Pengaruh asam humat dan cara pemberiannya terhadap pertumbuhan dan produktivitas tanaman padi (Oryza sativa)

Abstract

Agricultural land in Indonesia degraded continuously, characterized by decreasing in soil organic matter resulting from the utilization of chemical fertilizers which is not followed by organic fertilizers. In the rice field, the decrease of organic matter is followed by soil compacting and the decrease in soil pH. In order to increase paddy production, it is needed to improve the soil qualities plants growth. This can be achieved by providing ameliorants such as organic matter with chemical fertilizers. But there is a problem in applying organic matter because of its huge volume. Therefore, it is necessary to find a way to replace the organic matter with other materials that are easier not only in procurement but also in application. Humic acid is an extract of organic material which is expected to be able to replace the role of organic matter in improving physical, chemical, and biological properties of soils. Humic acid is expected to be able for improve plant growth through its role in accelerating the absorption of soil nutrients and water. The research was conducted in a greenhouse located at Cikabayan, Bogor Agricultural University with paddy var. Ciherang as the indicator plant. Soil was taken from Situ Gede, Bogor. Basal fertilizers were 300 kg/Ha SP-18, 200 kg/Ha KCl, and 200 kg/Ha urea. Humic acid dosages used were 0 L/Ha, 5 L/Ha, 10 L/Ha and 15 L/Ha. The methods of humic acid application were spraying on the surface of leaves, spraying underside of leaves, and spraying on the soil. The result showed that humic acid can increase the growth of rice plants by increasing tiller number. Humic acid dosage of 15 L/Ha spraying on the soil is the best treatment indicated by tiller number and dry weight of unhulled rice.