MODELING OF THE AMOUNT OF AEROBIC AND NITRIFICATION SOIL BACTERIA ON GROWTH AND RESULTS OF SAWI PLANT CULTIVATION (Brassica juncea var. Tosakan) WITH BRASSICA WASTE ORGANIC FERTILIZER

• Main Author: FAUZIYYAH RAHMAT (NIM : 11414054), AFIFAH
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/25079
• Institution: Institut Teknologi Bandung

<br /> <p align="justify">The use of inorganic fertilizers is often considered as a solution to increase crop productivity. However, the productivity produced does not last long, because the use of inorganic fertilizers in a certain period of time can change the structure of the soil, reduce the content of natural nutrients available in the soil, and pollute the environment. The results of previous studies in Sukamandi, West Java showed a decrease in vegetable production during the 25 growing seasons caused by a decrease in the organic matter content that NPK fertilizer cannot provide. Green mustard (Brassica juncea) as one of the types of vegetables with high production in Indonesia certainly cannot be separated from the use of inorganic fertilizers in the field. One way that can be used to reduce the use of inorganic fertilizer is by using organic fertilizer. This study aims to study the effect of the use of organic fertilizer on changes in population of aerobic bacteria and soil nitrifying bacteria compared to control on mustard growth and determine mathematical models of changes in aerobic bacterial populations and nitrification during mustard growth. Compost fertilizer is made using basic ingredients of vegetable waste from the decomposed Brassica genus with the help of mushrooms Marasmius sp. and yeast Saccharomyces sp. The research was carried out in a screen house with 132 plant polybags and using drip irrigation system. Control treatment was carried out using manure with additional NPK fertilizer. Planting media samples are taken every four days for twenty-eight days of growing Sawi. Calculation of aerobic bacterial populations and nitrifying soil bacteria was carried out using the TPC (Total Plate Count) method with NA media for aerobic bacteria and Winogradsky media for nitrifying soil bacteria. In compost organic fertilizer treatment there are 11 types of soil aerobic bacteria colonies and 14 types of bacterial colonies of nitrifying soil with dominant white colonies and have the characteristics of circular, flat, entire colonies. While in the control there were 11 types of aerobic bacterial colonies and 13 types of bacterial colonies of nitrifying soils with dominant colonies white and had the characteristics of circular, convex, entire colonies. Modeling for aerobic soil bacteria on compost media is y = -0.0058x6 + 0.1573x5 - 1.6548x4 + 8.5962x3 - 22.909x2 + 29.267x - 6.6971 with R² = 0.9973, while modeling for nitrifying soil bacteria on compost media is y = -0.0059 x6 + 0.1744x5 - 2.0477x4 + 11.996x3 - 36.379x2 + 52.918x - 22.3388 with R² = 0.9941. Plant conditions observed were leaf area, leaf number, yield weight, and chlorophyll content of plants. The yield of mustard plants showed the total chlorophyll content for compost treatment was 15.66 mg / L and for the control treatment was 12.83 mg / L, while the harvest weight for compost treatment was 90.84 grams and for the control treatment was 59.63 grams . The leaf area for compost treatment was 118.89 cm2 and the control treatment was 81.49 cm2. The number of leaves for compost treatment was 11 and for the control treatment was 10. <br /> <p align="justify">