Abstract— Semanggi (Marsilea crenata Presl.) is one of the aquatic plants that have been widely used by the community as food and medicinal raw materials. One of the important factors in cultivating clover is optimal fertilizer management. The incorporation of organic and inorganic nutrients has an effect on soil fertility has been repeatedly demonstrated in several studies, but there are not specific guidelines on clover cultivation. The challenge now is to combine organic matter of different qualities with inorganic fertilizers to optimize nutrient availability for the clover plant. The results of research on clover cultivation have also not been widely carried out. Therefore, it is very important to do this research with the aim of knowing the optimal effect of organic (cow manure) and inorganic (nitrogen, potassium) fertilizers on the growth and yield of clover (Marsilea crenata Presl.). The research was conducted at the Screen House of the Faculty of Agriculture, Brawijaya University. The study was designed using a non-factorial randomized block design (RBD) with 8 (eight) treatment combinations of soil types and fertilization [inorganic (N, K) cow manure organic fertilizer (CM)], namely: P0 = soil, without fertilizer; P1 = soil, 138 kg N ha -1 ; P2 = soil, 136 kg K ha -1 ; P3 = soil, N and K, 138 and 136 kg ha -1 ; P4 = soil, 20x10 3 kg of cow manure ha -1 ; P5 = soil, 20x10 3 kg of cow manure ha -1 , 138 kg N ha -1 ; P6 = soil, 20x10 3 kg of cow manure ha -1 , 136 kg K ha -1 ; P7 = soil, 20x10 3 kg of cow manure ha -1 , N and K, 138 and 136 kg ha -1 with 3 replications, so that 24 experimental units were obtained. Each experimental unit consisted of 5 plants. Growth observations were observed destructively at the ages of 4, 8, 12, 16, 20, 24, 28, 32 days after planting (DAP). The results showed that there was an increase in the growth and yield of biomass in the soil combination, 20x10 3 kg of cow manure ha -1 (P4) was compared with the treatment without the addition of organic fertilizers (cow manure) on plant growth and yield parameters, such as stolon length (74.78 cm), number of leaves (160.44), leaf area (1379.28 cm 2 ), root length (23.85 cm), stomata density and number of stomata (13.25); Stomata width (10.87 cm); Stomata length (19.76 cm), leaf fresh weight (12,907 g), leaf dry weight (1,802 g), total fresh weight 210,830 g, total dry weight 7,823 g, leaf harvest fresh weight (64.19 g); stalk (130.54 g); root (79.75 g); total 274.48 g), harvest dry weight of leaves (11.36 g); stalk (24.88 g); root (9.55 g); a total of 45.78 g) and the chlorophyll a content (0.804 mg.g -1 ); chlorophyll b (1.121mg.g -1 ); and total chlorophyll (1.924 mg.g -1 ). Keywords: organic fertilizer, inorganic, biomass, semanggi I. INTRODUCTION Semanggi (Marsilea crenata Presl.) is one of the aquatic plants that has been widely used by the community as food. Semanggi (Marsilea sp.), Is one of the ferns that usually grows in muddy environments, moist soils, watery places or wet habitats such as rice fields [1], ditches and shallow puddles [2],[3], lakes under full sun and shady conditions have a cosmopolitan distribution, but are rarely distributed in subtropical areas. So far, people know that the clover plant is a lowland rice weed, some of which use it as a vegetable, medicinal plant [4], and also as a phytoremediation plant [5]–[7]. Indonesian people are more familiar with semanggi as one of the typical culinary delights of the city of Surabaya, East Java Province which has been known since ancient times as "Semanggi Suroboyo". The clover plant commonly consumed by the people of Surabaya and its surroundings is Marsilea crenata Presl [5]. Apart from that, it also has plant-derived phytochemical compounds, phytoestrogens are naturally occurring estrogenic compounds that have structural similarities to estrogens [8]–[11]. So that estrogenic activity can play a role in preventing cancer, reducing menopausal symptoms, and other health effects [12]. This clover plant can be found in rice fields in Kendung Village, Sememi Village, Benowo District. Initially this plant for the people of Kendung Village was a wild plant between rice fields. But now it is finally planted as a substitute for rice. Application of Organic and Inorganic Fertilizers Affects the Growth and Biomass Semanggi (Marsilea crenata Presl.) Mustika Tripatmasari* 1,2 , Ariffin 3 , Ellis Nihayati 3 , Mangestuti Agil 4 1 Postgraduate Program, Faculty of Agriculture, Brawijaya University, Malang, Indonesia 2 Faculty of Agriculture, University of Trunojoyo Madura, Indonesia 3 Faculty of Agriculture,University of Brawijaya Malang, Indonesia 4 Faculty of Pharmacy, Airlangga University, Indonesia Received: November 3, 2020. Revised: April 14, 2021. Accepted: May 13, 2021. Published: May 17, 2021. INTERNATIONAL JOURNAL OF BIOLOGY AND BIOMEDICAL ENGINEERING DOI: 10.46300/91011.2021.15.19 Volume 15, 2021 Ε-ISSN: 1998-4510 150