Seasonal patterns of root C and N reserves of lucerne crops (Medicago sativa L.) grown in a temperate climate were affected by defoliation regime

2007 ◽  
Vol 26 (1) ◽  
pp. 10-20 ◽  
Author(s):  
Edmar I. Teixeira ◽  
Derrick J. Moot ◽  
Michael V. Mickelbart
Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1438
Author(s):  
Gazali Issah ◽  
Jeff J. Schoenau ◽  
Herbert A. Lardner ◽  
J. Diane Knight

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.


2010 ◽  
Vol 61 (6) ◽  
pp. 493 ◽  
Author(s):  
K. G. Pembleton ◽  
R. S. Smith ◽  
R. P. Rawnsley ◽  
D. J. Donaghy ◽  
A. W. Humphries

Genotype by environmental interactions in lucerne (Medicago sativa L.) present considerable challenges when selecting an appropriate cultivar for a particular location and farming system. Data on the yield and persistence of a range of lucerne cultivars and experimental lines grown in two Tasmanian environments, Forth (41.20°S, 146.27°E, Red Ferrosol soil, under cutting with high fertiliser inputs, i.e. a high yield potential environment) and Cranbook (42.00°S, 148.03°E, Red Ferrosol soil, under grazing with low fertiliser inputs, i.e. a low yield potential environment) were examined using winter activity class as the experimental factor. At Forth, winter-dormant lucernes were the lowest yielding genotypes. In contrast, at Cranbrook, highly winter-active genotypes had lower plant persistence and dry matter yield than winter-dormant genotypes. Modified joint linear regression analysis showed that in a cool temperate climate, winter-dormant genotypes are more suited to a low yield potential environment, whereas highly winter-active genotypes are adapted to a high yield potential environment. Both the semi-winter-dormant and the winter-active genotypes were adapted to all environments. The dry matter yield of winter-dormant and highly winter-active genotypes was most sensitive to environmental conditions in winter and spring, while performance of all cultivars and experimental lines was most stable over summer.


Plant Science ◽  
2018 ◽  
Vol 272 ◽  
pp. 301-308 ◽  
Author(s):  
William Kess Berg ◽  
Sofia Lissbrant ◽  
Suzanne M. Cunningham ◽  
Sylvie M. Brouder ◽  
Jeffrey J. Volenec

2005 ◽  
Vol 32 (4) ◽  
pp. 321 ◽  
Author(s):  
Frédéric Meuriot ◽  
Marie-Laure Decau ◽  
Annette Morvan-Bertrand ◽  
Marie-Pascal Prud'Homme ◽  
François Gastal ◽  
...  

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.


Author(s):  
Francisco Gavi Reyes ◽  
César Botello-Aguillón ◽  
Leonardo Tijerina-Chávez ◽  
Arturo Galvis-Spíndola ◽  
Rodrigo Roblero-Hidalgo

E Objetivo: Desarrollar un procedimiento para estimar biomasa con imágenes digitales captadas desde un dron y modelación 3D (ID-Dron-3D) aplicable en alfalfa (Medicago sativa L.) y avena forrajera (Avena sativa L.). Diseño/metodología/aproximación: Con una cámara digital acoplada al dron se obtuvieron imágenes antes de la cosecha de los cultivos, que fueron procesadas con software para luego estimar volumen de biomasa. En cada cultivo se midió altura de la planta y área cosechada, volumen aparente y real de biomasa, y peso de biomasa fresca y seca. Resultados: Con base en el análisis de regresión se obtuvieron modelos lineales a una p<0.05 para predecir: biomasa fresca en avena (R2=0.70) y alfalfa (R2 =0.47); y biomasa seca en avena (R2=0.78) y en alfalfa (R2=0.31) mediante ID-Dron-3D. Limitaciones del estudio/implicaciones: Considerando las R2 de los modelos obtenidos, los resultados en la avena forrajera fueron mejores, respecto a los detectados en alfalfa, lo cual se puede deber a la mayor variabilidad de la cobertura vegetal, ya que, en algunas unidades de muestreo, las plantas de alfalfa no cubrían completamente el suelo. Hallazgos/conclusiones: El rendimiento de biomasa fresca y seca de ambos cultivos se correlacionó significativamente con su respectivo volumen aparente estimado con imágenes digitales tomadas desde un dron y su procesamiento 3D (ID-Dron-3D).


Author(s):  
CC. Castillo-Águilar

Se comparó el uso de diferentes dietas con base en heno de alfalfa cultivada (Medicago sativa L.) en Campeche y su relación con un concentrado comercial y pasto Taiwán (Pennisetum purpureum), T1=concentrado comercial, T2=T1+heno de alfalfa, T3=T1+pasto Taiwán, T4=heno de alfalfa. Se evaluó el comportamiento productivo y metabólico de corderos en sistema intensivo utilizando 20 corderos machos con encaste de Pelibuey, Dorper y Black Belly de 12.5±1 kg de peso vivo (PV). Se midió el consumo de materia seca total (CMS), la ganancia diaria de peso (GDP), la conversión alimenticia (CA), y la digestibilidad in situ de la materia seca (DISMS). También fueron evaluados el pH, nitrógeno amoniacal (NH3) y la concentración de ácidos grasos volátiles (AGV) en líquido ruminal. La mejor GDP en gramos por día, de 234 g (p?0.05) se obtuvo en el T2; en contraste, el T3 mostró la menor GDP. La dieta que incluyó la mezcla de heno de alfalfa y concentrado mejoró significativamente las condiciones de las variables pH, NH3 y AGV (p?0.05).


Author(s):  
Galina Stepanova

The article describes the main morphological and biological features of alfalfa varieties included in the State register of breeding achievements approved for use in the Central Chernozem zone of Russia. A total of 32 alfalfa varieties are included in the State register. This is 9 varieties of blue alfalfa (Medicago sativa L. subsp. Sativa) of domestic selection and 8 foreign, 11 varieties of variable alfalfa (Medicago sativa L. nothosubsp. varia (Martyn) Arcang.) domestic selection and 1 variety of foreign and 3 varieties of yellow alfalfa (Medicago sativa L. subsp. falcata (L.) Arcang.). It shows the average and maximum yield of varieties determined in the process of state variety testing, as well as independent evaluation in research institutions in the region. Varieties of blue alfalfa of domestic selection Kevsala, Elena, Satellite, Vavilovskaya Yubileynaya were the most productive. The average yield of dry matter of these varieties reaches 8.4–9.2 t/ha, the maximum — 15.3–17.7 t/ha. Alfalfa varieties Timbale and Galaxy were the most productive among foreign varieties: the average yield of dry matter was 8.1 and 8.3 t/ha, the maximum – 15.5 and 17.2 t/ha. Varieties of alfalfa variable Vitalina and Vela provided an average yield of dry matter of 7.6 and 9.0 t/ha, the maximum yield reached 15.4 and 18.1 t/ha.


Sign in / Sign up

Export Citation Format

Share Document