Dry Period Research Articles

Effects of strain and season on incubation parameters of Nigerian local guinea fowls

The study was conducted to determine the effects of strain and season on incubation parameters of Nigerian local guinea fowls. A total of three thousand six hundred (3600) fertile eggs (400 eggs per strain in each of the three seasons; early rainy, late rainy and early dry) generated from 144 matured guinea fowls (120 guinea hens and 24 guinea cocks) were used to obtained the following parameters; number of eggs set (NOES), number of fertile eggs (NOFE), number of dead in shell (NODIS), number of eggs hatched (NOEH), fertility (%) and hatchability (%). Data generated for the study were subjected to multivariate analysis of variance (MANOVA) of SPSS 25 (2017) to determine the effects of season and strain on incubation parameters. The results of the study showed that Pearl strain had significantly higher (p<0.001) NOFE (320.00), NODIS (36.00), NOEH (274.89), fertility (80.00 %) and hatchability (85.91 %). Season wise, late rainy and early dry seasons had significantly higher (p<0.001) values on most incubation parameters observed. The interaction effect of strain and season on incubation parameters of guinea fowls was not significant, except on NOEH (p<0.001) where estimates obtained for Pearl at late rainy and early dry seasons had the highest values, while the least were observed in Lavender during early rainy, late rainy and early dry periods. In conclusion, Pearl strain of Nigerian local guinea fowl had the best results for incubation parameters during late rainy and early dry seasons than white and Lavender types.

Inconsistent using FLOOD and Flooding Development of EPA SWMM for Assessing Flood Occurrences in Vulnerable Urban Watershed Considering Extreme Rainfall Events

Urban flood, commonly known as urban water congestion, is a type of water hazard that poses significant challenges for urban residents and water management experts. Chittagong, an essential economic hub in Bangladesh, renowned for its role as a port city, comprises a diverse range of land use, including residential, industrial, and commercial sectors. The Chaktai canal, an important element of Chittagong drainage system, is connected to the Karnaphuli river, playing a vital role in managing drainage by handling a substantial portion of the city water. Therefore, this research evaluated the operational efficiency of a specific drainage network under the influence of altered rainfall events using the Storm Water Management Model (SWMM). Using ArcGIS 10.4, the land use pattern of the area was researched, incorporating data from field surveys and secondary sources. SWMM 5.1 integrated watershed data, and further simulation was carried out to estimate runoff in various sub-catchments and drainage network limitations during heavy rain. During the intense monsoon period, the tool determined the average runoff depth, considering backwater effects and robust tidal surges, resulting in a depth of 3.3m compared to 2.6m in the dry season. This research evaluated the influence of impervious land use changes on urban drainage systems. While meteorological factors alone render drainage network sufficient in dry periods, the outfall shows vulnerability during the rainy season, with an allowance of only 0.7m, jeopardizing the catchment through flood. It contributed a schematic sub-catchment representation, emphasizing that flood events depend on volume runoff and peak flow in urban drainage system. SWMM model was used to illustrate the catchment surface runoff and interconnected node depths via conduits, as well as the current catchment scenario comprehensively.

TTOOLS FOR IMPROVING REPRO ON DAIRY FARMS

The studies presented in this article are part of the PTF of the Kazakhstan Ministry of Agriculture. Most consultants, when dealing with herd fertility problems, advise first setting specific goals (S), measurable (M), achievable (A), relevant (R), and time-bound (T) – SMART goals. Each farm has different assets, goals, and challenges and therefore a consultant must tailor their recommendations to the farm and avoid generalizations or textbook recommendations based on national averages. To create the standards for feeding, reproduction, and maintenance of dairy, during 2021-23 improved diets, assessed animal welfare, and reproduction data was collected monthly, the basis of the collected data in the article shows the dynamics of the fertility of cows in one of the basic farms participating in Execution of the program. By improving the conditions of feeding and maintenance, the fertility of cows had a positive dynamic. One of the important indicators is the number of calves per 100 cows from 77 calves in 2021 increased to 86 in 2023. The number of cows with an elongated dry period from 14.7% decreased to 6.3%. Pregnancy Rate increased by 2 times from 11.9% to 20.8%. The mortality rate of calves also decreased from 23.2% in 2021 to 6.7% in 2023. Introducing the system for heat detection cuts the heat detection rate coefficient, the indicator has grown to 54% from a low 23% in 2021. In general, we can conclude that by improving the level of feeding and maintenance, the fertility of the cows had positive dynamics.

Ritual schedule and worshippers’ origin at an ancient Maya ritual cave site, Las Cuevas, Belize: a pilot study of jute snail shell sclerochemistry

Sequential stable carbon and oxygen isotope data were measured on 15 jute snail shells (Pachychilus sp.) excavated from the Cave at Las Cuevas, a ritual cave site in western Belize. The shells were found intact in the undisturbed, excavated ritual activity area, suggesting they were left as offerings, not as food waste. The offering of jute snails is thought to be associated with ancient Maya concern for rainfall needed for agriculture, thus the interpretation of the isotope data focused on assessing if the shells were offered in rainy or dry periods. Seven of the shell profiles did not contain oscillations in isotope profiles, and so could not be interpreted for wet or dry season of capture. The remaining shells’ isotope profiles indicate some were captured in rainy, dry, and intermediate conditions. Significant variation in the ranges in absolute carbon and oxygen isotope values suggest they were collected from two or more locations, therefore at least some of the snails were brought in from a distance rather than collected locally prior to offering. More detailed conclusions cannot be confidently made without additional method validation studies, but this project supports the potential utility of jute shell sclerochronology in Maya archaeology.

Design of irrigation scheme for an improved fodder crop production as food for ranch cattle

The object of this research is Cattle Ranches. Cattle Ranches is the practice of raising herds of cattle on large landscape including the structures and crops of legumes, grasses or forages, devoted to the raising, and grazing of the herds. Organized animal productions have been successfully practiced for decades in developed countries, but have been of minor Agricultural consideration in arid regions and Sub-Saharan Africa. Most African herders relied on natural pasture in the tropics which are either forested with high incidences of disease and parasites detrimental to profitable animal production, or dry zone which calls for tremendous physical exertion on the animal in order to obtain feed and water. Feed shortage and low quality of available feeds are constraints for livestock production and has been a major constraint for animal production during dry periods. Therefore, farmers use different coping mechanisms ranging from purchasing of feeds from the market and destocking unproductive animals as drastic measures. The negative trend results into many pastoralists resorting to grazing in crops farm lands. The pressure from increasing population and diminishing availability of land for pastoral range practice causes farmers- herders’ clashes which results into loss of lives. Rise in the toll of farmers-herdsmen crisis and clashes across many African countries in recent years, became worst. This brings to fore, the need to set up Cattle Ranches as an alternative to nomadic agriculture. The viability of setting up ranches for Cattles using improved irrigation systems to make up for the dry zone/season condition is practicable and profitable as practiced in developed countries. Ranches provide feed from grown forage legumes and fodder trees species through irrigation, combined with appropriate postharvest handling practices. Feeds availability mitigate the constraints of food scarcity and improves livestock productivity. The study consisted of outlining design procedure for the establishment of an irrigation scheme for an improved fodder crop production as food for ranch cattle.

Ba theory applied in clay pot irrigation for smallholder farmers in brazilian Eastern Amazon

The objective of this work was to apply the theoretical “Ba” of knowledge management in the “Ba” space, having as its place of evolution the Technological Reference Unit (TRU) with clay pots that reuse rainwater to keep crops irrigated with clay pots on rural properties, in the Eastern Brazilian Amazon. Installed in 2016 in the community of Lavras in Santarém, being a place frequently visited by those interested in learning about the technology. The irrigation has low energy consumption, as the rainwater is distributed to the pots by gravitational force and it is possible to diversify agricultural crops, types of arrangements and different strategies to provide new financial gains for rural producers, due to the possibility of production in dry periods. The TRU is a space where research, teaching, extension and rural producers work in evolutionary partnership. The analysis of main components showed that farmers significantly expanded their knowledge, adding quality of life and improving family income, after installing IrrigaPote. The location is typical of a “Ba” space with sustainable collective learning, pointing out indicators in the social, environmental and economic scope, which can be replicated by rural family-based farmers interested in the efficient use of water, in irrigated crops anywhere in the world terrestrial.

The association between calf birth weight and the postcalving performance of its dairy dam in the absence of dystocia

The objective of the study was to quantify the association between the birth weight of a calf and the subsequent performance of its dairy dam in the absence of any recorded calving assistance. A total of 11,592 lactation records from 4,549 spring-calving dairy cows were used. The association between a series of quantitative cow performance metrics (dependent variable) and calf birth weight (independent variable) was determined using linear mixed models; logistic regression was used where the dependent variable was binary. Nuisance factors in the models were calf sex, heterosis coefficient of both the cow and calf, dry period length immediately before the birth of the calf, cow age at calving relative to the median cow age per parity, breed proportion of the cow, cow live weight between 100 and 200 d of lactation relative to the mean cow weight per parity, and contemporary group. Calf birth weight was included in the model as either a continuous or a categorical variable. Primiparous and multiparous cows were analyzed separately. Mean (SD) calf birth weight was 36.2 (6.8) kg. In primiparous cows, calf birth weight was associated with milk yield in the first 60 d of lactation, calving to first service interval, calving body weight (BW), and both nadir BW and body condition score (BCS). In multiparous cows, calf birth weight was associated with total milk, fat, and protein yield in the first 60 and 305 d of lactation, peak milk yield, total milk solids, both calving and nadir BW, and BCS loss from calving to nadir. Relative to primiparous cows that gave birth to calves weighing 34 to 37 kg (i.e., population mean), their contemporaries who gave birth to calves that weighed 15 to 29 kg produced 9.82 kg more milk in the first 60 d of lactation, had a 2-d shorter interval to first service, and were 8.08 kg and 5.51 kg lighter at calving and nadir BW, respectively; the former was also 0.05 units lower in BCS (5-point scale, 1 = emaciated and 5 = obese) at nadir. Relative to multiparous cows that gave birth to calves that were 34 to 37 kg birth weight, multiparous cows that gave birth to calves that were 15 to 29 kg yielded 59.63 kg, 2.44 kg, and 1.76 kg less milk, fat, and protein, respectively, in the first 60 d of lactation; produced 17.69 kg less milk solids throughout the 305-d lactation; and were also 10.49 kg lighter at nadir and lost 0.01 units more BCS to nadir. In a separate series of analyses, sire breed was added to the model as a fixed effect with and without calf birth weight. When calf birth weight was not adjusted for, 60-d milk yield for multiparous cows who gave birth to calves sired by a traditional beef breed (i.e., Angus, Hereford) produced 59.63 kg more milk than multiparous cows who gave birth to calves sired by a Holstein-Friesian. Hence, calf birth weight is associated with some subsequent dam performance measures; however, where associations do exist, the effect is biologically small.

Runoff and erosion from three unpaved road segments in northern Vietnam

Study regionTruong Son Commune, Luong Son District, Hoa Binh Province in north Vietnam. Study focusRunoff and erosion from three road surface and three adjacent cutslope plots in a young plantation forest to evaluate how unpaved forest roads affect runoff and erosion. New hydrologic insights for the regionThe 10-m long road surface plots generated similar amounts of runoff with runoff coefficients of 24–32 % over 24 rainstorms divided into an initial wetter period followed by a relatively drier period. Runoff coefficients for the two monitoring periods were not statistically different, and the relatively low runoff coefficients compared to previous studies were due to infiltration outside the narrow compacted tracks created primarily by motorbike traffic. Runoff from the base of the cutslopes varied by a factor of three, associated with the topographic convergence of the hillslopes. Road surface erosion over the two monitoring periods was consistent among the three plots and storm-based sediment production was strongly correlated with both storm precipitation and surface runoff. The amounts of runoff and sediment collected at the base of the cutslopes increased with increasing hillslope convergence, and the mass of collected sediment was 52–97 % of the corresponding amounts from the road surface plots. The results provide data on the extent of unpaved road runoff and erosion in this seasonally wet tropical environment, and the need to consider topographic convergence in road design and drainage.

Multitechnique characterization of secondary minerals near HI-SEAS, Hawaii, as Martian subsurface analogues

Secondary minerals in lava tubes on Earth provide valuable insight into subsurface processes and the preservation of biosignatures on Mars. Inside lava tubes near the Hawaii-Space Exploration and Analog Simulation (HI-SEAS) habitat on the northeast flank of Mauna Loa, Hawaii, a variety of secondary deposits with distinct morphologies were observed consisting of mainly sodium sulphate powders, gypsum crystalline crusts, and small coralloid speleothems that comprise opal and calcite layers. These secondary deposits formed as a result of hydrological processes shortly after the formation and cooling of the lava tubes and are preserved over long periods of time in relatively dry conditions. The coralloid speleothem layers are likely related to wet and dry periods in which opal and calcite precipitates in cycles. Potential biosignatures seem to have been preserved in the form of porous stromatolite-like layers within the coralloid speleothems. Similar secondary deposits and lava tubes have been observed abundantly on the Martian surface suggesting similar formation mechanisms compared to this study. The origin of secondary minerals from tholeiitic basalts together with potential evidence for microbial processes make the lava tubes near HI-SEAS a relevant analog for Martian surface and subsurface environments.

Rainwater: Harvesting and Storage through a Flexible Storage System to Enhance Agricultural Resilience

Many climatic variables are projected to occur with more intense and frequent extreme events, possibly unpredictable patterns and negative feedback loops with other environmental processes. Agriculture has faced uncertainty regarding ground temperature and rainfall distribution during the last few years, making water availability one of the major concerns for farm management. In this scenario, rainwater harvesting could represent a powerful tool to mitigate this problem, and consequently, the research community has been fostering new technical solutions. On the other hand, a few studies on agronomic assessment of rainwater harvesting systems are present in scientific literature. The present study reports preliminary data of a long-term study on a Flexible Water Storage System (FWSS) evaluating the possibility of enhancing agriculture systems resilience, shifting from rainfed production to irrigated agriculture relying on excessive rainfall, collectible from extreme events. The idea of intercepting excess rainfall, which is generally lost, thanks to an innovative water harvesting system, and using it to mitigate drought stress for crops is in line with sustainable approaches aiming to improve the resilience of agricultural systems. The results highlighted that the system studied could potentially collect an annual average of 831.7 m3 of water, mitigating the excess of water in the ditch that can potentially cause flooding and storing fresh water to provide irrigation during dry periods.

Frequency analysis of extreme air temperature events in an urban center in the Brazilian savanna

The increase in the planet's average air temperature in recent years has influenced the pattern of natural climatic phenomenons, with levels outside the normal range, the occurrence of prolonged dry periods, torrential rains and heat waves. Due to the climate crisis, extreme events have become increasingly frequent and more intense. With that in view, the aim of this article was to analyze the frequency of occurrence of extreme air temperature events between 2003 and 2023 in Cuiabá-MT-Brazil, as well as to understand the relationship between these extreme heat wave events and the occurrence and intensity of ENOS events. To this purpose, extreme events were analyzed using daily maximum air temperature data for the period from January 1, 2003 to October 31, 2023 obtained from the automated station of the National Meteorological Institute (INMET) located in Cuiabá - MT (CÓDA907), and ONI (Oceanic Niño Index) data. The results showed a significant increase of 86% in the occurrence of extreme events in 2020, compared to 2007, the year with the lowest number of occurrences. Therefore, it is extremely important that issues such as climate emergency, climate change and climate resilience are discussed as a means of public policy, preventing these increases from becoming even worse in frequency and/or intensity.

Applicability of statistical and deep-learning models for rainfall disaggregation at metropolitan stations in India

Study regionMetropolitan stations in India with distinct climatic conditions, namely, Delhi, Chennai, Kolkata, and Mumbai were selected for this study. Study focusRainfall disaggregation models were studied based on four models, namely Neyman-Scott Rectangular pulse (NSRP) process, Microcanonical Multiplicative Random Cascade (MMRC) process and its variant MMRC-K, and one Deep-Learning based process (ANN-K), using metrics like dry periods, event rainfall volumes, extreme rainfall characteristics, etc. New hydrological insights for the regionThe study successfully established individual rainfall volume, event rainfall volume, and event durations are all within 10% of each other for the four stations. Delhi due to its continental climate showed a higher percentage of dry periods and longer dry periods, which were most successfully modelled by MMRC and MMRC-K. Kolkata and Mumbai stations displayed a higher number of extremely intense and cloudburst types of rainfall, which were modeled effectively by the Deep-Learning Model. Chennai has a different rainfall pattern due to returning monsoon which was also captured by the models. Generally, for extreme rainfall parameters, the ANN-K model performs significantly better, successfully reproducing the characteristics at all quantiles, especially with rainfall above 100 mm/hour intensity or cloud bursts, while 50% of the models overestimated these. NSRP on the other hand performs reasonably well for most considered parameters, without being exceptional at any of them. MMRC and MMRC-K most accurately modeled the dry period parameters.

Adaptability of variety and rootstock combinations of peach and nectarine in the Russia subtropics

The article presents the results of research into a collection of peaches and nectarines cultivated at the Federal Scientific Research Center of the Russian Academy of Sciences in Sochi. The experiment was conducted in open ground, plot area is 0.5 hectares, planting pattern is 5x2.5m, 5x2, 5x1.5m. In 2019, the Center’s assortment was replenished with 28 variety-rootstock combinations of peach and nectarine based on eight varieties (Pamyat Simirenko, Redhaven, Zolotoy Yubiley, Osenniy Rumyanets, Obilny, Orion, Pyatnitsa 13, Silver Roma) of different ripening periods on four clonal rootstocks: Kuban 86, BP, Best, VVA. The physiological and biochemical characteristics of variety-rootstock combinations of peach and nectarine, resistant to abiotic factors in the humid subtropics of Russia, have been studied. The object of study is peach leaves. Physiological analyzes were carried out in the plant physiology and biochemistry department using classical methods: water deficiency of peach leaves was determined according to Pochinok; tissue hydration - according to Gunar; water holding capacity - according to Arland; dry matter - by drying in a drying cabinet to constant weight. Leaves were collected from June to August. Agricultural technology is generally accepted for peach culture. Brown forest soils. It has been established that the best varieties of peach and nectarine in terms of ability to retain water during the dry period are: Redhaven (AP), Pyatnitsa 13 (AP), Pyatnitsa 13 (Best), Pyatnitsa 13 (BP) with low water deficit (11.06-4. 78%) and high water-retaining system of leaves (64-76%). They were distinguished by an increase in the turgor of leaf tissues to 66.33-69.27%, which is considered a sign of plant adaptability to disturbances in the water-thermal regime.

CONTAMINAÇÃO POR NITRATO EM ÁGUAS DE POÇOS RASOS DESTINADAS AO CONSUMO HUMANO EM ICOARACI, MUNICÍPIO DE BELÉM, ESTADO DO PARÁ

The research aims to assess the water quality of shallow wells utilized by the local inhabitants of the Parque Guajará neighborhood, located in the Icoaraci District of Belém Municipality, State of Pará. This assessment was conducted in accordance with the criteria delineated by Ordinance GM/MS nº 888, an edict established by the Ministry of Health. In the year 2016, a series of samples were collected from 15 specifically chosen shallow wells. This sampling was arranged to align with the distinct climatic patterns of the region, spanning the rainy season (January and May) and the drier period (August and October). The investigation analyzed the following parameters: pH, electrical conductivity, nitrite, ammonium, and nitrate content. During the time of the sample collection phase, recorded pH values oscillated between 3.93 and 6.42, while the measurements of electrical conductivity exhibited a peak at 527 µS/cm. Notably, ammonium concentrations peaked during the rainy season at 6.01 mg/L, whereas nitrite levels reached their peak during the less rainy season at 0.44 mg/L. High nitrate levels were particularly observed, predominantly during the rainy season, increasing up to 64.03 mg/L. Signs of a nitrification process could be seen within the samples from two wells under investigation. Statistical analysis highlighted positive correlations between electrical conductivity and nitrate levels, as well as between pH and ammonium concentrations. Based on these data, it became evident that nitrate contamination was pervasive in the residual groundwater of the shallow wells. This nitrate contamination, a fundamental concern throughout the sampling period, under scored the significant influence of septic tank systems on the analyzed water. This contamination, in turn, threatens the well-being of the people who depend on these water sources for consumption, thereby requiring urgent attention.

Diurnal cycle of precipitation over coastal sea and small islands in the eastern region of Sumatra including season and Madden Julian Oscillation signatures

The Barisan Mountains influence atmospheric circulation in Sumatra and surrounding areas. Yet, precipitation patterns in eastern Sumatra, especially along the coast, are poorly understood. This study examines diurnal precipitation cycles in coastal seas and small islands of eastern Sumatra, utilizing 2015–2021 IMERG Version 06 rainfall data, data from 21 island rain gauges, and ERA5 reanalysis data to assess precipitation through three parameters: precipitation amount (PA), precipitation frequency (PF), and precipitation intensity (PI). The diurnal cycle of PA and PF is more pronounced than PI. Distinct diurnal precipitation patterns emerge between coastal seas and small islands despite their shared east coast location on Sumatra. Coastal seas exhibit early morning precipitation peaks forming Sumatras squall, influenced by offshore Sumatra and Malay Peninsula propagations, accentuated by high wind speeds. Coastal shape, land topography, and Sumatra's island size also impact coastal sea precipitation. On small islands, rainfall peaks earlier (12:00–15:00 LT) with gentle winds, indicating local convection due to land heating dominance. In addition, the low-amplitude topography of Bangka and Belitung islands also increase rainfall, so PA and PF are higher on these islands than on other small islands. Seasonal analysis reveals rising PA and PF near the equator during the dry southeast monsoon (SEM), linked to the dominant Inter-Tropical Convergence Zone (ITCZ). Conversely, areas like Bangka, Belitung, and the South Coast of Sumatra, farther from the equator, witness higher PA and PF during the wet northwest monsoon (NWM). The South Coast of Sumatra saw a substantial PA increase during NWM, about 60% higher than the southeast dry period. Despite varying cycle amplitudes, peak times for PA and PF remain consistent across seasons. MJO analysis during NWM highlights heightened PA and PF amplitudes across eastern Sumatra, especially over equator-adjacent coastal regions and small islands, reaching 40–70% above non-active MJO phases. In summary, this research examines diurnal precipitation variations in coastal seas and small islands of eastern Sumatra, enhancing understanding of regional climate patterns and factors impacting precipitation cycles in the area.

Water management and irrigation for bulb onion (Allium cepa L.) growth and development in the Papua New Guinea Highlands

Water is crucial for nutrient intake, transportation, temperature regulation, and photosynthesis in bulb onion (Allium cepa L.) growth and development. Water scarcity, caused by climate variability and particularly during prolonged dry periods, has proved to be an obstacle to cultivating bulb onions in the Papua New Guinea (PNG) Highlands. Farmers have a limited grasp of the interdependence of soil, water, and plants. They have traditionally depended on precipitation, and water from streams and rivers, to irrigate their bulb onion crops. The main method for providing irrigation support is manual irrigation, with agricultural organisations assisting with basic irrigation technologies. Despite farmers and organisations efforts to improve irrigation practices, the prolonged dry season still raises labour demands for bulb onion farms. Farmers’ lack of knowledge about irrigation technology and soil water conservation contributes to this issue. Moreover, the lack of irrigation suppliers worsens the issue of limited soil water in onion farms. This paper gives an overview of onion production in PNG, focusing on irrigation practices and constraints in the Highlands region. It aims to stress irrigation’s importance in crop growth and explore PNG’s irrigation methods and soil moisture conservation practices. There is a need for a sustainable irrigation and soil water conservation system that is easy to use and incorporates crop water requirements. This system is vital for watering onions and conserving soil moisture, promoting their growth and yield. In this context, the use of mulch and irrigation systems can preserve and enhance soil moisture during prolonged dry phases.

Effect of Different Macronutrient Supply Levels on the Drought Tolerance of Rainfed Grass Based on Biomass Production, Water Use Efficiency and Macroelement Content

Water shortage, one of the main limiting factors for plant growth and development, can be alleviated by an adequate nutrient supply. The effect of different nitrogen (N), phosphorus (P) and potassium (K) supply levels and their combinations was examined in different rainfall supply periods (wet, normal, dry) on a grass sward in a field experiment. Dry and fresh aboveground biomass production were primarily increased by the N–rainfall supply interaction, from 0.739 to 6.51 and from 1.84 to 21.8 t ha−1, respectively, but the P–rainfall supply and N–P interactions and K treatment all had significant effects. Dry matter content was primarily influenced by the N–rainfall supply interaction, increasing in response to N in dry periods and declining in wet periods. Water use efficiency (WUE) was increased by the N–rainfall supply interaction from 28.3 to 127 kg ha−1 mm−1, but the N–P interaction had a similarly strong effect, and K treatment increased it in the dry period. The N, P and K contents of the aboveground biomass were increased by treatment with the corresponding element, but were also influenced by rainfall supply. The increase in biomass, mainly due to N treatment, caused the dilution of the P and K contents in grass in treatments poorly supplied with P and K. Biomass production and WUE were significantly improved up to a dose of 200 kg ha−1 year−1 of N, up to a supply level of 153 mg kg−1 of P2O5, and 279 mg kg−1 of K2O measured in the soil. Treating grass with the N, P and K macroelements may effectively increase biomass production and water use efficiency, but above a certain level their application is unnecessary.

Beyond Expectations: Recent Discovery of New Cave-Restricted Species Elevates the Água Clara Cave System to the Richest Hotspot of Subterranean Biodiversity in the Neotropics

The Água Clara Cave System was previously recognized as a prominent hotspot of subterranean biodiversity in South America, harboring 31 cave-restricted species. However, a recent expedition conducted in September 2023, coinciding with an exceptionally dry period in the region, provided access to previously unexplored areas. Therefore, the objective of this research was to investigate the cave-restricted invertebrate species, extending the findings from a previous article on the Agua Clara Cave System published in June 2023, and emphasizing the significance of this system as one of the most crucial tropical biodiversity hotspots. This survey unveiled an additional 10 species, raising the count of cave-restricted species within the system to an impressive 41. This remarkable diversity not only solidifies the Água Clara Cave System’s position as a paramount hotspot of subterranean biodiversity in the tropics but also serves as a stark warning about the imminent risks faced by these species. The escalating human-induced alterations in the region, notably deforestation, pose a significant risk to the survival of many of these unique and endemic species.

Prediction and countermeasures of heavy metal copper pollution accident in the Three Gorges Reservoir Area

In order to mitigate the hazards of water pollution in drinking water source areas (DWSAs), developing applicable models and proposing effective solutions is of paramount significance. The study developed the Heshangshan Drinking Water Source Area (HDWSA) Hydrodynamic Model, integrating Geographic Information System (GIS) into a two-dimensional hydrodynamic water quality model using FORTRAN. TECPLOT360 software (Software Tools for Numerical Simulation with Visualization) visualized contamination transportation and diffusion. The model's relative error is less than 6%, indicating its strong stability and high reliability. The HDWSA in the Three Gorges Reservoir Area (TGRA) was used as a case study, focusing on copper (Cu) as a pollutant. By regulating the flow downstream from the Xiangjiaba Reservoir, Scheduling Group 1 and Scheduling Group 2 respectively increased the flow by 4000 m3/s and 8000 m3/s. The study analyzed the spatio-temporal variations of Cu concentration following pollution accident and flow scheduling. Under accident conditions, it took 71, 61, 49, and 56 min for the Cu concentration in the study area to decrease to below the standard value (1 mg/L) during dry, falling, flood, and storage periods. Scheduling Groups 1 and 2 reduced the pollutant exceedance duration by 19–26 min and 12–18 min across the four water periods.

A protective foliar complex boosts sugarcane quality and energy yield by reducing oxidative stress under drought

AbstractWater stress negatively impacts plant morphology and physiology by inducing metabolic oxidative stress, which leads to cellular damage. Applying nutrients and/or organic molecules, such as amino acids, may mitigate the effects of drought stress. In the present study, the effects of a protective foliar complex (PFC) on late‐harvest sugarcane (Saccharum spp L.) (dry season) were evaluated. Four field experiments were carried out in commercial areas of sugarcane production in the central‐south region of Brazil using sugarcane variety CTC4: in the fourth and second ratoons in 2019 and in the fifth and third ratoons in 2020. The treatments consisted of foliar application or no application of the PFC at the beginning of the dry period in June. The PFC was applied at a dose of 10 L ha−1 in a water volume of 100 L ha−1. PFC application increased the activities of antioxidant enzymes (superoxide dismutase, peroxidase, and catalase) in sugarcane leaves. PFC application also reduced leaf levels of malondialdehyde and hydrogen peroxide (H2O2). On average, PFC application increased sucrose accumulation by 2.26 and 1.74 Mg ha−1 in 2019 and 2020, respectively, indicating improved raw material quality. In addition, PFC application mitigated damage caused by drought, with average increases in stalk productivity of 10.7 and 7.6 Mg ha−1 in 2019 and 2020, respectively. The positive effects of PFC application on plant antioxidant enzymes enabled greater biomass accumulation and, in turn, higher energy cogeneration.