Fait partie de [OMC12]

1995 - 280 p.

Phosphorus use efficiency of Medicago polymorpha in the 'secano interior' of central Chile

Del Pozo A.

The responses of burr medic (Medicago polymorpha) to posphorus (P) was studied on field conditions. The available P-Olsen increased linearly after the application of increasing amounts of P, and approximately 7 kg.ha-1 of P was needed to change the available P in 1 mg.kg-1. The percentage of P in shoots of M. polymorpha increased with increasing P supply, and ranged between 0.18 and 0.25 per cent. Shoot dry weight reached 2682 kg.ha-1 in 1987, and 3050 kg.ha-1 in 1988 both at the highest P application rate. Seed yield ranged between 305 and 681 kg.ha-1 in 1987, and between 300 and 387 kg.ha-1 in 1988. Phosporus utilization efficiency, measured as shoot dry weight per unit of P content, ranged between 391 and 566 kg DW/kg P. Phosphorus use efficiency, measured as shoot dry weight per unit P applied, was 73, 36 and 27 kg DW/kg P, with the application of 24, 62 and 97 kg P.ha-1, respectively. Shoot dry weight increased curvilinearly with increasing P available in the soil at the top 5 cm.

Mots-clés    

MEDICAGO POLYMORPHA, PHOSPHORE, ZONE ARIDE

Citer cet article    

Del Pozo A. Phosphorus use efficiency of Medicago polymorpha in the 'secano interior' of central Chile. Systèmes sylvopastoraux. Pour un environnement, une agriculture et une économie durables . Zaragoza : CIHEAM, 1995. p. 83-86. (Cahiers Options Méditerranéennes; n. 12). Réunion du Groupe de Travail Méditerranéen du Réseau Interrégional FAO/CIHEAM de Recherche et Développement sur les Pâturages et les Cultures Fourragères, 1995/05/29-1995/06/02, Avignon (France). http://om.ciheam.org/om/pdf/c12/96605492.pdf