The effect of tillage and crop rotation on the composition of weed flora in maize based on cropping systems

Abstract

The study was conducted in order to determine the effects of tillage and crop rotation systems on the floristic composition and structure of weed flora in maize. This investigation was performed at the experimental field of the Institute of Field and Vegetable Crops in Novi Sad. The following treatments were evaluated: plowing (25 cm depth), chisel (25 cm depth), disking, and no-till (direct sowing). The cropping systems included maize cropping in two-year crop rotation and maize monoculture with split-plot arrangement and 4 replications. Experimental plot was 262.5 m2 (30 x 8.75 m). Weeds evaluated twice a year: in the summer (I evaluation) and autumn (II evaluation). The determination of weed infestation rate was performed in 1 m2 of each unit. In this study, floristic composition under the investigated cropping systems comprised 30 weed species, 21 of which were annual (17 broad-leaved species and 4 grass species) and 9 biannual (6 broad-leaves species and 3 grass species) Therophytes were the most dominant species, irrespective of tillage, time of determination or year. The number of weed species was found lowest-to-highest under moldboard plowing, chiseling, disking and no-till, respectively. The average number of weeds was highest in maize monoculture, compared to two-year crop rotation. .

U radu je ispitivan uticaj sistema obrade zemljišta i plodoreda na floristički sastav i građu korovske zajednice useva kukuruza. Istraživanja su obavljena na oglednim poljima Instituta za ratarstvo i povrtarstvo na Rimskim Šančevima u dvogodišnjem periodu. U ogledu su ispitivani sledeći sistemi obrade zemljišta: oranje na 25 cm, razrivanje (čizel) na 25 cm, tanjiranje i no-till (direktna setva). Kukuruz je gajen u monokulturi i dvopolju (kukuruz-soja). Ogled je postavljen po split-plot metodi u 4 ponavljanja. Veličina elementarne parcele je iznosila 262,5 m2 (30 m x 8,75 m). Analiza stanja zakorovljenosti izvedena je dva puta u toku vegetacije: leto (I ocena) i jesen (II ocena). Procena intenziteta zakorovljenosti je obavljena uzimanjem uzoraka sa 1 m2 na svakoj elementarnoj parceli. Analizom dobijenih rezultata konstatovano je ukupno 30 korovskih vrsta: 21 jednogodišnja i 9 višegodišnjih, odnosno 17 jednogodišnjih širokolisnih, 4 jednogodišnje uskolisne, 6 višegodišnjih širokolisnih i 3 višegodišnje uskolisne korovske vrste. Analizom životnog spektra korova utvrđeno je dominantno učešće terofita, nezavisno od varijante obrade zemljišta, ocene, kao i godine ispitivanja. Najmanja prosečna brojnost korova utvrđena je na varijanti oranja, nešto veća brojnost je konstantovana na varijanti primene razrivanja (čizel) i tanjiranja, dok je najveća brojnost utvrđena na no-till varijanti obrade zemljišta. Prosečna brojnost korovskih vrsta je bila veća na monokulturi kukuruza, u poređenju sa prosečnom brojnošću korova na dvopolju kukuruz-soja. .