Complex sentence: Kerala was a major spice exporter since 3000 BCE, according to Sumerian records and it is still referred to as the "Garden of Spices" or as the "Spice Garden of India".
Split into simpler sentences: Kerala was a major spice exporter as early as 3000 BC, according to Sumerian records. According to Sumerian records and Kerala still referred to as the "Garden of Spices" or as the "Spice Garden of India".