Soil fertility is an important element in agricultural sustainability, especially in supporting plant growth. One natural way to increase soil fertility is through Biological Nitrogen Fixation (FNB) by Rhizobium bacteria. These bacteria have a symbiotic relationship with legume plants, forming root nodules that convert atmospheric nitrogen into compounds that plants can absorb, such as ammonium (NH4+). The purpose of this article study is to determine the potential of Rhizobium bacteria in increasing and efficiency of nitrogen fixation which has an impact on soil fertility and increasing plant productivity. This study adopts a library research method or approach, which involves a series of systematic activities, starting from collecting data through various library sources, reading in depth, recording important information, to processing the research materials. The study results show that Rhizobium can reduce dependence on chemical fertilizers, increase soil fertility, and produce growth hormones that support nutrient absorption. These findings emphasize the important role of Rhizobium in supporting sustainable agriculture, especially in tropical regions where access to synthetic fertilizers is minimal.

Using organic fertilizer can increase soil fertility, which is crucial for plant growth. Another organic material source that may be utilized as fertilizer is water hyacinth (Eichhornia crassipes). The chemical makeup of water hyacinth was examined in this study, and the results indicated that its organic matter content was 78.47%, its organic carbon content was 21.23%, its total nitrogen content was 0.28%, its total phosphorus content was 0.0011%, and its total potassium content was 0.016%. It has been demonstrated that applying water hyacinth-based liquid organic fertilizer to corn (Zea mays) plants actually affects crop output. Utilizing water hyacinth not only improves soil fertility but also lessens pollutants in the environment caused by overgrowth in waterways. Water hyacinth can therefore be utilized as a sustainable and eco-friendly organic fertilizer option.