Benih gagal tumbuh bukan kerana baja, tetapi kerana saliran kurang baik.

In this sentence, bukan is used because the speaker is rejecting one reason and replacing it with another:

bukan kerana baja, tetapi kerana saliran kurang baik
= not because of fertilizer, but because the drainage is poor

A very common pattern in Malay is:

bukan ... tetapi ...
= not ..., but ...

Even though kerana is involved, this is still a contrastive structure, so bukan sounds natural.
If you used tidak here, it would sound unnatural in standard Malay.

It is a fixed contrast pattern:

• bukan kerana X
• tetapi kerana Y

So the sentence is structured like this:

• Benih gagal tumbuh = the seeds failed to grow
• bukan kerana baja = not because of fertilizer
• tetapi kerana saliran kurang baik = but because the drainage was not good / was poor

This is directly parallel to English not because X, but because Y.

Gagal tumbuh literally means failed to grow/sprout. It suggests that growth was expected, but it did not happen successfully.

By contrast:

• tidak tumbuh = did not grow / did not sprout
• gagal tumbuh = failed to grow / failed to sprout

So gagal tumbuh often sounds a bit more specific or formal, especially in agricultural or scientific contexts.

Benih can be singular or plural depending on context. Malay nouns usually do not have separate singular/plural forms the way English does.

So benih gagal tumbuh could mean:

• the seed failed to grow
• the seeds failed to grow

Context tells you which is meant. In many practical contexts, English may translate it as seeds even though Malay does not mark the plural.

Usually, benih means seed. In farming or gardening contexts, it can also refer more broadly to planting material, depending on the crop.

Related words:

• biji = seed, grain, pip, kernel, or a small round item
• benih = seed, especially in the sense of something planted or used for propagation

So in this sentence, benih is the natural word for agricultural seed(s).

No. Saliran means drainage, not watering.

It refers to how well excess water can flow away from the soil or planting area. If drainage is poor, seeds may rot or fail to sprout properly.

So:

• saliran = drainage
• penyiraman = watering
• pengairan = irrigation

This sentence is specifically talking about a drainage problem, not a lack of fertilizer and not necessarily a watering issue.

Kurang baik literally means less good or not very good, and in context it often means poor or inadequate.

Malay often prefers softer or less absolute wording in formal or neutral statements.

Compare:

• saliran kurang baik = the drainage is not good / is inadequate / is poor
• saliran buruk = the drainage is bad

Both are possible, but kurang baik can sound a bit more measured and natural in explanatory writing.

Malay often leaves out the verb to be in sentences like this.

So:

• saliran kurang baik literally looks like drainage less-good
• natural English: the drainage is poor / was poor

This is very normal in Malay. Adjectives can function directly as predicates without a separate is/are/was/were.

Other examples:

• Cuaca panas = The weather is hot.
• Rumah itu besar = That house is big.

Malay does not normally use articles equivalent to English a/an/the.

So Malay can say:

• benih
• baja
• saliran

without adding anything like a or the.

English translation has to supply articles based on context:

• the seeds
• the fertilizer
• the drainage

This is one of the biggest differences between Malay and English sentence structure.

Yes, often it can.

• kerana = because
• sebab = because / reason

So you may hear:

Benih gagal tumbuh bukan sebab baja, tetapi sebab saliran kurang baik.

However, kerana usually sounds more formal or more suitable for written standard Malay.
Sebab is very common in everyday speech.

In careful written Malay, the original sentence with kerana is a very natural choice.

Yes. Malay word order is somewhat flexible, especially when expressing contrast.

For example, you could also say:

Benih gagal tumbuh kerana saliran kurang baik, bukan kerana baja.

That still means essentially the same thing, but the emphasis shifts slightly.
The original version is especially clear because it uses the full contrast pair:

bukan kerana X, tetapi kerana Y

That structure strongly highlights the correction of the wrong assumption.

No, but it is the standard and safest choice.

Common options include:

• tetapi = but
• tapi = but, more informal spoken form
• namun = however, more formal/literary

In this sentence, tetapi fits very well because it pairs neatly with bukan in the pattern:

bukan ..., tetapi ...

A simple approximate pronunciation is:

Benih → beh-nih
gagal → gah-gahl
tumbuh → toom-boh
bukan → boo-kahn
kerana → kuh-rah-nuh
baja → bah-jah
tetapi → tuh-tah-pee
saliran → sah-lee-rahn
kurang → koo-rahng
baik → bah-eek

A few helpful points:

• g in Malay is always a hard g, like in go
• j sounds like English j in jam
• r is usually lightly rolled or tapped
• vowels are generally pronounced clearly, not heavily reduced like in English

It sounds neutral to fairly formal, and it would fit well in:

• educational writing
• agricultural explanations
• reports
• textbooks
• news-style prose

The formality comes from words like gagal, kerana, and the clean contrast structure bukan ..., tetapi ....

In casual speech, someone might say something simpler, such as:

Benih tak tumbuh bukan sebab baja, tapi sebab saliran tak baik.

That is more conversational, while the original sentence is more standard written Malay.