Rainy months of July to January produce 30 cm rain per month. At driest months of February to April, rainfall averages 21 cm per month. Agriculture, tourism and marine resources are the backbone of Palauan economy. Subsistence farmers focus on cassava, taro, sweet potato, banana and coconut. There exist 15 commercial farms that grow vegetables and are mostly located in the biggest island of Babeldaob.
Some islands are of limestone formation.
Two of them are platform and reef islands, while one is a coral reef. The usual traditional way of planting crops is accompanied by the addition of organic matter. The soil is dug and set aside. Compost and other green plant materials like leaves, twigs and grasses are added then covered with small amount of loose soil. Crops are planted and some organic materials and sometimes ash are added.