Nitrogen fixation in chickpea, 1. Influence of prior cropping or fallow nitrogen fertilizer and tillage [Queensland]

• Published in: Australian journal of agricultural research Vol. 44; no. 6
• Main Authors: Doughton, J.A. (Queensland Dept. of Primary Industries, Roma (Australia). Wheat Research Inst.), Vallis, I. (Commonwealth Scientific and Industrial Research Organisation, St Lucia (Australia). Div. of Tropical Crops and Pastures), Saffigna, P.G. (Griffith Univ., Nathan (Australia). Div. of Australian Environmental Studies)
• Format: Journal Article
• Language: English
• Published: 1993
• Subjects: ABONOS NITROGENADOS; CICER ARIETINUM; ENGRAIS AZOTE; FIJACION DEL NITROGENO; FIXATION DE L'AZOTE; LABRANZA; ROTACION DE CULTIVOS; ROTATION CULTURALE; TRAVAIL DU SOL
• ISSN: 0004-9409
• DOI: 10.1071/AR9931403

In a field experiment on the Darling Downs, Queensland, the 15N natural abundance method was used with barley as a non-fixing control crop. When chickpea was grown after sorghum both the percentage and amount of N in the tops derived from fixation were larger than after fallow. N fertilizer additions reduced percent but not total N fixation. Stubble management had no influence on total N fixed. There was a close inverse relationship between soil nitrate measured at establishment of chickpea and percent of N derived from fixation. All treatment differences in percent N fixation whether due to prior cropping, fallowing, N fertilizer or tillage could be explained through treatment influences on soil nitrate. Chickpea that had a plentiful supply of soil mineral N for growth accumulated significantly more plant N than plants dependent on N fixation. Chickpea grain yields were, however, unaffected by the source or quantity of plant N accumulated. Chickpea provided a positive soil N balance at high fixation rates and a negative balance at low fixation rates.