The changes of weed ecological groups in the winter rye monocrop

Abstract

In 2003 and 2015 years the highest abundance of weed belonged to indifferent to soil pH, nitrogen and moisture weed species (growing at wide pH, nitrogen and moisture range). In 2003 the higher abundance was determined of moderately alkaline, dry and moderately moist, moist soil weed species in 2015 – moderately nitrogen rich and nitrogen rich, moist soil weed species. In 2003 in winter rye monocrop with fertilization and spraying with herbicides the most abundant weed species were Apera spica-venti, Viola arvensis, Galium aparine, in 2015 – Mentha arvensis. In 2003 weed species distributed into 5 ecological groups according to soil pH, nitrogen demand and soil moisture, in 2015 – into 2 groups according to soil pH, into 3 groups according to nitrogen and into 4 groups according to soil moisture. In 2003 the highest abundance was obtained of moderately alkaline, indifferent to nitrogen, moderately moist and moist soil weed species, in 2015 – indifferent to soil pH, nitrogen and moisture, moist soil weed species. In the long-term cultivated winter rye monocrop whit fertilization and spraying with herbicides decreased the diversity of weed ecological groups. In winter rye monocrop without / whit fertilization and without / whit spraying whit herbicides the highest abundance of weed belonged to indifferent to soil pH, nitrogen and moisture, moist soil weed species. In long-term cultivated winter rye monocrop without fertilization and spraying with herbicides the higher abundance was determined of moderately nitrogen rich and nitrogen rich weed species. Weed species can be associated with a particular range of conditions, for example pH, site moisture and soil fertility, and on this basis can be given values denoting the position along environmental gradients at which each, on average, reaches peak abundance. The objective of this investigations was to determine the changes of weed ecological groups in the long-term cultivated winter rye (Secale cereale L.) monocrop without / whit fertilization and without / whit spraying with herbicides. The field experiment was established since 1967 and investigations were carried out in 2003 and 2015 at the Experimental Station of Aleksandras Stulginskis University. Soil – Calc(ar)i-Endohypogleyic Luvisol. The treatments of the experiment: 1) without fertilization and spraying with herbicides, 2) with fertilization (N92P45K75) and spraying with herbicides (in autumn – Legacy Pro, 2.0 l ha-1; in spring – Mustang 0.6 l ha-1). The weed classification into ecological groups was done according to Ellenberg et al. (1992). In 2003 in winter rye monocrop without fertilization and spraying with herbicides dominated Apera spica-venti, Viola arvensis, Arenaria serpyllifolia, Equisetum arvense, in 2015 – Tripleurospermum perforatum, Equisetum arvense, Cirsium arvense, Mentha arvensis. In 2003 weed species distributed into 6 ecological groups according to soil pH, into 7 groups according to nitrogen demand and into 5 groups according to soil moisture, in 2015 – into 4 groups according to soil pH, into 6 groups according to nitrogen and into 5 groups according to soil moisture.