Non-irrigated Areas Research Articles

Hydrochemical characteristics of groundwater and their controlling mechanisms in irrigation and non-irrigation areas - a comparative study in the Guanzhong Plain of China

Gaining insight into groundwater chemistry and its evolution in irrigation areas is essential for optimizing irrigation strategies. This study explores the origins and influencing variables of groundwater chemistry across both irrigated and non-irrigated areas of the Guanzhong Plain, aiming to elucidate how irrigation practices impact hydrochemical changes. Hydrochemical data, isotopic data, multivariate statistical techniques and hydrochemical methods were used in this study. The findings underscored that groundwater in non-irrigation areas had low total dissolved solids, with 90% of the groundwater samples exhibiting the HCO3-Ca•Mg type. In comparison, groundwater from irrigation areas showed elevated total dissolved solids levels and diverse hydrochemical types, including HCO3-Ca•Mg, HCO3-Na, and SO4•Cl-Ca•Mg types. These categories collectively represented 88% of the water samples from irrigation areas. Isotopic and hydrochemical analyses revealed that groundwater in irrigation areas experienced more intense evaporation and cation exchange. Furthermore, anthropogenic activities like sewage and manure had a more pronounced effect on groundwater chemistry in irrigation areas. Groundwater suitability for irrigation deteriorated from the western irrigation area to the eastern irrigation area. This research offers a robust scientific foundation for the careful management and conservation of groundwater resources in the region.

Landscape metrics as predictors of water-related ecosystem services: Insights from hydrological modeling and data-based approaches applied on the Arno River Basin, Italy

The study addresses the challenge of integrating complex landscape-hydrological interactions into predictive models for improved water resource management. The aim is to investigate the effectiveness of landscape metrics—quantitative indices measuring landscape composition and configuration—as predictors of WES in the Arno River Basin, Italy. Utilizing two hydrological models alongside a random forest algorithm, we assessed spatial and temporal variations in water yield, runoff, and groundwater recharge. The findings indicate that landscape metrics derived from high-resolution land use data significantly impact WES outcomes. Specifically, the models demonstrated average landscape metric importances of 16.8 % for spatial and 17.8 % for temporal predictions concerning runoff. For water yield, these averages were 32.9 % spatially and 43.5 % temporally, while groundwater modeling showed importances of 14.09 % spatially and 33.8 % temporally. Key landscape metrics identified include the core area index for broad-leaved forests and the perimeter-to-area ratio for non-irrigated agricultural areas as critical spatial and temporal predictors of water yield and groundwater recharge. Thresholds were observed, indicating landscape configurations that minimize hydrological variability. For instance, runoff variation is minimal when the landscape exhibits high forest fragmentation (over 1000 coniferous patches), low aggregation (aggregation index <75), and reduced connectivity (cohesion index under 80). Similarly, groundwater variation is minimized with decreased boundary length of vegetation patches (perimeter-to-area ratio <0.8), agricultural lands (perimeter-to-area ratio under 1), and the presence of low core agricultural areas (core area index above 8). The identified thresholds could inform land-use policies, such as targeted afforestation or crop diversification strategies, to optimize WES provision.

Characteristics of groundwater drought and its propagation dynamics with meteorological drought in the Sanjiang Plain, China: Irrigated versus nonirrigated areas

Study regionSanjiang Plain, China Study focusThe characterization of groundwater drought is inadequate, particularly in terms of the differences in the drought propagation dynamics between cropland and other regions. In this study, we identified groundwater drought events and characteristics in the Sanjiang Plain, using the standardized groundwater drought index (SGDI); we also quantified the mechanism of dynamic factors influencing drought propagation characteristics based on the geodetector method and wavelet coherence analysis and discussed the correlation between the NDVI and SGDI.New Hydrological Insights for the Region: The drought propagation time was shorter during summer and longer during spring and autumn in irrigated areas than in nonirrigated areas. The groundwater system exhibited greater resistance to drought during summer, and spatially nonirrigated area was more vulnerable to meteorological drought. The factor that best explained the variation in propagation time and threshold differed across seasons. A significant correlation time-frequency domain existed between all the factors and SGDI in nonirrigated area, with the SGDI exhibiting the fastest response to soil moisture. The relationship between the SGDI and factors was characterized by a discontinuous response of less than 8 months and a continuous response of more than 30 months. The correlations between the SGDI and NDVI in irrigated and nonirrigated area exhibit different changes due to groundwater exploitation and differences in plant physiology between artificial crops and natural vegetation.

Infant and young child feeding practice among mothers-child pair in irrigated and non-irrigated areas of Dangila district, Northwest Ethiopia, 2020: a community based comparative cross-sectional study

BackgroundThe issue of Infant and Young Child Feeding practices was widespread; it was estimated that infants were not exclusively breastfed in the first six months of life. Complementary foods were frequently provided too soon or too late, and they were often nutritionally deficient. Even, there are nutrition-sensitive activities like irrigation schemes, evidence on infant and young child feeding practices between irrigated and non-irrigated areas is scarce or limited.ObjectiveTo assess the prevalence of infant and young child feeding practices among 0–23 months of age children in irrigated and non-irrigated areas of Dangila District, North-west Ethiopia, 2020.MethodsA community based comparative cross-sectional study was conducted from Dec 1, 2020, to Jun 1, 2020. A stratified sampling technique was implemented to select 823 mothers with children age 0–23 months from irrigated (411) and non-irrigated (412) kebeles. Data were collected using structured questionnaires. Multivariable logistic regression was used to identify the associated factors of infant and young child feeding practice. Adjusted odds ratios with a 95% CI were used to determine the degree of association between the independent and outcome variables. A p-value < 0.05 was used as a cutoff point to declare statistically significant variables with the outcome variable.ResultsAmong 823 households visited, 802 respondents with a response rate of 97.8% in irrigated and 96.11% in non-irrigated areas gave complete responses. The overall prevalence of good IYCF practice was 62.5% (95% CI: 34.2, 41.3), and it shows a significant difference between irrigated (72.2%) and non-irrigated areas (52.8%). Moreover, the study identified that education primary and above (AOR = 1.889, 95% CI: 1.38, 2.648) knowledge above mean (AOR = 2.347, 95% CI: 1.555, 3.542), positive attitude (AOR = 1.716, 95% CI: 1.139, 2.587), PNC follow-up (AOR = 1.606, 95% CI: 1.154, 2.360), women’s decision-making power (AOR = 1.840, 95% CI: 1.226, 2.763), and multiple delivery (AOR = 0.352, 95% CI: 0.213, 0.583) were significant factors for IYCF among 0–23 month-old children.Conclusion and recommendationsThe infant and young child feeding practice among 0–23 month-old children was better in an irrigated area than in a non-irrigated area. Promoting irrigation practices, empowering women, and strengthening postnatal care are recommended interventions to increase infant, young, and child feeding practices in the study area.

Urbanization Impacts on Rice Farming Technical Efficiency: A Comparison of Irrigated and Non-Irrigated Areas in Indonesia

By 2050, the world population is expected to double, with the majority living in urban areas. Urbanization is a result of population pressure, often emphasized in developing countries. It has various impacts on all economic sectors, among which is agriculture through irrigation, which plays an important role in the production and sustainability of farming. This paper aimed to analyze the effect of urbanization on farm performance using a sequential mixed method. The data of approximately 80,053 farmers were extracted from the Indonesian Rice Farm Household Survey (SPD) dataset. A stochastic frontier was employed to analyze technical efficiency (TE) and its determinants, which consist of farmers’ age, education level, climate change, land ownership, membership status, and pest infestation. The estimation results showed that the mean technical efficiency in both irrigation and non-irrigation rice farming was 64.7% and 66.2%, respectively. Although TE’s achievement in non-irrigated rice farming areas was greater than in irrigated ones, rice productivity in irrigated areas was greater than in non-irrigated. All technical efficiency determinants have significant effects on technical efficiency. The estimation results also showed that rice farming in urban areas tends to decrease technical efficiency.

Guidelines for Sustainable Agriculture of Thai Farmers in Non-irrigated Areas

Guidelines for Sustainable Agriculture of Thai Farmers in Non-irrigated Areas

Historical floods in the southeastern Iberian Peninsula since the 16th century: Trends and regional analysis of extreme flood events

Studies related to historical floods have generated much knowledge about flood patterns and frequencies in recent years. Extending the series of floods to a longer range of time allows society to clarify what has happened in the past, and thus know what may happen in the future. From the descriptions of primary and secondary sources, a classification of historical floods has been carried out following a method specifically adapted for the study area. The southeastern Iberian Peninsula is the last region to compile historical floods in the Mediterranean Iberian Peninsula. Therefore, the main objective of the present study is to extend the flood series of historical events for four river basins: the Almanzora, Antas, Aguas and Andarax. First, flood events are classified according to their descriptions, generating a dataset of all flood events from 1500 to the present day for each basin. Second, we analyze the trends in the historical series, identifying four trend periods linked with the availability of records: 1500–1850, 1850–1900, 1900–1955 and 1955–2000. Notably, the trend in recent decades has broken with normality because of the large number of lower magnitude events. Lastly, we compare our dataset with seven historical series from different rivers elsewhere in the Iberian Peninsula. The results show a high correlation with all southeastern basins and less with the northern and Atlantic basins. For the purposes of the analysis, we considered only the extraordinary and catastrophic floods in all basins, that is, the floods of magnitude 3 or 4 (M3 or M4), and we identified two flood gaps in 1500–1540 and 1660–1720; two flood-poor periods in 1790–1845 and 1955–1970; and five flood-rich periods in 1540–1560, 1610–1654, 1720–1745, 1860–1891 and 1970–1990 in relation to the four river basins in the study area and the other seven Iberian basins, the last century is highly biased by the construction of reservoirs in all basins. The analysis of historical floods shows a link between the flood-gap periods and negative phases of NAOi and TSI. From 1970, lower flood magnitudes occurred during periods of highest amounts of information, an increase in tourism areas. Consequently, the last flood-rich period clearly stands out because of the disparity of the data, and the consequences are biased, for example, by surface runoff in urban areas where non-irrigated agricultural areas were traditionally located, resulting in an increase in economic damage.

Protective role of Ascophyllum nodosum seaweed biomass conjugated organic minerals as therapeutic nutrients to enhance tomato plant grown under salinity stress

AbstractClimate changes and stresses negatively affected the physiological processes inside plant cells, which led to a clear imbalance in the global diet. In both irrigated and non-irrigated areas, salinity is one of the principal abiotic factors influencing plant growth and production, especially in crop plants. The present experiment was designed to evaluate two types of foliar feeding as anti-salt stress by measuring stress tolerant and antioxidant levels. Foliar feedings, Gluamin Cu, and Ascophyllum nodosum (WeGrow Special) were used as therabutic nutrients and stress raisers on plants irrigated with saline solution (150 mmol) and others irrigated with tap water. After 70 days of plant life, morphological characteristics, plant pigments, osmosis levels, phenols, and antioxidant enzyme activity were measured as indicators of plant recovery from stress damage. Measurements of vegetative growth, photosynthesis, sugars, and protein content decreased significantly in stressed plants. On the contrary, the level of proline, phenol, malondialdehyde, hydrogen peroxide, and sodium (Na +) and the activity of antioxidant enzymes increased compared to non-stressed plants. The beneficial impacts of the foliar feedings (Gluamin Cu and WeGrow Special) have been broadened to increase all growth parameters, photosynthetic pigments, proline, phenol, and enzyme activities, in both unstressed and stressed plants in comparison to control. Interestingly, the harmful impact of salinity on tomato plants was significantly decreased and it can be evident from reduced MDA and H2O2 levels. The results indicated that Gluamin Cu at a concentration of 3 cm L−1 foliar was the best treatment in increasing shoot length by 18.75%, root length by 51.8%, number of leaves by 31.5%, chlorophyll A by 98.9% and chlorophyll B by 47.6%, proline 12.6%, peroxidase by 39.6%, polyphenol oxidase by 14.29%, super oxide dismutase by 16.4%, and catalase by 54.9% in stressed plants compared to the stressed control. These results indicated that the use of any of the foliar nutrients (Gluamin Cu and WeGrow Special) considered to raise the salt stress in the plant and improve its morphological characteristics and metabolic processes inside the cells, and thus it can be used and applied commercially as environmentally friendly anti-salt stress.

Performance Assessment of Irrigation Projects in Nepal by Integrating Landsat Images and Local Data

With growing global concern for food and water insecurity, an efficient method to monitor irrigation projects is essential, especially in the developing world where irrigation performance is often suboptimal. In Nepal, the irrigated area has not been objectively recorded, although their assessment has substantial implications for national policy, project’s annual budgets, and donor funding. Here, we present the application of Landsat images to measure irrigated areas in Nepal for the past 17 years to contribute to the assessment of the irrigation performance. Landsat 5 TM (2006–2011) and Landsat 8 OLI (2013–2022) images were used to develop a machine learning model, which classifies irrigated and non-irrigated areas in the study areas. The random forest classification achieved an overall accuracy of 82.2% and kappa statistics of 0.72. For the class of irrigation areas, the producer’s accuracy and consumer’s accuracy were 79% and 96%, respectively. Our regionally trained machine learning model outperforms the existing global cropland map, highlighting the need for such models for local irrigation project evaluations. We assess irrigation project performance and its drivers by combining long-term changes in satellite-derived irrigated areas with local data related to irrigation performance, such as annual budget, irrigation service fee, crop yield, precipitation, and main canal discharge.

Irrigation Cooling Effect on Local Temperatures in the North China Plain Based on an Improved Detection Method

Irrigation has excellent potential for altering surface characteristics and the local climate. Although studies using site observations or remote sensing data have demonstrated an irrigation cooling effect (ICE) on the air temperature (Tem) and land surface temperature (LST), it is difficult to eliminate other stress factors due to different backgrounds. We characterized the irrigation effect as the differences (Δ) of LST and DCT (DCT = LST − Tem) between irrigated and adjacent non-irrigated areas. An improved method was proposed to detect it over the North China Plain (NCP) based on satellite observations. We also investigated the effects of irrigation on Tem, precipitation, NDVI, and ET, and explored the relationships between them. The results show that irrigation induced a decrease in the daytime/nighttime LST and DCT (−0.13/−0.09 and −0.14/−0.07 °C yr−1), Tem (−0.023 °C in spring), and precipitation (−1.461 mm yr−1), and an increase in NDVI (0.03 in spring) and ET (0.289 mm yr−1) across the NCP. The effect on nighttime LST and NDVI increased by 0.04 °C 10 yr−1 and 0.003 10 yr−1, and that on ET weakened by 0.23 mm 10 yr−1 during 2000–2015. The ICE on the LST had evident spatiotemporal heterogeneity, which was greater in the daytime, in the spring, and in the northern area of the NCP (dry–hot conditions). The daytime ICE in the NCP and northern NCP was 0.37 and 0.50 °C during spring, respectively, with the strongest ICE of 0.60 °C in Henan; however, the ICE was less evident (&lt;0.1 °C) in the southern NCP throughout the year. The ΔNDVI, ΔET, and ΔTem were the main factors driving ICE, explaining approximatively 22%, 45%, and 25% of the daytime ICE, respectively. For every unit of these measures that was increased, the daytime ICE increased by about 7.3, 4.6, and 1.5 °C, respectively. This study highlights the broad irrigation effect on LST, ET, NDVI, and the climate, and provides important information for predicting climate change in the future. The improved method is more suitable for regions with uneven terrain and a varying climate.

Influence of Irrigation on Vertical Migration of Soil Organic Carbon in Arid Area of Inland River

Soil organic carbon is very important to increase crop yield. Understanding the composition changes and migration characteristics of SOC under different irrigation conditions in arid oasis areas is of great significance for the sustainable development of agro-ecosystem and the estimation of carbon balance of farmland ecosystem in arid areas. In this paper, classical statistics and geostatistics were used to study the leaching characteristics and migration laws of soil organic carbon under different irrigation conditions in Minqin Oasis, and the leaching amount and loss process and mechanism of SOC under different irrigation conditions were quantified. The research results showed that: (1) Irrigation increased the average 0–100 cm SOC content. After irrigation, SOC content decreased first and then increased with the increase in soil depth, with the maximum value of 8.56 g/kg and the minimum value of 1.82 g/kg. Compared with that before irrigation, SOC content in 0–30 cm surface layer was in leaching state, SOC content in 30–70 cm surface layer was accumulated, and SOC content in 70–100 cm surface layer had no obvious change. (2) Water was an important factor affecting soil carbon. The greater the irrigation amount, the higher the carbon leaching rate and the greater the migration amount. The SOC content in 0–30 cm soil layer was most significantly affected by irrigation, and the migration amount of SOC gradually decreased with the increase in soil depth. The maximum leaching rate of SOC was 36.8%, the minimum leaching rate was 13.5%, and its average leaching rate was 23.4%. (3) Due to the influence of soil infiltration rate under water, SOC content in different irrigation periods showed that the greatest SOC occurred in the 0–70 cm layer, and SOC content in soil was basically the same as that in non-irrigated areas on the fifth day after irrigation. (4) Precipitation, plastic film mulching, soil physical and chemical properties and other environmental factors were important factors affecting the migration and change in SOC content.

Malaria diagnosis in rural healthcare facilities and treatment-seeking behavior in malaria endemic settings in western Kenya.

Accurate malaria diagnosis and timely treatment are requirements for effective management of the disease. However, treatment efficacy may be significantly reduced in resource-constrained healthcare facilities with poorly equipped laboratories and frequent drug and rapid diagnostic test kit (RDT) stock-outs. Furthermore, patient may avoid seeking treatment from such facilities. The study's goal was to determine treatment-seeking behavior, malaria diagnosis and treatment quality, and likely treatment-seeking determinants in the local population. Passive case detection, which targeted all patients with suspected malaria cases, was conducted in ten public healthcare facilities over a three-month period. Monthly malaria cases, methods of diagnosis and antimalarial drug availability were assessed. A household-based survey was also carried out. Structured questionnaires were used to collect knowledge, attitude and practice (KAP) data from household heads. Malaria knowledge, treatment seeking behavior, and predictors of malaria treatment-seeking were all determined. Three of the seven dispensaries lacked a laboratory to conduct microscopy- diagnosis. These three dispensaries also experienced frequent RDT stock-outs, which resulted in depending on clinical signs as diagnosis for malaria. The majority of local residents with fever (50.3%) purchased antimalarial drugs from a chemist. About 37% of fever patients sought treatment at healthcare facility while the remaining 12.7% did not treat their fevers. In irrigated areas, 45.5% (46/64) of fever patients sought treatment at healthcare facilities, compared to 25% (18/64) in non-irrigated areas (p = 0.009). Most children aged below 5 who had fever (77.7%) were taken to healthcare facility for treatment compared to 31.4% of children aged 5-14 years or 20.9% of adults (0.0001). Predictors of treatment seeking included access to healthcare facility (OR = 16.23, 95% CI: 2.74-96.12), and ability to pay hospital bills (OR = 10.6, 95% CI: 1.97-57). Other factors that influenced health-seeking behavior included the severity of symptoms, the age of the patient and knowledge of malaria symptoms.

POPULATION FLUCTUATION OF SUCKING INSECTS IN IRRIGATED AND NON-IRRIGATED COTTON CROPS

In the cotton crop (Gossypium hirsutum L.), there is a complexity of pests that appear systematically, thus significantly reducing crop yield; and their population fluctuation is strongly influenced by meteorological conditions that result in a greater or lesser density of these insects. Thus, this work aimed to evaluate the population fluctuation of insect pests with sucking feeding behavior in an area with and without irrigation in the cotton plant under second-harvest conditions. The experiment was developed at the State University of Maringá - Campus of Umuarama. In the experimental area, grid meshes of 10 × 10 m were demarcated, forming plots of 100 m², resulting in a total of 64 points in the irrigated area and 42 points in the non-irrigated area. The sampling points were demarcated in the center of each grid where three randomly selected plants were sampled. Samplings were carried out weekly, from 37 to 122 days after the emergence (DAE) of cotton, examining the aerial part of the plant, to observe the presence of aphids (Aphis gossypii), thrips (Frankliniella schultzei), and whitefly (Bemisia tabaci). The non-irrigated area provided the highest population peaks of whiteflies and thrips. On the other hand, the irrigated area had a higher incidence of aphids. However, with the increase in the population of ladybugs, the incidence of pests reduced significantly, showing the efficiency and importance of the control carried out by natural predators.

Effects of bacterial composition and aquatic habitat metabolites on malaria vector larval availability in irrigated and non-irrigated sites of Homa Bay county, western Kenya.

Gravid Anopheles malaria vectors depend on both chemical and physical (including microbial) cues for selection of preferred habitats for oviposition. This study focused on assessing the effects of bacterial composition and habitat metabolites on malaria vector larval availability in irrigated and non-irrigated potential larval sources. Water samples were collected from larval positive and negative habitats in the irrigated and non- irrigated areas of Homa Bay county. Bacteria cultured from the water samples were subjected to Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) for species identification. DNA was extracted from the colonies and polymerase chain reaction (PCR) and sequencing done. Finally, the metabolite composition of larval positive and negative habitats was determined. MALDI-TOF MS results revealed that Bacillus was the only genera identified from larval sources in the non-irrigated zone. In the irrigated area, Shigella was the dominant genera (47%) while Escherichia coli was the abundant species (13/51). Of the sequenced isolates, 65% were Bacillus. Larvicidal isolates Brevibacillus brevis, Bacillus subtilis, and Exiguobacterium profundum were isolated and grouped with Bacillus mojavensis, Bacillus tequilensis, Bacillus stercoris, and Brevibacillus agri. Irrigated areas with larvae had reduced crude fat (0.01%) and protein content (0.13%) in comparison to those without larvae. In irrigated and non- irrigated areas, larval presence was evident in habitats with high total chlorophyll content (1.12 μg/g vs 0.81μg/g and 3.37 μg/g vs 0.82). Aquatic habitats with larvae in both irrigated and non-irrigated areas exhibited higher sugar concentration than habitats without larvae; however, when compared, non-irrigated areas with larvae had higher sugar concentration than similar habitats in irrigated areas. In addition, substantial concentrations of Manganese, Calcium, and Copper were found in aquatic habitats containing larvae in both irrigated and non-irrigated areas. These results allow for prospective examination as potential larvicidal or adulticidal agents and could be considered when designing potential vector control interventions.

The surface-boundary layer connection across spatial scales of irrigation-driven thermal heterogeneity: An integrated data and modeling study of the LIAISE field campaign

Irrigation in semi-arid regions induces thermal heterogeneity across a range of spatial scales that impacts the partitioning of energy at the surface, the development of the atmospheric boundary layer, and the bidirectional interactions between the atmosphere and the surface. In this analysis, we use data from the Land Surface Interactions with the Atmosphere in the Iberian Semi-Arid Environment (LIAISE) experiment combined with a coupled land–atmosphere model to understand the role of the scales of irrigation-induced, thermal heterogeneity on the surface fluxes and consequently, the development of the diurnal convective boundary layer. The surface heterogeneity is characterized by Bowen ratios that range from ∼0.01 in the irrigated areas to ∼30 in the non-irrigated areas; however, the observed boundary-layers dynamics in both locations are similar. In this analysis, we address the questions of how the surface fluxes impact the development of the boundary-layer dynamics and how the boundary layer influences the diurnal cycle of surface fluxes. To interpret the observations, we introduce a heterogeneity scaling scheme where length scales range from local scale (∼100 m) to regional scale (∼10 km) to investigate the role of scale on surface representation in numerical models and to address the discrepancy between surface observations and their representation in weather and climate models.We find that at the surface, both the available energy and its partitioning depend on spatial scale. The observed boundary-layer properties can be explained through the composite of surface fluxes at the regional scale. Surface fluxes at the local scales are unable to replicate the observed boundary layer — even when including large-scale contributions. We find that non-local boundary layer processes like advection are important for partitioning energy at the local scale. We explore the connection between surface fluxes and the development of the boundary layer and the potential non-local effects on boundary-layer development.

Mapping global maximum irrigation extent at 30m resolution using the irrigation performances under drought stress

Accurate global irrigation information is essential for managing water scarcity and improving food security. However, the mapping of high-resolution irrigation at the global scale is challenging due to the wide range of climate conditions, crop types and phenology, ambiguous and heterogeneous spectral features, and farming practices. Here, a robust method is proposed using irrigation performance under drought stress as a proxy for crop productivity stabilization and crop water consumption. For each irrigation mapping zone (IMZ), dry months in the 2017–2019 period and the driest months in the 2010–2019 period were identified over the growing season. The thresholds of the normalized difference vegetation index (NDVI) in the dry months from 2017 to 2019 and the NDVI deviation (NDVIdev) in the driest month were identified to separate irrigated and rainfed cropland with samples. The final threshold from either the NDVI or the NDVIdev of the IMZ was determined with a higher overall accuracy in separating irrigated and non-irrigated areas. The results show that the global maximum irrigation extent (GMIE) at a 30-m resolution was 23.38% of global cropland in 2010–2019, with an overall accuracy of 83.6% globally and significant regional differences in irrigation proportions ranging from 1.1% in western Africa to 100% in Old World deserts among the 110 IMZs and from 0.4% in Belarus to 80.2% in Pakistan and 100% in Egypt among 45 countries. The study quantitatively distinguished annually and intermittently irrigated regions, which had values of 42% and 58% of global cropland, respectively, by applying indicators. This method, using the NDVI and NDVIdev thresholds, is simple, concrete and reproducible and better for zones with homogeneous weather conditions. The study offers independent, consistent and comparable information for defining the baseline, tracking changes in irrigation infrastructure, and leading future changes in how stakeholders plan and design irrigation systems.

Importance of snowmelt on soil nitrate leaching to groundwater – A model study

The movement of nitrate to surface water bodies during snow accumulation and melting has been extensively studied, but there are only limited studies on the influence of snow processes on nitrate leaching to groundwater. The present study investigated the impact of snow processes on nitrate leaching to groundwater based on a simulation modeling approach using HYDRUS-1D. HYDRUS-1D model has a temperature threshold-based snow model in addition to water, solute, and heat simulation components. The snow component in HYDRUS-1D was previously not applied to snow simulation studies since the method does not consider a detailed physical and process-based representation of snow accumulation and melting. In the present study, HYDRUS-1D was used to simulate snow accumulation and melting over 30 years for a location in Waverly, Lancaster County, Nebraska, USA. From the simulations, it was observed that the calibrated temperature threshold based snow module in HYDRUS-1D is effective in simulating snow accumulation and melting, as shown by the index of agreement and root mean squared error of 0.74 and 2.70 cm for calibration (15 years) and 0.88 and 2.70 cm for validation (15 years), respectively. The impact of snow melt on nitrate leaching was studied based on a study area with corn cultivation (Waverly, Nebraska, USA). A long-term (60 years) analysis was carried out for irrigated and non-irrigated agriculture with and without precipitation as snow. A higher nitrate leaching to groundwater was observed in the order of irrigated–with snow (54,038 kg/ha), irrigated-without snow (53,516 kg/ha), non-irrigated-with snow (7,431 kg/ha), and non-irrigated-without snow (7,090 kg/ha). This displays a 0.98% and 4.81% increase in nitrate leaching due to snow in irrigated and non-irrigated conditions, respectively. When extrapolated over the corn cultivated regions in Nebraska, this resulted in a difference of 1.2E+09 kg and 6.1E+08 kg of nitrate when considering snow in irrigated and non-irrigated areas over 60 years. This is the first study that has analyzed the long-term impact of snow on nitrate transport to groundwater based on a simulation modeling approach. The results show that snow accumulation and melting plays a vital role in the nitrate leaching into the groundwater and indicates the importance of considering snow components in similar studies.

Diverging Global Dry and Humid Heat Responses to Modern Irrigation

Abstract The moderating influence of irrigation on dry heat extremes is well established, but the effect of irrigation on humid heat is more uncertain. Here, we study the impact of modern irrigation on both dry and humid heat-wave occurrences during the boreal summer using the NASA GISS Earth System Model (ModelE) with and without present-day irrigation. We show that the presence of modern irrigation reduces the total number of dry heat waves in most land areas, especially in arid and temperate regions. In contrast, humid heat waves occur more frequently under modern irrigation, especially in the Mediterranean Sea region, northern Africa, southern Africa, and the Middle East. Present-day irrigation reduces dry heat extremes by favoring latent heating over sensible heating and lowering surface solar radiation by increasing total cloud cover. Meanwhile, modern irrigation drives increases in humid heat through increases in specific humidity and precipitation. Notably, the reduction in dry heat is mostly localized over irrigated grid cells while humid heat increases both in locally irrigated areas and remote (nonirrigated) regions because of widespread increases in humidity associated with irrigation. Our results suggest that irrigation may amplify humid heat, even in nonirrigated areas, highlighting the importance of improving our understanding of both local and remote effects of the irrigation forcing on climate hazards.

The management of microbiological regime of the irrigated light chestnut soils in the Nizhnee Povolzhye under drip irrigation

There is a certain relation between soil fertility and its microorganism content. The article considers the microbiological characteristics of irrigated light chestnut soils in the Nizhnee Povolzhye on various media. The soil samples were taken in the plow horizon (0-20 cm) in five replications for each experimental variant. To determine and account for the microorganism groups in the studied soil, the following nutrient media were used: MPA (meat-and-peptone agar), Wort – Agar and Czapek’s, Waksman’s. The studies also included the determination of the nutrient content in the soil in order to adjust the fertilizer application system for drip irrigation, since the soil arable layer on the experimental plot was poorly provided with easily hydrolyzed nitrogen and exchangeable potassium, and in medium way with mobile phosphorus. On the irrigated area one selected the plots with onion and cucumber crops with different mineral nutrition and the levels of maintaining pre-irrigation soil moisture, as well as a variant with a virgin (nonirrigated) plot. The development features of microbial communities on irrigated and non-irrigated lands were revealed. In the arable layer of the irrigated light chestnut soil of the Volgograd region, a fungus of the genus Fusarium, bacteria Bacillus subtilis, bacteria of the genus Erwinia were found, which can make it difficult to grow and store agricultural products. The options for maintaining pre-irrigation soil moisture during drip irrigation of vegetable crops did not have any significant effect on the quantitative and qualitative composition of microorganisms. The studied soil, according to agro-chemical analysis, is fertile and can be used for crop growing. Crop cultivation on non-irrigated areas should be carried out with the application of appropriate fertilizers.

Floristički sastav i održavanje vegetacionog pokrivača u organski održavanom vinogradu

In the organic cultivation of the Panonia grape variety in the Belgrade vineregion, the vegetation cover in the vineyard is maintained with minimal intervention. It consists of spontaneous flora with occasional reseeding of grass and legume species. This study examined the composition of the vegetation cover after two years of irrigation at 50% and 100% ETc (crop evapotranspiration) and compared it to a non-irrigated area. Irrigation was applied in 2021 and 2022, and floristic composition was recorded in the spring of 2023. It was found that the weed flora in the organically managed vineyards consists predominantly of hemicryptophytes and therophytes (mainly biennial and perennial species from the hemicryptophyte group). This indicates that the weed flora tends towards a weed-ruderal-meadow character in terms of its floristic composition. In contrast to the floristic life spectrum, the vegetation life spectrum provides a somewhat more realistic picture. Quantitatively (in terms of the number of individuals per unit area), biennial and annual species dominate, and the community is characterised as therophyte-hemicryptophytic.