Seasonal Drought Research Articles

Efficient hygro-thermal and ammonia control in day-old chick brooding box using internet of things and Tsukamoto Fuzzy controller

Abstract Day-old chick brooding box systems play a pivotal role in optimizing chicken production by providing ideal environmental conditions. Controlling hygro-thermal parameters (temperature and relative humidity) and ammonia levels in poultry buildings is paramount. In this study, we introduce a novel approach where an Internet of Things (IoT) based prototype for day-old chick brooding box management is integrated with an Android application for real-time monitoring and control. The prototype incorporates an innovative hybrid control strategy, combining a Tsukamoto (TSUKAMOTO) fuzzy logic controller (FLC) with IoT. This approach is rigorously tested through experimental measures and studies over a 90-day period, encompassing both rainy and drought seasons. Comparative analysis reveals that the T-FLC controller outperforms conventional methods, exhibiting lower root mean square errors for temperature and relative humidity response (0.9°C, 1.35%) compared to the FLC (1.18°C, 1.89%) and On/Off controller (2.08°C, 3.07%). Importantly, all controllers maintain ammonia concentrations below 4 ppm. Furthermore, the T-FLC system demonstrates superior efficiency, achieving a daily weight gain rate of 95%, surpassing the FLC (89%) and On/Off controller (81%). Additionally, the T-FLC controller significantly reduces energy consumption, saving up to 40% compared to the On/Off controller and 16% compared to the fuzzy controller. These findings underscore the exceptional efficiency and effectiveness of the proposed control strategy for day-old chick brooding box applications, promising enhanced poultry production and sustainability.

Storylines for Global Hydrologic Drought Within CMIP6

AbstractFuture global increases in the duration and severity of hydrologic drought present an emerging challenge for water resource management. However, projected changes to drought within global climate models are often complex, including potentially co‐occurring changes to the timing, duration, and severity of drought. Here, we apply a storyline approach for interpreting projections of future hydrologic drought to identify coherent narratives that include runoff trends, shifts in the seasonal drought timing, increases in multi‐year drought frequency, and increased drought severity within the Coupled Model Intercomparison Project Phase 6. We develop a framework to classify future drought storylines (2015–2100) and quantify model consensus to determine the most‐likely “dominant” storyline under four emission scenarios Shared Socioeconomic Pathways (SSPs) 1–2.6, 2–4.5, 3–7.0, and 5–8.5. Under a low‐emission scenario (SSPs 1–2.6) approximately one third of the land‐area is projected to be impacted by a dominant storyline of minimally detectable runoff trend paired with increased frequency of multi‐year drought. However, under the highest‐emission scenarios (SSPs 5–8.5), the most likely storyline shifts to an increase in multi‐year drought frequency, increased severity of drought, and negative long‐term runoff trends for 62% of the area in those same regions. Shifts in the seasonal timing of drought are a component of dominant storylines for the northern latitudes across all emission scenarios. These results provide an alternative mode of interpretation of co‐occurring changes to the features of future drought, framed in a way to support regional adaptation strategies to mitigate future drought impacts.

Destabilization Mechanism and Stability Study of Collapsible Loess Canal Slopes in Cold and Arid Regions

The combination of seasonal shutdowns, water conveyance, cold, and drought can easily lead to the deterioration of the anti-seepage system and loess foundation of the canal, which contributes to the destruction of the slope. To reveal the failure mechanism of the collapsible loess canal slope, this paper is based on the results of laboratory tests and adopts numerical simulations to analyze the stability of the canal slope under different conditions. The results show that the shear strength indexes and elastic modulus E of loess decrease following an exponential pattern with the increase in wetting-drying and freezing-thawing (WD-FT) cycles. The height of the seepage overflow point yields little effect on the water level behind the impermeable membrane, whereas the height of the water level has a significant effect. In the operation period, the slope under any working conditions is in a relatively stable state. However, the slope with a water level of 4.5 m behind the impermeable membrane tends to be unstable after three WD-FT cycles during the shutdown period. By replacing the surface-degraded loess with sand gravel and picking a depth of 0.9–1.2 m, the slope will maintain a long-term stable state.

Drought in the middle growing season inhibited carbon uptake more critical in an anthropogenic shrub ecosystem of Northwest China

Large-scale ecological restoration efforts of the degraded desert steppe ecosystem in northwestern China have effectively combated desertification but have also resulted in the encroachment of shrubs. However, the function of the anthropogenic shrub ecosystem is still unknown under climate change, especially the response of carbon fluxes to drought, which hinders our further understanding of its sustainability in the future. Hence, based on the eddy covariance and environment sensors, continuous carbon and water fluxes and biophysical factors were monitored during 2019–2022 to investigate the characteristics of carbon fluxes and their response to seasonal drought in an anthropogenic shrub ecosystem dominated by Caragana liouana in the southern Mu Us sandy land, northwestern China. The results showed the shrub ecosystem was a stable carbon sink over the 4 years despite large interannual variability, with annual net ecosystem production (NEP) ranging from 54.37 to 150.35 g C·m−2·y−1. Interannual variability in NEP was mainly due to variation in gross primary productivity (GPP), which is driven by the fact that interannual variability in GPP was higher than interannual variability in ecosystem respiration (Reco). While drought inhibited GPP more than Reco, thus weakening the carbon sequestration ability of the ecosystem during the middle growing season, and thereby carbon fluxes in the shrub ecosystem were significantly suppressed by drought in the middle growing season but slightly in the early growing season. Furthermore, the magnitude and variation of carbon fluxes were determined by the maximum apparent photosynthetic capacity of the canopy (Pmax), leaf area index (LAI), and canopy conductance (gc), all of which are limited by water stress during drought. The work suggests that to keep the carbon sink of anthropogenic shrub ecosystems in arid and semi-arid areas, managers should focus on drought-relief measures in the middle growing season that are better adapted to future climate change.

Response of tropical forest productivity to seasonal drought mediated by potassium and phosphorus availability

Tropical forest productivity is increasingly reported to be nutrient limited, which may affect its response to seasonal droughts. Yet experimental evidence on nutrient limitation from Afrotropical forests remains rare. We conducted an ecosystem-scale, full factorial nitrogen (N)–phosphorus (P)–potassium (K) addition experiment in a moist forest in Uganda to investigate nutrient controls on fine litter production and foliar chemistry. The eight factorial treatments were replicated four times in 32 plots of 40 × 40 m each. During the three-year nutrient additions, we found K and P limitations on leaf litter production, exhibiting strong links to ecosystem responses to seasonal drought. Specifically, leaf litterfall consistently decreased in dry seasons with K additions, whereas P additions caused a reduction only during prolonged drought in the first year. Leaf litterfall was not significantly affected by N additions. Furthermore, K additions delayed the timing of leaf litterfall peak, underscoring the crucial role of K in regulating stomatal aperture and signalling during water-stress conditions and suggesting a prolonged leaf lifespan. Foliar N increased with N and P additions whereas K was the most resorbed nutrient. We conclude that the productivity and resilience of tropical forests, particularly under drier conditions, may depend on terrestrial K and P availability.

Tall wheatgrass response toward phosphorus deficiency: a constraint to its use as a forage resource in marginal soils

Tall wheatgrass is cultivated for pasture in marginal areas around the world due to its tolerance to abiotic stress including seasonal droughts and floods, as well as saline and alkaline soils. However, there is concern about its biomass productivity, which often does not exceed that of natural pastures. In this work we hypothesize that tall wheatgrass is a plant more sensitive to low P availability than commonly assumed. A glasshouse sand culture experiment was conducted to analyze morpho-physiological responses of tall wheatgrass to different P availability levels: 1 µmol L−1 phosphorus (severe deficiency, P1), 10 µmol L−1 phosphorus (representative value of soil solution in the region, P10) and 500 µmol L−1 phosphorus (full P supply, P500). Our results show that both limiting P conditions strongly decreased plant development and biomass accumulation, and altered above- and below-ground morphology, in comparison with P500 plants. The latter, in turn, had relative growth rate values comparable to those of other cultivated grasses under non-limiting conditions. In both P-deficient treatments, plant development was severely delayed starting from leaf number 3, even when P concentration in the pseudostem at early stages was similar or even higher than that of P500 plants. Our results suggest that developmental inhibition of tall wheatgrass at low P supply may be the consequence of a specific plant response to P concentration in soil solution, rather than to direct P starvation in plant tissues, and underlines the need of improvement of this species to enhance productivity in this environment.

Propagation process‐based agricultural drought typology and its copula‐based risk

AbstractDetermining the risks associated with different drought event types can be beneficial for related scientific research and management strategies. In this study, we proposed an agricultural drought event pair and typology based on the governing drought propagation processes in the Yellow River basin at the catchment scale. In total, seven agricultural drought event pairs were distinguished, namely single meteorological drought event pair (MDonly), single soil moisture drought event pair (SDonly), single agricultural drought event pair (ADonly), soil moisture and meteorological drought event pair (SDMD), agricultural and meteorological drought event pair (ADMD), agricultural and soil moisture drought event pair (ADSD) and agricultural, soil moisture and meteorological drought event pair (ASMD). The SDMD and ADMD events had the highest copula‐based risk probabilities with the shortest joint return periods. Six agricultural drought types were distinguished in this study, namely classical rainfall deficit, rain‐to‐snow‐season, wet‐to‐dry‐season, cold snow season, warm snow season and composite drought events. The classical rainfall deficit, wet‐to‐dry season and composite drought events were the major agricultural drought types in the Yellow River basin. The agricultural drought typology results of the present study provide a comprehensive understanding of drought propagation and improvement of drought forecasting and management.

Spatial Differentiation and Influencing Factors Analysis of Drought Characteristics Based on the Standardized Precipitation Index: A Case Study of the Yellow River Basin

It is crucial to identify drought characteristics and determine drought severity in response to climate change. Aiming at the increasingly serious drought situation in the Yellow River Basin, this study firstly selected the standardized precipitation index (SPI) and streamflow drought index (SDI) to analyze the characteristics of drought seasons, then identified the frequency, duration, and intensity of drought based on the run theory, and finally recognized the abrupt changing and driving factors of major drought events in specific years by the Mann–Kendall trend test. The conclusions showed the following: (1) The drought in the downstream of the Yellow River Basin was more severe than that in the upstream. The drought characteristics showed significant regional differentiation and deterioration. (2) The drought intensity and duration had an obvious spatial correlation. Compared with the other seasons, the drought duration and severity in spring and autumn were the most serious, and in winter, they showed an aggravating trend. (3) According to a time series analysis of drought conditions in the Yellow River Basin, the worst drought occurred in 1997–2001 with the least rainfall on record and a sudden rise in temperatures. This study could provide a scientific reference for agricultural drought disaster prevention and mitigation.

Identification of seasonal drought and its impacts on cropping season in Bangladesh

PurposeThis study aims to identify seasonal drought using standardized precipitation index (SPI). The following specific objectives are to generate result and identify seasonal drought and determine different scale of seasonal drought and its impacts on cropping season.Design/methodology/approachSeasonal SPI was calculated using long-term rainfall data for three seasons. The SPI was calculated using the formula and it is effective for the determinants. This study showed the functional relationship between drought duration, frequency and drought time scale using the SPI. SPI=X−X¯σ.FindingsSeasonal drought occurs more frequently in Bangladesh that affects crops and the agricultural economy every year. More severe drought was recorded during the Kharif-1 and Kharif-2 seasons and most crops were affected in these two seasons. No severe or moderate drought was recorded during the Rabi season. The results showed that monsoon crops were severely affected severely by extreme and severe droughts during the Kharif-2 season. Eventually, the people remain jobless during the monsoon, and they experience food shortages like monga. Several obstacles were recorded during the season, including delayed preparation of land, sowing, transplanting and other farming activities because of monsoon droughts. This study revealed that very frequently, mild dryness occurs in winter, but crop loss is minimal. The scale and occurrence of extreme droughts are more frequent during monsoons and reduce crop yields, affecting livelihoods in the study area. Seasonal drought affects cropping patterns as well as reduce crop yields.Originality/valueThe outcome of this study derived from the secondary data and field data.

A new drought model for disaster risk management in the Punjab, Sindh and Baluchistan provinces of Pakistan

Drought poses a continual threat to both lives and livelihoods in the Global South. Although the impact on food security from drought could be reduced through early release of funds, the humanitarian sector typically reacts to crises rather than anticipates them. A significant challenge lies in devising a drought monitoring and forecasting system that can function across environmentally and economically diverse regions. This is particularly evident in Pakistan, which encompasses environments ranging from fertile riverbeds to arid deserts. This paper details the development, implementation, and operation of an anticipatory drought Disaster Risk Financing (DRF) programme for the provinces of Punjab, Sindh, and Baluchistan in Pakistan. Key to the DRF development are a new yield model for the primary crop in the target season (winter wheat), and a novel forecasting system for four seasonal drought indicators - namely winter wheat yield, precipitation, normalised difference vegetation index (NDVI) and vegetation health index (VHI). Formal evaluations demonstrate that the forecasts are skillful up to 2 months in advance of the end of the season – enabling anticipatory release of funds. The work presented here is applicable beyond Pakistan. Indeed, the model and the methodologies are sufficiently broad and adaptable to be utilised in arid and semi-arid regions across the Global South.

Global eight drought types: Spatio-temporal characteristics and vegetation response

The traditional classification of drought events into seasonal and flash types oversimplified the complexity and variability of global drought phenomena, limiting a deeper understanding of drought characteristics and their impacts on vegetation. To address this issue, soil moisture percentile methods and the Soil Moisture Anomaly Percentage Index (SMAPI) were employed to create time series for flash drought (FD) and seasonal drought (SD) events globally from 1981 to 2020. A novel categorization framework was proposed to subdivide the two basic drought categories into eight distinct drought types using a set relationship identification method. The results showed fluctuating trends in the frequencies of Independent FD and Inclusion FD, which declined rapidly after 2011 at rates of 0.05 and 0.04 times/year, respectively. Independent FD frequency was highest in humid areas and decreased with increasing aridity. The spatial distributions of Inclusion FD and SD were similar, with both frequencies highest in extremely arid areas and decreasing with increasing humidity. The frequency of Independent SD, which peaked in semi-arid areas, increased significantly after 2011 at a rate of 0.01 times/year. The occurrence of FD evolving into SD or emerging at the end of SD was rare, with a global average of 0.46 events/decade and little spatial variation. Between 1981 and 2020, FD showed a U-shaped trend in drought duration, while SD showed no clear pattern. The duration of FD showed little difference across arid and humid zones, but the duration of SD decreased significantly with increasing humidity. Vegetation responses to drought varied, with arid regions showing longer response time compared to humid regions. A positive correlation between temperature and solar-induced chlorophyll fluorescence (SIF) during droughts was observed, while precipitation generally showed a negative correlation with SIF. Radiation had a minimal effect on SIF during droughts. The study offered a comprehensive categorization of drought events, enhancing our understanding of their spatiotemporal characteristics and vegetation responses on a global scale.

Community Based Adaptation To Climate Change And Social Economic In Xe Champhone Wetland, Champhone District, Savannakhet Province

Climate change is key significant factor that impacts on multi-dimensions, which is relevant to social economic development, livelihood and environment, hence, Community Based Adaptation (CBA) to climate change is a mechanism of adapting based on the existing practices, knowledge, policy and experiences of the rice farmers to sustain their lives on changing climate, the objective of the study is to assess the social economic and find the practice management of rice farmers to adapt during flood and drought seasons. Hence, according to the research finds that, majority of the rice farmers are experienced and learnt from the previous effect and adjust themselves by using knowledge skills, experiences to build the resilience for their rice and crop planting in order to prevent and avoid the damages from climate change within the wetland. Besides that, the local communities still utilize the existing potential natural based adaptation to be flexible sustainably their agricultural activities and livelihood during rainy and dry season

Analysis of community preparedness in facing fire disaster (case study of Sekaa Teruna Dharma Yowana, Pekutatan district, Jembrana-Bali)

Background: Fire disasters are a significant risk during the dry season and prolonged drought conditions, Pekutatan is one of the sub-districts in Jembrana Regency, Bali, where most people are clove or coffee farmers. The risk of fire disasters in clove or coffee fields may occur because Bali is currently experiencing a dry season. Preparedness is an activity carried out to deal with disasters through quick and appropriate steps so that property loss and loss of life can be minimized.Objective: This research aims to determine the community’s readiness to face fire disaster.Methods: This research is descriptive quantitative research, where data was obtained from the results of fire disaster mitigation, with a purposive sampling technique where the sample consisted of 40 people. The research result was analyzed using descriptive analysis techniques.Results: The research results show an attitude of concern for disasters in the ready category (index value 87), emergency response plans in the ready category (index value 86), early warning systems in the ready category (index value 85), and resource mobilization in the ready category (index value 82).Conclusion: It can be concluded that the community is ready to mitigate fire disasters

Partitioning evapotranspiration of Camellia oleifera during the growing season based on the Penman-Monteith model combined with the micro-lysimeter and stable isotope methods

Frequent seasonal droughts impact on crop growth and yield in the hilly areas of southern China. A good knowledge of its evapotranspiration partitioning of the main economic oil crop Camellia Oleifera is particularly important to increase water productivity and improve water resource management. The isotope-based method was applied to partition ET in the hilly Camellia Oleifera Forest of southern China. The isotopic composition of evapotranspiration vapor (δET), transpiration vapor (δT) and evaporation vapor (δE) were calculated by the Keeling plot method, the Craig-Gordon model (C-G model), and isotopic steady-state assumptions, respectively. The conventional Penman-Monteith model and the micro-lysimeter method (PM-L) were used to compare and assess the ET partitioning results (Ft). It showed that the Ft values calculated by the two methods were in good agreement. The isotopic composition of soil water at the evaporating front (δS) ahead and after DOY151 was sampled at 5 and 10 cm depth, respectively, where the correlation coefficients (R2) of the Ft values calculated by δ18O and δ2H were 0.84 and 0.66. Ft Calculated by δ18O was more accurate than δ2H because of the higher correlation coefficient of δ18O in the keeling plot regression and in the linear fit with PM-L. The isotopic composition of soil evaporation vapor（δE）calculated by dynamic εk (kinetic fractionation effects) values can be more accurate to quantify the ET partitioning results (with the R2 of 0.90). The mean values of Ft were 0.79 and 0.82 by the PM-L method and the isotope-based method respectively over the whole growing season, indicating the isotope method is robust in calculating ET partitioning for Camellia oleifera in the region. We also found that the seasonal variation of Ft is mainly controlled by temperature (T), soil water content (SWC), and leaf area index (LAI), all of which can be effectively expressed as power functions. The results provide potential assistance for water management in Camellia oleifera woodlands.

The complete genome sequence of the protogynous hermaphrodite North American annual killifish Millerichthys robustus (Rivulidae, Cyprinodontiformes).

The Mexican Rivulus, Millerichthys robustus, is an enigmatic species of seasonal killifish endemic of the Southeast Mexico that has changed paradigms on the evolution of annualism in killifishes. This species survives in ephemeral environments that experience a period of seasonal drought that causes the death of all adult fish. However, populations persist due to their drought-resistant embryos capable of arresting their development in diapause until the next the rainy season. Millerichthys evolved unique characteristics within annual killifishes as a functional sequential hermaphroditism, in which females change to males (protogynous) under perceived conditions of mate competition. Also, M. robustus express different color phenotypes in both sexes: five-color phenotypes continuously distributed in various perceptual units between yellow and red in males, and different number of ocelli disposed in caudal peduncle in females. The phylogenetic relationships of M. robustus revealed that it is a sister clade to two non-annual species found exclusively in Cuba (Rivulus cylindraceus and Rivulus berovidesi), indicating that the annual life cycle, through the acquisition of embryonic diapause, has evolved independently in this species. Here, we present the complete genome sequences for the North American annual killifish Millerichthys robustus. The raw data and assembled genome are available in GeneBank.

Composición bioquímica y mineral de especies vegetales consumidas por cabras en pastoreo en tres temporadas del año

Objetive. Determine and compare the biochemical and mineral composition of plant species consumed by grazing goats in three seasons of the year (drought, rain, and transition). Materials and methods. Sampling of the plant species that consume goats in each season of the year were made, during the time the goats feed on the rangeland, following them by the feeding paths and registering the species, the organs consumed, and the proportion of consumption This data were used to calculate a preference index, registering the frequency of consumption The three most consumed species by goats per season were selected. Results. The most consumed species in the drought season were Cyrtocarpa edulis, Pithecollobium confine, and Cercidium floridum. During the rainy season, the most consumed species were Forchhammeria watsonii, Tecoma stans, and Cercidium floridum. The most consumed species during rainy season were, Cyrtocarpa edulis, Indigofera suffruticosa, and Mimosa distachya. The protein content and ethereal extract were superior (p≤0.05) in the drought season. The content of Ca, Mg, Mn, K, P, and total-N were superior (p≤0.05) in the rainy season. Conclusions. The plant species associated with the rangeland in the study area, showed variation per season of the year in mineral and biochemical content, although are a source of minerals and nutrients for goats.

Prediction of heavy metal lead contamination accident in Three Gorges Reservoir Area.

Water contamination incidents have become a significant ecological and environmental threat, particularly concerning the security of drinking water source areas (DWSAs). This research aimed to address this issue by integrating Geographic Information System (GIS) into bidimensional hydrodynamic water quality mathematical model developed using C + + and FORTRAN programming languages. The focus was on the Heshangshan drinking water source area (HDWSA), and the TECPLOT360 software was utilized for visualizing pollutant migration and dispersion processes. The study specifically considered a hypothetical lead (Pb) contamination accident, which is situated in the Three Gorges Reservoir Area (TGRA). The spatio-temporal variations in Pb concentration throughout the entire DWSA were analyzed, along with a comparison of Pb concentration changes during different water seasons. The results indicate that, during the accident, the Pb concentration at the water intake in the drought season, decline season, flood season, and impounding season reached the standard limits at 76, 58, 44, and 48 min, respectively. Moreover, the entire DWSA achieved standard levels of Pb concentration at 124, 89, 71, and 74 min during the respective seasons. The study also observed an expansion and subsequent contraction of the Pb contamination area in the DWSA, with the transfer rate of Pb concentration ranked as flood season > impounding season > decline season > drought season.

Genomic wide association study and selective sweep analysis identify genes associated with improved yield under drought in Turkish winter wheat germplasm

A panel comprising of 84 Turkish winter wheat landraces (LR) and 73 modern varieties (MV) was analyzed with genome wide association study (GWAS) to identify genes/genomic regions associated with increased yield under favorable and drought conditions. In addition, selective sweep analysis was conducted to detect signatures of selection in the winter wheat genome driving the differentiation between LR and MV, to gather an understanding of genomic regions linked to adaptation and yield improvement. The panel was genotyped with 25 K wheat SNP array and phenotyped for agronomic traits for two growing seasons (2018 and 2019) in Konya, Turkey. Year 2018 was treated as drought environment due to very low precipitation prior to heading whereas year 2019 was considered as a favorable season. GWAS conducted with SNPs and haplotype blocks using mixed linear model identified 18 genomic regions in the vicinities of known genes i.e., TaERF3-3A, TaERF3-3B, DEP1-5A, FRIZZY PANICLE-2D, TaSnRK23-1A, TaAGL6-A, TaARF12-2A, TaARF12-2B, WAPO1, TaSPL16-7D, TaTGW6-A1, KAT-2B, TaOGT1, TaSPL21-6B, TaSBEIb, trs1/WFZP-A, TaCwi-A1-2A and TaPIN1-7A associated with grain yield (GY) and yield related traits. Haplotype-based GWAS identified five haplotype blocks (H1A-42, H2A-71, H4A-48, H7B-123 and H7B-124), with the favorable haplotypes showing a yield increase of > 700 kg/ha in the drought season. SNP-based GWAS, detected only one larger effect genomic region on chromosome 7B, in common with haplotype-based GWAS. On an average, the percentage variation (PV) explained by haplotypes was 8.0% higher than PV explained by SNPs for all the investigated traits. Selective sweep analysis detected 39 signatures of selection between LR and MV of which 15 were within proximity of known functional genes controlling flowering (PRR-A1, PPR-D1, TaHd1-6B), GY and GY components (TaSus2-2B, TaGS2-B1, AG1-1A/WAG1-1A, DUO-A1, DUO-B1, AG2-3A/WAG2-3A, TaLAX1, TaSnRK210-4A, FBP, TaLAX1, TaPIL1 and AP3-1-7A/WPA3-7A) and 10 regions underlying various transcription factors and regulatory genes. The study outcomes contribute to utilization of LR in breeding winter wheat.

Benefit distribution of the irrigation system: irrigation reservoir in Geyongan Village, Cirebon Regency, Indonesia

This study aim to identify the impact of the development of the irrigation reservoir through the benefit distribution received by the community in Geyongan Village, Cirebon Regency. The stages of research include: identifying the research conceptual framework, data collection, qualitative analysis of benefit distribution referring to conceptual framework before and after irrigation reservoir construction. The role of irrigation infrastructure is very important in terms of ensuring the water provision during dry season. As one of the solutions to the drought problems related to water scarcity, the impact of irrigation reservoirs is essential to determine water sustainability. The previous research has been conducted generally shown that the impact of irrigation reservoir construction gives positive results to agricultural land. However, some research has not been considerate how the benefit distribution of irrigation condition before and after construction. The result shows that during dry and drought season, water availability for irrigation system before and after the reservoir construction is still limited which causes gap of water availability between lower and higher area of agriculture from the secondary irrigation system. Optimum condition occurs after the Geyongan irrigation reservoir constructed during normal rainy season. The results suggest that construction of reservoir irrigation infrastructure can be an alternative option to equalize water allocation in agriculture. Furthermore, it is also important to maintain the sustainability of water availability from water sources or upstream to prevent drought

Evaluation of N nutrition and optimal fertilizer rate for ridge-furrow mulched maize based on critical N dilution curve under different water conditions

Optimizing nitrogen (N) management based on the critical N dilution curve (NCDC) has been proven a precision fertilization strategy to diagnose crop N nutrition status. However, few explorations have been done to establish a NCDC for dryland maize under double ridge-furrow mulching, a planting system that has been widely adopted in semi-arid areas. Moreover, the influences of various rainfall conditions on NCDC remain unclear. Therefore, a 9-yr field nitrogen fertilization experiment from 2013 to 2021 (five nitrogen rates: 0, 75, 150, 225, and 300 kg N ha–1, respectively, represented by N0, N0.25, N0.50, N0.75, and N1) was applied to established the NCDC under two planting systems (Flatting without mulching, CK; Double ridge-furrow with mulching, DRFM) and two rainfall types (rainfall season and drought season). Compared with CK, DRFM significantly increased plant dry matter (PDM, 5.5–12.8%) and N concentration (4.2–6.9%), ultimately improved grain yield (+16.9%), cumulative nitrogen recovery efficiency (CNRE, +9.8%) and crop water productivity (WPc, +26.3%). Rainfall from jointing to silking stage was an important contributor to grain yield. Compared with rainy season, drought season triggered a 51.7% yield loss and 17.1% reduction in NRE, respectively. The NCDC of the CK and DRFM were Nc=36.6×PDM−0.37 and Nc=38.4×PDM−0.36 in rainy season, respectively; the NCDC of the CK and DRFM were Nc =34.5×PDM−0.27 and Nc=37.3×PDM−0.30 in drought season, respectively. The nitrogen nutrition index (NNI) and plant nitrogen requirement (PNR) based on the NCDC intuitively recorded the N nutritional status. The improved soil micro-environment, PDM and N uptake was recorded in N0.75 (225 kg N ha–1 yr–1) under wet season and in N0.50 (150 kg N ha–1 yr–1) under drought season, respectively, which brought an increase in crop productivity with a suitable N nutrition status. The findings highlight an accurate and effective method for assessing the N nutrition status of rainfed maize, and optimize fertilization strategy for sustainable production in semi-arid regions.