds, rinse them thoroughly, and replace the water with clean water. During soaking, change the water every 5-6 hours for a total of 28-30 hours. After soaking, remove the seeds, rinse them thoroughly until they no longer smell foul, then place them in a basket or container for germination.

During the composting process, regular checks must be carried out by:

If your hand dries when you dip it into the seed-germinating container, immediately spray water on it and mix the seeds to ensure they have enough moisture.

If your hands get wet and sticky when you dip them into the seed-germinating basket, you must immediately wash off the stickiness with water before continuing to germinate the seeds. If you don't wash the seeds promptly, they won't sprout and will rot.

If you dip your hand into the middle of the basket of germinating seeds and find it cold, you need to spray warm water on the seeds and mix them well so that the seeds have the conditions to germinate.

If you see that the seeds have germinated, but the sprouts are long and the roots are short, you must spray more water on them, mix the seeds, and continue incubating them. Conversely, if the sprouts are too short and the roots are too long, you must mix the seeds from the inside out, from the outside in, from top to bottom, and from bottom to top to provide enough oxygen for the sprouts to develop.

During the germination process, if the sprouts have grown to about two-thirds the length of the roots, then it's time to transplant them to the field for sowing.

When sowing rice seedlings, ensure the field is free of weeds, the soil is thoroughly plowed and leveled, the beds are 1.2 – 1.4 meters wide, and when sowing, sow evenly and gently toss the seeds so that 2/3 of the seedling is buried in the soil.

After sowing, cover the seedling beds with plastic sheeting and regularly maintain the soil around the seedlings to prevent cracking.

When the seedlings have 2.5-3 leaves, they can be transplanted. Three to five days before transplanting, the plastic covering should be gradually removed to allow the seedlings to acclimate to unfavorable external conditions, thereby increasing their resistance to adverse weather.

Doan Tri Tue