Impact of stage of use and nitrogen fertilizer on yield and quality of field pea and oat mixtures

Jedan od načina da se ublaži negativan uticaj intenzivne poljoprivredne proizvodnje na životnu sredinu i poboljša proizvodnja kabaste stočne hrane jeste združivanje različitih vrsta biljaka. Zbog kratkog vegetacionog perioda, pozitivnog delovanja na zemljište, dobre otpornosti na korove, bolesti i poleganje, stočni grašak i ovas predstavljaju perspektivne vrste za ovaj vid gajenja. Trogodišnje istraživanje je sprovedeno na oglednim poljima Instituta za stočarstvo u Beogradu sa ciljem da se ustanovi produktivnost stočnog graška i ovsa u datim agroekološkim uslovima i pod uticajem različitih tretmana. U okviru različitih tretmana ispitivani su: prihrana mineralnim azotom (0, 40 i 80 kg ha-1), setveni odnos stočnog graška i ovsa u smeši (100:15% i 100:30%) sa dva kontrolna useva (čist stočni grašak 100% i čist ovas 100%) i optimalno vreme košenja (faza punog cvetanja i faza formiranja mahuna useva stočnog graška). Na osnovu prinosa, kompeticijskih odnosa i kvaliteta hraniva ocenjen je uticaj pojedinih tretmana i produktivnost gajenih smeša. Trogodišnjim istraživanjem ustanovljeno je da smeše imaju veću produktivnost po jedinici površine za približno 20% u odnosu na čiste useve. Smeše obezbeđuju veće prinose zelene mase (100:30% - 21 t ha-1, 100:15% - 20,2 t ha-1, ovas - 19,9 t ha-1, stočni grašak - 16,7 t ha-1) i suve mase (100:30% - 4,82 t ha-1, 100:15% - 4,44 t ha-1, ovas - 4,99 t ha-1, stočni grašak – 3,17 t ha-1) u odnosu na čiste useve. Najveći prinos sirovih proteina je ostvaren kod smeše 100:15% (730 kg ha-1), zatim smeše 100:30% (693 kg ha-1), stočnog graška (633 kg ha- 1), pa kod ovsa (456 kg ha-1). Kod smeše 100:15% je zabeležen viši sadržaj pravih proteina (9,21%) i veća svarljivost (64,3%) nego kod smeše 100:30% (8,26% i 60,7%). Kod svih useva najveći prinosi proteina postignuti su prihranom sa 80 kg N ha-1 (704 kg ha-1) u odnosu na 40 kg N ha-1 (638 kg ha-1) i kontrolu (543 kg ha-1). Prihrana azotom ima značajan uticaj i na povećanje prinosa zelene i suve mase. Prosečan prinos suve mase smeša je bio značajno veći u drugoj fazi košenja u odnosu na prvu. Prinos proteina je bio veći u drugoj fazi košenja u odnosu na prvu kod smeše 100:15% (I - 700 kg ha-1; II - 761 kg ha-1), dok kod smeše 100:30% razlike nisu bile značajne. Združeno gajenje stočnog graška i ovsa za proizvodnju voluminozne hrane predstavlja superiorniji vid gajenja u odnosu na pojedinačno gajenje ovih vrsta. Primena azota se može smatrati neophodnom, naročito na zemljištima niže plodnosti. Smeša sa setvenim odnosom 100:15% ostvarila je veće prinose sirovih proteina i biomasu veće svarljivosti, dok je smeša 100:30% ostvarila veće prinose biomase. Veći prinos suve mase je bio u fazi formiranja mahuna. Takođe, smeša 100:15% je imala veće prinose proteina u drugoj fazi košenja. Međutim, košenjem u drugoj fazi dobija se stočna hrana niže svarljivosti.Intercropping plants can reduce the adverse effects of modern agriculture on the environment and enhance feed quality. Due to a short growth period, pronounced positive impact on soil, and strong resistance to weeds, diseases, and lodging, field pea and oat mixtures are promising crops for intercropping. A three-year study was conducted at the Institute of Animal Husbandry in Belgrade to assess the productivity of field pea and oat mixtures in a specific agro-ecological environment, under the influence of various treatments. The treatments included examination of nitrogen application (0, 40, and 80 kg ha-1), different sowing ratios of the two species in the mixture (100:15% and 100:30%), with two control crops (sole field peas at 100% and sole oats at 100%), and the optimal mowing phase (full flowering and full pod formation). The study evaluated the influence of individual treatments and the productivity of the cultivated mixtures based on yields, competition relations, and feed quality. The three-year study revealed that mixtures showed a 20% higher productivity per unit area compared to pure crops. The mixtures produced higher yields of green mass (100:30% - 21 t ha-1, 100:15% - 20.2 t ha-1, oats – 19.9 t ha-1, field peas – 16.7 t ha-1), and dry mass (100:30% - 4.82 t ha-1, 100:15% - 4.44 t ha-1, oats – 4.99 t ha-1, field peas – 3.17 t ha-1) compared to pure crops. The highest yield of crude protein was obtained with the 100:15% mixture (730 kg ha-1), followed by the 100:30% mixture (693 kg ha-1), field peas (633 kg ha-1), and the lowest yield was from oats (456 kg ha-1). The 100:15% mixture showed higher true protein content (9.21%) and digestibility (64.3%) compared to the 100:30% mixture (8.26% and 60.7%). In all crops, the application of 80 kg N ha-1 showed the highest protein yield (704 kg ha-1) compared to 40 kg N ha-1 (638 kg ha-1) and the control treatment without nitrogen application (543 kg ha-1). The application of nitrogen fertilizer had a significant impact on increasing the yield of green and dry mass as well. The dry mass yield for mixtures was higher on average in the second mowing phase compared to the first. The protein yield was higher in the second mowing phase compared to the first for the mixture 100:15% (I - 700 kg ha-1; II - 761 kg ha- 1), whereas no significant difference was observed for the 100:30% mixture. Combined cultivation of field peas and oats for the production of fodder feeds has proven to be a superior way of cultivation compared to individual cultivation of these species. Nitrogen application is considered necessary, mainly on soils of lower fertility. The mixture with a sowing ratio of 100:15% achieved higher crude protein yields and higher digestibility biomass, while the mixture with a higher percentage share of oats (100:30%) achieved higher biomass yields. Higher biomass yields were achieved in the full pod formation phase. Higher protein yields were also achieved for the mixture 100:15% in the second mowing phase. However, mowing in the second phase yields biomass with lower digestibility