Irrigation Management Evaluation And Hydrosalinity Balance Within Kalaat El Andalous Irrigation District, North‐East Tunisia

Abstract. Daghari I, Daghari H, Ben Khalifa N,, Mahmoud M. 2022. Saline irrigation management in field conditions of a semi-arid area in Tunisia. Asian J Agric 6: 103-108. Tunisian saline soils occupy about 25% of the total irrigated area. The irrigated area of ??"Dyiar-Al-Hujjej" in Tunisia was considered because seawater intrusion took place and salinization of the aquifer reached a very high water electrical conductivity value of 15 dS/m in the 90s, which caused many local farmers to abandon land parcels and wells. In addition, salinity has reduced plant growth and water quality, leading to lower crop yields and degradation of stock water reserves. Excess salt affects overall soil health, reducing productivity. It kills plants, leaving bare soil prone to erosion. In this study, the electrical conductivity of the soil under several irrigated crops was evaluated for two soil layers (0-20 cm and 20-40 cm). Follow-up surveys of agricultural practices have shown that the irrigation water's quality has a considerable effect on the soil's electrical conductivity and, therefore, on the choice of crops. We also showed that crop rotation is a practice done by farmers to maintain and improve soil fertility by utilizing soil nutrient losses due to salinization. This study can be the basis of a valuation to allow farmers to have the best cultural practices to fight the salinization of their soils.

Section: Discussionmentioning

confidence: 99%

Saline irrigation management in field conditions of a semi-arid area in Tunisia

et al. 2022

“…Even if salinities increase during the irrigation season and decrease during the rainy season; very high (EC) were measured under crops during the irrigated season and which are the cause of drop in yields. (EC) increases from 3 to more than 8 dS/m within the surface layer between the start and the end of the tomato irrigation season (Saidi et al 2018). Salinity management is directly linked to irrigation management and scheduling.…”

Section: Case Of Farmers Having An Important Volume Of Surface Water ...mentioning

confidence: 99%

Rethinking water and crop management in the irrigated district of Diyar-Al-Hujjej (Tunisia)

Abouaziza

2021

Environ Sci Pollut Res

Self Cite

In Diyar-Al-Hujjej irrigated area, aquifer's over-exploitation, sea intrusion and abandonment of irrigated areas and wells were took place. A yield decrease for all crops was observed. Average aquifer water electrical conductivity (EC) jumps from 4 dS/m to 6.6 dS/m between 1969 and 2017. A fresh surface water transfer over more than 100 km was launched in 1998 to safeguard this irrigated area but this fresh water supply is not stable, it varies from one year to another (about 1,900,000 m 3 in 2015 and only 60,000 m 3 in 2018) while annual cops water requirements of the perimeter is about 2,500,000 m 3 . An adaptation by farmers to this new situation of saline and water stress was observed. The follow-up surveys of the farmer's practices showed that: (i) new crops with high added-value grown during the rainy season were introduced in association with dry season crops (strawberry-pepper association), (ii) rainfed crops, fallow and water blending are common practices, and (iii) growing of rainy season crops in the aim to reduce water supply. The instability of fresh surface water volume transferred constitutes the main threat for this perimeter. The use of aquifer salt water must be stopped; it is the cause of the large quantities of salts supplied (over 13,000 kg / ha) and also of the low annual net income achieved. Net revenue was less than 2,000 US $/ha under salt water and reached even 8,000 US $/ha when su cient surface water is available. An agrarian reform policy must be applied for this perimeter; only crops whose water requirements are partially met by rain should be grown. Introduction of another more sustainable water source should be initiated (as desalination) even at private farm level.

Rethinking water and crops management in the irrigated district of Diyar-Al-Hujjej (Tunisia)

Abouaziza

2021

Preprint

Self Cite

In Diyar-Al-Hujjej irrigated area, aquifer’s over-exploitation, sea intrusion and abandonment of irrigated areas and wells were took place. A yield decrease for all crops was observed. Average aquifer water electrical conductivity (EC) jumps from 4 dS/m to 6.6 dS/m between 1969 and 2017. A fresh surface water transfer over more than 100 km was launched in 1998 to safeguard this irrigated area but this fresh water supply is not stable, it varies from one year to another (about 1,900,000 m3 in 2015 and only 60,000 m3 in 2018) while annual cops water requirements of the perimeter is about 2,500,000 m3. An adaptation by farmers to this new situation of saline and water stress was observed. The follow-up surveys of the farmer’s practices showed that: (i) new crops with high added-value grown during the rainy season were introduced in association with dry season crops (strawberry-pepper association), (ii) rainfed crops, fallow and water blending are common practices, and (iii) growing of rainy season crops in the aim to reduce water supply. The instability of fresh surface water volume transferred constitutes the main threat for this perimeter. The use of aquifer salt water must be stopped; it is the cause of the large quantities of salts supplied (over 13,000 kg / ha) and also of the low annual net income achieved. Net revenue was less than 2,000 US $/ha under salt water and reached even 8,000 US $/ha when sufficient surface water is available. An agrarian reform policy must be applied for this perimeter; only crops whose water requirements are partially met by rain should be grown. Introduction of another more sustainable water source should be initiated (as desalination) even at private farm level.