Determining the wet season onset toward crop water availability under the tropical monsoon climate

Abstract

Climate change has lead to the uncertainty of wet and dry season onset. Season onset is important information for farmers to consider the agriculture activity. Climate policy in Indonesia is authorized by the Indonesian Agency for Meteorology, Climatology and Geophysics (abbreviated as BMKG in Indonesian), which determine the initial of the season based on ten-days rainfall (decadal). Water availability in the soil is not just influenced by rainfall, but also soil characteristics. This research aims to determine the season onset based on rainfall and soil moisture availability for crops under the tropical monsoon climate. Climatic and soil moisture data were collected from Karanganyar District, Province of Central Java, Indonesia in October 2016 to February 2018. Soil moisture data collected by soil moisture logger. The result found that the wet season onset for agricultural activity was different than based on climatic data.