Analisis Produksi Biomassa Tanaman Singkong (Manihot esculenta) Pada Tiga Tanah (Latosol Cikarawang, Regosol Sindang Barang, dan Andisol Sukamantri)

Abstract

Cassava is a tropical plant that extensively cultivated at Africa, Asia and South America. In the world, Indonesia is the fourth largest of cassava producer after Nigeria, Brazil, and Thailand. In Indonesia, cassava has long been recognized as carbohydrate source as well as food source. For food diversification, cassava is also widely used for snacks. Cassava is used as raw material for tapioca, syrop, sorbitol, monosodium-glutame, ethanol industries, and othe processed forms. However, those utilization limited only from the cassava tuber. Overall potential production of cassava, including tuber, tuber skin, stem, and leaves was studied. Field observation and biomass production measurement of cassava at harvest time (was conducted in three cassava cultivations which different in their soils, i.e. Latosol Cikarawang, Regosol Sindang Barang, and Andisol Sukamantri. At the same time, composite soil sampling for soil fertility analysis was conducted. Laboratory analysis of N, P, and K of soil samples and each of biomass part of cassava was conducted. In addition, tuber was analyzed for its carbohydrates, fats, and protein; while stem was analyzed for its holocellulose and lignin. The results of soil fertility analysis indicated that in general Regosol Sindang Barang has the highest fertility, followed by Andisol Sukamantri and Latosol Cikarawang. The highest overall dry (65ºC) biomass was produced on Latosol Cikarawang 29.8 ton/ha, the highest tuber without skin was produced on Latosol Cikarawang 27.1 ton/ha, the highest trunk and leaves were produced on Andisol Sukamantri 3.2 and 1.3 ton/ha. The highest tuber skin were produced occur in common to Latosol Cikarawang and Regosol Sindang Barang 0.8 ton /ha. Average carbohydrate, protein, and fat of the tuber without skin produced on the three soils were 74.80%, 2.64%, and 0.42%, respectively. Meanwhile, average holocellulose and lignin of the stem produced on the three soil were 49.22% and 20.73%. Total nutrients uptake by the overall biomass on the three soils were in the range of 83.8-166.4 kg/ha, 17.6-54.4 kg/ha, and 106.5-217.8 kg/ha, respectively for N, P, and K. Both tuber without skin and stem of cassava are potential for the future production of bioethanol. In order to maintain soil productivity, it is suggested that the tuber skin and the leaves should be returned to the soil. If the tuber skin and the leaves both were returned to soil, it is equivalent with 44.2-74.3 kg Urea/ha, 16.6-26.7 kg SP-36/ha, and 38.6-85.1 kg KCl/ha.