Guardamos la semilla local para la cosecha.

Guardamos comes from the verb guardar. In this sentence, it means we keep, we store, or we save.

In an agricultural context, guardar la semilla often means to keep seed for future use, such as planting later.

This is different from:

• salvar = to save/rescue
• ahorrar = to save money/time

So here, guardar is the natural verb for keeping seed aside.

Because Spanish often drops the subject pronoun when the verb ending already shows who is doing the action.

• guardamos = we keep/save

The ending -amos tells you the subject is nosotros.

So:

• Guardamos la semilla local... = normal, natural Spanish
• Nosotros guardamos la semilla local... = also correct, but usually only used for emphasis, contrast, or clarity

For example:

• Nosotros guardamos la semilla, pero ellos la venden.
  We keep the seed, but they sell it.

Yes. For -ar verbs, the nosotros form is the same in:

• the present: we keep/save
• the preterite: we kept/saved

So guardamos can mean either:

• we keep
• we saved
• we stored
• we kept

You need context to know which one is meant.

In your sentence, if the meaning shown to the learner is present-time, then it is being understood as we keep/save.

In Spanish, la semilla can be used as a collective or mass noun, meaning seed in a general sense, not necessarily one single seed.

So:

• la semilla = seed / seed stock / seed supply
• las semillas = seeds, individual seeds, or different kinds of seeds

In farming, guardar la semilla is very natural if you mean keeping seed for future planting.

So the singular does not necessarily mean only one seed.

In Spanish, most descriptive adjectives normally come after the noun.

So:

• la semilla local = the local seed

That is the standard word order.

If an adjective comes before the noun in Spanish, it often adds a more subjective, literary, or emphatic feeling. But with local, the normal position is after the noun.

So la semilla local sounds natural, while la local semilla would sound unusual in ordinary Spanish.

Here, local means from the local area or locally produced.

So la semilla local suggests:

• seed from this region
• local seed varieties
• seed that belongs to the local agricultural tradition

It does not mean small or nearby in a vague way. It specifically refers to something from the place itself.

Para usually expresses purpose, intended use, or destination.

So para la cosecha means something like:

• for the harvest
• for harvest
• intended for the harvest

It tells you why the seed is being kept or what it is for.

This is different from por, which usually relates more to:

• cause
• reason
• exchange
• movement through
• duration

So para is the right preposition for the idea of keeping something for a future purpose.

Spanish uses the definite article more often than English.

So Spanish may say:

• la semilla
• la cosecha

where English might simply say:

• seed
• for harvest

In this sentence, the articles make the nouns sound like known or understood things in context:

• the local seed
• the harvest

This is very normal in Spanish, even when English would sound more natural without the.

Cosecha most directly means harvest or the harvested yield.

It can refer to:

• the act of harvesting
• the harvest season
• the produce that is harvested

It is not exactly the same as:

• cultivo = crop / cultivation / the growing of plants

Depending on context, English might translate the whole phrase more naturally in different ways, but cosecha itself is basically harvest.

The sentence is understandable and grammatically correct, but in real agricultural contexts, a speaker might sometimes be more specific.

For example:

• Guardamos la semilla local para la próxima cosecha.
  We save the local seed for the next harvest.
• Guardamos la semilla local para sembrarla después.
  We save the local seed to plant it later.

Your original sentence is still fine, but para la próxima cosecha may sound a little more precise if the idea is future use.