THE EFFECT OF DROUGHT ON ECONOMICALLY OPTIMAL NITROGEN FERTILIZATION RATES OF DRYLAND WHEAT IN THE SUMMER RAINFALL AREA

A quadratic nitrogen response model for dryland wheat with moisture stress dependent coefficients is described and validated. The model was used to estimate the effects of moisture stress on the nitrogen levels corresponding to a maximum yield and an economically optimal yield, respectively. For the range of stress values representative of dryland cropping conditions in South Africa the nitrogen level needed for a maximum yield was largely independent of the stress level. In contrast, the nitrogen level needed for an economically optimal yield increased sharply with increasing moisture stress. The implications of these results with respect to the problem of nitrogen fertilization in semi-arid regions are discussed.


Issue Date:
1987-06
Publication Type:
Journal Article
Record Identifier:
http://ageconsearch.umn.edu/record/267151
ISSN:
0303-1853
Language:
English
Published in:
Agrekon, Volume 26, Issue 2
Page range:
20-26




 Record created 2018-01-24, last modified 2018-04-02

Fulltext:
Download fulltext
PDF

Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)