Weed species composition and diversity in maize as affected by tillage and fertilization in the Northern steppe of Ukraine

Abstract

The structure of weed phytocenoses in maize crops is determined by the adaptive capacity of weeds and the specific characteristics of crop area distribution in rotation systems. The main factors driving weed dominance include herbicide resistance, a broad germination range, morphological plasticity, and the presence of neotenic traits. The use of shallow non-inversion mulching tillage methods (such as chisel plowing and flat-cut loosening) in maize cultivation increases weed infestation levels by 1.4–1.8 times, necessitating additional applications of pre-emergence and post-emergence herbicides to control weeds and prevent yield reduction. Research indicates that plow tillage and chisel plowing provide a slight advantage in maize grain productivity on unfertilized soils and under fertilization with N₃₀P₃₀K₃₀. This advantage arises from improved nutrient availability and reduced weed infestation levels. However, with increased nitrogen application (N₆₀P₃₀K₃₀), shallow flat-cut loosening becomes more effective, yielding similar results to plow tillage and chisel plowing, thus mitigating earlier disadvantages. At low overall weed infestation levels (9.0–12.6 plants/m²), primary soil tillage methods have no significant impact on maize grain quality. The application of mineral fertilizers, particularly nitrogen, increases protein content in maize grain while reducing carbohydrate levels, particularly starch.