A soil test based n recommendation model for dryland wheat1
作者:
P. N. Soltanpour,
M. El Gharous,
A. Azzaoui,
M. Abdelmonum,
期刊:
Communications in Soil Science and Plant Analysis
(Taylor Available online 1989)
卷期:
Volume 20,
issue 9-10
页码: 1053-1068
ISSN:0010-3624
年代: 1989
DOI:10.1080/00103628909368135
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Since soil test based N recommendations are not practiced in Morocco, this study was conducted to develop a N recommendation model based on soil nitrate level and other parameters for dryland wheat (Triticum aestivumL.) grown in common rotations in shallow (Rendolls), moderately deep (Calcixerolls) and deep (Chromoxererts) soils of Settat Province in Morocco. Sixteen N‐P Factorial experiments were conducted. Significant grain yield increases due to N fertilization averaged 76% over the check plot yields in all sites and in both seasons. Uptake of N was highly related to soil nitrates only in deeper soils with r2values of 0.89, 0.76, and 0.64 for 20‐, 40‐ and 60‐cm deep profiles. Apparent uptake efficiency of fertilizer N averaged 34% in the drier year and 50% in the wet year. Relative yield was a linear function of initial soil nitrate content in 20‐, 40‐ and 60‐cm profiles with r2values of 0.87, 0.94, and 0.89, respectively. For maximum grain yield 18, 31, and 50 kg of nitrate N/ha were required in 20‐, 40‐ and 60‐cm profiles, respectively. Nitrogen mineralization potentials were 144, 164, and 179 mg/kg for the above soils, respectively. A model based on critical level of soil nitrates, initial level of soil nitrates and apparent uptake efficiencies of soil and fertilizer N was developed to predict the fertilizer N requirement of wheat in deeper soils. If legume or mixed volunteer pastures preceded the wheat crop, the N fertilizer requirement was lower.
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