baiyoudo wo tukau.

It is read:

ばいようど を つかう

More naturally without spaces:

培養土を使う。

A few notes:

• 培養土（ばいようど） = potting soil / cultivation soil / growing medium
• 使う（つかう） = to use

Also, the particle を is written を but pronounced お.

を marks the direct object of the verb.

So in:

培養土を使う

the thing being used is 培養土.

You can think of it like:

• 培養土 = potting soil
• を = marks what receives the action
• 使う = use

So the structure is basically:

[object] を [verb]

Because Japanese normally puts the verb at the end of the sentence.

So the basic order here is:

培養土 + を + 使う
object + particle + verb

This is very normal Japanese word order. English usually says use potting soil, but Japanese prefers potting soil use in terms of sentence structure.

The subject is omitted.

Japanese often leaves out the subject when it is obvious from context. So this sentence could mean:

• I use potting soil
• You use potting soil
• We use potting soil
• Use potting soil (in an instructional context)

The exact subject depends on where the sentence appears:

• in a conversation
• in a gardening guide
• on a label
• in instructions

This kind of omission is extremely common in Japanese.

使う is the plain/dictionary form.

You often see the plain form:

• in dictionary entries
• in textbook examples
• in notes or labels
• in casual speech
• in instructional writing

The polite version would be:

培養土を使います。

Both are grammatical. The difference is mainly style and level of politeness:

• 使う = plain
• 使います = polite

Not exactly.

土（つち） means soil / earth / dirt in a broad sense.

培養土（ばいようど） is more specific. It usually means prepared soil for growing plants, such as:

• potting soil
• planting mix
• cultivation soil

So 培養土 sounds more technical or gardening-specific than just 土.

It can be understood either way depending on context.

By itself, 培養土を使う。 is literally just use potting soil in plain form, but in real Japanese it may function as:

• a simple statement: (We/I) use potting soil
• an instruction in a manual or guide: Use potting soil

Japanese often uses the plain form in instructions, especially in:

• manuals
• recipe-like directions
• gardening guides
• captions

If you wanted a more explicitly polite instruction, you might see:

培養土を使ってください。
= Please use potting soil.

No, normally Japanese is written without spaces:

培養土を使う。

Spaces are often added only for learners, worksheets, or language study materials to make the sentence easier to read.

So the natural written form is:

培養土を使う。

使う is a u-verb (also called a godan verb).

That matters because its forms change in a certain pattern:

• dictionary form: 使う
• polite form: 使います
• te-form: 使って
• past: 使った
• negative: 使わない

This is a very common verb, and it is used for many kinds of use:

• use a tool
• use money
• use language
• use a method
• use a product

Yes:

• 培 = cultivate, foster
• 養 = nourish, raise
• 土 = soil, earth

Together, 培養土 refers to soil prepared for cultivation or plant growth.

You do not need to memorize the individual kanji meanings right away, but knowing the breakdown can help you remember that this is a gardening-related word.