The effects of irrigation regimes and nitrogen rates on some agronomic traits of canola under a semiarid environment

B. Kamkar, A.R. Daneshmand, F. Ghooshchi, A.H. Shiranirad and A.R. Safahani Langeroudi

Agricultural Water Management, 2011, vol. 98, issue 6, 1005-1012

Abstract: This study was aimed to investigate dual effects of irrigation regimes and N fertilizer rates on some agronomic traits (with emphasis on yield qualitative and quantitative characteristics) and finding optimized irrigation level and N application rate for two canola (Brassic napus L.) cultivars. For this purpose, two variety of canola (Zarfam and Modena), four irrigation regimes including 30%, 45%, 60% and 75% (I1-I4) of maximum allowable depletion (MAD) of available soil water (ASW) and four nitrogen rates (viz. 0, 90, 180 and 270Â kg NÂ ha-1 (N1-N4) were involved in Karaj, Iran for two successive years (2007-2008). Our results revealed special fertilizer threshold for each irrigation regime in respect to seed yield. Response rate to fertilizers was ceased in lower fertilizer rates by prolonging irrigation. The response rate showed a decrease of 15.4%, 17.2% and 30.7% in I2, I3 and I4 in comparison with I1, but I2 response to fertilizer ceased in higher N rate as Ncritical (189.8Â kg NÂ ha-1). This implies that I2 improved response of canola cultivars to N fertilizer, which was accompanied by its higher WUE. Also, all estimated Ncriticals for all irrigation levels were higher than the current recommendation of 130Â kg NÂ ha-1. This show the capability of increasing canola cultivars yield in study region by reasonable increasing of fertilizer rate (decreasing gap between recommended N rate and estimated values) in advisable irrigation regime (I2). Cultivars tended to respond similarly to irrigation and nitrogen for seed yield in both years, but Zarfam was more efficient than Modena in respect to response to diverse treatments.

Keywords: Maximum; available; depletion; Leaf; area; index; Seed; oil; content; Seed; yield; Cultivar; Above-ground; dry; matter (search for similar items in EconPapers)
Date: 2011
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (3)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378-3774(11)00016-3
Full text for ScienceDirect subscribers only

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:agiwat:v:98:y:2011:i:6:p:1005-1012

Access Statistics for this article

Agricultural Water Management is currently edited by B.E. Clothier, W. Dierickx, J. Oster and D. Wichelns

More articles in Agricultural Water Management from Elsevier
Bibliographic data for series maintained by Catherine Liu ().