Rain and Dew..

There is a difference between praying  to Hashem to provide income  or praying for your income to be protected.

The Gmarra in Taynis equates parnassa with "G'shamim" (rains). It says the key to Parnassa that is in the Hands of Kavyachol is synonymous with the key for Rain. 

There are differences in Halacha in how one prays for dew.

Dew  is not considered something as necessary for growth as is rain,  matar.

The reason that Nusach Sfard says “Morid Hatal” is because in the summer, the sun in Eretz Yisroel, is very intense. When the sun is that intense, it can literally burn up the fruit that have already grown, especially the fruit that's not in the shade. When there's dew that surrounds the grapes, it protects the grapes from being burnt up by the sun because it takes dew long to evaporate a so the grapes are being warmed, but they're not being burned, since that layer of dew is protecting them.

Ashkenazim do not have a special "bakasha" for "tal, which means there is no special "bakasha" for that which will protect.  However you can be "Mazkeer" it when mentioning the praises of Hashem in the second Bracha of Shmone Esray.  It is part of the praises of the Ribono Shel Olam  because the fact that you produce the dew is such an incredible thing. It is an incredible thing of how it protects!

Eidut Mizrach, Sfardim and Nusach Ari, say Bareich Aleinu that special  Bracha  from the summer because you need protection from the sunlight.

So that means that there are different opinions and therefore different approaches in Tefillah.

These ideas shared are from Machberes Avodas Hashem