Impact of COVID-19 lockdown on the water quality of the Damodar River, a tributary of the Ganga River in West Bengal.

The COVID-19 (SARS-CoV-2) pandemic is wreaking havoc on the planet, yet control of waste materials comforted the ecosystem during the lockdown restricting human activities. Damodar is the most important tributary of the lower Ganga River in West Bengal. It flows through an industrially developed, agriculturally flourished populated area. Different methods are applied to identify the changing pattern of water quality during the lockdown. BOD graph shows an increase in pollution levels in residential areas but a sharp decline in coliform levels in urban residential sites. The National Sanitation Foundation Water Quality Index (NSFWQI) shows the same pattern of water quality throughout the course. Irrigation suitability of water is examined using sodium percentage (%Na), sodium absorption ratio (SAR), potential salinity (PS), magnesium absorption ratio (MAR), and Kelly's ratio (KR). Mujhermana (received maximum pollutants from industries and residential areas) station shows a decrease in ions concentration and subsequent improvement in agriculture water quality during the COVID-19 period. According to Kelly's ratio, the water at this sample site is unfit for agricultural use; however, the water quality improved and became acceptable for cultivation during the lockdown period. Cluster analysis is used to understand the similar pollution concentration of eleven sampling stations in different periods. Mujhermana site makes a separate cluster due to its high pollution load compared to other sampling sites before the COVID-19. But during the lockdown period, this site was clustered with the most petite contaminated sites. Supplementary Information: The online version contains supplementary material available at 10.1007/s40899-022-00790-2.

Detection of SARS-CoV-2 RNA in selected agricultural and food retail environments in Tehran, Iran.

The SARS-CoV-2 pandemic has and continues to impose a considerable public health burden. Although not likely foodborne, SARS-CoV-2 transmission has been well documented in agricultural and food retail environments in several countries, with transmission primarily thought to be worker-to-worker or through environmental high touch surfaces. However, the prevalence and degree to which SARS-CoV-2 contamination occurs in such settings in Iran has not been well documented. Furthermore, since SARS-CoV-2 has been observed to be shed in the feces of some infected individuals, wastewater has been utilized as a means of surveilling the occurrence of SARS-CoV-2 in some regions. This study aimed to investigate the presence of SARS-CoV-2 RNA along the food production and retail chain, from wastewater and irrigation water to vegetables in field and sold in retail. From September 2020 to January 2021, vegetables from different agricultural areas of Tehran province (n = 35), their irrigated agricultural water (n = 8), treated wastewater mixed into irrigated agricultural water (n = 8), and vegetables collected from markets in Tehran (n = 72) were tested for the presence of SARS-CoV-2 RNA. The vegetable samples were washed with TGBE buffer and concentrated with polyethylene glycol precipitation, while water samples were concentrated by an adsorption-elution method using an electronegative filter. RT-qPCR targeting the SARS-CoV-2 N and RdRp genes was then conducted. SARS-CoV-2 RNA was detected in 51/123 (41.5%) of the samples overall. The presence of SARS-CoV-2 RNA in treated wastewater, irrigation water, field vegetables, and market produce were 75, 37.5, 42.85, and 37.5%, respectively. These results indicate that SARS-CoV-2 RNA is present in food retail and may also suggest that produce can additionally be contaminated with SARS-CoV-2 RNA by agricultural water. This study demonstrates that SARS-CoV-2 RNA was detected in waste and irrigation water, as well as on produce both in field and at retail. However, more evidence is needed to understand if contaminated irrigation water causes SARS-CoV-2 RNA contamination of produce, and if there is a significant public health risk in consuming this produce.

Effects of COVID-19 era on a subtropical river basin in Bangladesh: Heavy metal(loid)s distribution, sources and probable human health risks.

The COVID-19 era has profoundly affected everyday human life, the environment, and freshwater ecosystems worldwide. Despite the numerous influences, a strict COVID-19 lockdown might improve the surface water quality and thus provide an unprecedented opportunity to restore the degraded freshwater resource. Therefore, we intend to investigate the spatiotemporal water quality, sources, and preliminary health risks of heavy metal(loid)s in the Karatoya River basin (KRB), a tropical urban river in Bangladesh. Seventy water samples were collected from 35 stations in KRB in 2019 and 2022 during the dry season. The results showed that the concentrations of Ni, Cu, Zn, Pb, Cd, and Cr were significantly reduced by 89.3-99.7 % during the post-lockdown period (p < 0.05). However, pH, Fe, Mn, and As concentrations increased due to the rise of urban waste and the usage of disinfectants during the post-lockdown phase. In the post-lockdown phase, the heavy metal pollution index, heavy metal evaluation index, and Nemerow's pollution index values lessened by 8.58 %, 42.86 %, and 22.86 %, respectively. Besides, the irrigation water quality indices also improved by 59 %-62 %. The total hazard index values increased by 24 % (children) and 22 % (adults) due to the rise in Mn and As concentrations during the lockdown. In comparison, total carcinogenic risk values were reduced by 54 % (children) and 53 % (adults) in the post-lockdown. We found no significant changes in river flow, rainfall, or land cover near the river from the pre to post-lockdown phase. The results of semivariogram models have demonstrated that most attributes have weak spatial dependence, indicating restricted industrial and agricultural effluents during the lockdown, significantly improving river water quality. Our study confirms that the lockdown provides a unique opportunity for the remarkable improvement of degraded freshwater resources. Long-term management policies and regular monitoring should reduce river pollution and clean surface water.

Socioeconomic Characteristics Associated with Farming Practices, Food Safety and Security in the Production of Fresh Produce—A Case Study including Small-Scale Farmers in KwaZulu-Natal (South Africa)

Farmer practices may influence the microbial quality and safety of fresh produce. The increasing demands to create ready-to-eat (RTE) fresh produce while providing potential niche markets for smallholder farmers might be contributing to increased numbers of fresh produce-associated foodborne disease outbreaks. This study determined the demographic and socioeconomic characteristics and farmer hygiene practices of farmers using open-ended questionnaires and key informant interviews. Additionally, the relationships between farmer socioeconomic characteristics and hygiene practices were statistically analyzed. The semi-organic smallholder farmer population and the farmworkers of the organic farm were female-dominated. Tertiary education was a predominant characteristic in the organic and semi-conventional workforces. While the semi-organic and semi-conventional farms relied on a combination of ‘store-bought’ synthetic and composted organic fertilizers, the organic farm owner only used composted organic fertilizer. The irrigation water sources varied amongst the farm types. However, most of the semi-organic farmers did not pre-treat irrigation water prior to use. The irrigation water source and fertilizer type selected by farmers varied and might affect the microbial quality and safety of fresh produce. Socioeconomic factors such as gender and education may influence farmer hygiene practices. These characteristics should therefore be considered when planning farmer support interventions.

Spatiotemporal evolution and suitability of apple production in China from climate change and land use transfer perspectives

Apple production in China, the world's largest apple producer and consumer, is challenged by a huge and growing population coupled with rapid industrialisation and urbanisation. China's apple output has increased continuously over the past 42 years with distinctive spatial differences. Herein, changes in the spatial patterns of apple production increases, and their potential impact factors in China are described at the provincial level. Between 1978 and 2019, the centre‐of‐gravity of apple production shifted southwest towards the upper reaches of the Yellow River, the main water source for agricultural irrigation in North China. Analysis of absolute and relative growth of apple output reveals that the Loess Plateau, characterised by fragile habitat and low land productivity, has gradually become a major contributor to apple production. Despite annual increases in apple output, apple production system has become more fragile and unstable overtime, especially in the Shaanxi‐Gansu region where apple cultivation is prevalent. With continuous changes in policy, the amount of forest transfer (i.e. the area of other land use types converted to forest) has significantly affected the impact of standardised precipitation evapotranspiration index on apple production increases in China. Thus, to prevent the degradation of new forests, a differentiated management and protection system should be implemented for apple planting sub‐regions. This should include altering subsidy policies on apple production, enhancing soil erosion control in the Loess Plateau and strengthening ecological management of forests and grassland.

Assessing Barriers in Adaptation of Water Management Innovations under Rotational Canal Water Distribution System

This study assessed problems associated with irrigation water provisions and the potential barriers to the adaptation of the interventions (soil moisture sensors, on-farm water storage facilities and the drip method) under rotational canal water distribution in Punjab, Pakistan. Three groups of stakeholders were individually surveyed during September–December 2020: (i) 72 farmers, (ii) 15 officials, and (iii) 14 academicians. We used descriptive statistical analysis, cross-tabulation and the Fisher test to explore the pattern of responses across the groups. The main problems in the canal water distribution system were expressed by the farmers as limited water allocation, while academicians were concerned mostly with inflexibility and officials indicated discussion among neighbors. According to the farmers’ responses, the conventional depth/interval of irrigation is flooding the field with water and observing the plants, indicating over-irrigation behavior. Moreover, the most important barriers in the adaptation of the interventions that were highly rated by the three groups were low awareness, lack of training and financial resources. Additionally, farmers’ education revealed a statistically significant influence on awareness of soil moisture sensors and water storage facilities, while large farm holders showed a positive relationship to conducting a joint experiment with scientists and farmers’ associations on part of their land to improve water use efficiency.

Microclimate control to increase productivity and nutritional quality of leafy vegetables in a cost-effective manner

Food security is one of the key global challenges in this century. In Singapore, our research team has been using novel aeroponic technology to produce fresh vegetables since 1997. Aeroponic systems allow for year-round production of not only tropical, but also sub-tropical and temperate fresh vegetables, by simply cooling the roots suspended in aeroponic systems while the aerial parts grow under tropical ambient environments. It has also been used to investigate the impacts of root-zone CO2 on vegetables by enriching root-zone CO2 while their aerial portions were subjected to constant atmospheric CO2. To compensate for the lack of available land, Singapore also needs to develop a farming system that can increase productivity per unit land area by many-fold. Over the past 10 years, my research team has established a commercially viable LED integrated vertical aeroponic farming system to grow different leafy vegetables under different LED spectra, intensities, and durations in the tropical greenhouse. The results demonstrate that it is possible to increase shoot production and rate of shoot production of leafy vegetables by increasing light intensity and extending the photoperiod under effective LED lighting. Furthermore, temperate vegetable crops such as lettuce were able to acclimate to high light intensity under supplementary LED lights to natural sunlight in the greenhouse. Supplementary LED lightings promote both leaf initiation and expansion with increased photo synthetic pigments, higher Cyt b6f and Rubisco protein contents on a per area basis and thus improve photosynthetic capacity and enhance productivity. Plants sense and respond to changes in their immediate environments (microclimate), manipulating the root zone temperature (RZT) and water supply will impact not only their growth and development but also their nutritional quality. Our on-going research aims to investigate if the nutritional quality of leafy vegetables could be improved under suboptimal RZT and mild water deficit through deficit irrigation. If substantial energy and water savings in urban farming can be achieved without substantial yield penalty but with higher nutritional quality, the amount of water and energy saved can bring substantial benefits to society.

A review of South African sugarcane production the 2020/21 season

This paper characterises South African sugarcane production for the 2020/21 milling season from an agricultural perspective, in order to evaluate recent production strategies, and to identify priorities for improved efficiencies. The industry produced 18.22 million tons of cane, harvested from an estimated 254 028 ha (71.73 t/ha). The cane to sugar ratio was 8.89, and sugar production decreased from the 2019/20 season by 7%, to 2.28 million tons. After closing early in 2019/20, the Darnall Mill (along with Umzimkulu) remained closed in 2020/21, resulting in cane oversupply at some mills and considerable carryover tonnages. Cane quality improved in northern irrigated areas. Decreasing cane quality in the Noodsberg and UCL mill supply areas warrants investigation. Rainfall was generally below-average, with dry 2019 and 2020 winters;however, relief was offered by good spring/summer rains. Irrigation water supplies from the Bivane Dam and the Umhlatuze Catchment were significantly improved. The 2020 winter was particularly cold, and the Midlands cane was affected by frost. Eldana incidence decreased overall from the previous season, but flourished in carryover cane in the South Coast and Amatikulu regions. Smut prevalence was slightly higher than in 2019, and efforts to reduce these levels remain a priority in the northern parts of the industry, particularly in Pongola. A 19% increase in the Recoverable Value (RV) price saw a return to profitability for large- and small-scale growers alike. The negative impacts of the COVID-19 pandemic on local sugarcane producers were minimal, and the increase in the RV price is partly attributed to COVID. The Sugar Industry Value Chain Master Plan also contributed to the increase in the RV price, by securing local sales and more effectively discouraging imports.

Impact of zebra chip disease and irrigation levels on potato production

While many studies on zebra chip (ZC) disease in potatoes have focused on the epidemiology of the disease and the characterization of infected potato plants, this study quantifies the impact of ZC disease on crop response and investigates the relationship between irrigation level and ZC disease severity. In this two-year study chipping potatoes were planted under a variable rate irrigation center pivot sprinkler using a split-plot design with a 2 × 3 factorial combination of ZC disease level (diseased and non-diseased) and irrigation levels of 100%, 80% and 60% replenishment of soil water depletion to field capacity, designated I 100 , I 80 and I 60. Crop response of tuber yield, evapotranspiration (ET c), crop water productivity (CWP) and irrigation water productivity (IWP) from ZC diseased plots were compared with non-diseased (control) plots. Tuber yield and CWP in the infested plots were significantly reduced by at least 58% in 2018 and by 21% in 2019 as compared with results in the control plots. Year significantly affected crop response in the control plots, however, crop response in the ZC diseased plots was devastative to potatoes from year to year. There was no interaction between irrigation level and ZC disease occurrence. In both years, stomatal conductance measurements in ZC diseased plants were reduced 35 and 44 days after infection as compared with control plants. Since irrigation did not lessen the severity of ZC disease, as soon as diseased plants are identified within a field, withholding irrigation to the affected areas could improve IWP at the field level. Future studies should consider the use of thermal imaging or spectral reflectance of the plant canopy for spatiotemporal detection of ZC disease as early as possible in the growing season. • Zebra chip disease reduced fresh tuber yield by at least 58% in 2018 and by 21% in 2019. • Stomatal conductance and the ability to uptake water were limited in ZC diseased potato plants. • The interaction between Zebra chip disease and irrigation level was not significant. [ FROM AUTHOR] Copyright of Agricultural Water Management is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

The combination of the quality index, isotopic, and GIS techniques to assess water resources in a semi-arid context (Essaouira watershed in Morocco)

In arid and semi-arid zones, water resources remain unknown in terms of quality and quantity. The current paper aims to evaluate the water quality for drinking and irrigation purposes within the Essaouira basin and to define the origin and recharge areas of groundwater. 122 samples from the Plio-Quaternary, Cenomano-Turonian, and Hauterivian aquifers, as well as surface water, were taken in July 2020 are the subject of hydrogeochemical analyses. Based on the results of these analyses, almost all elements are within the allowable limit fixed by WHO except Cl− and SO42− in a few points, which require treatment before human consumption. The indices SAR, %Na, KR, MR, CR, RSC, PI, and EC, show that the water of the study area is adequate for agricultural purposes. Therefore, the waters of Essaouira basin meet the standards according to the indices used except for EC where almost 50% of the points have poor quality and for CR the waters require a non-corrosive pipe. The spatial distribution of WQI shows a slight improvement of the quality even though the prolonged drought in the region. This is explained by the impact of the Covid 19 pandemic, which has caused a total shutdown of tourist activity. Tracing the waters using stable isotopes 18O and 2H show that the recharge of these waters is ensured by precipitation of Atlantic origin without significant evaporation and the recharge altitude varies between 400 and 1400 m. The mixing ratios deduced from the mass balance of stable isotopes shows that surface water contributes between 32.16 and 70.42% to the Cenomano-Turonian aquifer recharge. However, the results of this study could provide valuable information on the water quality for drinking and agricultural purposes.

Drip irrigation enhances water use efficiency without losses in cucumber yield and economic benefits in greenhouses in North China

The cultivation mode of planting offseason crops, such as cucumber, with drip irrigation has been widely used in greenhouses in North China to achieve high yields, obtain large economic benefits, and improve water use efficiency. The objectives of this study were to evaluate the effects of drip irrigation on the irrigation water amount, irrigation water use efficiency (IWUE), and cucumber yield and the corresponding economic benefits. These objectives were achieved using data from a seven-season experiment in a commercial greenhouse with cucumber plants in North China. Local furrow irrigation was used as the control. The results showed that the cucumber yields and income with drip irrigation were 4.3% and 3.1% higher than those under furrow irrigation, respectively. However, the seasonal total irrigation depth for drip irrigation was approximately 50% lower than that for furrow irrigation. The IWUE averaged 0.41 in furrow irrigation but increased to 0.79 in drip irrigation. The irrigation water productivity and the economic irrigation water productivity for drip irrigation were approximately 100% higher than those for furrow irrigation. The mean economic irrigation water productivity was 19.8 US$ m−3 for drip irrigation, which is 7 times higher than the 2019 value of 2.7 US$ m−3 in the agricultural sector in China, indicating potential high economic benefits. In conclusion, drip irrigation is recommended in greenhouses to reduce irrigation water by approximately 50% and increase cucumber yield and economic benefits by approximately 3–4% compared to traditional furrow irrigation in North China. [ FROM AUTHOR] Copyright of Irrigation Science is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Greening Urban Areas with Decentralized Wastewater Treatment and Reuse: A Case Study of Ecoparque in Tijuana, Mexico

In rapidly growing urban areas, such as Tijuana, Mexico, the presence of urban green spaces (UGSs) can help stem soil erosion, improve infiltration, slow runoff, decrease flooding, reduce air pollution, and mitigate climate change. In many water-scarce parts of the world, where centralized wastewater treatment is not accessible or practical, decentralized wastewater treatment systems (DEWATSs) have the potential to supply the water needed for irrigating UGSs. Here, we first review UGS systems supported by DEWATSs and the water quality guidelines and challenges associated with implementing DEWATSs for urban greening in different countries, including Mexico. We also critically examine the linkages between the lack of UGSs in Tijuana, Mexico, extensive soil erosion, and failing sanitation infrastructure that has led to the infamously poor water quality in the Tijuana River. Tijuana’s Ecoparque Wastewater Treatment Facility, a low-energy, aerobic DEWATS, which collects, treats, and discharges residential sewage for localized landscape irrigation, demonstrates how DEWATSs can meet the water demands for urban greening in rapidly urbanizing cities. The aerobic decentralized treatment using a gravity-fed trickling biofilter resulted in a >85% removal of chemical oxygen demand and dissolved organic carbon. Prior to treatment facility upgrades, there was a ~2 log reduction in total coliform and Escherichia coli and a <20% decrease in ammonia from the influent to final effluent. After the addition of a maturation pond in 2020, the effluent met Mexico standards for irrigation reuse, with a ~4 log reduction in fecal coliforms from the influent to final effluent. Case study results demonstrated the potential for decentralized wastewater treatment to meet effluent standards for landscape irrigation, provide water for urban greening, and prevent pollution in the Tijuana River and other urban waterways.

Assessment on Land-Water Resources Carrying Capacity of Countries in Central Asia from the Perspective of Self-Supplied Agricultural Products

Despite the declining hunger in Central Asia, food insecurity remains an important issue due to the dry climate. Taking Kazakhstan, Uzbekistan, Kyrgyzstan, Turkmenistan, and Tajikistan as examples, this study assesses their land-water resources carrying capacity in 1999, 2009, and 2018, on the premise that agricultural water and farmland are spatially matched based on the “buckets effect”, using the ecological footprint and water footprint methods. Results show the following: (1) the total farmland area in Central Asia is sufficient to achieve food self-sufficiency;the available farmland area is 2.45 times that of the farmland required for self-sufficiency in 1999, which decreased to 1.71 times in 2009, but slightly increased to 1.92 times in 2018. Specifically, Kazakhstan maintains a surplus of more than 15 × 106 ha in farmland, while the other 4 countries could not achieve self-sufficiency. (2) The water resources pressure rises;the available agricultural water resource (AAWR) in Central Asia is 3.07 times that of the water demand for agricultural irrigation (WDAI), and 3.06 times that of the water demand for irrigation and environmental purification (WDIEP) in 1999, which decreased to 1.69 times of WDAI and to 1.60 times of WDIEP in 2018. Tajikistan has the highest level of water surplus, followed by Kyrgyzstan and Kazakhstan. Turkmenistan and Uzbekistan do not have enough water to sustain agricultural production. (3) The trend of land-water resources carrying capacity declines in Central Asia. In 1999, 2009, and 2018, the land-water resources could support the population’s food demand in this region when only considering farmland matched with WDAI. However, the population carrying capacity deficit would emerge if we considered the matching farmland with WDIEP.

Resilience of Interdependent Urban Water Systems

[...]the enhancement of resilience of urban water management solutions is an emerging topic for water research and the water industry. [...]it is important to understand how urban water systems behave when they fail and to ensure that they can recover quickly. For the resilience of such smart systems, the authors considered an integrated resilience assessment consisting of the performance of the combined sewer overflows, rain-water harvesting efficiency, and irrigation volume. [...]the smart systems also rely on the quality of digital parameters, such as the reliability of the communication technology and the quality of weather forecasts, for control strategies. [...]in this study, these disturbances of usually optimal working conditions were implemented in an integrated resilience analysis of a large-scale implementation of smart rain-water harvesting.

Informing Equitable Water and Food Policies through Accurate Spatial Information on Irrigated Areas in Smallholder Farming Systems

Accurate information on irrigated areas’ spatial distribution and extent are crucial in enhancing agricultural water productivity, water resources management, and formulating strategic policies that enhance water and food security and ecologically sustainable development. However, data are typically limited for smallholder irrigated areas, which is key to achieving social equity and equal distribution of financial resources. This study addressed this gap by delineating disaggregated smallholder and commercial irrigated areas through the random forest algorithm, a non-parametric machine learning classifier. Location within or outside former apartheid “homelands” was taken as a proxy for smallholder, and commercial irrigation. Being in a medium rainfall area, the huge irrigation potential of the Inkomati-Usuthu Water Management Area (UWMA) is already well developed for commercial crop production outside former homelands. However, information about the spatial distribution and extent of irrigated areas within former homelands, which is largely informal, was missing. Therefore, we first classified cultivated lands in 2019 and 2020 as a baseline, from where the Normalised Difference Vegetation Index (NDVI) was used to distinguish irrigated from rainfed, focusing on the dry winter period when crops are predominately irrigated. The mapping accuracy of 84.9% improved the efficacy in defining the actual spatial extent of current irrigated areas at both smallholder and commercial spatial scales. The proportion of irrigated areas was high for both commercial (92.5%) and smallholder (96.2%) irrigation. Moreover, smallholder irrigation increased by over 19% between 2019 and 2020, compared to slightly over 7% in the commercial sector. Such information is critical for policy formulation regarding equitable and inclusive water allocation, irrigation expansion, land reform, and food and water security in smallholder farming systems.

Deficit Water Irrigation in an Almond Orchard Can Reduce Pest Damage

Irrigated almond orchards in Spain are increasing in acreage, and it is pertinent to study the effect of deficit irrigation on the presence of pests, plant damage, and other arthropod communities. In an orchard examined from 2017 to 2020, arthropods and diseases were studied by visual sampling under two irrigation treatments (T1, control and T2, regulated deficit irrigation (RDI)). Univariate analysis showed no influence of irrigation on the aphid Hyalopterus amygdali (Blanchard) (Hemiptera: Aphididae) population and damage, but Tetranychus urticae Koch (Trombidiformes: Tetranychidae) damage on leaves was significantly less (50–60% reduction in damaged leaf area) in the T2 RDI treatment compared to the full irrigation T1 control in 2019 and 2020. Typhlocybinae (principal species Asymmetrasca decedens (Paoli) (Hemiptera: Cicadellidae)) population was also significantly lower under T2 RDI treatment. Chrysopidae and Phytoseiidae, important groups in the biological control of pests, were not affected by irrigation treatment. The most important diseases observed in the orchard were not, in general, affected by irrigation treatment. The multivariate principal response curves show significant differences between irrigation strategies in 2019 and 2020. In conclusion, irrigation schemes with restricted water use (such as T2 RDI) can help reduce the foliar damage of important pests and the abundance of other secondary pests in almond orchards.