U istraživanju je vrednovan utjecaj gustoće sjetve (6 i 9 g m-2) i višekratne berbe (dva i tri navrata) na prinos rige sorta ‘Coltivata’ u plutajućem hidroponu. U cjelogodišnjem uzgoju u zaštićenom prostoru također je promatran utjecaj abiotskih čimbenika tijekom tri razdoblja uzgoja (ljeto, jesen-zima i proljeće). Tijekom 339 dana istraživanja provedena su 24 pokusa, postavljena po metodi slučajnog bloknog rasporeda u četiri ponavljanja. Promatrani abiotski čimbenici (temperatura, količina otopljenog kisika, pH- i EC-vrijednost) hranjive otopine bili su u rasponu: 12,4 do 26,1°C, 3,6 do 8,1 mg L-1, 5,4 do 6,6 i 2,7 do 3,3 dS m-1. Najmanja i najveća temperatura zraka bile su u rasponu 5,3 do 18,0°C i 16,4 do 45,1°C, a relativna vlaga zraka 48,1 do 78,9%. Najkraći proizvodni ciklus (36 dana od sjetve do druge berbe) bio je u ljetnom roku uzgoja s prosječnim vrijednostima abiotskih čimbenika: temperatura zraka i hranjive otopine 28,1 i 25,3°C, relativna vlaga zraka 53,6% i količina otopljenog kisika 5,0 mg L-1. Najduži proizvodni ciklus (77 dana) bio je u jesensko-zimskom roku uzgoja s najmanjom temperaturom zraka i hranjive otopine (14,2 i 15,2°C), najvećom relativnom vlagom zraka (73,5%) i količinom otopljenog kisika (6,9 mg L-1). Veća gustoća sjetve u prvoj, drugoj i trećoj berbi rezultirala je 17, 30 i 50% većim prinosom u odnosu na manju gustoću sjetve. Bez obzira na gustoću sjetve najveći udio u ukupnom prinosu (53%) ostvaren je u prvoj berbi, manji (29%) u drugoj i najmanji (18%) u trećoj.The research valued the effect of sowing density (6 i 9 g m-2) and multiple harvest (two and three occasions) to arugula yield of “Coltivata” variety in a floating hydroponic. The effect of abiotic factors was also monitored in a year-long cultivation in a protected space during three periods of cultivation (summer, autumn – winter and spring). During 339 days of research there were conducted 24 experiments, set by the method of of randmomized block design in four replicates. The observed abiotic factors (temperature, content of dissolved oxygen, pH- and EC- value) of nutrient solution were in the range: 12.4 to 26.1 °C, 3.6 to 8.1 mg L-1, 5.4 to 6.6 and 2.7 to 3.3 dS m-1. The lowest and highest temperature of the air were in the range from 5.3 to 18.0 °C and 16.4 to 45.1 °C, and relative air humidity 48.1 to 78.9 %. The shortest production cycle (36 days from sowing to the second harvest) was in the summer period of cultivation with average values of abiotic factors: air temperature and nutrient solution 28.1 and 25.3°C, relative air humidity 53.6% and content of dissolved oxygen 5.0 mg L-1. The longest production cycle (77 days) was in the autumn – winter period of cultivation with the lowest air temperature and nutrient solution (14.2 and 15.2°C), the highest relative air humidity (73.5%) and content of dissolved oxygen (6.9 mg L-1). Higher sowing density in the 1st, 2nd and 3rd harvest resulted in 17, 30 and 50% higher yield in comparison to lower sowing density. Regardless of sowing density, the highest share in total yield (53%) was achieved in the 1st harvest, lower (29%) in the 2nd and and the lowest (18%9 in the 3rd one
