Winter cover crops as green manure in a temperate region: the effect on nitrogen budget and yield of silage maize
Published by: Crop & Pasture Science
Abstract:
Winter cover crops may provide different environmental benefits in agricultural systems. The aim of this study was to determine the effect of cover crops used as green manure on the soil nitrogen (N) budget and yield of silage maize (Zea mays L.). A field experiment was conducted between 2011 and 2013 at three locations in Vojvodina Province, Serbia. It compared common vetch (Vicia sativa L.), triticale ( Triticosecale Wittm. ex A. Camus), their mixture grown as cover crops, N fertilisation at two doses (N1 and N2), and an unfertilised fallow as a control. Cover crops were sown in autumn 2011 and 2012 and were ploughed in during May of the year after which silage maize was sown. Results show that the ability of cover crops to provide benefit for a subsequent crop is highly related to weather conditions, mainly precipitation. The two years of the study experienced completely different weather conditions, showing two aspects of how cover crops can affect subsequent crop yield and amount of N left in the soil. In 2012, the N budget was higher in all three cover crops at all locations than N1 and the control because of unfavourable weather conditions for mineralisation of organic matter. However, the cover crops had a negative effect on silage maize yield. In 2013 (an average year), theNbudget was significantly higher after cover crops, and was followed by a higher yield of silage maize. Based on the 2-year average, the highest value of apparent N remaining in the soil was recorded in the mixture treatment (288.13 kg N ha–1); treatments with vetch and triticale had approximately equal values (272.17 and 272.71 kg N ha–1). The N fertilisation treatments and the control had significantly lower average values of residual N.
Additional keywords: ARNS, legumes, silage corn.
http://dx.doi.org/10.1071/CP17070
Naslov: Uticaj ozimih međuuseva za zelenišno đubrivo na budžet azota i prinos silažnog kukuruza
Rezime: Savremena poljoprivredana proizvodnja omogućava ostvarivanje visokih prinosa i profita, ali ona istovremeno mora da odgovori na sve veće zahteve u pogledu zaštite životne sredine i smanjenja troškova proizvodnje. Ovakav sistem gajenja primenjuje se i na plodnom zemljištu Vojvodine prouzrokujući smanjenje sadržaja organske materije, narušavanja strukture i bioloških svojstava zemljišta. Kako je stočarstvo u nasim agroekoloskim uslovima na niskom stepenu razvoja, a time i primena organskih djubriva, gajenje međuuseva može biti jedno od rešenja za nastale probleme u toku dugogodišnjeg intenzivnog korišćenja zemljišta. Međuusevi predstavljaju čiste useve ili njihove smeše između dva glavna useva, a u agroekološkim uslovima Vojvodine najčešće se gaje kao ozimi međuusevi. U toku trogodišnjeg istraživanja na tri lokaliteta u Vojvodini ispitivan je uticaj ozimih međuuseva (obične grahorice, tritikalea, njihove smeše) gajenih za zelenišno đubrivo, dve doze azotnog mineralnog đubriva i kontrole bez đubrenja na budžet azota u zemljištu i prinos silažnog kukuruza. Utvrđeno je da pozitivan uticaj međuuseva na naredni usev umnogome zavisi od vremenskih uslova, pre svega količine i rasporeda padavina. U 2012. godini, koju je karakterisala izrazita suša i visoke temperature, sadržaj mineralnog azota bio je veći na tretmanima sa međuusevima i kontroli, usled nepovoljnijih uslova za razlaganje organske materije. Ovo je negativno uticalo na prinos silažnog kukuruza, dok je s druge strane na tretmanima sa primenjenim mineralnim đubrivima prinos silažnog kukuruza bio veći. U prosečnoj 2013. godini budžet azota bio je značajno veći na tretmanima sa međuusevima, pri čemu je ostvaren i visok prinos silažnog kukuruza. Na tretmanima sa đubrenjem i na kontrolnoj varijanti količina preostalog azota bila je znatno niža.
