Gembili (Dioscorea esculenta) is a tuber-producing plant containing 14.63% inulin, a Water-Soluble Polysaccharide (WSP). This study aims to determine the optimum point of material to solvent ratio and Microwave-Assisted Extraction (MAE) time needed to extract gembili WSP, and determine the WSP's characteristics produced. The optimization process uses the Response Surface Methodology-Central Composite Design (RSM-CCD) with Design Expert 7.0 software. The material to solvent ratio's minimum and maximum points are 1:25 g/L and 1:45 g/L, while the minimum and maximum points of extraction time are 20 minutes and 40 minutes. This study observed 13 experimental combinations and responses from gembili WSP yield, WSP powder inulin levels, and WSP solubility. The results showed that the optimum conditions of material to solvent were at a 1:33.81 g/mL ratio, and the extraction time was 29.26 minutes. This optimum condition resulted in 32.42% WSP yield, 40.8% inulin content in WSP powder, 26.98% WSP solubility, 12.24% WSP water content, and 49.3 cp WSP viscosity. These results indicate that extraction using a microwave can increase WSP's rich inulin yield from gembili tubers. Keywords: gembili, inulin, microwave, optimization, Water-Soluble Polysaccharides

Soil is one of the main components that affect agricultural productivity. Soil quality certainly needs to be considered as an effort to increase plant growth and production. One of the most influential components of soil quality is the chemical nature of the soil. Research on Analysis of Soil Chemical Content in Horticultural Farmers' Land in Ladogahar Village, Nita District, Sikka Regency has been carried out from October to December 2021. The purpose of this study was to determine the chemical content of the soil in Horticultural Farmers' Land in Ladogahar Village, Nita District, Sikka Regency. This research uses observation methods, literature studies, and laboratory tests. Composite soil sampling using the zigzag method. The results showed that the land had a low C-organic content (1.00-2.00%), a slightly acidic pH (5.6-65), a low phosphorus content (21-40), and a Potassium content in the soil. moderate range (21-40).

Research on Analysis of Soil Chemical Content in the Practical Garden of the Faculty of Agriculture, University of Nusa Nipa, East Alok District, Sikka Regency has been carried out from October to December 2021. This study aims to determine the chemical content of the soil in the Practical Garden of the Faculty of Agriculture, University of Nusa Nipa, East Alok District, Sikka Regency. . The research method used is observation, laboratory testing, and literature study. Analysis of soil chemical content using a dry soil test device with a diagonal composite soil sampling method. The results showed that the soil in the practice garden had low organic C content (1.00-2.00%), neutral pH (6.5-7.5), high phosphorus content (26-35), and also Potassium content is in the moderate to low range.