3rd Africa Rice Congress Theme 2: Rice intensification and diversification Mini symposium: Getting it right: integrated approaches to enhanced and sustainable increase in rice productivity Author: Mohamed Dicko, et al.

1. Analysis of pollution risks associated
with agricultural intensification and
diversification in Office du Niger - Mali
Mohamed DICKO (M.D.), Mamadou K. N’Diaye, Brehima Tangara, Soungalo Sarra
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

2. Study zone
Office du Niger
85-90,000ha
Irrigated rice
Full control water
5-6 t/ha of
paddy rice
Semi-arid climate : Tmin 11 – 25 C ; Tmax 31 –
42 C; Rainfall 300-600 mm ; ETP 2430 mm/year
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

3. Context
National rice demand increasing by
7.5% each year inducing a rice demand
of up to 1,400,000 t/year by 2015
Important contribution expected from
Office du Niger
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

4. Context
Transplanted Rice area increased
from 80’s, intensification to
improve productivity
Based on Transplanting and
use of varieties with high yield
potential
Increased use of fertilizers
increased use of fertilizers
based on N, P and more
recently, K
…but the doses are generally low
and use efficiency rarely
exceeds 20%
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

5. Context
Increasing in groundwater table
Inefficient water management
Groundwater table close to soil surface
Double cropping contributes
to ground water table
rising
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

6. Context
use of more and more increased pesticide, but
lacks sufficient quantitative data
Insecticides
Organophosphates
(monocrotophos)
Pyrethroids (DECIS)
Association of
Organophosphates/ pyrethroids
Herbicides related to lack of labor
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

7. Context
Irrigation (as well as drainage)
water is used for domestic needs
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

8. Consequences
Yield correlated to
fertilizers use
Yield increasing from
80’s related to rice
intensification
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

9. Consequences
Soil salinization (with high Na-exch),
HCO3, etc.) but impact on rice is low
Small NO3 rate (less than 1mg/l)
GHG from rice field end
if the contribution of
rice is low
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

10. Consequences
Bad using condition of pesticides
Institut d’Economie Rurale
Sub-Theme 2 : Sustainability

11. Conclusion - Risks evaluation
There is evidence of increasing of
groundwater level and soil
alkalinization.
Submergence conditions do not
allow a significant accumulation of
nitrate in the soil
There are no quantitative results
related to pesticide pollution
But in the context of an agriculture
increasingly intensified, sharing
water, and low use of good
agricultural practices, there is a
real risk of damage to the soil and
water quality in Office du Niger
Institut d’Economie Rurale
Florence Brondeau, 2004
View all the potential risks it is
important to implement a good
monitoring tools of irrigation
system to prevent and advise on
soil and water pollution.
Sub-Theme 2 : Sustainability