Process of soaking and composting winter-spring rice seeds

Properly soaking seeds helps seeds germinate evenly, limits pathogens and reduces seed loss when sowing. In the Winter-Spring crop, you need to pay attention to keeping it warm, changing the water regularly and not letting the sprouts grow too long.

Summary: In the Winter-Spring season, the weather is cool, sometimes cold, so soaking seeds cannot be done lightly. Seeds need to be selected cleanly, treated for pathogens, soaked in enough water and then incubated at a stable warm temperature. The goal is that the seeds crack evenly, the roots just sprout, they are not sour, they are not hot, and they do not let the sprouts get too long before sowing.

Applies to: Rice varieties sown in the Winter-Spring crop, especially in the Mekong Delta and areas with cold nights.
Duration: Usually 3-5 days from processing to sowing, depending on variety and temperature.
Difficulty level: Basic. Need to follow each step correctly and check regularly.
Estimated additional costs: Low, mainly preparation, clean water, lime or salt if needed.

Choose seeds before soaking

Good seeds need to meet several requirements:

Exactly the same, not mixed.
Pest-free, no weed seeds.
The seeds are firm, bright, not moldy.
The germination rate is at least 80 percent.
Do not take seeds from fields with loose seeds, cotton blast or heavily weedy rice.

If the input seed is poor, soaking it thoroughly can only partially save it. The fields will grow unevenly, require many miles and will be difficult to manage later.

Remove flat and bad seeds

Grain can be cleaned with fans, sieves or 15 percent brine.

How to make salt water:

Use 1.5 kg of table salt.
Mix with 8.5 liters of clean water.
Stir until the salt solution is about 15 percent.

How to do:

Place the seeds in the salt solution.
Stir gently for about 5 minutes.
Discard floating seeds, flat seeds and bad seeds.
Remove the sunken seeds and rinse immediately with clean water.

Brine method is suitable for relatively pure breeds. After using salt water, you must wash it thoroughly to avoid remaining salt and reducing germination.

Treat seeds before soaking

The purpose of grain treatment is to reduce pathogens attached to the husk. There are two popular ways.

Treat with warm water at 54 degrees Celsius

Mix according to the principle 3 parts boiling water + 2 parts cold water. The amount of water should be 3-5 times the amount of seed for a more stable temperature.

How to do:

Place the seeds in warm water.
Stir well so that the seeds come into contact with the water evenly.
Do not use water that is too hot, because it can kill the sprouts.
After treatment, rinse again and move to the step of soaking in clean water.

Treat with 2-3 percent clear lime water

How to mix:

Dissolve 200-300 g of slaked lime in 10 liters of water.
Let it settle for 15-20 minutes.
Filter to get the clear lime water.

About 6-7 liters of clear lime water can treat 6-7 kg of seeds. Soaking time in lime water is usually 10-12 hours, then rinse with clean water.

Soak the seeds

In the Winter-Spring crop, soaking time is usually 2-3 days, depending on variety and temperature. During soaking, it is necessary to change the water or wash the seeds every 10-12 hours.

Proper soaking is when:

The grain is full of water, the husk is slightly tense.
Small white sprouts can be seen at the tip of the embryo.
Bite into the grain and see that the rice is soft, but the middle of the grain is still a bit hard.
The soaking water does not have a sour smell.

If the soaking water has a sour smell, the seeds are slimy or foamy, you need to wash immediately with clean water and then continue soaking or switch to incubation depending on the condition of the seeds.

With hybrid rice, the husk is often thin and absorbs water faster. Soaking time should be shortened by about half compared to pure rice, and water should be changed more often.

Incubate seeds

After the seeds have been filled with water, wash them, remove the remaining flat seeds and drain. Then put the seeds in a cloth bag, basket or basket, cover with a damp cloth.

The Winter-Spring crop needs to be kept warm from the beginning. The appropriate temperature is about 30-32 degrees Celsius in the early stages of incubation.

Incubation needs to be checked every 8-10 hours:

If the seeds are dry, water or rinse gently with warm water and then drain.
If the seeds smell sour, wash them immediately.
If the pile is too hot, stir gently and spread thinly.
When the seeds crack evenly, lower the temperature to about 25 degrees Celsius and cover lightly.

After about 36-48 hours, the seeds usually germinate evenly. The best sprouts are newly sprouted roots, about one-third the length of the seed. Sprouts that are too long are easily broken during transportation and sowing.

Tools that should and should not be used

Recommended use:

Clean pots, buckets, tubs for soaking.
Basket, basket, cloth bag or airy material for composting.
Clean water, not contaminated with heavy alum or chemicals.

Should not be used:

Tight nylon cover.
Old bags of stool and cigarettes.
The woven bag retains too much heat and traps air.
Dirty tools have a sour or chemical smell.

The water ratio when soaking can be referred to as 1 part seed: 3 parts water. For example, 10 kg of seeds use about 30 liters of water.

Checklist before sowing

[ ] The seeds have had their flat and bad seeds removed.
[ ] Treated with warm water or clear lime water if necessary.
[ ] During soaking, change the water every 10-12 hours.
[ ] The seeds do not smell sour and are not slimy.
[ ] The sprouts are evenly cracked, the roots are not too long.
[ ] The seeds have been drained and not clumped before sowing.
[ ] The field has been prepared, you can sow immediately.

Common mistakes

Soaking too long for fear that the seeds will not be saturated with water: the seeds will easily become sour, lack oxygen and reduce the germination rate.

Composting too hot: the heat inside the compost pile makes the sprouts weak and the seeds germinate unevenly.

Leave the sprouts too long to sow: sprouts break when scattered, plants grow sparsely and unevenly.

Use nylon bags to compost: pumpkin seeds are steamy, easily sour and locally hot.

Do not change the water during the cold season: the water can still be sour even in cool weather, especially when soaking a large amount of seeds.