Residual effects of nitrogen fertiliser on the yield and N composition of succeeding cereal crops and on soil chemical properties of an Ethiopian highland Vertisol

• Published in: Canadian journal of soil science Vol. 80; no. 1; pp. 63 - 69
• Main Authors: Kidanu, S, Tanner, D.G, Mamo, T
• Format: Journal Article
• Language: English
• Published: 01-02-2000
• Subjects: corn; corn straw; crop rotation; crop yield; Eragrostis tef; highlands; nitrates; nitrogen content; nutrient uptake; residual effects; soil fertility; soil organic matter; soil pH; Triticum turgidum subsp. durum; urea; Vertisols; Ethiopia
• ISSN: 0008-4271; 1918-1841
• DOI: 10.4141/S99-008

A trial was conducted on an Ethiopian Vertisol from 1990 to 1995 to determine the residual effects of fertiliser N applied to tef [Eragrostistef (Zucc.) Trotter] on the grain and straw yield, N content, and total N uptake of succeeding crops of durum wheat (Triticum turgidum var. durum) and tef. The mean agronomic efficiency of 60 kg fertiliser N ha
−1
was 13.1 kg grain kg
−1
fertiliser N applied in the current year and 5.4 kg grain kg
−1
fertiliser N applied in the previous year. Thus, the residual fertiliser N benefit was equivalent to 41.2% of the response to current season N application for the two cereal crops. The mean rates of apparent recovery of fertiliser N were 65.8% for current season N application and 31.0% for previous season N application. Soil organic matter and nitrate levels increased linearly in response to both previous and current season N application rates. The current study demonstrates that the residual effect of fertiliser N enhanced the yields and N contents of the grain and straw of both wheat and tef, resulting in a significant increase in total N uptake. Any analysis of the profitability of fertiliser N response should reflect the multi-year benefit period. Key words: N recovery, N residue, N uptake, tef, wheat