Why is both 盐 (salt) and 咸 (salty) in 尝尝他们的盐一样咸的咸菜? From the book 活着 (on my Kindle):


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Transcribing this:

我最喜欢的是傍晚来到时，坐在农民的屋前，看着他们将提上的井水泼在地上，压住蒸腾的尘土，夕阳的光芒在树梢上照射下来，拿一把他们递过来的扇子，尝尝他们的盐一样咸的咸菜，看看几个年轻女人，和男人们说着话。

I'm interested in the part in bold, which I translate to:

... try [尝尝] their [他们的] salt [盐] type of [一样] salty [咸的] salted vegetables [咸菜] ...

Having 盐 in there makes no sense to me; it seems redundant and even ungrammatical (but presumably I'm incorrect).  Moreover, writing 咸的咸菜 seems tautological.  It seems to me that 尝尝他们的咸菜 would convey the same meaning.
Question: Why is both 盐 (salt) and 咸 (salty) in 尝尝他们的盐一样咸的咸菜?
The part is actually fine. This is a parsing problem; the whole meaning is


  trying their pickled vegetables which taste as salty as (pure) salt



「鹹菜」does not just mean salty vegetables, it's the name of a specific dish known as Chinese pickles in English.
「鹽」is used as a measure of saltiness (in taste) between Chinese pickles and pure salt.




Note that salty is actually a measure of the richness of flavour of 鹹菜, so while translating the above into English (as salty as salt) sounds a bit unpleasant, it's meant to be a praise of the tastiness of the villagers' dishes.