Effects of Stubble Height and Cutting Frequency on Regrowth of Berseem Clover in a Mediterranean Semiarid Environment

Abstract

Defoliation management of forage crops affects endogenous reserves (in the root and in the stubble), the residual leaf area, and, consequently, the regrowth and biomass yield. The aim of this study was to evaluate the effect of cutting frequency (28-d vs. 35-d intervals) and stubble height (3 vs. 6 cm) on forage yield, regrowth, and persistence of berseem clover {Trifolium alexandrinum L.). Neither cutting interval nor cutting height affected plant survival during the crop cycle. Frequent clipping reduced crop yield. Residual biomass and leaf area were less when plants were cut at a height of 3 cm compared with 6 cm, but stubble height did not affect the total amount of dry matter (DM) removed. However, with a cutting interval of 28 d, DM yield was greater with a stubble height of 6 cm compared with 3 cm, whereas stubble height generally had no effect with a cutting interval of 35 d. This study shows that severe defoliation, which substantially reduces residual photosynthetic area, forces berseem clover plants to mobilize reserves from the taproot. With frequent clipping, taproot reserves are depleted and regrowth is impaired, whereas less frequent clipping enables taproot reserves to be restored. In contrast, less severe defoliation, which results in a considerable residual leaf area, promotes rapid regrowth regardless of the frequency of defoliation. Università degli Studi di Palermo, Dipartimento dei Sistemi Agroainbientali, Viale delle Scienze, 90128 Palermo, Italy. Received 12 Oct. 2010. *Corresponding avtthor (amato@unipa.it). Abbreviations: DM, dry matter; LAI, leaf area index.B ERSEEM CLOVER {TrifoUum alexandrinum L.) is an annual forage legume commonly cultivated in Mediterranean environments for its high biomass production, nutritive value, and palatability (Knight, 1985;Martiniello et al, 1996). It is grown as a pure stand or as a mixture species with annual ryegrass {Loliutn multiflorum Lam.), oat {Avena sativa L.), or vetch {Vicia sativa L.) for hay production (Giambalvo et al., 2011). It has a higher capacity to recover after cutting or grazing than traditional forage legumes such as vetch, crimson clover {Trifolium incarnatum L.), fenugreek {Trigonella focnuni-graecuin L.), and sulla {Hedysarum coronarium L.).This characteristic makes multiple defoliations an option during the late autumn to late spring period (Knight, 1985). However, the stubble height (the residue height of tissue remaining after grazing) and frequency (the interval between successive bouts of grazing) varies widely according to animal type, grazing management (rotational or continuous stocking and stocking rate), and environmental characteristics. Defoliation management of legumes affects the endogenous reserves in the crowns and taproots as well as morpho-physiological traits such as the number of growth points and root size. Consequently, defoliation affects yield, nutritive value, shoot regrowth, and persistence (Parsons et al.

Influence of Arbuscular Mycorrhizae on Biomass Production and Nitrogen Fixation of Berseem Clover Plants Subjected to Water Stress

“…On the whole, when berseem clover did not experience WS (i.e., in WW treatments), aboveground biomass production was about 12 Mg dry matter ha –1 ; this is similar to the biomass obtained in the same environment when rainfall during the growing season was 30% higher than the long-term average [12], [20]. On average, no differences between –AM and +AM conditions were observed in terms of total aboveground biomass production (11.7 vs. 12.0 Mg dry matter ha –1 , calculated as a sum of C1+C2+R28 in WW treatments).…”

“…In Mediterranean areas, it is usually sown in the autumn and grown until early summer as a multicut forage species, thanks to its ability to regrow after cutting [12]. However, during the spring, plant regrowth is often limited by water deficiency, which negatively affects photosynthesis and symbiotic N 2 fixation and leads to a reduction in accumulation and quality of biomass.…”

Effect of Autumn Cutting Date on Regrowth, Turning Green, Yield and Quality of <i>Leymus chinensis</i> Grassland in Songnen Plain, Northeast China

“…So the farmer usually harvests the forage from later summer to early winter in order to gain the maximal yield and quality，and this is the best time for making hay of Songnen grassland because of the good weather, and the height of the remaining stubble usually is 4 -5 cm [5]. But different cutting dates may not only effect on the grass regrowth, and biomass at the current year [17] [18] [19], but also effect on the turning green date, biomass, layering distribution of the biomass for the next year [11] [14] [20]. Previous studies have showed that all the cutting dates run through the whole growing season, such as moderate levels of spring defoliation could improve winter range forage quality [21], cutting in May or June decreased vegetative tillers, but increased crude protein content and in vitro dry digestibility [22], autumn harvest date gained different quality forage [13], winter cutting or grazing didn't affect the spring ground or spring forage yield if it was accomplished before spring growth [23].…”

Management strategies for forage rape (Brassica napus L. cv Goliath): Impact on dry‐matter yield, plant reserves, morphology and nutritive value

“…Fulkerson and Slack (2003) reported that perennial ryegrass (Lolium perenne) defoliated to 20 or 50 mm height in winter yielded 21% more DM than when defoliated to 120 mm. In contrast, Giambalvo, Amato, and Stringi (2011) reported no difference in DM yield when berseem clover (Trifolium alexandrinum L.) was harvested either at 3 or 6 cm DI. There is also conflicting information regarding the impact of intensity of defoliation (DI; height at which plants are cut) on regrowth.…”