Lucerne (Medicago sativa L.) annual yield and its distribution

Cilj istraživanja bio je prikazati prinos zelene mase i suhe tvari nadzemne mase lucerne, te distribuciju prinosa na pojedine otkose tijekom vegetacije lucerne na jednoj lokaciji u sjeveroistočnoj Hrvatskoj. Istraživanje je provedeno poljskim pokusom na plodnom tlu u okolici Tenje. Pokusni usjev je uspješno zasnovan kasnozimskom sjetvom sredinom veljače, i to nakon neuspješnog prezimljenja usjeva posijanog krajem rujna prethodne godine. Prinosi pojedinih otkosa su mjereni u tri roka košnje: 8. lipnja 2022., 13. srpnja 2022. i 7. rujna 2022. Prvi otkos je bio najprinosniji, po prinosu je slijedio treći otkos, a najmanjega prinosa je bio drugi otkos (vjerojatno zbog najkraćeg razdoblja porasta). Ostvareni prinos lucerne u provedenom istraživanju bio je vrlo nizak zbog utjecaja izrazite suše tijekom vegetacije mladoga usjeva lucerne. Usjev je bio izrazito osjetljiv na sušu zbog utjecaja kasnozimske sjetve, jer se biljčice nisu stigle dovoljno duboko ukorijeniti prije nastupa proljetne suše. Stečeno iskustvo upućuje da bi preferirani rok zasnivanja lucerišta trebao biti u kasnoljetnom sjetvenom roku, s ciljem veće otpornosti na sušu i većega prinosa krme u prvoj godini korištenja usjeva. Istraživanje je pokazalo i da bi za pouzdano prezimljavanje mladoga lucerišta u uvjetima sjeveroistočne Hrvatske, usjev trebalo zasnivati u tradicionalno preporučenom roku od sredine kolovoza do kraja prve dekade rujna, bez kašnjenja.The goal of the research was to show the yield of herbage and herbage dry matter of lucerne, and the distribution of the seasonal yield on individual cuts taken during the lucerne vegetation at one location in northeastern Croatia. The research was conducted as a field experiment on fertile soil in the vicinity of Tenja village. The experimental crop was successfully established by late winter sowing in mid-February, after the unsuccessful overwintering of the crop sown at the end of September of the previous year. The yields of individual cuts were measured in three mowing dates: June 8, 2022, July 13, 2022, and September 7, 2022. The first cut was the most productive, followed by the third cut, and the second cut had the lowest yield (probably due to the shortest growth period). The yield of lucerne in the conducted research was very low due to the influence of severe drought during the growing season of the young lucerne crop. The crop was extremely sensitive to drought due to the influence of late-winter sowing term, because the plants did not have time to develop root deep enough before the onset of the spring drought. The experience indicates that the preferred time for establishing lucerne fields should be in the late summer sowing term, with the aim of greater resistance to drought and higher forage yield in the first year of crop utilization. The research also showed that for reliable overwintering of young alfalfa in the conditions of northeastern Croatia, the crop should be sowed within the traditionally recommended period from mid-August to the end of the first decade of September, without delay