Forkultiveringen krever plantejord.

Because -en is the definite singular ending here. Norwegian usually puts the definite article on the end of the noun instead of using a separate word like English the.

So:

• forkultivering = indefinite, pre-cultivation / seed starting
• forkultiveringen = definite, the pre-cultivation / the seed starting

That means the sentence is talking about a specific instance or a specific process already understood from the context.

Yes, in some varieties and writing styles you may see -a on nouns like this.

Many Norwegian nouns ending in -ing are feminine, and feminine nouns in Bokmål can often appear in two ways:

• forkultiveringen
• forkultiveringa

Both can be understandable, but forkultiveringen is a very normal Bokmål form. Forkultiveringa may sound more feminine-leaning, dialectal, or closer to Nynorsk depending on context.

Krever is the present tense of å kreve.

So:

• å kreve = to require
• krever = requires / require

A useful thing for English speakers: Norwegian verbs do not change for person.

• jeg krever
• du krever
• den krever
• vi krever

The verb form stays the same.

Because å kreve normally takes a direct object.

So Norwegian says:

• krever plantejord

not something like:

• krever for plantejord
• krever av plantejord

In this sentence, plantejord is simply the thing being required.

Because Norwegian normally writes compound nouns as a single word.

Here:

• plante = plant
• jord = soil / earth

Together they form plantejord, a compound noun.

This is very common in Norwegian. English often writes these as two words or with a different structure, but Norwegian prefers one word:

• blomsterpotte
• hagejord
• tomatplante

So plantejord follows a very standard Norwegian pattern.

Because plantejord is being used as a mass noun, like soil, water, or sand in English.

In this sentence it means the material in general, not a single unit of it. So Norwegian naturally says:

• krever plantejord

If you added en, it would sound like you were talking about one specific kind, package, or instance of potting soil, which is not the normal meaning here.

No, this is basic Norwegian main-clause word order:

• Forkultiveringen = subject
• krever = verb
• plantejord = object

So it follows the same basic pattern as English:

• The pre-cultivation requires potting soil

This is a standard subject–verb–object sentence.

Yes. That would sound more general or more like a statement about the process in general.

Compare:

• Forkultivering krever plantejord = pre-cultivation requires potting soil, as a general fact
• Forkultiveringen krever plantejord = the pre-cultivation requires potting soil, referring to a specific one or one already mentioned

So the version with -en is more definite and context-specific.

Usually it is treated as uncountable in ordinary use, just like soil in English.

That is why the singular form without an article is natural here.

You can make it plural in special contexts, for example when talking about different kinds of soil:

• ulike plantejorder = different potting soils / different planting soils

But in everyday sentences like this one, it is normally just a material noun.

It shows one of the biggest differences very clearly:

• English often uses a separate word: the
• Norwegian often puts definiteness at the end of the noun

So instead of the forkultivering, Norwegian says forkultiveringen.

That is a core pattern in Norwegian grammar. If there were an adjective, you would often see both a separate definite marker and a definite ending, for example:

• den tidlige forkultiveringen = the early pre-cultivation

So this sentence is a good example of how Norwegian handles definiteness directly on the noun.