High Water Scarcity Research Articles

Mexico city’s decline in per capita domestic water use: a comprehensive spatial-temporal study

ABSTRACT Facing the growing challenges in water supply in urban areas, characterized by high demand and water scarcity, Mexico City, with its high population density and limited water resources, exemplifies the challenges in ensuring equitable management and water supply in complex urban environments. This study combines GIS tools, statistical analysis and spatial regression to analyze the spatiotemporal changes in per capita water consumption in Mexico City households between 2010 and 2019. The results show a 40% decrease in average consumption and a spatial reconfiguration that reflects an increase in inequalities in access to drinking water. The influence of five key factors in the reconfiguration is identified: intermittent supply, economic income, water feasibility, households without piped water, and an increase in dwellings. The findings are essential for developing equitable and effective water policies, emphasizing the need to address inequalities in water access in urban planning to achieve the Sustainable Development Goals.

Zinc outperforms other foliar fertilisers in enhancing lentil yield and harvest index in semi-arid regions

ABSTRACT Lentil yield in semi-arid regions is limited by heat, drought stress and nutrient deficiencies induced by high soil pH and water scarcity. In this study, we investigated the effect of foliar fertiliser treatments on lentil yield and yield components in a semi-arid region of South-East Anatolia, Türkiye. The control treatment and six foliar treatments were as follows: (i) Control: non-amended control, (ii) Zn: zinc sulphate, (iii) K: potassium sulphate, (iv) Zn + K (zinc sulphate + potassium sulphate), (v) Flo: Florea-UPL (containing boron and molybdenum), (vi) Mac: Macarena-UPL, an organomineral foliar fertiliser and (vii) Flo + Mac. Foliar fertilisers were applied at the first blooming stage of field-grown lentils. Total biomass yield was largely unaffected across treatments except in the K treatment. However, foliar Zn supply was the only treatment that significantly increased grain yield (55% higher), harvest index and total grain N uptake compared to the control, likely due to enhanced translocation of nitrogen-containing assimilates. SPAD values and total N analysis showed that stover N content depleted more rapidly in the Zn treatment than in other treatments during the grain-filling phase. The tested commercial products slightly increased SPAD values, biomass and grain yield. Among the treatments, Zn, as a foliar fertiliser, was the most cost-effective solution for improving grain yield in this region.

What is behind water user satisfaction with irrigation organizations´ performance? An empirical analysis under different water scarcity conditions

The level of satisfaction of individuals within a community sharing a common pool resource is essential to strengthening collective actions. In the case of irrigation water, which is becoming a critical resource due to its declining availability in many regions worldwide, the satisfaction level in Water User Associations (WUAs) is not guaranteed and also varies across individuals within these organizations. This study analyzed the satisfaction of users in WUAs and identified organization- and user-level characteristics associated with it. Using a sample of 393 users of 20 WUAs from the Mediterranean portion of Chile, we performed confirmatory factor analysis, correlational analyses, and multilevel regressions. A composite indicator of user satisfaction showed significant correlations with the positive evaluation of the WUA staff performance, the effectiveness of monitoring and enforcement, and the confidence that other users do not withdraw more water than they are allocated. We also compared users’ satisfaction levels from WUAs facing higher and lower water scarcity problems and found that user satisfaction is significantly higher in the latter case. The results of the multilevel econometric models show that in WUAs under higher water scarcity, user satisfaction is affected by several structural characteristics (water withdrawal mechanism and location along the canal) and users' human and social capital variables (experience, education, and participation in organizations); in contrast, in WUAs with a low level of scarcity, few covariates were significant while unobserved characteristics became more relevant (34 % of total variance explanation). Our study contributes to the existing literature on user satisfaction in community resource management, which could be useful to promote effective and cohesive governance structures as, ultimately, users determine cooperation rates and willingness to participate in WUA actions.

Fatty Acid Profile and Physicochemical Properties of Moringa oleifera Seed Oil Extracted at Different Temperatures.

Moringa oleifera Lam. (Moringaceae) is a tropical plant native to India. It is widespread throughout the southern hemisphere, with great adaptability to high temperatures and water scarcity. Its seeds have a great amount of oil with a high content of oleic acid, quite similar to olive oil. Therefore, this study is focused on the extraction of oil from moringa seeds via an automatic screw press extractor at different temperatures (70, 100, 130, 160, 190, and 220 °C) and on the analysis of its acidity, acid value, peroxide value (PV), saponification value (SV), iodine value (IV), optical properties, and fatty acids profile. The results showed that the oil yield was 19 ± 3% regardless of the temperature applied. The oil was stable from the oxidative point of view, with a high acidity. Temperature extraction did not significantly affect the SV and the IV. However, the extraction temperature should be below 190 °C to obtain a translucent and luminous oil with light yellow tones. The oil contains high levels of unsaturated fatty acids, especially oleic acid (ω9) (up to 77.8%) and linolenic acid (ω3) (3.4%). On the other hand, behenic (7%), palmitic (6%), stearic (5%), and arachidic (0.2%) were the dominant saturated acids. The good properties of moringa oil make it a good, sustainable alternative to vegetable oils.

Geospatial identification of possible rainwater harvesting locations within a high-altitude Gilgit River basin, Pakistan

The management of water resources is no longer an option but a necessity especially in countries with a high rate of population growth like Pakistan. Pakistan has a high-water scarcity, an extremely varying topography, and is also one of the countries encountering the problem of climate change. Therefore, prudent utilization of available water resources is a matter in the plains of Pakistan as in its high-altitude regions. Instead of wasting water which is a valuable resource, rainwater harvesting is a way of saving rainwater as an alternative source of fresh water for better use. The aim of this study was to search for potential rainwater-harvesting areas in a high-altitude Gilgit River basin. This research employed the SCS-CN technique in estimating surface runoff in the GIS environment. The geospatial study used four input parameters: slope of the land, land covers, surface runoff and drainage density. The research concluded that some lands, especially those that are deserted in dry area and agricultural lands, can serve as the sites of rainwater harvesting, with only 4% of area that was highly suitable for the purpose. Nevertheless, 37% of the investigated area was shown as totally unviable for rainwater collection installations because of steep slopes and substantial volume of snow. Simultaneously, the rainwater storage design solutions suggested were check dam, percolation tank, and agricultural ponds with the area of 3.5%, 1%, and 0.75% of the given land area, respectively, for rainwater harvesting. The locations of potential catchment and planned rainwater harvesting structures would assist the local authorities and the policy makers to provide plans and design on the construction of water storages and also the optimization of water use.

Understanding Links Between Water Scarcity and Violent Conflicts in the Sahel and Lake Chad Basin Using the Water Footprint Concept

AbstractWhilst there are several empirical studies linking water scarcity and violent conflicts, existing quantitative studies use mostly climate and environmental variables even though such variables have been shown to not be strong predictors of water conflicts by some studies. The aim of this study was to use the water footprint concept and the Falkenmark index to identify water scarcity hotspots at the sub‐national scale and to understand the links between water scarcity and violent conflicts in the Sahel and Lake Chad Basin over a period of two decades (2000–2021). We achieve this by developing five water scarcity metrics at a monthly timescale using runoff, soil moisture, potential evapotranspiration, water consumption and demographic data. The developed metrics show high levels of water scarcity across the study area during the dry, pre‐monsoon and post‐monsoon seasons. Analyses further reveal high green water scarcity (GWS) (soil moisture deficit) and low Falkenmark index scores (water stress) during the dry, pre‐monsoon and post‐monsoon seasons, across all reported water conflict locations. This suggest that there is an indirect link between GWS, the Falkenmark index scores and water conflicts. Results from this study may be used to enhance water management, mitigate, and prevent water conflicts in the study area and likewise the methodology adopted may be used to address water scarcity and conflicts in other regions.

Hierarchical Model-Based Irrigation Control for Vertical Farms

As high energy costs and water scarcity remain major problems in the context of vertical farming, we present a hierarchical control system developed for the optimization of irrigation processes in these farms. The main objective is to minimize the energy cost and water consumption associated with the operation of a vertical farm, with special emphasis on irrigation in a soil-based environment. At a higher level, an optimal control problem based on a dynamic crop growth model and the FAO Penman-Monteith equations is solved offline to determine the optimal daily inputs, considering temperature, radiation, and plant available water as decision variables. At a lower level, strategically placed Proportional-Integral-Derivative (PID) controllers are used to track these irrigation set-points online. These controllers are designed using a dynamic drip irrigation and soil model that simulates the movement of water through soil. In a simulation study, this integration of set-points and subordinate PID controllers shows a robust control system that effectively stabilizes the irrigation process. The results also show a uniform moisture distribution in the soil after a short time, which contributes to uniform plant growth in the farm. The proposed hierarchical control system combines computationally intensive offline open-loop optimization for daily input determination with fast and simple online PID control for real-time stabilization.

A Multi-Scale Climate Vulnerability and Risk Assesment (C-VRA) Methodology for Corporate Scale Investments: West Bank-Palestine Case Study

Assessing climate vulnerability and risk has become a critical part of feasibility studies for infrastructure investments due to the increased frequency and severity of atmospheric disasters. However, evaluating climate parameters and disturbances can become challenging in vulnerable regions, such as the dry Mediterranean terrain. This is why climate vulnerability and risk assessment (C-VRA) should cover several parameters and factors besides climate analysis. In our case, the political stress and conflicts between Palestine and Israel settlements in the West Bank add additional risks and vulnerabilities. Our paper presents a C-VRA in the Nabi Saleh Village-West Bank of Palestine, where a dairy factory with a wastewater treatment plant will be built. The factory is estimated to use around 120 m3 of water daily and produce wastewater that will be treated and reused for agricultural irrigation. Unfortunately, the current practice in the region is to use untreated wastewater to irrigate trees and vegetables without restraint since the treatment capacity is low, and a large part of the wastewater is discharged untreated into the streams. The dairy factory is planned on a ridge at the upper watershed (headwater) of the 1795.04 km2 Yarkon Rive r basin. The local communities in the region are vulnerable to climate change impacts and related atmospheric disasters due to poverty, agriculture dependency, and political issues. To evaluate future climate projections, we used the latest Intergovernmental Panel on Climate Change Assessment Report 6 (IPCC AR6) methodology. We also used the Mann-Kendal test to analyze the historical trend of climate parameters and projections for three scenarios (optimistic, moderate, and pessimistic) of AR6 for a future period until 2080, considering the life span of the investments and water-specific physical climate risks. Results showed that the historical temperature had a statistically significant increasing trend projected to continue in the next 60 years. Additionally, according to all three scenarios, the precipitation in the region will decrease in the coming decades. As a result, we identified one high (water scarcity) and two moderate-level risks (rainfall decrease and drought) for the corporate, all related to water security. Our methodology incorporates basin-scale assessments with regional and local vulnerabilities, making it a potential tool for critical infrastructure investments elsewhere.

Effects of CEO water shortage experience and power intensity on corporate water performance - Evidence from China

Corporate water performance and sustainable development are currently vital focus areas for scholars. Therefore, this paper investigates the experience of Chief Executive Officers (CEOs) with water shortage influences corporate water performance by focusing on listed companies in water-intensive and high-water-risk industries in China between 2014 and 2019. This paper manually collected information relative to the cities and provinces where CEOs grew up to evaluate their early exposure to water shortages. Furthermore, this paper develops an evaluation scale, based on the Enterprise Water Conservation Evaluation Guide (GB/T 7119-2006), to compute the enterprise water management practices scores. These results will constitute the enterprise water performance evaluation score. Moreover, this paper focuses on CEOs who have experienced water resource shortages through a positive impact on the water resource performance of their companies. As for the findings, they demonstrate that CEOs who grew up in regions with higher water scarcity have a more pronounced positive effect on their water shortage experience through corporate water performance. Furthermore, CEO power intensity positively moderates the relationship between the CEO's water shortage experience and corporate water resource performance. Further investigation reveals generational differences in the impact of CEO water shortage experience on company water performance. CEOs, who grew up during periods with a higher incidence of droughts, demonstrate a more significant promoting effect on corporate water performance. To sum up, this study expands the understanding of factors influencing corporate water resource performance and deepens the knowledge of the early life experiences of CEOs.

Impact Assessment of Livestock Production on Water Scarcity in a Watershed in Southern Brazil

This study presents the assessment of water scarcity associated with livestock production in a watershed in Southern Brazil where 115 farms (poultry, pig, and milk) are located. The methods, AWARE—available water remaining, and BWSI—blue water scarcity index, were applied monthly for the year 2018, and the characterization factors (CF) were regionalized into five scenarios evaluated by varying water availability and environmental water requirements. Livestock water consumption accounted for 94.1% of the total water consumed. Low water scarcity was observed in all scenarios (BWSI < 0). The highest CFAWARE was observed in scenario 3, ranging from 2.15 to 9.70 m3 world eq.m3, with higher water scarcity in summer. In the same scenario, pig production presented the highest annual average water scarcity footprint (WSF) of 90.3 m3 world eq./t carcass weight. Among milk production systems, pasture-based systems presented the highest annual average WSF of 52.7 m3 world eq./t fat protein corrected milk, surpassing semi-confined and confined systems by 12.4% and 3.5%, respectively. In scenario 3, poultry production presented an annual average WSF of 49.3 m3 world eq./t carcass weight. This study contributes knowledge to the livestock sector to perform the assessment of water scarcity.

Involvement of Dynamic Adjustment of ABA, Proline and Sugar Levels in Rhizomes in Effective Acclimation of Solidago gigantea to Contrasting Weather and Soil Conditions in the Country of Invasion.

Giant goldenrod (Solidago gigantea Aiton) is one of the most invasive plant species occurring in Europe. Since little is known about the molecular mechanisms contributing to its invasiveness, we examined the natural dynamics of the content of rhizome compounds, which can be crucial for plant resistance and adaptation to environmental stress. We focused on rhizomes because they are the main vector of giant goldenrod dispersion in invaded lands. Water-soluble sugars, proline, and abscisic acid (ABA) were quantified in rhizomes, as well as ABA in the rhizosphere from three different but geographically close natural locations in Poland (50°04'11.3″ N, 19°50'40.2″ E) under extreme light, thermal, and soil conditions, in early spring, late summer, and late autumn. The genetic diversity of plants between locations was checked using the random amplified polymorphic DNA (RAPD) markers. Sugar and proline content was assayed spectrophotometrically, and abscisic acid (ABA) with the ELISA immunomethod. It can be assumed that the accumulation of sugars in giant goldenrod rhizomes facilitated the process of plant adaptation to adverse environmental conditions (high temperature and/or water scarcity) caused by extreme weather in summer and autumn. The same was true for high levels of proline and ABA in summer. On the other hand, the lowering of proline and ABA in autumn did not confirm the previous assumptions about their synthesis in rhizomes during the acquisition of frost resistance by giant goldenrod. However, in the location with intensive sunlight and most extreme soil conditions, a constant amount of ABA in rhizomes was noticed as well as its exudation into the rhizosphere. This research indicates that soluble sugars, proline, and ABA alterations in rhizomes can participate in the mechanism of acclimation of S. gigantea to specific soil and meteorological conditions in the country of invasion irrespective of plant genetic variation.

Optimizing Solution in Decision Supporting System for River Basin Management Consisting of a Reservoir System

Decision support systems tackle problems and require systematic planning. They consider physical data, hydrological data, and sediment levels to achieve efficiency and adaptability in various situations. Therefore, this research aims to identify alternative engineering choices for the management of a river basin with a single reservoir system. Optimization techniques, including marine predator algorithm (MPA), genetic algorithm (GA), genetic programming (GP), tabu search (TS), and flower pollination algorithm (FPA), were applied to find the optimal reservoir rule curves using a reservoir simulation model. The study focused on the Ubolratana Reservoir in Thailand’s Khon Kaen Province, considering historic inflow data, water demand, hydrologic and physical data, and sedimentation volume. Four scenarios were considered: normal water scarcity, high water scarcity, normal excess water, and high excess water. The optimal rule curves derived from the reservoir simulation model, incorporating sedimentation and hedging rule (HR) criteria, were found to be the best engineering choices. In the normal and high water scarcity scenarios, they minimized the average water shortage to 95.558 MCM/year, with the lowest maximum water shortage 693.000 MCM/year. Similarly, in the normal and high excess water scenarios, the optimal rule curves minimized the average excess water, resulting in a minimum overflow of 1087.810 MCM/year and the lowest maximum overflow 4105.660 MCM/year. These findings highlight the effectiveness of integrating optimization techniques and a reservoir simulation model to obtain the optimal rule curves. By considering sedimentation and incorporating HR criteria, the selected engineering alternatives demonstrated their ability to minimize water shortage and excess water. This contributes to improved water resource management and decision-making in situations of scarcity and excess.

Prefectures vulnerable to water scarcity are not evenly distributed across China

Water scarcity has become a significant constraint to sustainable development. While the water scarcity has been widely assessed, its social impacts are infrequently evaluated. Here, we developed a framework to integrate the water scarcity and climate sensitivity to examine social vulnerability at the prefecture level across China. Results showed that 41% of the 301 prefectures were highly water stressed and 30% were highly sensitive to changing climate. We identified 44 hotspot prefectures using a combination of high water scarcity and climate sensitivity. We mapped the gradient in social vulnerability to water stress and climate sensitivity in these 44 prefectures and found that prefectures with ‘very high’ social vulnerability were primarily distributed in Central and Southwest China. These ‘very high’ vulnerable prefectures are home to more than 58 million people. The consideration of both water scarcity and climate sensitivity across management units has potential to formulate policies regarding water resources management.

Effect of biomass ash vermicompost on Sorghum bicolor var. saccharatum (L.) Mohlenbr under hot and dry agro ecological condition

Generation of the huge amount of bio-waste and their residues, including incineration ash, is a major technical and sustainability problem. To solve this problem, incorporating nutrient-rich residues into crop production has become an efficient practice to increase crop production. Vermicomposting of these wastes could be a viable option to manage both biowastes and their products in an environmentally friendly manner and close the material loop in bioenergy production. Therefore, the main objective of this study was to investigate the effect of vermicompost from biomass ash under hot and dry climatic conditions in summer on growth, yield and yield components of sweet sorghum (Sorghum bicolor var. saccharatum (L.) Mohlenbr). The high photosynthetic activity of sweet sorghum is important for biofuel production under conditions of high solar energy and water scarcity. This study provides a general overview of the feasibility of biomass ash vermicomposting processes and their potential use as a nutrient source for C4 sorghum under Bitlis ecological conditions of high solar potential and low water availability. Under Bitlis climatic conditions, the best yield was obtained when vermicompost was applied with a biomass ash content of 10.0% (T3). Plant height, plant weight, sugarcane and juice yields were reported as 133 cm, 146 g, 180 kg/da and 105 L/da, respectively.

EVALUATION OF ARTEMISININ CONTENT AS AFFECTED BY SOIL AND WATER MANAGEMENT STRATEGIES UNDER GRAVITY-DRIP IRRIGATION SYSTEM I SAMARU, NIGERIA

ABSTRACT Malaria has been among the dangerous diseases not only in Nigeria but Africa as whole. Artemisia crop has an artemisinin, which is a strong anti- malaria drug. However, despite its importance in curing this disease, it is only produced under rain-fed but hardly produced under irrigation in Nigeria. The experiment consisted of three levels of irrigation water application at 100, 80, and 60% ETo (reference evapotranspiration); two mulch levels (rice straw mulch and no mulch) giving a total number of six treatments, replicated three times, totaling eighteen treatments laid in Randomized Complete Block Design (RCBD). The soil moisture was monitored throughout the crop growing season with access tubes installed at different incremental depth of 0-20 cm, 20-40 cm and 40-60 cm below the soil surface. The artemisinin content was determined in the Faculty of Pharmaceutical Sciences, Ahmadu Bello University, Zaria. The artemisinin content obtained ranges from 0.27 % w/w to 1.84 % w/w. The least artemisinin content was obtained from the treatment with irrigation at 60% ETo with no mulch. While the highest value was obtained with irrigation at 100% ETo with rice straw mulch. The artemisinin content of artemisia annua is affected by water stress. Irrigating the crop fully results in higher artemisinin content of artemisia annua followed by 20 % deficit. The least artemisinin content of artemisia annua was obtained at much water stress of 40 %. The study, recommends a full irrigation could be practiced for effective production of artemisia crop under drip irrigation. However, up to 40 % irrigation water deficit could be applied in areas of high water scarcity. Moreover, since rice straw is cost effective, it is recommended for use as mulching material for the cultivation of artemisia crop under irrigation.

CURRENT SITUATION AND PROSPECTS OF COTTON PRODUCTION IN PAKISTAN

Pakistan is the world's fifth-largest cotton producer. It is grown largely for fibre, and its oil is used as a vegetable oil and contributes significantly to the local oil industry. Cottonseed oil meets 18.1% of Pakistan's edible oil needs. In 2030, there will be 5.5 million tonnes of total demand for this purpose, with 2 million tonnes of local supply. Bt cotton, which was introduced in 2010 to remove three harmful lepidopteran insects, currently accounts for more than 90% of all cotton grown in Pakistan. Pakistan offers a lot of potential for organic cotton cultivation, particularly in unconventional cotton-growing locations with low insect burdens. Climate change-induced high temperatures and water scarcity are a big worry because contemporary agriculture is practiced in areas that already experience very high temperatures. Phenotypic selection in breeding is ineffective in creating stress-tolerant cotton. Marker-assisted selection technologies have considerably increased the effectiveness of traditional breeding. Modern breeding techniques contributed to the development of novel cotton breeding strategies. Furthermore, CRISPR/Cas9 and genome editing can establish a good foundation for improving resistance against biotic and abiotic stresses.

Comparative Analysis of Canopy Cooling in Wheat under High Temperature and Drought Stress

The size and the weight of wheat grains vary across the length of each spike (Triticum aestivum L.). High temperature and water scarcity often reduce the single grain weight, and this reduction also varies across the spike length. Plants tend to cope with high temperature and drought stress through inherent mechanisms such ascanopy cooling through transpiration, which can contribute to yield stability. The effect of canopy cooling on the average grain weight at different positions in spike is still unknown. In this study, we planned to assess the role of canopy temperature, yield-related traits, and spike shape in final grain weight. For two years (2017–2018 and 2018–2019), fifteen diverse genotypes released for cultivation in different environmental conditions were grown in the field. They were examined for canopy temperature, spikelets spike−1, grain number spike−1, grain yield spike−1, and grain weight of the spike’s basal, median, and distal regions. The Pearson correlation coefficient (r) was obtained for all pair-wise combinations of traits under different treatments and spike shapes. The results indicated that cooler canopy is correlated to grain weight in normal spike shape at all three positions within the spike irrespective of stress. The advantage of the cooler canopy in improving grain-filling at basal, median, and distal regions was more conspicuous in the high temperature stress conditions compared to non-stressed and drought conditions.

Bryophyte ultraviolet-omics: from genes to the environment.

Ultraviolet (UV) radiation has contributed to the evolution of organisms since the origins of life. Bryophytes also have evolutionary importance as the first clearly identified lineage of land plants (embryophytes) colonizing the terrestrial environment, thus facing high UV and water scarcity, among other new challenges. Here we review bryophyte UV-omics, the discipline relating bryophytes and UV, with an integrative perspective from genes to the environment. We consider species and habitats investigated, methodology, response variables, protection mechanisms, environmental interactions, UV biomonitoring, molecular and evolutionary aspects, and applications. Bryophyte UV-omics shows convergences and divergences with the UV-omics of other photosynthetic organisms, from algae to tracheophytes. All these organisms converge in that UV damage may be limited under realistic UV levels, due to structural protection and/or physiological acclimation capacity. Nevertheless, bryophytes diverge because they have a unique combination of vegetative and reproductive characteristics to cope with high UV and other concomitant adverse processes, such as desiccation. This interaction has both evolutionary and ecological implications. In addition, UV effects on bryophytes depend on the species and the evolutionary lineage considered, with mosses more UV-tolerant than liverworts. Thus, bryophytes do not constitute a homogeneous functional type with respect to their UV tolerance.

Hydrogeochemical variability and appraisal of water quality of groundwater in Mahoba district, Uttar Pradesh, India

Mahoba district comes under the state of Uttar Pradesh (U.P.), India which is a part of mighty Bundelkhand Granitic Terrain known for its water debt condition. The region is hard rock terrain having recent alluvium cover of variable thickness relating to slope and level of erosion. Secondary porosity i.e. in the fractures and cracks present hosts the groundwater in the study area. The high-water scarcity and poor drinking quality led us to carry out our research work in the study area. The water facies analysed shows Ca–Mg–HCO3 and Na–HCO3 water types which indicated their compositional source from rock and anthropogenic inputs. Majority of the samples showed the dominance of alkaline earths over alkalies and weak acids over stronger counterparts. The correlation coefficients calculated between hydrochemical parameters projects a strong positive correlation of EC and TDS with most of the major ions, including SO42−, NO3−. The hierarchical cluster analysis of all samples was classified into five clusters (C1A, C1B, C2A, C2B1 and C2B2). The sites of cluster C1 water samples were found located closer to drainage streams than C2 cluster water samples. The excessive fertilizers, unplanned municipal wastes and agricultural wastes resulted in high SO42− and NO3−. High F− showed concentration in various samples may have geogenic sources due to flour-apatite in granitic terrain and Fe found in excess gives an unpleasant taste on drinking. The analysed irrigation parameters (%Na, MR, TDS, RSC, SAR, TH, and KI) revealed perfect under permissible quality. Various negative human health issues like indigestion, bone problems, alimentary canal problems have been seen due to excess of SO42−, NO3− and F−). The study reflects the need for immediate preventive measures to improve drinking quality from health alarming ion concentrations and also would help for further management programs.

Taro production, phytomass input by Sesbania and Flemingia and improvement in soil fertility in agroforestry systems in floodplains

Floodplains were the first deforested areas for agriculture use all over the world. In Brazil these areas can be restored by the growth of guanandi Calophyllum brasiliense, a slow-growing native forest species adapted to flooding. The aims of this study were to: (i) evaluate the taro, Colocasia esculenta, management under two agroforestry systems (AFS) (Simple and Biodiverse) in succession to a reforestation with guanandi, (ii) evaluate the contribution of macronutrients from the green manure Flemingia macrophylla and Sesbania virgata, both managed using pruning for green manure in the respective AFSs, and (iii) the effects on soil nutrients levels compared to monoculture of guanandi (control). The randomized block was designed with eight replication and 216.0 m² plots with four rows of six guanandi trees in each line. In the simple AFS (SAFS), the taro was intercropped with Flemingia and in the biodiverse AFS (BAFS), Sesbania, banana shrub (Musa sp.), edible palm (Euterpe edulis) and fourteen species of native trees were included. Production was evaluated in seasons with high rainfall and water scarcity. With floods the taro has produced around 15 Mg ha-1 of marketable corms in the SAFS and 9 Mg ha-1 in the BAFS, but the drought has made commercial production unfeasible, with no differences between cormels and corms planting. However, enough rhizomes were harvested for a new planting. Flemingia has accumulated 17 Mg ha-1 of fresh matter and Sesbania contributed with 2 Mg ha-1. Soil pH and macronutrient content, especially K, were significantly higher in AFSs areas compared to guanandi monoculture.