PROXIMITY EFFECT OF SPRING CEREALS AND LEGUMES IN STRIP INTERCROPPING. PART III. RESPONSE OF BARLEY TO THE PROXIMITY OF WHEAT, TRITICALE, PEA AND YELLOW LUPINE
Background. Strip intercropping brings together the advantages of pure sowing and intercropping, but its production value depends on the reciprocal effect of the various species at the contact point of neighbouring rows of different plant species. The aim of the experiments was to find out the response of spring barley to the neighbouring occurrence of spring wheat, spring triticale, pea and yellow lupine and to estimate the production effects of strip intercropping of barley in the proximity of those species.
Material and methods. In this study, the results of field experiments on mixed sowings carried out in the years 2008–2010 at Mochełek near Bydgoszcz (53°13’ N; 17°51’ E) were used. Experimental factor was the position of plant row on the plot: four rows into the plot away from the respective neighbouring species. First row (contact row) was situated 12.5 cm away from the first row of the respective neighbouring species. Experimental unit was subsequent plant rows, each 4 meters long.
Results. Proximity of spring wheat and spring triticale was unfavourable to the growth and yield of spring barley, especially in the row directly adjacent to the field with the above species. No significant effect was found of the vicinity of pea to spring barley plants. Estimated decrease in barley yield in strip intercropping, with 3-m-wide strips and bilateral proximity of wheat, triticale and pea, would amount to 2.76%, 4.25% and 3.21%, respectively. However, the direct neighbourhood of yellow lupine caused a slight increase in the plant mass, including straw, the number of grains per spike and grain yield, but only in the first row. Estimated increase in the yield of spring barley grown in strip intercropping with yellow lupine, with 3-m- -wide strips, was small and would amount to only 0.58%.
Conclusion. Selection of plant species adjacent to spring barley in strip intercropping has a significant effect on results of its cultivation.