Dynamics of Accumulation and Partitioning of N in Leaves, Stems and Roots of Lucerne (Medicago sativa L.) in a Dense Canopy

Lemaire, G.; Khaity, Mahmoun; Onillon, B.; Allirand, Jean Michel; Chartier, Michel; Gosse, Ghislain

doi:10.1093/oxfordjournals.aob.a088499

Cited by 90 publications

(43 citation statements)

References 7 publications

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“…Similar to the observations of [50], who described that about 80% of the nitrogen present in the aerial component formed in the first week after grazing or cutting may come from the translocation of roots and stems, with the other part coming via soil absorption. However, [51], affirmed that the remobilization pattern of these nitrogen reserves towards the new tissue is associated to the amount of nitrogen present in the soil-plant system.…”

Section: Organic Reserves In the Grasssupporting

confidence: 84%

Organic Reserves in ropical Grasses under Grazing

Ferro¹,

Zanine²,

Ferreira³

et al. 2015

AJPS

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Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.

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Section: Organic Reserves In the Grasssupporting

confidence: 84%

Organic Reserves in ropical Grasses under Grazing

Ferro¹,

Zanine²,

Ferreira³

et al. 2015

AJPS

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“…As a result, leaves have two to three times more CP than stems [33]. Increased leaf N leads to increased leaf area, thus increasing the leaf/stem ratio [34,35], but this could also be accounted for by the reduced stem height caused by salinity. The leaf-to-stem ratio increase leads to decreases in both ADF and NDF.…”

Section: Forage Qualitymentioning

confidence: 99%

Nutrient Composition, Forage Parameters, and Antioxidant Capacity of Alfalfa (Medicago sativa, L.) in Response to Saline Irrigation Water

et al. 2015

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Although alfalfa is moderately tolerant of salinity, the effects of salinity on nutrient composition and forage parameters are poorly understood. In addition, there are no data on the effect of salinity on the antioxidant capacity of alfalfa. We evaluated four non-dormant, salinity-tolerant commercial cultivars, irrigated with saline water with electrical conductivities of 3.1, 7.2, 12.7, 18.4, 24.0, and 30.0 dS·m −1 , designed to simulate drainage waters from the California Central Valley. Alfalfa shoots were evaluated for nutrient composition, forage parameters, and antioxidant capacity. Salinity significantly increased shoot N, P, Mg, and S, but decreased Ca and K. Alfalfa micronutrients were also affected by salinity, but to a lesser extent. Na and Cl increased significantly with increasing salinity. Salinity slightly improved forage parameters by significantly increasing crude protein, the net energy of lactation, and the relative feed value. All cultivars maintained their antioxidant capacity regardless of salinity level. The results indicate that alfalfa can tolerate moderate to high salinity while maintaining nutrient composition, antioxidant capacity, and slightly improved forage parameters, thus meeting the standards required for dairy cattle feed. OPEN ACCESSAgriculture 2015, 5 578

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“…However, optimum PNC depends on aboveground biomass. If two different plants have the same PNC but differ in aboveground biomass, it is possible that the plant with higher aboveground biomass is well supplied with N, whereas the one with lower biomass may be suffering from N deficiency (Lemaire et al, 1992). Plant N uptake is highly variable within a single year, between years, sites and crops, even when the N supplies from both the soil and additional fertilizer inputs are plentiful (Gastal and Lemaire, 2002 that PNC decreases during the growth cycle in dense canopies (Greenwood et al, 1986;Ziadi et al, 2010b) and have a close non-linear relationship to the aboveground biomass, whatever the climatic conditions of the year, or the species and genotype (Lemaire et al, 2005).…”

Section: Introductionmentioning

confidence: 99%