EFFECTS OF COVER CROP AND WEED CONTROL METHOD ON YIELD AND ENERGY EFFICIENCY OF WHEAT

A field experiment on growing spring wheat on rendzina soil was conducted in the central-eastern part of Poland during the period 2009-2011. The study included two factors: 3 types of stubble crop (white mustard, lacy phacelia, and a mixture of legumes - narrow-leaf lupine with field pea) and 3 weed control methods in wheat (mechanical, combined mechanical and chemical, chemical). Grain yield and energy efficiency of wheat production were evaluated. The study found that the legume mixture stubble crop resulted in the highest increase in grain yield (on average by 9.2%) compared to the control treatment. On the other hand, mechanical-chemical and chemical weed control contributed to higher wheat yields by 13.2 and 9.8%, respectively, relative to the mechanical treatments. The highest energy efficiency of wheat grain production was obtained in the treatment without stubble crop (control), whereas stubble cropping reduced this efficiency by 7-10%. In the structure of energy inputs, mineral fertilizers (on average 37%) and fuel (31%) were predominant.