نظام الرش الآلي صالح للعمل.

There is no separate word for is in the present tense here. This is a nominal sentence in Arabic:

• نظام الرش الآلي = the subject
• صالح للعمل = the predicate

So Arabic simply says, in effect, The automatic spraying system fit for operation, and English supplies is: The automatic spraying system is fit for operation.

If you wanted a past-tense version, Arabic would use a verb such as كان.

It is built from:

1. an iḍāfa (possessive/genitive construction):
   
   • نظام الرش = system of spraying / spraying system
2. plus an adjective:
   • الآلي = automatic / mechanical

So the structure is:

• نظام = system
• الرش = the spraying
• الآلي = automatic

A very literal reading is the system of automatic spraying, which in natural English becomes the automatic spraying system.

Because نظام is the first word of an iḍāfa construction.

In an iḍāfa:

• the first noun usually does not take الـ
• the second noun determines whether the whole phrase is definite or indefinite

So:

• نظام رش = a spraying system
• نظام الرش = the spraying system

Even without الـ on نظام, the whole phrase can still be definite because الرش is definite.

Grammatically, الآلي most directly describes الرش, because adjectives in Arabic normally follow the noun they modify and agree with it.

So the structure is:

• الرش الآلي = automatic spraying
• نظام الرش الآلي = system of automatic spraying

In natural English, that often becomes automatic spraying system.

If you wanted to make it clearer that automatic describes system, a more explicit Arabic wording would be:

• النظام الآلي للرش = the automatic system for spraying

Because adjectives in Arabic agree with the noun they describe in:

• definiteness
• gender
• number
• case

Since الرش is definite (الرش), the adjective must also be definite:

• الرش الآلي = the automatic spraying

If the noun were indefinite, the adjective would also be indefinite:

• رش آلي = automatic spraying

Because the main subject of the sentence is نظام, and نظام is masculine singular.

The predicate adjective therefore appears in the masculine singular form:

• نظام ... صالح = a system ... fit/suitable

If the subject were a feminine singular noun, you would expect صالحة instead.

صالح means something like:

• fit
• suitable
• serviceable
• valid
• usable

The phrase صالح للعمل means fit for work/operation or ready for use.

In technical contexts, it often suggests that something is operational or suitable to be put into service.

The preposition لِـ often means for.

So:

• العمل = work / operation
• للعمل = for work / for operation

With صالح, Arabic commonly uses لِـ to show what something is suitable for:

• صالح للاستعمال = suitable for use
• صالح للشرب = suitable for drinking
• صالح للعمل = fit for operation/work

Also, لِـ + الـ becomes لِلـ in writing and pronunciation:

• لِ + العمل = للعمل
• pronounced roughly lil-ʿamal

A fully vowelled version would be:

نِظامُ الرَّشِّ الآلِيِّ صالِحٌ لِلْعَمَلِ

Breakdown:

• نِظامُ
  nominative (-u) because it is the subject of the nominal sentence

• الرَّشِّ
  genitive (-i) because it is the second term of the iḍāfa

• الآلِيِّ
  genitive (-i) because it is an adjective describing الرش

• صالِحٌ
  nominative (-un) because it is the predicate

• لِلْعَمَلِ
  genitive after the preposition لِـ

In normal everyday Arabic writing, these short vowels are usually omitted, which is why you see:

نظام الرش الآلي صالح للعمل.

In this kind of sentence, the predicate is often indefinite.

So Arabic naturally says:

• النظام صالح = the system is suitable

not usually:

• النظام الصالح = the suitable system

The second one is not a complete sentence; it is a noun phrase. It means the suitable system, not the system is suitable.

So:

• نظام الرش الآلي صالح للعمل = complete sentence
• نظام الرش الآلي الصالح للعمل = noun phrase, something like the automatic spraying system that is fit for operation