Spinach is one of the most important needs for humans, but spinach production in Indonesia has decreased from year to year, so it needs improvement in terms of cultivation technology. The purpose of this study was to analyze the interaction between varieties of spinach and the dose of organic seaweed fertilizer on spinach production; analyzed the dose of organic seaweed fertilizer on spinach production and analyzed the effect of spinach varieties on spinach production. This study was arranged in a factorial randomized block design (RBD), which consisted of two factors, the first factor was the variety of spinach (b) which consisted of two levels, namely green spinach variety Giti Hijau (b1) and red spinach variety Giti Merah (b2), the second factor is the dose of organic fertilizer (d) which consists of 4 levels, namely control (d0), 2 mL/L water (d1), 3 mL/L water (d2), 4 mL/L water (d3). The treatment was divided into 3 blocks as repetition. Data analysis used ANOVA and follow-up test with a DMRT level of 5%. The results showed that the variety of spinach had a significant effect on plant height from 3 to 5 WAP, the number of leaves at 2 WAP and 3 WAP, and the fresh weight of spinach. Fertilizer dosage did not significantly affect plant height, number of leaves, root length, fresh weight, and dry weight of plants . There was no interaction between spinach varieties and doses of organic seaweed fertilizer on all growth parameters and production of spinach.

Low feed quality in fish culture reduces fish digestibility; therefore, the feed quality needs improvement. An effort to increase the nutritional value of feed is by adding probiotics. However, on the one hand, feed residues that form organic and inorganic compounds can affect water quality in the cultivation medium; on the other hand, suitable water quality plays a vital role in fish farming. Adding probiotics containing microorganisms, such as EM4 probiotics, can benefit aquaculture businesses. Probiotic EM4 (Effective Microorganisms), one of the probiotics given in fish farming, is a brown liquid with a sweet and aromatic taste, containing a mixed culture of fermentative microorganisms, namely lactic acid bacteria (Lactobacillus casei) and yeast (Saccharomyces cerevisiae). This research is a literature review with data from various relevant articles assembled from Google Scholar, accredited journals, textbooks, and theses. In conclusion, it can be presumed that using EM4 probiotics in aquaculture has beneficial effects, including improving the quality of aquaculture water, increasing the growth rate of fish, suppressing pathogenicity, and reducing feed conversion.   ABSTRAK Kualitas pakan yang rendah dalam akuakultur menyebabkan daya cerna ikan menjadi kurang optimal. Oleh karena itu, kualitas nutrisi pakan yang lebih baik perlu ditingkatkan. Upaya yang dapat dilakukan untuk meningkatkan nilai gizi pakan adalah dengan menambahkan probiotik. Namun di satu sisi, residu pakan yang membentuk senyawa organik dan anorganik dapat mempengaruhi kualitas air pada media budidaya; di sisi lain, kualitas air adalah salah satu faktor penting yang berperan dalam budidaya ikan. Penambahan probiotik yang mengandung mikroorganisme, seperti probiotik EM4, dapat menguntungkan usaha perikanan budidaya. Probiotik EM4 (Effective Microorganisms), salah satu probiotik yang diberikan dalam usaha budidaya ikan, merupakan cairan berwarna coklat dengan rasa manis dan aromatik, yang mengandung kultur campuran mikroorganisme fermentatif yaitu bakteri asam laktat (Lactobacillus casei) dan ragi (Saccharomyces cerevisiae). Penelitian ini merupakan literature review (kajian literatur) dengan data yang bersumber dari berbagai artikel relevan yang diperoleh dari google schoolar, jurnal terakreditasi, text book, skripsi, dan lain-lain. Berdasarkan hasil kajian, dapat dikatakan bahwa penggunaan probiotik EM4 dalam perikanan budidaya memberikan dampak menguntungkan, antara lain: memperbaiki kualitas air akuakultur, meningkatkan laju pertumbuhan ikan, menekan patogenitas, dan memperkecil konversi pakan. Kata Kunci: Akuakultur, konversi pakan, laju pertumbuhan ikan, probiotik, probiotik EM4