| dc.description.abstract | Organic fertilizer is a fertilizer derived from various natural fertilizer-making materials such as animal manure, animal body parts, plants, which are rich in minerals and good for the use of soil fertilization. Many scientific reports explain that there are several indications that can be used as indicators to determine the maturity of organic fertilizers using sensors other than based on temperature changes, such as weight changes, odor changes, color changes and texture changes. But actually there are still other indicators that can be used to determine the maturity of organic fertilizers, namely based on the concentration of gases formed as a result of decomposition processes such as ammonia gas (NH3), carbon dioxide gas (CO2), Methane (CH4), Nitrogen (N2), Hydrogen (H2), Hydrogen Sulfide (H2S), Oxygen (O2). In this case, Ammonia Gas is the basis for the development of a system to determine the level of maturity in fertilizers. This system works automatically by controlling the concentration of ammonia gas during the composting process. The working system in this tool is that the system will function to measure the value of macro and micro nutrients in organic fertilizer samples. This measurement uses the gas detection method. The system starts to turn on. It then retrieves sensor data and sends the data to a serial. For the initialization process. Send the sensor grade value to the slave with the system using SPI communication and in the process. The MQ 135 sensor takes NH3 content measurements. Then the sensor data will be displayed on the LCD. From the measurement results, ammonia gas was detected at a gas value of 757 ppm and 781 indications of high ammonia gas. From the measurement results of ammonia gas detected at a gas value of 523 ppm and 598 indications of normal ammonia gas | en_US |
