Analisis Neraca Air dan Kebutuhan Air Tanaman Jagung (Zea Mays L.) Berdasarkan Fase Pertumbuhan Di Kota Tarakan

Abstract

Abstrak. Salah satu upaya peningkatan produktivitas tanaman jagung adalah penyediaan air yang cukup untuk pertumbuhan tanaman. Tanaman jagung sangat membutuhkan air dalam proses pertumbuhan dan perkembangannya. Ketepatan pemberian air sesuai dengan fase pertumbuhan tanaman jagung sangat berpengaruh terhadap produksi. Kelebihan dan kekurangan air akan mengakibatkan tanaman jagung mengalami penurunan dalam proses pertumbuhan dan produksinya. Penelitian ini bertujuan untuk menganalisis neraca air dan kebutuhan air pada tanaman jagung berdasarkan fase pertumbuhan di wilayah Kota Tarakan. Penelitian ini dibagi dalam beberapa tahapan yaitu pengumpulan data iklim bulanan periode 2008-2017, analisis neraca air dengan metode Thornthwaite-Mather, dan analisis kebutuhan air tanaman jagung berdasarkan fase pertumbuhan. Hasil penelitian menunjukan bahwa (1) Wilayah Kota Tarakan memiliki curah hujan andalan 3497,68 mm/tahun. (2) Total surplus 2997,84 mm/tahun, limpasan 1630,31 mm/tahun, dan pengisian air tanah 1367,53 mm/tahun. (3) Selama satu periode penanaman tanaman jagung rata-rata membutuhkan air sebesar 256,55 mm. (4) Total evapotranspirasi tanaman jagung selama 4 periode penanaman sebesar 1026.18 mm/tahun dan memiliki ketersediaan air yang sangat cukup serta setiap bulannya memiliki nilai surplus sepanjang tahun.Analysis of Water Balance and Crop Water Requirements of Corn (Zea mays L.) Based on Growth Phases in Tarakan CityAbstract. The effort to increase the productivity of corn plants is the provision of sufficient water for plant growth.  Corn is a plant that needs water for the process of growth and development. The accuracy of the water supply following the growth phase of corn plants is very influential in production. Excess and deficiency of water will cause corn plants to decrease in the process of growth and production. This study aims to analyze the water balance and crop water requirements in corn-based on the growth phase in the City of Tarakan. This research was divided into several stages, namely the collection of monthly climate data for the period 2008-2017, analysis of water balance by using Thornthwaite-Mather method, and analysis of corn crop water requirements based on the growth phase. The results showed that (1) the Tarakan City area had a rainfall of 3497.68 mm/year. (2) The rainfall surplus is 2997.84 mm/year, runoff 1630.31 mm/year, and groundwater recharge 1367.53 mm/year. (3) During the one planting period, corn plants require an average of 256.55 mm of water. (4) The consumptive use (ETc) of corn plants during the 4 planting periods is 1026.18 mm/year and has a very adequate water supply and every month has more value throughout the year.