De wisselteelt beschermt de grond.

Because Dutch normally writes compound nouns as a single word. English often uses two words, but Dutch joins them together.

So English crop rotation becomes Dutch wisselteelt.

It is made from:

• wissel = change, switch, alternation
• teelt = cultivation, growing crops

So the word literally suggests alternating cultivation.

Both wisselteelt and grond are de-words.

In Dutch, singular nouns take either de or het. Unfortunately, this is often something you simply have to learn with each noun:

• de wisselteelt
• de grond

A useful habit is to memorize nouns together with their article.

The infinitive is beschermen = to protect.

Its stem is bescherm-.
With a third-person singular subject such as de wisselteelt, Dutch adds -t in the present tense:

• ik bescherm
• jij/u beschermt
• de wisselteelt beschermt
• wij/jullie/zij beschermen

So beschermt means protects.

They are different forms:

• beschermt = present tense verb, protects
• beschermd = past participle or adjective, protected

For example:

• De wisselteelt beschermt de grond. = crop rotation protects the soil
• De grond is beschermd. = the soil is protected

This is a very common distinction in Dutch.

The sentence follows the basic main-clause pattern:

• De wisselteelt = subject
• beschermt = finite verb
• de grond = direct object

So the order is subject + verb + object, just like in English here.

Dutch main clauses also follow the verb-second rule. That means if another element comes first, the verb still stays in second position:

• In de landbouw beschermt de wisselteelt de grond.

Here grond is being used as a mass noun, like soil or land in English.

So de grond does not mean one individual piece of ground. It means the soil/land in a general sense.

This is very normal in Dutch:

• de grond = the soil / the land
• het water = the water
• de lucht = the air

It can mean several related things, depending on context.

Common meanings of grond include:

• ground
• soil
• land
• basis/foundation
• reason

In this agricultural sentence, grond most naturally means soil or land used for growing crops.

Roughly:

• de = duh
• wisselteelt = VIH-sul-taylt
• beschermt = buh-SKHERMT
• grond = roughly khront

A few important pronunciation points:

• The ch/g-type sound in words like beschermt and grond is usually more guttural than in English.
• In grond, the final written d is pronounced like t. This is very common in Dutch and is called final devoicing.

Wisselteelt is a normal Dutch word and is understandable.

Another common word for crop rotation is vruchtwisseling. Depending on the context, you may see either one. For a learner, it is useful to recognize both.

Yes. Beschermen is a regular verb.

Some useful forms are:

• infinitive: beschermen
• present singular: beschermt / bescherm
• past tense: beschermde
• past participle: beschermd

So this sentence uses a very standard, regular verb pattern.