scholarly journals Simulation of water and salts dynamics in Bouhajla (Central Tunisia): exceptional rainfall effect

2012 ◽  
Vol 7 (No. 1) ◽  
pp. 36-44 ◽  
Author(s):  
S. Kanzari ◽  
M. Hachicha ◽  
R. Bouhlila ◽  
J. Battle-Sales
Keyword(s):  
Model Calibration ◽  
Arid Regions ◽  
Flood Irrigation ◽  
Central Tunisia ◽  
Term Evolution ◽  
1D Model ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Hydrus 1D

Arid and semi-arid regions face the risk of soils and aquifers salinization. Rainy events are rare which is characteristic of these regions. They play a significant role in the leaching of salts from topsoil to deeper layers, which increases the risk of aquifers salinization. For this reason, a plot was selected in the semi-arid region of Bou Hajla (Central Tunisia). The simulation of water and salts dynamics was carried out by Hydrus-1D. Model calibration was realised on a flood irrigation experiment during 10 days and in a depth of 4 m. The hydrodynamic parameters were determined by inverse modelling. Model validation was performed successfully during 577 days. The simulation of water and salts dynamics has allowed the analysis of two scenarios: (i) the effect of a very rainy event (> 50mm/day) on the dynamics of salts. This type of event allows leaching of the accumulated salts in the topsoil which promotes their burial in the depth; (ii) the long-term evolution of the saline profile in 20 years showed the cyclical nature of salts leaching in the topsoil, the permanent accumulation of salts in the depth of around 2 m, and a continuous leaching in the deeper layers (around 4 m), which may increase groundwater contamination risk.

scholarly journals VARIEDADES DE CANA-DE-AÇÚCAR SUBMETIDAS A DIFERENTES LÂMINAS DE REPOSIÇÃO HÍDRICA POR GOTEJAMENTO SUBSUPERFICIAL

2019 ◽  
Vol 34 (3) ◽  
pp. 350-363
Author(s):  
Anderson Ramos de Oliveira ◽  
Marcos Brandão Braga
Keyword(s):  
Water Availability ◽  
Arid Regions ◽  
Sugarcane Juice ◽  
Sugarcane Varieties ◽  
Raw Sugar ◽  
Technological Quality ◽  
Subsurface Drip ◽  
Semi Arid Region ◽  
Semi Arid

VARIEDADES DE CANA-DE-AÇÚCAR SUBMETIDAS A DIFERENTES LÂMINAS DE REPOSIÇÃO HÍDRICA POR GOTEJAMENTO SUBSUPERFICIAL   ANDERSON RAMOS DE OLIVEIRA1, MARCOS BRANDÃO BRAGA2   1 Embrapa Semiárido, Rodovia BR-428, Km 152, Zona Rural, 56302-970, Petrolina, PE, Brasil, [email protected] 2 Embrapa Hortaliças, Rodovia BR-060, Km 09, Fazenda Tamanduá, 70275-970, Brasília, DF, Brasil, [email protected]   RESUMO: A região semiárida brasileira apresenta grande potencial de produção de cana-de-açúcar. Contudo, verifica-se que existem oscilações na produção devido à baixa e irregular disponibilidade hídrica. O objetivo deste estudo foi avaliar o comportamento de variedades de cana-de-açúcar irrigadas por gotejamento subsuperficial submetidas a diferentes lâminas de irrigação. O experimento foi conduzido no Campo Experimental de Bebedouro, na Embrapa Semiárido, em Petrolina, PE. Foram realizadas análises de produtividade e de qualidade tecnológica do caldo. As variedades com maior tolerância ao déficit hídrico foram RB92579 e RB961003, pois alcançam máxima produtividade utilizando-se menor lâmina de reposição hídrica, em torno de 80% da ETc. A qualidade tecnológica do caldo apontou diferenças no °Brix e na porcentagem bruta de açúcares das variedades que reduziram em função do aumento da reposição hídrica. Contudo, estas diferenças não foram limitantes à qualidade tecnológica. Sendo assim, o cultivo das variedades RB92579 e RB961003 sob menor lâmina de reposição hídrica pode ser recomendado, pois as mesmas atingem alta produtividade e mantém a qualidade tecnológica do caldo.   Palavras-chave: biomassa, irrigação, estresse hídrico, regiões semiáridas.   SUGARCANE VARIETIES SUBMITTED TO DIFFERENT WATER REPLENISHMENT DEPTHS BY SUBSURFACE DRIP   ABSTRACT: Brazilian semi-arid region presents great potential for sugarcane production. However, due mainly to low and irregular water availability, there are fluctuations in production. This study proposed to evaluate the performance of sugarcane varieties irrigated by subsurface drip, submitted to different water replenishment depths. The experiment was carried out at Campo Experimental de Bebedouro, belonging to Embrapa Semiárido, Petrolina, PE, Brazil. Productivity and technological quality of sugarcane juice analysis were performed. The varieties with higher tolerance to water deficit were RB92579 and RB961003, which reached maximum productivity using lower water replenishment depths of ETc, around 80%. Technological quality of sugarcane juice showed differences in °Brix and raw sugar percentage of varieties that reduced due to water replacement depths increasing. However, these differences were not limiting to the technological quality of sugarcane juice. In summary, the cultivation of RB961003 and RB92579 cultivars under lower water replenishment depth can be recommended, because they maintain the technological quality of sugarcane juice.   Keywords: biomass, irrigation, water stress, semi-arid regions.

scholarly journals Extreme rainfall deficits were not the cause of recurring colonial era famines of southern Indian semi-arid regions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ranjini Ray ◽  
Atreyee Bhattacharya ◽  
Gaurav Arora ◽  
Kushank Bajaj ◽  
Keyle Horton ◽  
...  
Keyword(s):  
Arid Regions ◽  
Human Impacts ◽  
Rainfall Variability ◽  
Extreme Rainfall ◽  
Southern India ◽  
Colonial Era ◽  
Regional Rainfall ◽  
Semi Arid ◽  
Rainfall Deficits

AbstractUsing information contained in the eighteenth to twentieth century British administrative documents, preserved in the National Archives of India (NAI), we present a 218-year (1729–1947 AD) record of socioeconomic disruptions and human impacts (famines) associated with ‘rain failures’ that affected the semi-arid regions (SARs) of southern India. By mapping the southern Indian famine record onto long-term spatiotemporal measures of regional rainfall variability, we demonstrate that the SARs of southern India repeatedly experienced famines when annual rainfall reduced by ~ one standard deviation (1 SD), or more, from long-term averages. In other words, ‘rain failures’ listed in the colonial documents as causes of extreme socioeconomic disruptions, food shortages and human distress (famines) in the southern Indian SARs were fluctuations in precipitation well within the normal range of regional rainfall variability and not extreme rainfall deficits (≥ 3 SD). Our study demonstrates that extreme climate events were not necessary conditions for extreme socioeconomic disruptions and human impacts rendered by the colonial era famines in peninsular India. Based on our findings, we suggest that climate change risk assessement should consider the potential impacts of more frequent low-level anomalies (e.g. 1 SD) in drought prone semi-arid regions.

scholarly journals Water restriction in cowpea plants [Vigna unguiculata (L.) Walp.]: Metabolic changes and tolerance induction

2022 ◽  
Vol 26 (3) ◽  
pp. 190-197
Author(s):  
Alberto S. de Melo ◽  
Yuri L. Melo ◽  
Claudivan F. de Lacerda ◽  
Pedro R. A. Viégas ◽  
Rener L. de S. Ferraz ◽  
...  
Keyword(s):  
Arid Regions ◽  
Global Climate ◽  
Tolerance Induction ◽  
Potassium Nitrate ◽  
Stress Factors ◽  
Water Restriction ◽  
Clear Vision ◽  
Rainfed Farming ◽  
Semi Arid Region ◽  
Semi Arid

ABSTRACT Global climate change tends to intensify water unavailability, especially in semi-arid regions, directly impacting agricultural production. Cowpea is one of the crops with great socio-economic importance in the Brazilian semi-arid region, cultivated mainly under rainfed farming and considered moderately tolerant to water restriction. This species has physiological and biochemical mechanisms of adaptation to these stress factors, but there is still no clear vision of how these responses can not only allow survival, but also ensure yield advances in the field. Besides acclimation mechanisms, the exogenous application of abiotic (salicylic acid, silicon, proline, methionine, and potassium nitrate) and biotic (rhizobacteria) elicitors is promising in mitigating the effects of water restriction. The present literature review discusses the acclimation mechanisms of cowpea and some cultivation techniques, especially the application of elicitors, which can contribute to maintaining crop yield under different water scenarios. The application of elicitors is an alternative way to increase the sustainability of production in rainfed farming in semi-arid regions. However, the use of eliciting substances in cowpea still needs to be carefully explored, given the difficulties caused by genotypic and edaphoclimatic variability under field conditions.

Effects of Genotype and Rainfall on Forage Oats in a Semi-arid Region

1977 ◽  
Vol 13 (3) ◽  
pp. 217-223 ◽  
Author(s):  
A. Hadjichristodoulou
Keyword(s):  
Arid Region ◽  
Selection Criteria ◽  
Crude Protein ◽  
Dry Matter ◽  
Arid Regions ◽  
Correlation Coefficients ◽  
Annual Rainfall ◽  
Varietal Response ◽  
Semi Arid Region ◽  
Semi Arid

SUMMARYThere were significant differences in dry matter yield among five forage oat varieties tested at ten environments during 1970–75. The correlation coefficients between annual rainfall and DM yield varied with variety from 0·69 to 0·88, late varieties tending to give higher yields. Lateness, and high varietal response to annual rainfall and improved environmental conditions, can be used as selection criteria in semi-arid regions. Late varieties had higher DM and lower crude protein contents, and forage produced under lower rainfall conditions tended to have more DM and crude protein.

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