scholarly journals Soil–water conservation and rainwater harvesting strategies in the semi-arid Mzingwane Catchment, Limpopo Basin, Zimbabwe

2006 ◽  
Vol 31 (15-16) ◽  
pp. 893-900 ◽  
Author(s):  
Walter Mupangwa ◽  
David Love ◽  
Steve Twomlow
Keyword(s):  
Soil Water ◽  
Water Conservation ◽  
Rainwater Harvesting ◽  
Semi Arid

scholarly journals Evaluating models for predicting hydraulic characteristics of layered soils

2012 ◽  
Vol 9 (1) ◽  
pp. 301-336 ◽  
Author(s):  
S. S. W. Mavimbela ◽  
L. D. van Rensburg
Keyword(s):  
Soil Water ◽  
Water Conservation ◽  
Hydraulic Properties ◽  
Rainwater Harvesting ◽  
Characteristic Curve ◽  
Parametric Models ◽  
Distribution Model ◽  
Layered Soils ◽  
In Situ Conditions

Abstract. Soil water characteristic curve (SWCC) and unsaturated hydraulic conductivity (K-coefficient) are critical hydraulic properties governing soil water activity on layered soils. Sustainable soil water conservation would not be possible without accurate knowledge of these hydraulic properties. Infield rainwater harvesting (IRWH) is one conservation technique adopted to improve the soil water regime of a number of clay soils found in the semi arid areas of Free State province of South Africa. Given that SWCC is much easier to measure, most soil water studies rely on SWCC information to predict in-situ K-coefficients. This work validated this practice on the Tukulu, Sepane and Swartland layered soil profiles. The measured SWCC was first described using Brooks and Corey (1964), van Genuchten (1980) and Kasugi (1996) parametric models. The conductivity functions of these models were then required to fit in-situ based K-coefficients derived from instantaneous profile method (IPM). The same K-coefficient was also fitted by HYDRUS 1-D using optimised SWCC parameters. Although all parametric models fitted the measured SWCC fairly well their corresponding conductivity functions could not do the same when fitting the in-situ based K-coefficients. Overestimates of more than 2 orders of magnitude especially at low soil water content (SWC) were observed. This phenomenon was pronounced among the upper horizons that overlaid a clayey horizon. However, optimized α and n parameters using HYDRUS 1-D showed remarkable agreement between fitted and in-situ K-coefficient with root sum of squares error (RMSE) recording values not exceeding unity. During this exercise the Brooks and Corey was replaced by modified van Genuchten model (Vogel and Cislerova, 1988) since it failed to produce unique inverse solutions. The models performance appeared to be soil specific with van Genuchten-Mualem (1980) performing fairly well on the Orthic and neucutanic horizons while its modified form fitted very well the prismatic and pedo-cutanic horizons. The lognormal distribution model of Kasugi (1996) showed an extraordinary good fit among the Swartland profile horizons especially the saprolite rock layer. It was therefore concluded that in-situ KL-coefficient estimates from SWCC parameters could be acceptable if only rough estimates were required. Optimization of parameters for in-situ conditions especially for HYDRUS 1-D carried much prospects in characterising the hydraulic properties of most of the layered soils earmarked for IRWH in the province.

Peach response to water deficit in a semi-arid region

2013 ◽  
Vol 27 (3) ◽  
pp. 305-311 ◽  
Author(s):  
C. Paltineanu ◽  
L. Septar ◽  
C. Moale ◽  
S. Nicolae ◽  
C. Nicola
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Water Conservation ◽  
Deficit Irrigation ◽  
Irrigation Treatment ◽  
Fruit Yield ◽  
Dry Matter Content ◽  
Irrigation Water Use ◽  
Future Global Warming ◽  
Semi Arid

Abstract During three years a deficit irrigation experiment was performed on peach response under the semi-arid conditions of south-eastern Romania. Three sprinkler-irrigated treatments were investigated: fully irrigated, deficit irrigation treatment, and non-irrigated control treatment. Soil water content ranged between 60 and 76% of the plant available soil water capacity in fully irrigated, between 40 and 62% in deficit irrigation treatment, and between 30 and 45% in control. There were significant differences in fruit yield between the treatments. Irrigation water use efficiency was maximum in deficit irrigation treatment. Fruit yield correlated significantly with irrigation application. Total dry matter content, total solids content and titrable acidity of fruit were significantly different in the irrigated treatments vs. the control. Significant correlation coefficients were found between some fruit chemical components. For the possible future global warming conditions, when water use becomes increasingly restrictive, deficit irrigation will be a reasonable solution for water conservation in regions with similar soil and climate conditions.

scholarly journals The role of water conservation strategies and benchmark ecotopes for increasing yields in South Africa’s semi-arid croplands

Water SA ◽  
2019 ◽  
Vol 45 (3 July) ◽  
Author(s):  
Malcolm Hensley ◽  
Pieter AL Le Roux ◽  
J Jacobus Botha ◽  
Leon D Van Rensburg
Keyword(s):  
Water Conservation ◽  
New Technologies ◽  
Rainwater Harvesting ◽  
Arable Land ◽  
Daily Rainfall ◽  
Crop Productivity ◽  
Conservation Strategies ◽  
Cumulative Probability ◽  
Study Results ◽  
Semi Arid

Recently published results regarding South Africa’s cropping potential show that about one third of the arable land is of low potential, located mainly in semi-arid areas, with the main problem being water shortage.  This is therefore an appropriate time to review priorities and procedures, for selecting benchmark ecotopes to represent marginal areas, and for research needs with regard to water conservation strategies to mitigate the problems of low yields.  Relevant international principles encapsulated in the words agro-ecology, sustainability and socio-economic conditions, are discussed. Relevant new technologies are described, namely: digital soil mapping that will facilitate the identification of benchmark ecotopes; a stochastic procedure to predict rainfall intensity data from daily rainfall that will facilitate runoff predictions; a crop yield cumulative probability procedure that enables sustainability to be described quantitatively. As a case study, results from a successful field experiment using the infield rainwater harvesting production technique on benchmark ecotopes in a semi-arid area, inhabited by subsistence farmers, are presented.  The objectives of the study, procedures used and the method of expressing the results are recommended as guidelines for contributing towards mitigating the problem of low crop productivity across a large portion of the arable area in South Africa.

SOIL WATER CONSERVATION, GROWTH, YIELD AND WATER USE EFFICIENCY OF SORGHUM AS AFFECTED BY LAND CONFIGURATION AND WOOD-SHAVINGS MULCH IN SEMI-ARID NORTHEAST NIGERIA

2006 ◽  
Vol 42 (2) ◽  
pp. 199-216 ◽  
Author(s):  
A. M. CHIROMA ◽  
O. A. FOLORUNSO ◽  
A. B. ALHASSAN
Keyword(s):  
Water Use Efficiency ◽  
Soil Water ◽  
Water Use ◽  
Water Conservation ◽  
Water Storage ◽  
Soil Water Storage ◽  
Wood Shavings ◽  
Use Efficiency ◽  
Semi Arid ◽  
Northeast Nigeria

Water is perhaps the most important single factor that limits crop production in the semi-arid northeast of Nigeria. A four-year field experiment was therefore initiated in 1999 to evaluate the influence of land configuration practices with or without wood-shavings mulch on water conservation, yield and water use efficiency (WUE) of sorghum. The experimental treatments consisted of flat bed (FB), open ridging (OR), tied ridging (TR), FB + mulch (FBM), OR + mulch (ORM), and TR + mulch (TRM). Ridge heights were 15 to 20 cm and furrows were left open (for OR and ORM) or tied (for TR and TRM). Wood-shavings mulch was used at the rate of 5 t ha−1 in 1999, but this was increased to 10 t ha−1 in subsequent years to ensure adequate soil coverage. Differences in soil water storage at various sampling dates were significant only in some cases in each year, but trends were towards greater soil water storage in the mulched treatments than in the non-mulched treatments, irrespective of tillage method. Growth parameters (plant height and leaf area index) indicated significant differences between treatments on only some measurement dates in each year. Sorghum water use varied significantly between years and treatments. Seasonal water use was greater with FBM, ORM and TRM than with the FB treatment in all cropping seasons. Averaged over the four-year period, mean increases in grain yield relative to the FB treatment were 16 % for OR, 25 % for TR, 77 % for FBM, 50 % for ORM and 57 % for TRM. Pooled across the experimental years, the WUE (ET) of FB, OR, TR, FBM, ORM and TRM were 1.95, 2.12, 2.13, 2.74, 2.36 and 2.48 kg ha−1 mm−1 respectively. The corresponding WUE(R) values for these treatments were 1.26, 1.46, 1.56, 2.22, 1.88 and 1.97 kg ha−1 mm−1 respectively. It is concluded that combining the practice of flat bed cultivation with mulching may eliminate the need for ridging in increasing the productivity of sorghum grain in semi-arid northeast Nigeria.

scholarly journals Assessing the Applicability of Low Impact Development Techniques in Arid and Semi-arid Regions

2021 ◽  
pp. 20-37
Author(s):  
Hadi Heidari ◽  
Mohammad Reza Kavianpour
Keyword(s):  
Water Conservation ◽  
Stormwater Management ◽  
Arid Regions ◽  
Rainwater Harvesting ◽  
Low Impact Development ◽  
Negative Consequences ◽  
Study Region ◽  
Climate Conditions ◽  
Harvesting Technique ◽  
Semi Arid

Low impact development (LID) techniques are increasingly used as a stormwater management strategy to maintain the hydrological conditions of developed areas and mitigate the negative consequences of stormwater runoff and nonpoint source pollution. Although LID techniques have been commonly used in moderate to humid areas, further information is needed on their effectiveness in semi-arid and arid regions. This study aims to examine and compare the effectiveness of LID techniques in arid and semi-arid climate conditions. First, a comprehensive study was conducted to rank LID techniques based on literature reviews while also incorporating different stakeholder priorities. Then, the city of Varamin, Tehran, Iran, was chosen as a low slope arid and semi-arid study region to assess the applicability of the best three high-ranked LID techniques using the storm water management model (SWMM). The results indicated that rainwater harvesting is the most effective technique in terms of stormwater quality and quantity management. The implementation of the rainwater harvesting technique across the case study is likely to decrease the average discharge, peak discharge, total volume, total runoff, and total suspended solids (TSS) by respectively 31.2%, 12.7%, 40.71%, 40.77% and 37.91%. Besides, rainwater tanks were projected to provide the water demands of home gardens during the five dry months, in addition to other domestic needs for water conservation objectives. The application of LID techniques in such water-limited regions can be useful for both stormwater management and water conservation.

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