@phdthesis{
author = "Katanski, Snežana",
year = "2017",
abstract = "The importance of alfalfa in Serbian agriculture, as well as its high market value, imposes a constant need for the improvement of this forage crop production that occupies large areas both in the world and in our country. The overall objective was to evaluate the effect of different growing systems (cutting regimes) on yield and nutritional value of alfalfa, contribute to solving practical issues in alfalfa production (redefine the optimal amount of seed for sowing) and specify the phenological stage in the moment of cutting when the balance of yield and dry matter quality of alfalfa is achieved. Three-year study (2009-2012) was carried out on experimental fields of Forage Crops Department of the Institute of Field and Vegetable Crops in Novi Sad, at two sites (Rimski Šančevi and Čenej). Field trial was set up in a randomized block design with three replications at both sites. Four cultivars of alfalfa were studied in this dissertation (Banat VS, Nijagara, NS Medijana ZMS V and NS Alfa); two sowing rates from 8 and 16 kg/ha and three cutting systems depending on crop phenological stage of development: I – early (10% of flowering plants), II – medium early (50% of flowering plants), and late (beginning of pod setting). Treatments were arranged by split-plot method, and the basic plot (size 72 m2) was used as the sowing rate, while all the other combinations of cultivars and cutting regimes were treated as sub-plots (6 m2). Sub-plot dimensions were 5 m in length and 1.2 m in width, with interrow distance of 20 cm. Inter-block distance was 1 m. There were no significant differences in yield and yield components of alfalfa dry matter, or in their quality, among the tested cultivars. Different amounts of seed for alfalfa sowing, from 8 and 16 kg/ha, did not affect the dry matter yield, or the yield components (crop height, leaf ratio in yield, number of shoots, and number of plants). In moderate-continental climatic conditions, which are present in the majority of the Republic of Serbia, there is no justification for increasing sowing rate above 16 kg/ha, because higher sowing rates do not provide long-term benefit in alfalfa production. Growing systems or cutting alfalfa in different stages of crop maturity (beginning of flowering, full flowering and green pods stage) had significant effect on the yield, yield components and nutritional value of tested alfalfa cultivars. The highest yield of green forage was achieved in early cutting at the stage of 10% flowering plants, while the dry matter yield was identical in cutting at the stage of 10% and 50% flowering plants and amounted to 15.9 t ha-1. Cutting system significantly conditioned plant height, when the highest plants (81.5 cm) were measured in cutting at the stage of green pods. The highest leaf ratio from 500.7 g/kg of dry matter was obtained when alfalfa was cut at the beginning of flowering. Frequency of cutting significantly affected the number of shoots per area unit, which notably decreased during cutting in short time intervals, i.e. at the beginning of flowering stage. Phenological development stage at the moment of cutting did not affect the number of plants per area unit. Alfalfa field density was similar to cutting at the stage of 10% and 50% flowering plants (240.7 and 246.3 plants/m2). Results of alfalfa nutritional value analysis indicated the significant effect of environmental conditions and development stage at the moment of cutting on crude protein content, while fibre content was conditioned only by the stage at the moment of cutting (cutting system). Alfalfa dry matter had better quality in wet year (2010) than in dry year (2011). Content of crude proteins in alfalfa dry matter decreased due to the reduction of leaf ratio, while the contents of NDF, ADF and ADL increased from the beginning of flowering stage to the stage of green pods. Similar yields of dry matter were achieved by cutting alfalfa with four and five cuts (15.9 t ha-1), while three cuts system did not use the genetic potential of NS cultivars, lead to bad quality and digestibility (higher fibre ratio) and to significant yield decrease of alfalfa dry matter (13.1 t ha-1). Cutting alfalfa at the beginning of flowering (five cuts a year) gives better quality of dry matter, i.e. higher protein content and lower fibre content (NDF, ADF i ADL)., Značaj lucerke u srpskoj poljoprivredi, kao i njena velika tržišna vrednost nameće stalnu potrebu za unapređenjem proizvodnje ove krmne biljke koja zauzima velike površine, kako u svetu tako i u našoj zemlji. Sveobuhvatni cilj doktorske disertacije je da se oceni uticaj različitih sistema gajenja (režima kosidbe) na prinos i hranljivu vrednost lucerke, doprinese rešavanju praktičnih pitanja u proizvodnji lucerke (redefiniše optimalna količina semena za setvu) i odredi fenološka faza u momentu kosidbe u kojoj se postiže balans prinosa i kvaliteta suve materije lucerke. Trogodišnje istraživanje (2010-2012) je izvedeno na oglednim poljima Odeljenja za krmno bilje Instituta za ratarstvo i povrtarstvo u Novom Sadu, na dva lokaliteta (Rimski Šančevi i Čenej). Poljski ogled je postavljen po slučajnom blok sistemu u tri ponavljanja na oba lokaliteta. U radu su analizirane četiri sorte lucerke (Banat VS, Nijagara, NS Medijana ZMS V i NS Alfa); dve setvene norme od 8 i 16 kg/ha i tri sistema kosidbe u zavisnosti od fenološke faze razvoja biljaka: I – rani (10% cvetalih biljaka), II – srednje rani (50% cvetalih biljaka), i kasni (početak zametanja mahuna). Tretmani su aranžirani po sistemu podeljenih parcela (split-plot metod), a kao osnovna parcela (veličina 72 m2) korišćena je setvena norma, dok su sve ostale kombinacije sorti i režima kosidbe tretirane kao podparcele (veličina 6 m2). Dimenzije podparcele su 5 m dužina i 1,2 m širina, sa međurednim razmakom od 20 cm. Razmak između blokova je 1 m. Među ispitivanim sortama nije bilo značajne razlike u visini prinosa i komponentama prinosa suve materije lucerke, kao ni u pogledu njihovog kvaliteta. Različite količine semena za setvu lucerke, od 8 i 16 kg/ha, nisu uticale na prinos suve materije kao ni na komponente prinosa (visina biljaka, udeo lista u prinosu, broj izdanaka i broj biljaka). U umereno-kontinentalnim klimatskim uslovima, kakvi vladaju u većem delu u Republike Srbije, nema opravdanja povećanja setvene norme iznad 16 kg/ha jer se setvom većih količina semena ne obezbeđuje dugoročna korist u proizvodnji lucerke. Sistemi gajenja, odnosno kosidba lucerke u različitim fazama starosti useva (početak cvetanja, puno cvetanje i faza zelenih mahuna) imala je značajan efekat na prinos, komponente prinosa i hranljivu vrednost ispitivanih sorti lucerke. Najveći prinos zelene krme ostvaren je pri ranoj kosidbi u fazi 10% cvetalih biljaka, dok je prinos suve materije bio identičan pri košenju u fazi 10% i 50% cvetalih biljaka i iznosio je 15,9 t ha-1. Sistem kosidbe značajno je uslovljavao visinu biljaka, pri čemu su najviše biljke (81,5 cm) izmerene pri košenju u fazi zelenih mahuna. Najveći udeo lista od 500,7 g/kg suve materije dobijen je kada se lucerka kosila na početku cvetanja. Učestalost kosidbe je značajno uticala na broj izdanaka po jedinici površine, koji se značajno smanjio pri kosidbi u kratkim vremenskim intervalima, odnosno u fazi početka cvetanja biljaka. Fenološka faza razvoja u momentu kosidbe nije uticala na broj biljaka po jedinici površine. Gustina lucerišta bila je slična pri košenju u fazi 10% i 50% cvetalih biljaka (240,7 i 246,3 bilj./m2). Rezultati analize o hranljivoj vrednosti lucerke ukazuju na značajan uticaj uslova sredine i faze razvoja u momentu kosidbe za sadržaj sirovih proteina, dok je sadržaj vlakana bio uslovljen samo fazom u momentu košenja (sistemom kosidbe). Bolji kvalitet suve materije lucerke ostvaren je u vlažnoj godini (2010) u poređenju sa sušnom godinom (2011). Sadržaj sirovih proteina u suvoj materiji lucerke se smanjivao zbog smanjenja udela lista, dok se sadržaj NDF-a, ADF-a i ADL-a povećavao od faze početka cvetanja do faze zelenih mahuna. Kosidbom lucerke u četvorootkosnom i petootkosnom sistemu dobijeni su slični prinosi suve materije (15,9 t ha-1), dok se primenom trootkosnog sistema kosidbe ne iskorišćava genetički potencijal NS sorti, dobija se loš kvalitet i svarljivost (veći udeo vlakana), i dolazi do značajnog smanjenja prinosa suve materije lucerke (13,1 t ha-1). Kosidba lucerke u početku cvetanja biljaka (pet otkosa u godini) daje bolji kvalitet suve materije, odnosno veći sadržaj proteina i manji sadržaj vlakana (NDF, ADF i ADL).",
publisher = "Univerzitet u Novom Sadu, Poljoprivredni fakultet",
title = "Yield and quality of alfalfa biomass (Medicago sativa L.) as affected by production management, Prinos i kvalitet biomase lucerke (Medicago sativa L.) u zavisnosti od sistema gajenja",
url = "https://hdl.handle.net/21.15107/rcub_nardus_12041"
}
