Pengaruh Berbagai Cara Pemberian Bahan Humat terhadap Produksi Ubi Jalar (Ipomoea batatas L.)

Abstract

Utilisation of humic substance has been widely known to have positive effect on plant productivity. Characteristic of this substance that is easily soluble in water and applied in small amount has brought several obstacles on its wide application. Zeolite that has porous structure is a potential mineral used for humic substance carrier. Various studies in order to examine the role of humic substance on crop yield enhancement were reported limitedly on rice and corn so far, whereas it is rarely conducted on sweet potato. Therefore, it is necessary to conduct research for determining the best method of humic substance application on increasing sweet potato yield. In this research, humic substance was applied in several methods i.e. control (without humic substance and zeolite), humic substance applied directly into soil, humic substance sprayed on leaves, zeolite without humic substance, and humic substance carried by zeolite. The results showed that the application of humic substance carried by zeolite was the best method on increasing sweet potato productivity. This improvement on sweet potato yield is shown by the greater amount and bigger size of tubers of each plant. Moreover, the application of humic substance carried by zeolite showed the highest soil exchangeable K.