Effects of pre‐treatment, renovation procedure and cultivar on the growth of white clover sown into a permanent pasture under both grazing and mowing regimes

Abstract

White clover (Trifolium repens) is a valuable pasture component that is frequently present in insufficient quantity for optimal animal nutrition. Several methods of reintroducing white clover into a permanent pasture without conventional tillage were investigated. Three seeders (Hunter, Vredo and a conventional seed drill), two white clover cultivars (Sacramento, and Sonja), two pasture pre‐treatments (a hard spring grazing or grazing plus light harrowing) and two defoliation regimes (grazing or mowing) were used to determine optimal seedling establishment conditions. Defoliation treatments were used as a method of investigating pasture improvement experiments. Measurements were taken to determine proportion of white clover present and total herbage mass. Plots renovated using a Hunter drill had the highest white clover content in the months immediately after renovation. Subsequently pre‐treatment method appeared to have no significant effect on herbage mass or species composition. The proportion of white clover in plots sown with the cultivar Sacramento was frequently higher than that in plots sown with the cultivar Sonja, but, overall, herbage production of cultivars was not different. Mowed plots had higher herbage production and tended towards a greater white clover content than grazed plots. Compaction of the surface to a depth of 10 cm in the grazed plots may have been a factor in the observed difference in herbage production. Regardless of management, within two years white clover content was similar among all treatments, including controls.

Comparison of Conventional and Minimal Tillage for Low-Input Pasture Improvement

“…Soil bulk density effects. Soil bulk density effects on pasture establishment specifically linked to the use of minimal tillage have not been identified, however, there is ample evidence that compaction of soil by field equipment (12,30,42) or by grazing animals (47,66) reduces plant growth and limits forage production. Increased soil bulk density reduced the rate of radicle‐entry of surface‐sown seeds (17) and decreased clover emergence by up to 32% with planting at a depth of 0.6 inches, but had only limited impact on emergence of tall fescue planted at the same depth (21).…”

Determining Thresholds for Grassland Renovation by Sod-Seeding

“…Sod-seeding is often used in cases where plowing is difficult or risky, when the botanical composition of the sward needs to be improved, or on farms seeking to exploit the feed value and N-fixing properties of legumes [3]. Direct drilling of desired forage species into the existing sod, i.e., sod-seeding, aims at increasing both grass productivity and quality [4,5]. Due to the low demands of labour, equipment and fuel, and by keeping the original vegetations sod-seeding reduces the risk of soil erosion and improves economic, environmental and agronomic grass management assets, without the production loss during the establishment season, associated with reseeding after plowing [6].…”

Effect of owersowing on yields and botanical composition of pasture sward

“…Bezorebným příse-vem lze docílit uchycení nových výnosnějších a kvalitnějších druhů ve stávajícím travním porostu (Muto a Martin, 2000; Pavlů et al, 2000). Největší význam se v současné době přisuzuje přísevu jetelovin díky jejich vysoké produkci, vysoké kvalitě píce, rovnoměr-nému rozložení výnosu v průběhu roku a schopnosti symbiotické fi xace dusíku, která umožňuje úplnou a nebo částečnou náhradu hnojení dusíkem (Bukvaj, 1991;Guretzky et al, 2004;Hrazdíra, 1989;Laberge et al, 2005;Mourino et al, 2003;Sleugh et al, 2000).…”

“…Zvýšení výnosů přísevem bylo zjiš-těno pouze v prvním užitkovém roce, a to u všech variant přísevu. Na rozdíl od námi dosažených vý-sledků, které nezjistily rozdíly v produkci mezi jednotlivými způsoby přísevu, uvádějí Tišliar (1993), Buchgraber, Pötsch (1994) a také Muto, Martin (2000) lepší výsledky u pásových přísevů než u diskového setí. Také Kohoutek et al (2002) dosáhli lepších vý-sledků se zvyšující se šířkou a hloubkou zpracovaného pásu půdy při využití technologie pásového setí.…”