Early Growth Period Research Articles

Dynamic Modeling of Soil Water Dynamics and Nitrogen Species Transport with Multi-Crop Rotations Under Variable-Saturated Conditions

Excessive application of nitrogen (N) fertilizers in agriculture poses significant environmental risks, notably nitrate leaching into groundwater. This study evaluates soil water dynamics and the transport of urea, ammonium, and nitrate under variable-saturated conditions in a long-term experimental field in Croatia, Europe. Utilizing HYDRUS-1D and HYDRUS-2D models, we simulated water flow and nitrogen transformation and transport across six lysimeter-monitored locations over four years (2019–2023), incorporating diverse crop rotations and N addition. Key modeled processes included nitrification, urea hydrolysis, and nitrate leaching, integrating field-measured parameters and climatic conditions. The models achieved high reliability, with R2 values for water flow ranging from 0.58 to 0.97 and for nitrate transport from 0.13 to 0.97; however, some cases reported lower reliability. Results revealed that nitrate leaching was influenced by precipitation patterns, soil moisture, crop growth stages, and fertilization timing. Peak nitrate losses were observed during early crop growth and post-harvest periods when elevated soil moisture and reduced plant uptake coincided. The findings highlight the importance of optimizing nitrogen application strategies to balance crop productivity and environmental protection. This research demonstrates the effectiveness of numerical modeling as a tool for sustainable nitrogen management and groundwater quality preservation in agricultural systems. It also indicates the need for further development by capturing some of the processes such as identification in the N cycle.

Supplementation of Parachlorella sp. in feed promote the gut microbiome colonization and fecal IgA response of broiler in both early and late period

This study evaluated the effects of Parachlorella sp. KSN1 (PA) supplementation on the gut microbiota and intestinal immunity of broilers of different ages. A total of 180 Ross 308 broiler chicks were weighed and divided into early (1 to 10 days post hatch) and late (11 to 28 days post hatch) periods, with six replicates of 10 chicks per cage assigned to two dietary groups. The experimental diets included a corn-soybean meal-based control diet and a treatment diet supplemented with 0.5% PA, replacing corn or corn starch, and fed ad libitum for the assigned experimental period. On days 10 and 28, two broilers from each of the six replicate cages, with 7 broilers per cage in each group, were selected and euthanized, and cecal feces and intestinal tissue samples were collected. PA supplementation did not significantly affect broilers growth performance during both the early and the late periods. However, PA supplementation altered the cecal microbiome, with Clostridiaceae and Clostridium exhibiting prominent and consistent changes. In terms of intestinal immunity, PA supplementation significantly increased the number of CD3+ and CD4+ T cells when administered only during the early period. Cecal IgA levels were significantly increased by PA supplementation during both the early and late periods. A significant positive correlation was observed between IgA, Clostridiaceae and Clostridium during the early and late periods. Gene expression analysis identified 40 upregulated genes, including polymeric immunoglobulin receptor (pIgR), and 142 downregulated genes, including marginal zone B and B1 cell specific protein and immunoglobulin lambda-like polypeptide 1 that were associated with the IgA response in PA-treated broilers during the early period. This study demonstrated that PA supplementation promotes gut microbial colonization and intestinal immunity development during the early age of broilers. These findings suggest that the early growth period of broilers is the optimal time for dietary immunomodulation to promote gut health in broilers.

Effects of maize residue and biochar applications on soil δ13C and organic carbon sources in a subtropical paddy rice ecosystem

AbstractThis study investigates the utility of plant δ¹3C natural labeling in predicting the impacts of environmental shifts on carbon cycling within ecosystems, particularly focusing on paddy fields treated with maize (Zea mays L.) residues and biochar. Specifically, it examines how soil δ¹3C and the sources of soil organic carbon (SOC), respond in paddy fields (which cultivate C3 plants like rice) when amended with maize residues, maize biochar, and silica‐enriched biochar (derived from C4 plants). Conducted in the Fuzhou paddy fields, the experiment included control groups and treatment groups with maize residue (4 t ha⁻¹), maize biochar (4 t ha⁻¹), and silicon‐modified maize biochar (4 t ha⁻¹) during both the early and late rice growth periods. The results indicate that all soil treatments increased soil δ¹3C. The application of maize residues notably affected the δ¹3C of the upper soil profile (0–15 cm) differently from the deeper layers (15–30 cm), and it increased soil organic C more than biochar or silicon‐modified maize biochar. Soil available P (AP) and pH emerged as significant factors linking δ¹3C, influencing rice yield through changes in soil physicochemical properties. Unlike maize residues, which reduced rice yields, applications of biochar and silicon‐modified maize biochar increased rice yields. The latter, which was particularly effective in lowering SOC decomposition rates and addressing rice's silica needs, emerged as the preferred option. The study highlights maize biochar and silicon‐modified maize biochar as sustainable alternatives to maize residues for rice cultivation, enhancing soil fertility, carbon pool stability, and yields.

Rice Growth and Leaf Physiology in Response to Four Levels of Continuous Drought Stress in Southern China

Exploring the growth and physiological response mechanisms of rice under continuous drought stress circumstances can provide a significant scientific foundation and technological assistance for meeting drought difficulties, improving drought resistance and rice (Oryza sativa L.) output, and ensuring food security. In this study, a rice field experiment was conducted under a rain shelter with five different treatments set up: P1 (drought stress from tillering stage), P2 (drought stress from jointing–booting stage), P3 (drought stress from heading–flowering stage), P4 (drought stress from grain filling stage), and CK (adequate water management throughout the growth stage). Continuous drought stress from different growth stages with four levels (mild, medium, moderate, and severe). The results showed that the effects of different drought stress treatments on rice growth varied significantly. Compared with the CK treatment, plant height was reduced by 12.10%, 8.14%, 3.83%, and 1.06% in the P1, P2, P3, and P4 treatments, respectively, and the number of tillers was reduced by 23.83%, 18.91%, 13.47%, and 8.68%, respectively. With the increase in drought stress levels, SPAD values and Rubisco activity of rice leaf continued to decrease; SOD activity showed a decreasing trend, but the decreasing trend of POD and CAT activities was not significant, while MDA content showed an increasing trend. For yield components, continuous drought stress significantly reduced spike length of rice by an average of 3.5%, effective number of spikes by 18.9%, thousand grain weight by 3.7%, grain number per spike by 11.6%, and fruiting rate by 1.8%, respectively, compared to CK treatments during the growth period. In general, continuous drought stress during the early growth period affected the effective spike number and the grain number per spike. Continuous drought stress after the grain filling stage had the least effect on yield (17.62% of yield reduction), and water use efficiency (1.76 kg m−3) was much higher than other treatments. These researchers’ findings provide insight into how rice physiology and growth react to continuous drought stress, which is significant for agricultural operations.

Analysis of Carbon Flux Characteristics in Saline–Alkali Soil Under Global Warming

ABSTRACTThe carbon cycle of saline–alkali ecosystems will be affected to some extent in the context of future global warming. Therefore, we investigated the net ecosystem exchange (NEE) of three typical crops (wheat, maize and soybean) in the saline–alkaline land of the Yellow River Delta. To further investigate CO2 fluxes, NEE was decomposed into gross primary productivity (GPP) and ecosystem respiration (Re). In terms of seasonal variation, wheat and soybean were carbon sources in the early and late growth periods, and carbon sinks in the rest of the period, whereas maize was a carbon sink in the majority of the period, and maize had good carbon sink potential. The cumulative NEE during the growth periods for wheat, maize, and soybean were 414.86, 258.24 and 228.92 g cm−2, respectively, and the daily variation showed that the peak NEE values for the three crops preceded the peak values of both GPP and ecosystem respiration, occurring approximately at 12:00 a.m. In the correlation analysis, NEE and GPP of the three crops were well correlated with photosynthetic photon flux density and net radiation, whereas Re was significantly correlated with air temperature. Through a comparative analysis of CO2 fluxes within various agricultural ecosystems, our findings indicated that wheat demonstrated moderate carbon sequestration capabilities, whereas maize and soybean exhibited strong carbon sink characteristics. Notably, saline–alkali crops exhibited lower Re, whereas GPP levels remained at a moderate range. Therefore, under the global warming trend, the respiration of saline crops and soils will be affected and may change the original carbon sink into a carbon source. Hence, implementing suitable measures targeting saline–alkali areas, such as the establishment of an effective crop rotation system and the enhance saline–alkali land conditions, can reduce emissions of greenhouse gases, thus reducing the pressure of global warming and maintaining a stable carbon cycle in saline–alkali land.

Dynamic variations in profile of intra- and extracellular paralytic shellfish toxins during the growth cycle of Alexandrium species and their accumulation in mussels

The toxigenic Alexandrium species can secrete paralytic shellfish toxins (PSTs) into seawater during their growth, potentially threatening marine organisms and human health. The release of intracellular toxins during the growth cycle of Alexandrium spp. and the uptake of dissolved PSTs by shellfish are still not clear. Three strains of A. minutum GY-H46, A. minutum ATDH and A. pacificum ATHK were used to explore the dynamic variations in profile of intra- and extracellular toxins during their growth cycles. And a comparative study was carried out on the accumulation and tissue distribution of PSTs in mussels Mytilus unguiculatus exposed to the dissolved and particulate toxins during a 5-days period. Results showed that the toxin cell quotas increased rapidly during the early exponential growth period, then decreased gradually and plateaued at the stationary growth period for ATHK and ATDH, while gradually increased during the stationary growth period for GY-H46. The toxin cell quotas for GY-H46, ATDH and ATHK ranged from 8.3 to 21.5, 5.3 to 11.7 and 7.4 to 9.3 fmol cell−1, respectively, during the whole growth cycle. The contents of extracellular toxins increased gradually throughout the growth of GY-H46, ATDH and ATHK, and the molar mass percentage of extracellular toxins ranged from 53% to 72%, 20% to 46% and 36% to 68%, respectively. Mussels can actively uptake the dissolved PSTs from seawater medium, and mainly accumulate toxins in the digestive glands. The accumulation level of PSTs from the dissolved phase by mussels was about 1% of that from feeding on microalgal cells. The results of this study will contribute to a comprehensive understanding of the dynamic release of intracellular PSTs during microalgal growth and the accumulation of dissolved toxins by shellfish.

Spatio-temporal change of winter wheat yield and its quantitative responses to compound frost-dry events – An example of the Huang-Huai-Hai Plain of China from 2001 to 2020

Extreme climate events such as frost and drought have great influence on wheat growth and yield. Understanding the effects of frost, drought and compound frost-dry events on wheat growth and yield is of great significance for ensuring national food security. In this study, wheat yield prediction model (SCYMvp) was developed by combining crop growth model (CGM), satellite images and meteorological variables. Wheat yield maps in the Huang-Huai-Hai Plain (HHHP) during 2001–2020 were generated using SCYMvp model. Meanwhile, accumulative frost days (AFD), accumulative dry days (ADD) and accumulative frost-dry days (AFDD) in different growth periods of wheat were calculated, and the effects of frost and drought on wheat yield were quantified by the first difference method and linear mixed model. The results showed that wheat yield increased significantly, while the rising trend was obvious at more than half of the regions. Extreme climate events (ECEs) showed a relatively stable change trend, although the change trend was significant only in a few areas. Compared with frost and drought in the early growth period, ECEs in the middle growth period (spring ECEs) had more negative effects on wheat growth and yield. Wheat yield was negatively correlated with spring ECEs, and yield loss was between 4.6 and 49.8 kg/ha for each 1 d increase of spring ECEs. The effects of spring ECEs on wheat yield were ranked as AFDD > AFD > ADD. The negative effect of ADD on wheat yield in the late growth period was higher than that in the other periods. The negative effects of spring ECEs on yield in southern regions were higher than those in northern regions. Overall, due to the adverse effects of frost and drought on wheat yield in the middle and late growth periods, the mean annual yield loss was 6.4 %, among which spring AFD caused the greatest loss to wheat yield (3.1 %). The results have important guiding significance for formulating climate adaptation management strategies.

UAV-based modelling of vegetation recovery under extreme habitat stresses in the water level fluctuation zone of the Three Gorges Reservoir, China

Impoundment of the Three Gorges Reservoir on the upper Yangtze River has remarkably altered hydrological regime within the dammed reaches, triggering structural and functional changes of the riparian ecosystem. Up to date, how vegetation recovers in response to compound habitat stresses in the water level fluctuation zone remains inexplicitly understood. In this study, plant above-ground biomass (AGB) in a selected water level fluctuation zone was quantified to depict its spatial and temporal pattern using unmanned aerial vehicle (UAV)-derived multispectral images and screened empirical models. The contributions of multiple habitat stressors in governing vegetation recovery dynamics along the environmental gradient were further explored. Screened random forest models indicated relatively higher accuracy in AGB estimation, with R2 being 0.68, 0.79 and 0.62 during the sprouting, growth, and mature periods, respectively. AGB displayed a significant linear increasing trend along the elevational gradient during the sprouting and early growth period, while it showed an inverted U-shaped pattern during late growth and mature period. Flooding duration, magnitude and timing were found to exert greater negative effects on plant sprouting and biomass accumulation and acted as decisive factors in governing the elevation-dependent pattern of AGB. Localized spatial variations in AGB were modulated by other stressors such as sediment burial, soil erosion, soil moisture and nutrient content. Occurrence of episodic summer floods and vegetation distribution were responsible for an inverted U-shaped pattern of AGB during the late growth and mature period. Generally, AGB reached its peak in August, thereafter an obvious decline by an unprecedent dry-hot climatic event. The water level fluctuations with cumulative flooding effects exerted substantial control on AGB temporal dynamics, while climatic condition played a secondary role. Herein, further restorative efforts need to be directed to screening suitable species, maintaining favorable soil condition, and improving vegetation pattern to balance the many trade-offs.

Implementasi Kebijakan Pemerintah Desa dalam Pencegahan dan Penanggulangan Stunting di Desa Gondosuli, Solo, Jawa Tengah

Implementasi Kebijakan Pemerintah Desa dalam Pencegahan dan Penanggulangan Stunting di Desa Gondosuli, Solo, Jawa Tengah

Reaction norm for genomic prediction of plant growth: modeling drought stress response in soybean

Key messageWe proposed models to predict the effects of genomic and environmental factors on daily soybean growth and applied them to soybean growth data obtained with unmanned aerial vehicles.Advances in high-throughput phenotyping technology have made it possible to obtain time-series plant growth data in field trials, enabling genotype-by-environment interaction (G × E) modeling of plant growth. Although the reaction norm is an effective method for quantitatively evaluating G × E and has been implemented in genomic prediction models, no reaction norm models have been applied to plant growth data. Here, we propose a novel reaction norm model for plant growth using spline and random forest models, in which daily growth is explained by environmental factors one day prior. The proposed model was applied to soybean canopy area and height to evaluate the influence of drought stress levels. Changes in the canopy area and height of 198 cultivars were measured by remote sensing using unmanned aerial vehicles. Multiple drought stress levels were set as treatments, and their time-series soil moisture was measured. The models were evaluated using three cross-validation schemes. Although accuracy of the proposed models did not surpass that of single-trait genomic prediction, the results suggest that our model can capture G × E, especially the latter growth period for the random forest model. Also, significant variations in the G × E of the canopy height during the early growth period were visualized using the spline model. This result indicates the effectiveness of the proposed models on plant growth data and the possibility of revealing G × E in various growth stages in plant breeding by applying statistical or machine learning models to time-series phenotype data.

Regularities of oogenesis and spermatogenesis of commercially valuable fish species in the water bodies of the Dagestan part of the Middle Caspian Sea

Based on our own research and literature data, it was proved that the features of vacuole location, size, and variability in the periods of early and late trophoplasmic growth require the closest attention. There are also certain inconsistencies of gametogenesis between different species of fish within the family. These consist in the fact that for fish species that have a shorter spawning period (roach, pike and perch), the general specificity of the annual cycles of development of the sex glands is characterized by the absolute termination of spermatogenesis by the period of the beginning of spawning, the absence of maturation or new formation of sexual products in this process. Individuals with extended spawning (for gouster and silver carp) are characterized by such features as the presence of an additional wave of spermatogenesis, which begins and ends during the spawning period, the incomplete development of sexual products by the beginning of spawning and the continuation of the process of their maturation in individual cysts of the testes throughout the spawning period (for bream and fish), continuous spermatogenesis,which allows the use of reproductive products at any time from spring to fall of the annual cycle, and under favorable conditions — throughout the year (for carp and catfish). In the experimental aspect, the obtained results can be applied in conducting a large-scale selection of female fish, based on the size of ovulated oocytes and individual selection according to the average statistical size of the latter. In fishery plan the above mentioned is required in connection with obtaining eggs from fish with batch spawning and asynchronous development of oocytes.

Analysis of the differentially expressed genes in the combs and testes of Qingyuan partridge roosters at different developmental stages

BackgroundThe sexual maturity of chickens is an important economic trait, and the breeding of precocious and delayed puberty roosters is an important selection strategy for broilers. The comb serves as an important secondary sexual characteristic of roosters and determines their sexual precocity. Moreover, comb development is closely associated with gonad development in roosters. However, the underlying molecular mechanism regulating the sexual maturity of roosters has not yet been fully explored.ResultsIn order to identify the genes related to precocious puberty in Qingyuan partridge roosters, and based on the synchrony of testis and combs development, combined with histological observation and RNA-seq method, the developmental status and gene expression profile of combs and testis were obtained. The results showed that during the early growth and development period (77 days of age), the development of combs and testis was significant in the high comb (H) group versus the low comb (L) group (p < 0.05); however, the morphological characteristic of the comb and testicular tissues converged during the late growth and development period (112 days of age) in the H and L groups. Based on these results, RNA-sequencing analysis was performed on the comb and testis tissues of the 77 and 112 days old Qingyuan Partridge roosters with different comb height traits. GO and KEGG analysis enrichment analysis showed that the differentially expressed genes were primarily enriched in MAPK signaling, VEGF signaling, and retinol metabolism pathways. Moreover, weighted correlation network analysis and module co-expression network analysis identified WNT6, AMH, IHH, STT3A, PEX16, KPNA7, CATHL2, ROR2, PAMR1, WISP2, IL17REL, NDRG4, CYP26B1, and CRHBP as the key genes associated with the regulation of precocity and delayed puberty in Qingyuan Partridge roosters.ConclusionsIn summary, we identified the key regulatory genes of sexual precocity in roosters, which provide a theoretical basis for understanding the developmental differences between precocious and delayed puberty in roosters.

ВОЗДЕЛЫВАНИЕ СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР В УСЛОВИЯХ ПОНИЖЕННЫХ ТЕМПЕРАТУР

Humanity at the present stage of development has already faced the consequences of its economic activities, which has caused global changes in the world around it. Climate change on our planet is observed in all regions. As is known, this period is geologically anthropogenic, which is characterized by alternating glaciations. The main development and implementation of the country's food security program is the creation of a sustainable food supply. And also, the growth of livestock production in line with population growth. Corn is widely distributed in the world due to its high productivity and nutritional value, as well as its ability to adapt to different climatic zones. Corn is a crop sensitive to cold, and it has a serious delay in growth and development when exposed to sudden cold spells in the early period of growth and development. For the successful promotion of this crop to more northern regions, it is necessary to include hybrids with low thermal requirements in agricultural production. It is also equally important to create favorable conditions for plants in new regions. The purpose of the research was to build a dynamic model of corn cultivation at low temperatures due to climate change at the global level. The main area of research was to identify the possibility of normal functioning of corn in conditions of low temperatures. The first experiment (2004-2007) was aimed at a comparative study of various subspecies and varieties of corn to identify morphobiological factors of adaptation process management. In the second experiment (2012-2013), the subject of the study was the effect of various drugs, including derivatives of indolylacetic acid, and the timing of crop sowing on its productivity. Thus, the morphobiological, agrotechnical and microbiological issues of increasing the cold resistance of corn as the main food and feed crop have been studied. The influence of the studied factors on the growth processes and yield of green mass has been determined.

Investigating the Influence of Pre-Grown Copper Oxide Film on Sulfide-Induced Corrosion of Copper

Used nuclear fuel should be confined safely and permanently due to its detrimental effect on human health and the environment. The universally proposed plan for the permanent disposal of used nuclear fuels is to bury the containers containing the nuclear used fuels in a multi-barrier system known as a deep geological repository (DGR) at a depth 500 m underground. The container is the key engineered barrier that can withstand long-term mechanical loads and the corrosive environment. The proposed container in some countries will be designed with either a cylindrical Cu shell containing a nodular cast iron insert (Sweden, Finland) or a Cu‐coated carbon steel vessel (Canada). After emplacement, the container will experience a range of conditions underground, evolving from warm, humid, and oxidizing to cool, dry, and anoxic over time.During the initial oxidizing period, the entrained oxygen, trapped in the DGR upon sealing, and the water-radiolysis will lead to the formation of an oxide/hydroxide film on the Cu container surface. Once anoxic conditions are eventually established, sulfide ions produced by the action of sulfate-reducing bacteria remote from the container will become the main potential oxidant.So far, considerable efforts have been devoted to investigating exclusively either the oxic period or the anoxic period. However, the significant gap that the current research aims to address is how the early period of oxide growth affects the later stages of the repository evolution, at which time the primary threat to the integrity of the Cu container would be sulfide ions within the groundwaters. In this series of experiments, various methods were applied to create different types of copper oxide/hydroxide layers with known compositions and unique structures, to investigate their role in the subsequent sulfide-induced corrosion of the underlying Cu under de-aerated conditions. The morphology of the surface oxide film and the nature and concentration of sulfide species will influence the possible manners in which the sulfide species could interact with the oxide film; for example: Chemical conversion of copper oxide to copper sulfideGalvanically-coupled processes between the copper oxide reduction and Cu oxidation by sulfideDirect corrosion of Cu by sulfide species arriving at the metal surface Our results have shown that regardless of the composition and nature of the oxide film, either a single-phase oxide film or a dual layer of combined copper oxides, the pre-grown oxide film on the Cu surface is partially converted to a copper sulfide film via chemical conversion and/or galvanically-coupled processes. Moreover, an unreacted remnant of the oxide layer was detected on the surface, surviving for longer than the duration of our experiments. This remnant oxide is non-protective, and permits direct corrosion of Cu by sulfide species arriving at the metal surface.Oxide films were grown either electrochemically, radiolytically, or chemically. The electrochemically-grown oxides, upon exposure to sulfide solutions, underwent quick conversion to copper sulfide (Cu2S) as shown by the corrosion potential (Ecorr) measurements and cathodic stripping voltammetry (CSV) at different immersion times. The same results were observed for the radiolytically-grown oxide with a multi-layer structure composed of Cu(I) and Cu(II) oxides. The thickness of the two mentioned oxides was on the nanometre scale.Chemically grown oxides were thicker than the electrochemically- and radiolytically-grown oxides. The results of CSVs showed that some parts of the oxide film and the sulfide film formed on top of the oxide film could not be cathodically stripped from the surface and remained in the form of a defective film, and that direct corrosion of Cu occurred, driven by sulfide species reaching the metal surface. This suggests that conversion of oxide to sulfide films is fastest when an electrochemical pathway is available, and much slower if it must depend on the chemical pathway. The regions of the oxide which were not connected electrically to the surface could only undergo chemical conversion. The results obtained from immersion of copper oxide powder in sulfide solution support the idea that the chemical conversion is not as quick as the electrochemical reaction in the presence of copper metal.

The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs.

The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species, this can affect the health of humans as well as livestock. Here, we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of Streptococcus suis, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography, and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of S. suis emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of S. suis and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of S. suis is yet to be fully realized.

Drought Priming and Subsequent Irrigation Water Regimes Enhanced Grain Yield and Water Productivity of Wheat Crop

The most important factor impacting wheat production is water stress that occurs during the reproductive growth stage. Therefore, the plant responses and water productivity as affected by drought priming were investigated during Rabi seasons 2021 and 2022. The field trials were conducted in the research field of the Department of Irrigation and Drainage, Faculty of Agricultural Engineering, Sindh Agriculture University, Tandojam. The Hamal-BNS wheat variety was subjected to differing irrigation water regime levels (40%, 50% and 60% of soil water holding capacity, SWHC) after being subjected to drought priming, irrigation water recovery (water closure period) and drought priming. There were six treatments: (1) DPP-40 (drought priming plants at 40% of SWHC), (2) DPP-50, (3) DPP-60, (4) CTP-40 (controlled treated plants at 40% of SWHC), (5) CTP-50 and (6) CTP-60. During the experiment period, soil moisture content was significantly affected by the different treatments at various growth stages of wheat. The results indicated that winter wheat pre-exposed to drought priming attained a stress imprint that improved the subsequent deficit water levels which occurred during the later plant growth stage as demonstrated by the progress of test weight, grain yield, plant level water use efficiency and irrigation water use efficiency as well as relative yield compared to CTP-50 (control treatment). Under the irrigation water regime levels during the post-anthesis period, primed wheat plants sustained grain yield and higher relative yield than wheat plants without priming due to the better irrigation water regime for drought-primed wheat plants. Similarly, primed wheat plants consumed 18.3% less irrigation water as compared to non-primed plants, which significantly increased plant level WUE and irrigation WUE and decreased dry biomass and root development of drought-primed wheat plants. Therefore, to conserve fresh water for other field crops and increase water productivity in the Sindh province, it is recommended that drought priming is used during the early growth period of wheat plants as a successful irrigation method.

Quantifying Multi-hazards and Impacts Over Different Growth Periods of Maize: A Study Based on Index Construction

AbstractOwing to the complexity and variability of global climate, the study of extreme events to ensure food security is particularly critical. The standardized precipitation requirement index (SPRI) and chilling injury index (ICi) were introduced using data from agrometeorological stations on the Songliao Plain between 1981 and 2020 to identify the spatial and temporal variability of drought, waterlogging, and low-temperature cold damage during various maize growth periods. Compound drought and low-temperature cold damage events (CDLEs) and compound waterlogging and low-temperature cold damage events (CWLEs) were then identified. To measure the intensity of compound events, the compound drought and low-temperature cold damage magnitude index (CDLMI), and compound waterlogging and low-temperature cold damage magnitude index (CWLMI) were constructed by fitting marginal distributions. Finally, the effects of extreme events of various intensities on maize output were examined. The findings demonstrate that: (1) There were significant differences in the temporal trends of the SPRI and ICi during different maize growth periods. Drought predominated in the middle growth period (MP), waterlogging predominated in the early growth period (EP) and late growth period (LP), and both drought and waterlogging tended to increase in intensity and frequency. The frequency of low-temperature cold damage showed a decreasing trend in all periods. (2) The CDLMI and CWLMI can effectively determine the intensity of CDLEs and CWLEs in the study area; these CDLEs and CWLEs had higher intensity and frequency in the late growth period. (3) Compared to single events, maize relative meteorological yield had a more significant negative correlation with the CDLMI and CWLMI.

Dispersed white roots in red beetroot influence the accuracy of root identification based on colours for intercropping studies

PurposeBeetroot is a model crop for studying root competition in intercropping systems because its red-coloured roots facilitate non-destructive visual discrimination with other root systems of intercropped plants. However, beetroot also has white roots, which could alter how root competition is interpreted. Here we investigated the quantity of white versus red roots in beetroot to quantify the effect of this phenomenon.MethodsBeetroot was mono-cropped or inter-cropped with white cabbage in a field trial. The distribution of beetroot roots was recorded to 2.5 m soil depth on three dates following the minirhizotron method. Roots in each 0.5 m soil layer were counted and categorised into groups based on colour (white roots, coloured roots, and white roots traced back to be coloured) to investigate the influence of white roots on accuracy of root registration. A pot experiment was conducted with three cultivars to verify if white roots are a general characteristic of beetroot.ResultsWhite roots in mono-cropped beetroot represented 2.5–4.8% of total roots, on average, across the rooted soil profile. However, white roots represented 6.9% and 11.6% of total roots in the deepest soil layer during August and October, respectively. White roots caused mono-cropped beetroot roots to be underestimated by 1–22% based on root colour discrimination. However, tracing white roots backwards and forwards to coloured parts of roots reduced underestimates to 0.5–15%. Intercropping did not influence the traceability of white roots compared to monocropping. The highest occurrence of white roots appeared during the early growth period and in the deepest soil layers, indicating a linkage to younger roots or higher root proliferation rates.ConclusionBeetroot represents a model crop for visual studies linking eco-physiology and root proliferation. The white roots of beetroot must be incorporated by studies of root competition in intercropping systems that use colour as a criterion.

Effects of different tillage management on the growth and yield of maize (Zea mays l.)

Effects of different tillage management on the growth and yield of maize were studied from early June to September 2017. The experiment was set up with three tillage treatments: traditional shallow moldboard plow tillage with straw removal (MT), sub-soiling/ plow tillage /sub-soiling rotation with straw mulch (ST) and no-till/sub-soiling/no-till rotation with straw retention (NT). The soil compaction of different soil layers, plant height, chlorophyll content, above-ground biomass and yield were determined through the three tillage practices. Results showed that NT and ST treatments helped to reduce soil compaction, and had a positive effect on maize root growth and development, plant height and chlorophyll content compared to the MT treatment. The chlorophyll value in early growth period under NT and ST increased by 31.8 and 24.6%, respectively, and the plant height was increased by 20.2 and 15.9% compared with MT, respectively. The size order of soil compaction was MT &gt; NT &gt; ST, and the soil compaction value was the maximum at 20 cm under MT treatment, which was 1007 kPa. Meanwhile, NT and ST also increased the plant above-ground biomass and yield of maize. Compared to MT treatment, the dry weight of plants for the NT and ST treatments significantly increased by 24.3 and 15.7%, respectively, and the grain yield significantly increased by 11.9 and 14.9%, respectively (P &lt; 0.05). NT and ST tillage treatments are effective measures to improve structure of soil, contribute to plant growth and development and thereby increase in yield. Bangladesh J. Bot. 52(2): 451-458, 2023 (June) Special

Effects of different tillage management on the growth and yield of maize (Zea mays l.)

Effects of different tillage management on the growth and yield of maize were studied from early June to September 2017. The experiment was set up with three tillage treatments: traditional shallow moldboard plow tillage with straw removal (MT), sub-soiling/ plow tillage /sub-soiling rotation with straw mulch (ST) and no-till/sub-soiling/no-till rotation with straw retention (NT). The soil compaction of different soil layers, plant height, chlorophyll content, above-ground biomass and yield were determined through the three tillage practices. Results showed that NT and ST treatments helped to reduce soil compaction, and had a positive effect on maize root growth and development, plant height and chlorophyll content compared to the MT treatment. The chlorophyll value in early growth period under NT and ST increased by 31.8 and 24.6%, respectively, and the plant height was increased by 20.2 and 15.9% compared with MT, respectively. The size order of soil compaction was MT &gt; NT &gt; ST, and the soil compaction value was the maximum at 20 cm under MT treatment, which was 1007 kPa. Meanwhile, NT and ST also increased the plant above-ground biomass and yield of maize. Compared to MT treatment, the dry weight of plants for the NT and ST treatments significantly increased by 24.3 and 15.7%, respectively, and the grain yield significantly increased by 11.9 and 14.9%, respectively (P &lt; 0.05). NT and ST tillage treatments are effective measures to improve structure of soil, contribute to plant growth and development and thereby increase in yield. Bangladesh J. Bot. 52(2): 451-458, 2023 (June) Special