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Accueil du site → Doctorat → Belgique → Analysis of yield gaps and constraints for rainfed wheat production on Vertisols in the Tigray Highlands, Ethiopia : case-study in Adigudum

Universiteit Gent (2002)

Analysis of yield gaps and constraints for rainfed wheat production on Vertisols in the Tigray Highlands, Ethiopia : case-study in Adigudum

Fassil Kebede Yimamu

Titre : Analysis of yield gaps and constraints for rainfed wheat production on Vertisols in the Tigray Highlands, Ethiopia : case-study in Adigudum

Auteur : Fassil Kebede Yimamu

Université de soutenance : Universiteit Gent

Grade : PhD Physical Land Resources 2002

Résumé
This study is aimed at determining the various wheat yield levels, establishing yield gaps, investigating constraints of wheat production on Vertisols under smallholder conditions thereby suggesting measures for sustaining better grain production. Four wheat yield levels were determined, namely the Radiation-limited Production Potential (RPP), the Water-limited Production Potential (WPP), yields from the experimental sites during the 1999-2000 cropping seasons and yields from farmers managed plots.
During the 1999 and 2000 cropping seasons, the highest aggregated wheat yield obtained from the experimental plots was 2.89 t/ha and 1.62 t/ha with the phosphorus rate of 24 kg/ha and 48 kg/ha from banding and broadcasting techniques of placement respectively. This implies that P placed in bands is more effective than that in broadcast. The RPP and WPP wheat yield levels were 5.48 t/ha and 4.99 t/ha respectively. The aggregated mean wheat yield from the farmers managed plots was 0.84 t/ha. The magnitude of Yield Gap I refers to the difference between the RPP and the WPP. The present study revealed that the difference between the RPP and WPP was the lowest (0.49 t/ha), which is 8.9%. The magnitude of Yield Gap II refers to the difference between the WPP and the experimental yield. During the investigation it was found that the yield levels from banding and broadcasting experimental plots was lower by 2.1 t/ha and 3.37 t/ha respectively than that of the WPP. The magnitude of Yield Gap II in percent was 38.3% and 61.5% respectively. The magnitude of Yield Gap III refers to the difference between the experimental and the farmers’ yields. In this study, it was found that the aggregated mean yield of farmers was lower by 2.05 t/ha than that of the banded plot and by 0.78 t/ha than that of the broadcasted one.
The constraints for Yield Gaps I and II were mainly due to climatic factors like amount of rainfall. The constraints for Yield Gap III were mainly moisture deficiency at flowering period, weed infestation, poor nutrient management and late sowing.
The current farmers’ wheat yield levels can be increased by improving the efficiency all along with wheat production line, beginning with timely sowing, increased and sustainable use of plant nutrients, adoption of supplemental irrigation practice, improved control of menacing weeds, pests and diseases.

Présentation

Source (Résumé) : Pedon 14 - Physical Land Resources - Universiteit Gent

Page publiée le 28 octobre 2015, mise à jour le 25 janvier 2017