Distribution of weed species in mulched and non-mulched rows of golden currant | Nezāļu sugu izplatība mulčētās un nemulčētās zelta jāņogu apdobēs

Several methods are used for soil maintenance of berry crop rows, including bare soil and organic mulch. Use of bare soil is the cheapest solution in the plantation, although organic mulch is often used because it saves water in the soil, protects roots from bare frosts, and helps to control weeds. However, efficiency of organic mulch for the weed control is not always satisfactory. The purpose of this experiment was to compare the weed weight and diversity of species in mulched and non-mulched rows of golden currant (Ribes aureum Pursh.). The plantation was established in August, 2017, at Latvia University of Life Sciences and Technologies, Jelgava, Latvia. The soil was treated with glyphosate and then left fallow before arranging the plantation with only manual control of weeds after planting. Two maintenance variants of soil under plants in 6 repetitions were used: bare soil and 5-cm-deep pine bark mulch. The width of rows was 1 m and the size of the plot was 4.5 m2 . Weed measurement was done in two periods during the 29th and 35th week of 2019; weed species were identified, the number of weed plants and weed weight were measured. In total, 35 weed species were identified, it turned out that 85% of plants belonged to one of the most common species in the plantation – Convolvulus arvensis, Taraxacum officinale, Elytrigia repens, Poa pratensis, and Ranunculus repens. The first two - Taraxacum officinale and Convolvulus arvensis formed 87% of total weed weight and the mass proportion of the rest did not exceed 2.5%. The average weight and the number of species of weeds were significantly lower in mulched plots, as well as both weight and diversity were significantly lower in the second examination time (in non-mulched plots). As regards the mulched plots, on average there were 230 g mE–2 of weeds and 5.1 species in 1 m2 , and in non-mulched – 488 g mE–2 of weeds and 9.3 species in 1 m2 . In the 29th week there were on average 419 g mE–2 of weeds and 9 species in 1 m2 , and in the 35th week – 299 g mE–2 of weeds and 5.4 species in 1 m2 . The main conclusions are: 1) in the middle of the 2nd growing season few perennial weeds dominated in the plantation (namely, Taraxacum officinale and Convolvulus arvensis); 2) pine bark mulch significantly reduced both weight and diversity of weeds, however, other control measures are necessary for satisfactory weed control.