Paper Title
Role of Biochar and Watering Frequency on Soil Water Availability for Corn Growth at Suboptimal Soil

Abstract
Ultisols is a soil order having been further weathered. The soil which is dominated by claycan retain high amount of water, but less available for plant growth. This research was aimed to evaluate the role of biochar in improving plant available water for corn growth at Ultisol as a suboptimal soil. Biochar was applied for 0 and 4 t/ha and mixed uniformly with soil. By using polybag, corn was planted and maintained under field capacity until the crop was 6 weeks in age after emergency. For the following 4 weeks (between 1.5 – 2.5 months old) the crops were treated with different frequency (once a day, once in two days, and once in three days) of watering. The result showed that plant height was significantly different between with and without application of biochar and. Watering frequency gave significant impact on corn growth and yield, as well. Corn dry matter(DM) slightly increased by biochar application, but limiting watering frequency from once a day to once in two days or in three days significantly decreased the total corn DM.It was concluded that biochar was able to retaine more water for a longer time available for corn growth. Keywords - Biochar, Corn, Ultisols, Watering Frequency