Analisis Curah Hujan pada Sistem Pranata Mangsa: Studi Kasus Penentuan Pola Tanam di Kabupaten Boyolali

Prosiding Seminar Nasional 2011 'Strategi Reduksi dan Adaptasi Perubahan Iklim dalam Bidang Pertanian', Yogyakarta, 29 Oktober 2011, p. 212-224Climate determines the failure or success of farming, therefore the understanding of the climate must be known by farmers. To reduce the risk of crop failure due to climate, the farmers in Central Java and Yogyakarta, always use a natural phenological (especially climatic and other biota behavior on the climate) as an indicator of the determination of Planting Pattern (cropping calendar, cropping intensity and crop rotation). Natural phenological are used as reference Pranatamansa. The existence of climate variability caused by the presence of anomalies or aberrations in global climate, it is currently difficult to predict climatic conditions as well as in the past 10 years. Compared with the climatic conditions at 10 - 20 years ago, that fact is happening now is a change at the beginning of the rainy and dry season, rainfall distribution and amount of rain that makes the system becomes ineffective used Pranatamangsa as a reference for the determination of Planting Pattern. Based on the above problems then the rainfall data analysis was performed on each Mangsa (12 Mangsa-Season) in Pranatamangsa system embraced by the people of Central Java. From the analysis of rainfall on any Mangsa that are then expected to be used as a guide for the farming community to revise the cropping pattern of paddy and pulses (secondary food crop). The study was conducted in Boyolali District with priority study areas in rainfed areas (Subdistrict Nogosari, Ngemplak and Andong). Based on the research results can be concluded that District Boyolali have changes on rainfall distribution patterns in a variety of Mangsa for the period 1969-1978, the period 1979 - 1989 and 2000-2009 periods. This condition affects the determination of cropping patterns, especially the determination of cropping calendar in each period. In the period of 1969-1978, peak rainfall occurs in Mangsa 7th (December-February), while the period of 1979-1989, peak rainfall occurs in Mangsa 6th (November-December) and the period from 2000 to 2009 the peak rainfall occurs in the Mangsa 7th (December-February). Subdistrict Ngemplak has a Planting Pattern: a). Paddy (conventional methods) - Paddy (SRI-Water Use Efficient Method) - Not Cultivation or b). Paddy (conventional method) - Secondary Food Crop - Not Cultivation. Early land preparation and seedling rice plants can be started Mangsa 5th (13 / 14 October - 9 / 10 November). While that subdistricts Nogosari and Andong in Boyolali District, has a Planting Pattern: Paddy (conventional method) - Secondary Food Crop - Not Cultivation. Early land preparation and seedling rice plants can be started Mangs 5th (13 / 14 October - 9 / 10 November