Contribution of initial C and N reserves in Medicago sativa recovering from defoliation: impact of cutting height and residual leaf area

2005 ◽  
Vol 32 (4) ◽  
pp. 321 ◽  
Author(s):  
Frédéric Meuriot ◽  
Marie-Laure Decau ◽  
Annette Morvan-Bertrand ◽  
Marie-Pascal Prud'Homme ◽  
François Gastal ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Leaf Area ◽  
Management Strategies ◽  
Positive Contribution ◽  
Forage Production ◽  
N Supply ◽  
Negative Effect ◽  
C And N ◽  
Medicago Sativa L ◽  
Cutting Height

We studied the effects of stubble carbon / nitrogen (C / N) reserves or residual leaf area (RLA) on the contribution of taproot C / N reserves to shoot regrowth of Medicago sativa L. after cutting. The study assessed the effects of two cutting heights (6 and 15 cm), two RLAs (0 or 100%), and two initial C / N reserve levels (high N or low N) on forage production, nitrogen (N) distribution, and C / N reserve dynamics within stubble and taproot. Alfalfa forage production was mainly affected by the initial taproot C / N reserve levels. However, stubble initial organic reserves (and to a lesser extent the RLA) were also of particular importance during early regrowth. The increase of cutting height led to increased stubble C / N supply to regrowing shoots, which partly offset the negative effect on forage production and on taproot C / N reserve depletion. Unlike taproot reserves, the positive contribution of stubble organic reserves to shoot C / N supply was effective for a single defoliation–regrowth cycle. Alfalfa management strategies that increase cutting height (and RLA) during the penultimate harvest in autumn should be considered in cold regions with significant winter stress in order to improve alfalfa winter survival and persistence, as well as spring herbage regrowth.

scholarly journals Nitrogen Fixation and Resource Partitioning in Alfalfa (Medicago sativa L.), Cicer Milkvetch (Astragalus cicer L.) and Sainfoin (Onobrychis viciifolia Scop.) Using 15N Enrichment under Controlled Environment Conditions

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1438
Author(s):  
Gazali Issah ◽  
Jeff J. Schoenau ◽  
Herbert A. Lardner ◽  
J. Diane Knight
Keyword(s):  
Medicago Sativa ◽  
Resource Partitioning ◽  
Dry Matter ◽  
Measured Parameter ◽  
Pasture Production ◽  
Soil C ◽  
Onobrychis Viciifolia ◽  
C And N ◽  
Medicago Sativa L ◽  
Astragalus Cicer

Availability of nitrogen (N) limits pasture production. Inclusion of legumes into grass pastures can provide an alternative N source through biological N2 fixation (BNF), and enhance retention and cycling of soil C and N. Despite the use of alfalfa (Medicago sativa L.), cicer milkvetch (Astragalus cicer L.) and sainfoin (Onobrychis viciifolia Scop.) in grass-legume pastures to improve forage quality, relative BNF potentials and resource partitioning are unknown. We quantified BNF using 15N isotope dilution and estimated resource partitioning in alfalfa, two cultivars of cicer milkvetch and two cultivars of sainfoin under controlled conditions. Percentage of nitrogen derived from atmosphere followed the order alfalfa (92%) > cicer milkvetch (87%) > sainfoin (81%); corresponding to estimated N contributions of 200, 128 and 65 kg N ha−1 yr−1, respectively, based on total herbage. Root dry matter was 24% to 36% greater than shoot dry matter in all of the legumes, providing substantial below-ground C and N. Cultivars of the same species did not differ in any measured parameter (p > 0.05). Despite the lower BNF in cicer milkvetch and sainfoin compared to alfalfa, their use may not negatively affect stand productivity and C storage.

Shoot growth on lucerne plants cut at different heights

1970 ◽  
Vol 21 (4) ◽  
pp. 583 ◽  
Author(s):  
GJ Leach
Keyword(s):  
Medicago Sativa ◽  
Dry Matter ◽  
Shoot Growth ◽  
Total Yield ◽  
Extension Growth ◽  
Medicago Sativa L ◽  
Cutting Height ◽  
Two Stages

Lucerne (Medicago sativa L.) plants grown to two stages of maturity were cut at 2, 5, or 10 cm above the crown. In addition, the leaf on the stubble and on basal shoots was either removed or retained. The change in the number and size of the regrowth shoots growing from different heights above the crown, and the total yield of dry matter, were observed for 4 weeks after cutting. Nearly all the regrowth shoots arose from very near to the crown, either on the crown itself or from within the first 2 cm above it, so that cutting at higher levels increased shoot numbers only slightly. Also most of the shoots arising from near the crown resumed extension growth earlier, and therefore grew larger, than the shoots arising from higher positions. In general the growth of shoots from one stubble segment was not influenced by whether segments were still present above. Increasing the cutting height above 2 cm consequently produced little effect on the yield of dry matter 2 and 4 weeks after cutting. Retaining stubble leaf and basal shoot leaf increased the shoot yield 2 and 4 weeks later, because the basal shoots resuming growth first grew larger than those on plants from which leaves were removed. The effect of retaining leaves was independent of the stage of maturity when the plants were cut and of the cutting height.

Farmer-directed on-farm experimentation examining the impact of companion planting barley and oats on timothyalfalfa forage establishment in central Newfoundland

2004 ◽  
Vol 84 (1) ◽  
pp. 217-221 ◽  
Author(s):  
D. Spaner and A. G. Todd
Keyword(s):  
Hordeum Vulgare ◽  
Medicago Sativa ◽  
Avena Sativa ◽  
Phleum Pratense ◽  
Forage Production ◽  
Hordeum Vulgare L ◽  
Medicago Sativa L ◽  
On Farm ◽  
The Impact ◽  
Phleum Pratense L

Oats (Avena sativa L.) or barley (Hordeum vulgare L.) sown at increasing seeding rates of 23, 45 and 68 kg ha-1 with a timothy (Phleum pratense L.)-alfalfa (Medicago sativa L.) mixture (harvested at cereal soft dough) resulted in increasing forage yields containing decreasing alfalfa, crude protein, P and Ca percentage in the planting year. Barley out-yielded oats by 11% in the planting year. Oats or barley sown at seeding rates up to 68 kg ha-1 do not impede underseeded forage establishment or forage production in the subsequent year in central Newfoundland. The implications of farmer-directed on-farm experimentation are discussed. Key words: Hordeum vulgare L., Avena sativa L., Phleum pratense L, Medicago sativa L., underseeding

Evaluation of tedera [(Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata]) as a forage alternative for sheep in temperate southern Australia

2012 ◽  
Vol 63 (12) ◽  
pp. 1135 ◽  
Author(s):  
M. C. Raeside ◽  
Z. N. Nie ◽  
S. G. Clark ◽  
D. L. Partington ◽  
R. Behrendt ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Nutritive Value ◽  
Field Experiments ◽  
Early Winter ◽  
Forage Production ◽  
High Rainfall ◽  
Forage Species ◽  
Bituminaria Bituminosa ◽  
Medicago Sativa L ◽  
Perennial Legume

Bituminaria bituminosa (L.) C.H. Stirton, commonly known as tedera, is a perennial legume of interest in Australia due to its adaptation to Mediterranean environments. Field experiments were conducted at two sites in Victoria, Australia, a high rainfall site at Hamilton and a low rainfall site at Bealiba, to evaluate tedera var. albomarginata lines against other forage species. At Hamilton, tedera achieved similar seedling densities to lucerne (Medicago sativa L.) following sowings in late spring 2009 and early winter 2010 (30–60 seedlings/m2). Forage production from the spring-sown tedera was between 1.0 and 2.3 t DM/ha at harvests in March and May 2010, but from May onwards the species failed to remain productive and its content in the swards decreased to become <10%. Forage production from all early winter-sown tedera swards was low (<0.5 t DM/ha). At Bealiba, some of the tedera lines outyielded lucerne. The tedera at Bealiba had a vigour rating of 8.3, on a scale of 1–10, in the summer of 2008–09, after surviving three summers. The tedera lines evaluated are unlikely to persist in cold wet winter environments but in drier zones tedera may persist and offer good DM yields of high nutritive value.

EVALUATION OF FACTORS AFFECTING YIELD REDUCTION IN MATURE ALFALFA (Medicago sativa L.)

1984 ◽  
Vol 64 (4) ◽  
pp. 901-907 ◽  
Author(s):  
E. R. JONES ◽  
R. H. SWAIN ◽  
K. W. BELL ◽  
R. B. CARROLL
Keyword(s):  
Medicago Sativa ◽  
Stand Density ◽  
Yield Reduction ◽  
Root Weight ◽  
Nonstructural Carbohydrates ◽  
Forage Production ◽  
Foliar Diseases ◽  
Total Nonstructural Carbohydrates ◽  
Crown Tissue ◽  
Medicago Sativa L

Alfalfa (Medicago sativa L.) stand longevity continues to be a problem even though progressive management practices are followed. The following parameters were evaluated on mature alfalfa stands to determine what factors were responsible for stand thinning: forage production, stand density, foliar and crown-root diseases, root and crown tissue weights, and total nonstructural carbohydrate levels. Foliar diseases did not affect stand density; however, three of five anthracnose-resistant cultivars had denser stands than susceptible parents. Fusarium infection was quite high but did not appear to be related to stand density. Individual root weight, root mass, and total nonstructural carbohydrates were not good indicators of stand density.Key words: Alfalfa stand longevity, foliar diseases, crown and root rot, root and crown tissue weight, total nonstructural carbohydrates, forage production

Phosphorus and potassium effects on taproot C and N reserve pools and long-term persistence of alfalfa (Medicago sativa L.)

Plant Science ◽  
2018 ◽  
Vol 272 ◽  
pp. 301-308 ◽  
Author(s):  
William Kess Berg ◽  
Sofia Lissbrant ◽  
Suzanne M. Cunningham ◽  
Sylvie M. Brouder ◽  
Jeffrey J. Volenec
Keyword(s):  
Medicago Sativa ◽  
C And N ◽  
Medicago Sativa L ◽  
Phosphorus And Potassium

Effects of initial N reserve status and residual leaf area after cutting on leaf area and organ establishment during regrowth of alfalfa

2004 ◽  
Vol 84 (4) ◽  
pp. 1059-1066 ◽  
Author(s):  
J. C. Simon ◽  
M. L. Decau ◽  
J. C. Avice ◽  
A. Jacquet ◽  
F. Meuriot ◽  
...  
Keyword(s):  
Medicago Sativa ◽  
Leaf Area ◽  
Dry Matter ◽  
Plant Morphology ◽  
Long Term Effects ◽  
Key Factors ◽  
Short And Long Term ◽  
Medicago Sativa L ◽  
The One

Nitrogen reserves in remaining organs and residual leaf area after cutting have long been recognized as key factors during alfalfa (Medicago sativa L.) regrowth. The present work examined which morphological components were influenced by contrasting initial N status and residual leaf area during 29 d of regrowth after cutting at 15 cm height. Two levels of initial N reserves (high and low) and of residual leaf areas (not or completely defoliated) were combined in four treatments. Both factors affected shoot dry matter (DM) production at the end of regrowth. The increase in DM of new organs observed with high N reserves resulted from a combination of short- and long-term effects on plant morphology; i.e., (1) an increase in the rate of axis appearance from the crown in the early regrowth stage (day 0–9) and (2) an increase in individual leaf area (ILA) all along the regrowth. Compared with completely defoliated plants, plants with a residual leaf area at cutting exhibited an increased rate of axillary stems appearance all along the regrowth. Then the architecture of plants with a residual leaf area was more branched than the one of defoliated plants. This increase in branching was always associated with smaller ILA. Hence, differences in plant leaf area were only significant in the early growth stage. This suggested that differences observed in new stems DM at the end of the regrowth were established by day 9 and remained unchanged in late regrowth. Our results clearly showed that initial N reserve status and residual leaf area both significantly modify the dynamic of leaf area establishment and new organ growth of alfalfa. Key words: Medicago sativa L., defoliation, morphology, N storage, stems regrowth

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