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3RD WASWAC CONFERENCE: Land degradation processes and mechanism
3RD WASWAC CONFERENCE
Towards more sustainable oasis system farming Applying biochar from date palm waste residues to improve the organic matter nutrient status and water retention in sandy oasis soil Melle Nissaf KARBOUT
3RD WASWAC CONFERENCE: Land degradation processes and mechanism
Introduction • Semi-arid and arid region are defined as region where evaporation exceeds precipitation, generally arid lands cover 41% of earth’s land surface (UNEP, 2007). • Oases only occupy less than 3% of the semi-arid regions of the world but feed from 7 to 10 million peoples (Clouet, 1995) • The oasis farming systems in south Tunisia occupy an area of 450 km² (FAO, 2013), that feed a population of over 1.5 million inhabitants. With over 4.5 data palm million present in that area (Hajj, 2013).
3RD WASWAC CONFERENCE: Land degradation processes and mechanism
Oasis system are characterized by a very important mass of waste better 200g m-2 of date palm waste and 100 g m-² of fruit tree waste (Ben Salah, 2014)
3RD WASWAC CONFERENCE: Land degradation processes and mechanism Farmers burn waste of date palm in the cleaning oasis season
• Among the problems facing arid lands is the global climatic trend towards an increase in temperatures (Global Warming) which would lead to an increase in aridity and a decrease in the available moisture
• Oasis system in south Tunisia suffers from degradation and reduced soil fertility
Nissaf 2014
Nissaf 2014
To protect environment
improve physical and chemical characteristics of soil
recycling waste of date palm oasis system
Compost
Biochar
-
composting is a long process to
have mature compost we need to weight more than 3 months - Compost heaps should have is suitable for more humid environments where there is potential for watering the compost Nissaf 2016
Biochar is produced in the partial or total absence of oxygen, the thermal decomposition of plant derived biomass (pyrolysis) can be manipulated to yield, and in addition to CO2 and in variable ratio, combustible gases (chiefly H2, CO2, CH4), volatile oils, tarry vapors, and a solid carbon-rich residue generally referred to as char. As distinct from char in general, biochar remains ill-defined . Waste of date palm tree
Gases Volatile oils Biochar
Study area 35
18 16
30
14 25
12
20
10
15
8 6
10
4 5
Temperature Rainfall
2
0
0
Month ( 1986-2015) 8
Wind speed (m/s)
7 6 5 4 3 Wind (m/s)
2 1 0
Month (1986-2015)
Biochar
Oasis Sandy soil
5t/ha
10 t/ha
15 t/ha
20 t/ha
Sandy soil+ Biochar
Sandy soil
Results
Parameters
pH
Electric conductivity (mS/cm)
Exc. Potassium (mg.kgˉ1)
Phosphorus Colwell (mg.kgˉ1)
Total nitrogen (%)
Control
A
5t/ha biochar 10t/ha biochar
15t/ha biochar
20t/ha biochar
LSD
P value
7.68±0.10a 7.62±0.046a
ns
0.1589
7.80±0.02a
7.71±0.03a
7.74±0.008a
7.66±0.07a
7.55±0.04a
7.7±0.02a
7.7±0.01a
7.78±0.02a
ns
0.1444
B A
1.90±0.6a
4.63±0.2a
5.95±0.16b
7.77±0.28c 9.47±0.64d
S
<.05
B
2.59±0.6a
4.58±0.3a
5.30±0.16b
6.43±0.28c
S
<.05
A
152 ±0.6a
508±0.64a
1105±0.19b
S
<.05
B
305±0.6a
665 ±0.2a
1387±0.1b
1453±0.29 1697±0.52d c 1846±0.3d 2592±0.6e
S
<.05
A
1356±0.2a
1708±0.3a
1719±0.07a
1746±0.3a
1749±0.2a
ns
0.4599
B
859±0.1a
871±0.1b
868±0.06ab
860±0.9ab
846±0.2d
S
<.05
A
0.37±0.4a
0.44±0.3b
0.47±0.2ab
0.48±0.3c
0.53±0.6d
S
<.05
B
0.27±0.1a
0.29±0.3b
0.33±0.1ab
0.34±0.2c
0.38±0.7d
S
<.05
7.58±0.6d
Parameters
Control
5t/ha biochar
10t/ha biochar
15t/ha biochar
20t/ha biochar
LSD
P value
WS (FC%) 4.38±0.6a
5.55±0.1a
8.53±0.1a
10.25±0.2a
13±0.6a
ns
0.774
3.99±0.6a
4.24±0.2a
6.46±0.1a
7.46±0.3a
9.68±0.6a
ns
0.626
2.076±0.007c
2.79±0.02c
3.32±0.03d
S
<.05
WS (wp %)
AW 0.478±0.05a
1.305±0.12b
Parameters
Control
5t/ha biochar
10t/ha biochar 15t/ha biochar
20t/ha biochar
LSD
P value
FM(%)
1.22±0.16a
1.28±0.16a
1.31±0.14a
1.34±0.08a
1.35±0.11a
Ns
0.7745
DM (%)
0.165±0.04a
0.166±0.08a
0.167±0.08a
0.178±0.16a
0.187±0.17a
Ns
0.6267
Total Production
1±0.28a
5±0.96b
2±0.60c
1±0.28a
0.66±0.29d
S
<.0001
Conclusion
- The results of this study support that the application of biochar to subtly influence soil characteristics leading to changes in physical and chemical proprieties of sandy soil and
increase production.
- With the climatic condition of south Tunisia the biochar can be a good solution to improve the situation of agriculture with low cost and help to save oasis environment in
poor country like south Tunisia.
- In this context world bank conclude that biochar may be a key element of climate-smart agriculture practices in developing country and help to mitigate climate change and
reduce vulnerability to its effects.
The question now is if the farmers of southern Tunisia accepted biochar as a new type of amendment with manure or compost and solve the problem of no usable waste in oases system
Thank you for Your Attention
