How to code multiple conditions inside if statement?
I'm not sure how quickly you soil could get dry, but I suspect what you want to do is to periodically check the dryness throughout the day. Say like every two hours:

// Check every 2 hrs (when hr is even)
if ( t.hour % 2 == 0 &amp;&amp; moistureOneSensorValue &gt;= 700 ) {...}


You could also bound it to only during the day time:

if ( t.hour &gt;= 7 // after 7a
  &amp;&amp; t.hour &lt;= 19 // before 7p
  &amp;&amp; t.hour % 2 == 1 // every 2 hrs (when hr is odd)
  &amp;&amp; moistureOneSensorValue &gt;= 700 // soil is dry
) {...}