Incidence des pratiques culturales et de la teneur en phosphore du sol sur la productivité des cultures en zone de savanne au Tchad

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Résumé

Un diagnostic agronomique a ete realise dans les exploitations proprietaires et non proprietaires de traction animale sur 3 sites (Ndaba, Nguette1 et Tala1). Les teneurs des sols en C, N et P total et assimilable ont ete determinees, de meme que, les rendements des principales cultures vivrieres que sont le mil, le sorgho et l'arachide, sous une predominance de la culture d'arachide ont egalement ete determines. A Tala1, la traction animale est communement utilisee sur des sols degrades et les planteurs apportent environ 2 200 kg ha -1 de fumier au sol. L'utilisation de la traction animale a coincide avec des teneurs du sol en P (total et assimilable) plus elevees. La teneur en P assimilable a ete positivement et significativement correlee avec le rendement de l'arachide. La fertilisation phosphatee et l'utilisation de fumier organique ont ete jugees necessaires a l'amelioration des rendements des cultures. Des subventions de l'Etat ou l'acces facilite au credit pourrait aider a vulgariser l'utilisation de la traction animale en vue de creer de meilleures conditions de gestion des terres et d'augmentation des rendements. An agronomic diagnosis was made in farmer exploitations using or not animal drive at 3 sites (Ndaba, Nguette1 and Tala1). The contents of C, N and total and available P were determined, as well as yields, of major n main crop subsistence that are millet, sorghum and groundnut under an ascendancy of the culture of groundnut were also determined. The farmers of Tala1, where land was fond to be much degraded, holders of the animal drives apply to the land, 2 200 kg ha -1 of fertilizer. The use of animal drive coincided with high P (total and available) contents. The content of available P was positively and significantly correlated to groundnut yield. Phosphate and manure fertilizations were found to be necessary in yield increase. This parameter determines the return on the groundnut. State subventions or easy access to funding can help to disseminate animal drive techniques in order to foster better land management techniques for yield improvement. Keywords : Food crops Yield, phosphorus, agronomic diagnosis, animal drive, Chad

Mots-clés

soil phosphorus, available phosphorus, soil organic carbon, soil nitrogen, animal traction, manure application, peanut yield, millet, sorghum, phosphorus fertilization, land degradation, savanna zone, Chad, land management, agricultural extension, access to credit, government subsidies, soil fertility management, savanna