Split-plot Research Articles

Impact of Scion Length and Cover Type on the Success of Durian Grafting

Grafting has become a technique with high potential for increasing the efficiency of modern and intelligent crop cultivation, and shows its adoption of power and robustness under different inspection situations. This study aims to determine impact of interaction between scions length and cover type on the success of durian grafting. It was carried out using a Split Plot Design method, with the main plot being the cover type composed of individual and mass of cover type, while the subplot consists of 10 and 20 cm scions length. The observed variable were time of bud emergence, percentage of bud emergence, bud length, leaves of number and grafting of success. The data were analyzed by Analysis of Variance (ANOVA). If there are significantly different treatments then proceed with the Least Significant Difference test at 5% level. The results showed that the interaction between scions of length and cover type treatment did not affect grafting technique. However, the treatment of cover type affected the percentage of bud emergence, bud length, leaves of number, and grafting success. The treatment of scions of length also affected the leaves of number. The mass cover type resulted in 93.5% bud emergence, 1.5 cm bud length, 2.73 increase in the leaves of number, and 93% grafting success. Meanwhile, the treatment of scions of length 20 cm increased the leaves of number by 2.13 strands. Scions of length that is successfully connected to grow and form new shoots has an impact on the development of healthy stems. The cover type in this study was able to protect grafting plants from direct exposure to sunlight, maintain plant moisture, prevent pests and diseases, protect from rain so that grafting can be successful.

Variation of Some Agro-Physiological and Biochemical Parameters of Wheat (Triticum aestivum L.) Varieties in Response to Nitrogen Fertilizer Rates at Djirataoua in Southern Niger Republic

Nitrogen is the most limiting plant nutrient element of soils in Niger. Farmers apply nitrogen to increase yield of cereal crops. A survey conducted at Djirataoua in southern Niger, revealed that wheat growers applied nitrogen fertilizer with less technical knowledge resulting in low response on growth and yield. To produce suitable recommendations to farmers, a field experiment was conducted during two dry seasons (2016/2017 and 2017/2018) at Djirataoua (13°25’59’’N, 7°8’12’’E). The aim of the study was to determine the optimum level of Nitrogen for highest yield and agro-physiological parameters of wheat varieties. Four Nitrogen levels (0, 100, 150 and 200 kg N ha-1) and four wheat varieties were evaluated in this study. The experiment was laid out in a split plot design with three replications. Data collected on grain yield, chlorophyll, Nitrogen uptake and protein content were subjected to the analysis of variance and mean comparison. The results showed that application of 150 kg N ha-1 Nitrogen resulted in highest grain yield (3202 kg ha-1), chlorophyll content (50.9 SPAD) N uptake (72.63 kg ha-1), and protein content (135.5 g kg-1). The wheat varieties were significantly different in these parameters. Reyna-28 and Sokoll/3/ produced higher grain yield and Nitrogen uptake. Higher protein content was observed in Norman and Sokoll/3/. Significant interactions were observed between Nitrogen rates and variety on yield characters, Nitrogen uptake and protein content. The highest grain yield, Nitrogen uptake and chlorophyll content were achieved by interaction of Reyna-28 and Sokoll/3/ with 150 kg N ha-1. Therefore, application of 150 kg N ha-1 and using varieties Reyna-28 or Sokoll/3/ is recommended to farmers for maximum grain yield and high protein content.

Micronutrient Content of Aboveground Biomass as Influenced by Different Proportions of Medicago media Pers. in Two-Component Alfalfa–Grass Mixtures

The aim of this study was to determine the effect of different proportions of hybrid alfalfa (Medicago media Pers.) in two-component mixtures with festulolium (Festulolium braunii (K. Richt.) A. Camus) and orchard grass (Dactylis glomerata L.) on the micronutrient content of aboveground biomass. The study was conducted in 2011–2013 in Poland. The experiment had a split-plot design with four replications, and the experimental variables were as follows: (i) mixtures: Dactylis glomerata (Dg) + Medicago media (Mm) and Festulolium braunii (Fb) + Medicago media (Mm), and (ii) proportion of Medicago media seeds in the mixture: 30%, 50%, and 70%. Pure-sown Dactylis glomerata and pure-sown Festulolium braunii were the control treatments. The proportion of hybrid alfalfa in the biomass yield of mixtures increased throughout the study, and this species was the dominant component of the sward already in the second year, regardless of the proportion of sown seeds. Orchard grass exerted greater competitive pressure on alfalfa than festulolium. Pure-sown Dactylis glomerata accumulated more manganese (Mn) and iron (Fe) than pure-sown Festulolium braunii; no significant differences in the copper (Cu) and zinc (Zn) content of aboveground biomass were found between species. The aboveground biomass of mixtures was characterized by higher Cu content and lower Mn content than the biomass of grass monocultures. As a component of mixtures, alfalfa had a negative influence on the Fe content of aboveground biomass (dry matter basis). No significant differences in Cu and Mn content were observed between the mixtures. The Fb50% + Mm50% mixture had the highest Zn content, and the Fb70% + Mm30% mixture had the highest Fe content. The present findings suggest that practical two-component alfalfa–grass mixtures should be composed based on species competitiveness and selection of a grass component adapted to local agroecological conditions, rather than on the proportion of alfalfa seeds in the mixture.

Energy efficient weed control in high density planting rainfed cotton

An experiment utilizing a split-plot design was done to ascertain the optimal plant population and weed management strategies for enhancing yield, net income, and energy efficiency in high-density rainfed cotton cultivation. The primary plot treatments comprised three spacing configurations: 100x10 cm, 150x50x10 cm, and 175x50x10 cm. Six weed management approaches were evaluated as subplot treatments, with each treatment replicated three times throughout the 2023-24 rabi season. These practices included power weeding on 20 and 45 days after sowing (DAS), intercropping with black gram, hand weeding on 20 and 45 DAS, herbicide application of Metolachlor (pre-emergence) on 5 DAS, and a combination of Pyrithiobac sodium plus Quizalofop ethyl (post-emergence) on 20 DAS, along with weedy check and weed-free check. The 100 x 10 cm spacing combined with power weeding proved superior, achieving higher yield parameters, greater yield, increased income (Rs. 67238/ha), a benefit-cost ratio of 2.27, energy productivity of 0.38 Kg/MJ, net energy productivity of 30334 MJ/ha, and an energy use efficiency of 4.0 in high-density planting. The narrow-row spacing (100x10 cm) with power weeding also optimized plant population and enhanced per-plant productivity. This configuration also supported proper soil tilling and aeration, enabling a higher uptake of inputs with minimum energy expenditure for weeding, leading to improved overall performance.

Comparative Assessment of the Effect of Three Plant Spacing on the Performance of Maize (Zea mays L.) Varieties in the Humid Tropics of Port Harcourt, Rivers State, Nigeria

Experiments were conducted in the late (dry) season and early (wet) season to determine the comparative growth response of maize varieties using various plant densities (spacings) at the Rivers State University Teaching and Research Farm Port Harcourt. The treatments consisted of four maize varieties (Bendel white, Oba super 6, Oba super 98 and Provit A) and three plant densities/spacings (60cm x 15cm, 60cm x 30cm, 60cm x 45cm). Treatments were combined in a split plot arrangement with maize varieties fitted in a Randomized Complete Block Design (RCBD) replicated three times. Parameters evaluated were plant height, leaf area, and number of leaves at 4, 6, and 8 weeks after planting (WAP). Insect infestation and stem girth were determined 8 weeks after planting. Results show that Provit A produced highest performance (P<0.05) in early (wet) season cropping in terms of plant height (70.2cm), number of leaves (9.3), leaf area (304.9cm). Bendel white was high in stem girth (7.8cm). Comparing growth in late (dry) season and early (wet) season showed that growth was better in the early (wet) season cropping. However, there was more insect infestation in the late (dry) season cropping than in the early (wet) season cropping. Oba super 6 had the highest incidence of insect pest infestation in late (dry) season cropping with a mean of 7.3%. Also spacing of 60cm x 30cm produced highest growth performance. Thus, Provit A variety is recommended for cultivation by farmers in Port Harcourt agroecological zone. Spacing of 60cm x 30cm is recommended for maize production in Port Harcourt agroecological zone.

Evaluating Trichoderma-containing Biofungicide and Grafting for Productivity and Plant Health of Triploid Seedless Watermelon in California’s Commercial Production

Two field experiments were carried out in 2022 and 2023 within commercial watermelon fields in Stockton and Modesto, CA, USA. Two Trichoderma-containing products were applied to the grafted and nongrafted watermelon seedlings through tray soaking or field chemigation. All seedlings were mechanically transplanted into a split-split plot design with the Trichoderma product as the main factor and application method (tray soaking and chemigation) as the sub-plot. The sub-sub-factor included three interspecific hybrid squash rootstocks (Cucurbita maxima × Cucurbita moschata) ‘Cobalt’, ‘Flexifort’, and ‘RS841’ that were grafted with the commercial seedless watermelon scion ‘Summer Breeze’. All treatments were replicated four times. Vine health was visually assessed three times, and canopy coverage was assessed for a total of six measurements for each year. Harvest was conducted three times in 2022 and twice in 2023 to analyze yield and quality differences among treatments. Aboveground and root samples from defective plants were taken amid the harvest and shipped to the University of California, Davis Fungal Pathology Diagnostics Research Laboratory for identification of soilborne fungal pathogens to confirm or rule out their involvement in vine declines initially attributed to nonpathogenic factors. The laboratory diagnosis indicated that Macrophomina was morphologically identified from the foot and root isolations of 67% of the submitted nongrafted, non-Trichoderma-biofungicide–treated plants in 2022. Further sequencing results confirmed the primary pathogen, Macrophomina phaseolina, from 50% of those submitted plant samples. In addition, putative Fusarium root and stem rot (Fusarium oxysporum f. sp. radices-cucurmerinum) and Falciforme crown rot and decline (Fusarium noneumartii) from runners and roots of nongrafted, noninoculated plants in the 2022 experiment were also reported. However, no significant soilborne fungal pathogens were found in the 2023 experiment. In both trials, the effects of Trichoderma-containing biofungicides and their application methods on preventing vine decline, maintaining canopy coverage, and enhancing fruit yield and quality were not as remarkable as grafting. The average grafting effect contributed to 83% and 53% decrease of vine decline compared with the nongrafted plants in 2022 and 2023. Overall, grafted plants yielded 47.6% and 32.4% more than the nongrafted counterpart in 2022 and 2023, respectively. In addition, grafting exerted predominant influence on fruit firmness and rind thickness. The study results indicated that grafting onto multipathogen resistance watermelon rootstocks serves as an effective production tool to maintain fruit yield, quality, and plant health under both pathogenic and disease-free conditions. Further work is still needed to continue evaluating best practical application protocols of Trichoderma-based biofungicides and other biopesticides to enhance product effectiveness and end users’ confidence in reducing soilborne diseases and reliance on conventional fumigants.

Exogenous melatonin improves peanut field productivity and quality at reduced nitrogen application

ContextNitrogen (N) plays integral roles in plant growth and yield. Finding ways to increase plant yield with reduced N usage will promote both agricultural and environmental sustainability. Melatonin acts as a multifunctional regulatory molecule in numerous metabolic processes crucial for plant growth and development as well as response to environmental stresses. The effects of melatonin on the material accumulation and transport, source-sink dynamics, as well as its association with yield and quality formation of peanut (Arachis hypogaea L.) remain unclear, especially at different N levels. ObjectivesWe aim to investigate the response mechanism of melatonin in peanut plants subjected to reduced N application, in order to confirm the hypothesis that melatonin regulates carbon and N accumulation and transport, and coordinates source-sink relationships to increase production and improve quality. MethodsThis study examined the effects of two seed dressing treatments (with or without 0.5μM MT) and three N fertilizer levels (90, 135, and 180kg/ha) using a randomized complete block design with split plots and three biological replications over 2021 and 2022. The evaluation focused on photosynthetic physiology, enzyme activities related to carbon and N metabolism, accumulation and transport of dry matter and N, yield, and quality, while exploring the relationships among these variables. ResultsMelatonin-treated plants had more stable carbon and N metabolism than the untreated ones. This stability was linked to improved photosynthesis, sucrose production, and N assimilation, especially at the reduced N levels (90 and 135kg/ha). Across three N levels and two years of field tests, MT increased peanut dry matter by 23.49% from 455.63g/m2 to 562.66g/m2, enhanced the accumulation and mobilization of dry matter and N to grains by increasing peanut grain mass by 22.41-29.07% at different N levels. This process appears to subsequently elevate the effective pod rate, leading to an average increase in pod yield, fat and protein content by 12.63%, 7.95%, and 10.33%, respectively, over a two-year period and across three N application levels. ConclusionsPlants subjected to melatonin treatment exhibited a coordinated source-sink relationship, which is manifested in high photosynthetic capacity and a high proportion of assimilates transported to pods, thus promoting effective proportions and pod fullness to improve peanut yield and quality under reduced N application. SignificanceOur research provided insights into the response mechanism of melatonin on peanut carbon and N metabolism across various N treatments, contributing to a deeper understanding of how melatonin enhances crop yield and quality.

Growth and Yield Responses of Common bean (Phaseolus vulgaris L.) to Tree Lopping and Organic Manure under Morus-Based Agri-Silvicultural System

Sustainable land management targets climate change by mitigating greenhouse gas emissions, bolstering resilience against climate-related disasters and advocating sustainable practices. India has significantly contributed to shaping the UN Sustainable Development Agenda 2030, in which agroforestry has emerged as a critical component. The tree-based intercropping practices implemented in agroforestry reduce competitive associations between woody and non-woody components, at the same time obtaining advantage of interactions that are beneficial. The present investigation was accomplished during the year 2019-20. The research trial was structured using a split-plot design to explore the possibilities of successfully cultivating Phaseolus vulgaris as an intercrop under Morus alba. The study incorporated 4 different levels of tree lopping (T0: 0 %; T1: 25 %; T2: 50 %; T3: 75 %) and 5 dosages of manure (S0: No manure; S1; FYM, S2: Jeevamrutha 5 %; S3: Jeevamrutha 10 %; S4: RDF+FYM). The results revealed that maximum values for above and below-ground growth parameters were recorded in treatment T3 (75 % lopping intensity) and treatment S4 (RDF + FYM). The treatments S1 (FYM) and S4 also significantly influenced soil parameters. Based on this investigation, it was inference that the integration of Phaseolus vulgaris with Morus alba provides the best possibility for diversity and enhanced profitability compared to a single species, if lopping is performed scientifically and a combination of manures are applied appropriately, besides offering numerous additional environmental gains.

Effect of Sowing Date and Nitrogen Rates on Morphometric Features and Photosynthetic Performance in Sugar Beet

Sugar beet is a critical crop for global sugar production, and optimizing its growth and yield requires a thorough understanding of the effects of agronomic practices such as sowing date and nitrogen fertilization. This study was conducted in the WULS-SGGW Experimental Field in Miedniewice, Poland, during two growing seasons. The aim of the research was to determine the impact of sowing dates and nitrogen fertilization on the morphometric features and photosynthetic performance of the Lubelska sugar beet variety grown in Luvisols soil. The experiments were arranged as split-plot designs (SPDs) with four replications. The factors of the experiment were the sowing date (optimal and delayed by two weeks) and nitrogen fertilization at doses of 0, 60, and 120 kg N·ha−1. The photosynthetic activity of sugar beet plants was measured four times during the growing season using chlorophyll fluorescence (ChlF) parameters. Morphometric features were determined by collecting sugar beet plants after each chlorophyll fluorescence measurement. The obtained results demonstrate the significant effect of nitrogen doses on the morphometric parameters of aboveground biomass. Increasing nitrogen doses also differentiated chlorophyll fluorescence parameters, such as FV/F0, FV/FM, PIABS, ET0/CS0, and ET0/CSM. A two-week delay in sowing affected both the fluorescence parameters and morphometric features of sugar beet, highlighting the interaction between agronomic practices and plant physiology.

Assessing the Impact of Substrate and Shelter on Cannibalism in Blue Swimming Crab (Portunus pelagicus)

Blue swimming crab (Portunus pelagicus) is one of Indonesia’s essential fishery commodities, but overfishing has depleted its population. Aquaculture, as an alternative to produce this crab, is hampered by high levels of cannibalism. Substrates or shelters can reduce cannibalism. This study compared the effectiveness of one substrate and two types of shelter for reducing cannibalism of P. pelagicus crablets. Crablets with average carapace length of 3.6 ± 2.2 cm and average weight of 6.4 ±1.5 g.ind-1 were stocked in 24 rectangular tarpaulin tanks with 1 m2 surface and 50 cm water depth. The stocking density was 8 crablets in each tank. A split-plot experimental design was applied with four main plots and two subplots with 3 replications. The main plot consisted of A0 (without shelter), A1 (seaweed), A2 (pipes), and A3 (seaweed and pipes), and sub-plots had either no-substrate (B0) or sand-substrate (B1). Cannibalism (K), survival (S), and four water quality parameters were recorded for 42 days. The data were analyzed using an ANOVA for a split-plot design and post-hoc Tukey. The results show that the sand substrate significantly (P>0.05) reduced cannibalism and increased survival of the P. pelagicus. Treatment A0B0, without substrate or shelter, showed the highest cannibalism (54±7%) and lowest survival rates (33±7%). While treatment A1B1, with Gracillaria sp. as shelter and sand as bottom-substrate resulted in the lowest cannibalism (4±7%) and highest survival rates (88±13%).

Optimal split-plot designs under individual word length patterns

For multi-factor experiments that cannot run all the factors in a completely random order, fractional factorial split-plot (FFSP) designs are often used in practice. When some prior knowledge has shown that some factors are more likely to be significant than others, Han et al. (2023) proposed the individual word length patterns (IWLPs) of whole-plot (WP) and sub-plot (SP), denoted by the IwWLP and IsWLP respectively, in the FFSP design. In this paper, we propose a construction method for optimal FFSP designs based on these two criteria, where the key of the method is to construct generating matrices for different FFSP designs from the generating matrix of a fractional factorial design, and hence we get a class of effective FFSP designs. These designs are more applicable in many situations. The results for 16-run two-level FFSP designs are tabulated in the supplementary material for possible use by practitioners.

Stem characteristics and yield of wheat is regulated to improve planting efficiency and reduce lodging risk by fertilizer rate and irrigation stage

Optimizing fertilizer and water application and using standardized and clean production methods are important for achieving green and sustainable agricultural development. The study was conducted from 2018 to 2021, arranged in a split-plot experimental design. Three fertilization levels (main plots) and four supplementary irrigation treatments (secondary plots) were set through three consecutive years of field positioning experiments. Chemical compound fertilizer application levels were 750 kg ha−1 (F1), 600 kg ha−1 (F2), 450 kg ha−1 (F3). Irrigation levels were as follows: no irrigation during the whole growth period after emergence (W0), irrigation only at jointing stage (W1), irrigation at jointing and anthesis stage (W2), irrigation at greening, jointing and anthesis stage (W3). The results indicated that the stem length of the base increased with the increase of irrigation and water and fertilizer, especially on the base stem node. There was a significant interaction between different fertilizer and water treatments. Correlation analysis revealed a significant negative correlation between stem strength and the stem lodging index. After anthesis, the lodging index was significantly lower in the F2 treatment than that in the F1 treatment. Moreover, the contribution of dry matter accumulation to the grain before anthesis was significantly higher under the W2 treatment than that under the W3 treatment but was significantly lower than that under the W0 treatment. Furthermore, the W2 treatment exhibited significantly greater fertilizer and water effects than those under the W3 treatment, irrigation benefit increased by 10.39 kg ha−1 mm−1, whereas the F2 treatment exhibited significantly greater effects than those of the F1 treatment. In terms of yield, grain yield of F2W2 treatment was significantly higher than that of F3W1 treatment. The maximum yield of F2W2 treatment over three years was 9900.05 kg ha−1. Therefore, reducing the amount of fertilizer and adjusting the irrigation regimes can enhance wheat growth and yield and mitigate the risk of lodging in the field.

Effect of Fertilizers and Humic Acids on Soil Micro Nutrients of Foxtail Millet Crop

Humic acids is an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The ecological benefits of Humic acids are diverse and represent profitable and effective solutions for environmental problems and preservation of the environment. It can be integrated into the soils in the form of manure; it improves the physico chemical and biological properties of the soil. A field experiment was conducted at the College Farm, Agricultural College, Mahanandi, ANGRAU during kharif & rabi seasons of 2020-21 and 2021-22. The experimental soil was sandy loam in texture with a pH of 7.52, an Electrical Conductivity (EC) of 0.42 dS/m, 0.32% Organic Carbon (OC), low available nitrogen (175 kg ha-1), medium phosphorus (P) at 18.48 kg ha-1, high potassium (K) at 580 kg ha-1, and sufficient zinc (Zn) status at 0.85 ppm. The experiment was laid out in split plot design with three replications with four main plots and six sub plots total twenty four treatments. After critical observation of the study, available iron, Zinc, Copper and Manganese contents in soil revealed that there was significant difference between the subplots that received different levels of Humic acids but main plots that received different levels of inorganic fertilizers and their interaction was found to be non significant at panicle initiation and harvest stages of foxtail millet crop in two kharif seasons of 2020 and 2021. Similar results were recorded in soil Copper and Manganese contents during two kharif seasons of Foxtail millet crop. However, the similar trend was followed in succeeding bengalgram crop.

Effect of Nutrient Management and Mulching on Growth Parameters, Yield Attributes and Yield of Pearl Millet [Pennisetum glaucum (L.) R. Br. Emend Stuntz] in Western Region of India

Aim: To assessed the effect of nutrient management and mulching on growth parameters, yield attributes and yield of pearl millet. Place and Duration of Study: A field experiment was conducted during two consecutive year 2021 and 2022 at Agronomy farm, S.K.N. College of Agriculture, Jobner (Rajasthan). Study Design and Methodology: The 16 treatment combinations consist different nutrients and mulching sources with replicated four times and laid out in split plot design. Various plant growth parameters, yield attributes and yield were recorded with standard procedures. Results: Results showed that Mustard straw mulch @ 2.5 t/ha gave significantly higher growth parameters (plant height, dry matter accumulation, number of tillers per plant, number of leaves per plant and chlorophyll content), yield attributes (number of effective tillers per metre row length, ear head length, ear head diameter, weight of grains per ear and number of grains per ear) leading to increased grain yield (1930 kg/ha), stover yield (3748 kg/ha) and biological yield (5678 kg/ha) over control on pooled data basis. Results showed that Liquid Azospirillium gave significantly higher growth parameters (plant height, dry matter accumulation, number of tillers per plant, number of leaves per plant and chlorophyll content), yield attributes (number of effective tillers per metre row length, ear head length, ear head diameter, weight of grains per ear and number of grains per ear) leading to increased grain yield (1954 kg/ha), stover yield (3742 kg/ha) and biological yield (5697 kg/ha) over control on pooled data basis. Results further indicated that among nitrogen management practices 50% RDN through urea + 0.2% foliar spray of nano urea at 30 DAS proved significantly superior for growth parameters (plant height, dry matter accumulation, number of tillers per plant, number of leaves per plant and chlorophyll content), yield attributes (number of effective tillers per metre row length, ear head length, ear head diameter, weight of grains per ear, number of grains per ear and test weight) and grain yield (1919 kg/ha), stover yield (3742 kg/ha), biological yield (5661 kg/ha) over control and remained at par with treatment RDN through urea and 0.2% foliar spray of nano urea on mean pooled data basis. Among all the treatments, 50% RDN through urea + 0.2% foliar spray of nano urea at 30 DAS, Mustard straw mulch @ 2.5 t/ha and Liquid Azospirillium are fond best with respect to growth parameters, yield attributes and yield.

Impact of seed rate and time of sowing on rice fallow crops and their sustainable production system in machine-harvested rice fields

A field experiment was conducted at the Department of Agronomy, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai to study the performance of rice fallow crops in machine-harvested rice fields. The primary objective of this study was to determine the optimal seed rate and the time of sowing rice fallow crops in machine-harvested rice fields. Rice fallow crop cultivation is the most significant low-cost production system in the delta region. However, the sustainability of the system is uncertain in the context of mechanical harvesting of rice using heavy machinery. The crops selected for the experimental trial were black gram (Vigna mungo (L.) Hepper.), sesame (Sesamum indicum), and proso millet (Panicum miliaceum). The field experiment was conducted using a strip plot design. Rice fallow crops were arranged in vertical plots, while various seed rates and sowing timings were arranged in horizontal plots. The results indicated that the sowing time and seed rate significantly influenced the growth and development of rice fallow crops in machine-harvested rice fields. On the day of rice harvest, a 20% increase in seed rate (36 kg ha−1) resulted in greater grain and straw yield among the black gram treatments. The increased seed rate compensated for the damage caused by mechanical harvesting on the day of the harvest when a combine harvester was utilized, increasing the yield and sustainability of the rice fallow crops.

Impact of planting systems and nutrient management on growth and yield of maize and soybean in a maize + soybean cropping system

A field experiment was conducted during Kharif 2023 at Lovely Professional University, Punjab, using a split-plot design (SPD) with five main plot treatments and five subplot treatments, replicated three times, to evaluate the effects of intercropping and nutrient management on maize growth and productivity. The main plot treatments consisted of cropping systems: Sole maize (M1), Sole soybean (M2), Maize + Soybean (1:1, M3), Maize + Soybean (1:2, M4) and Maize + Soybean (2:3, M5). Subplot treatments included nutrient management strategies: Absolute control (S1), 100% RDF through inorganic fertilizers (S2), 70% RDF + NPK nano fertilizer spray (S3), 70% RDF + homemade NPK spray (S4) and 70% RDF + plant extract NPK spray (S5). Results indicated that monocropped maize and soybean systems outperformed intercropping in terms of growth and grain yield, with similar trends observed for stover yield. Among nutrient management practices, foliar application of plant extract NPK showed the most significant improvement, enhancing growth attributes and crop growth rate (CGR) by 14.1% in maize and 43.4% in soybean and increasing productivity by 18% in maize and 30.6% in soybean compared to the control. The interaction of maize and soybean with foliar plant extract NPK spray led to grain yield increases of 36.6% in maize and 50.7% in soybean compared to untreated controls. Furthermore, the crop equivalent yield and land equivalent ratio were maximized in the maizesoybean intercropping system at a 1:1 ratio. This study underscores the role of strategic nutrient management and intercropping in optimizing maize and soybean productivity, with foliar NPK plant extract spray showing the most promising results for enhancing growth and yield.

Effects of heat stress on global DNA methylation and blood parameters of two strains of laying hens.

This study aimed to determine the global levels of DNA methylation and alterations in hematological and electrolytic parameters of two strains of laying hens subjected to heat stress and thermal comfort in climatic chambers. The experiment was conducted in two climate chambers with 192 laying hens of two strains: Dekalb White and Dekalb Brown. After the seven-day adaptation period, each climate chamber was programmed to a thermal condition for 28 consecutive days: Comfort (THI = 73.8) and Heat Stress (THI = 85.9). Blood samples were collected weekly. At each collection, a total of three milliliters of venous blood was collected from the ulnar wing or jugular vein. The experimental design was a randomized complete block design, with a 2 × 2 factorial scheme with split plots. Blood glucose, complete blood count, pH, ionized calcium, sodium, potassium, chloride, and global DNA methylation were evaluated. Stress increased chloride levels but did not affect the other evaluated blood parameters. At 28days of the experiment, the Dekalb Brown strain showed higher levels of leukocytes and hematocrit and lower concentrations of chloride and sodium compared to the Dekalb White strain. Leukocyte levels, plasma protein, sodium, and ionized calcium remained above reference values for both strains. There were no methylation differences between temperature treatments, but a significant difference was observed between strains at 28days of the experiment. Methylation patterns were independent of the evaluated blood parameters in this study but dependent on the bird strain, suggesting that strains respond with different biological mechanisms to heat adaptation. The absence of correlation does not completely exclude a causal relationship, and further studies are needed to investigate possible physiological and biological associations of blood and how strains respond to different heat adaptive mechanisms.

Nitrogen Residual Effect of Winter Cover Crops on Maize in Uruguay: Conventional and Isotopic Evaluation

This study aimed to evaluate the nitrogen (N) residual effects of winter cover crops (CCs) on soil N availability and corn (Zea mays L.) performance over two growing seasons and at two sites in Uruguay. Both conventional and isotopic methods were used to assess the N residual effects of two legume monocultures, a legume–grass mixture, an oat monoculture, and a control without CCs. The experimental design was a randomized block with split plots, where CCs were applied to main plots and N rates (0 and 100 kg ha⁻1) to subplots. An isotopic trial with 15N was included to measure fertilizer N use efficiency (NUE). Results varied between sites: at Site 1, legume monocultures enhanced soil N availability and, along with N rate, significantly increased corn yield and N uptake. At Site 2, only the N rate affected these variables. Site 1 had a low crop 15N recovery, averaging 9.5% due to weeds and heavy rainfall, while Site 2 showed higher recovery, notably when corn succeeded lupine (35%) and mixture CCs (40%). The soil’s top layer and corn grain showed the highest 15N concentration. The study suggests that specific CC combinations tailored to site conditions may optimize corn yield and NUE.

Nitrogen fertilization allows grazing intensification without degrading soil physical quality

Increasing pasture biomass production through nitrogen fertilization enables greater stocking rate and grazing intensification in pastoral livestock production systems. However, grazing intensification can compromise the soil physical quality if stocking rates exceed the soil bearing capacity to support treading. The objective was to quantify the impact of long-term (12 years) intensified grazing of Panicum maximum Jacq. cv. IPR-86 Milênio on the physical quality of a sandy soil (Luvisol Ferric soil) under subtropical climate. The 12-year field experiment was arranged in a completely randomized split-plot design with four replicates. The approach for moving the animals in and out of the paddocks varied across harvests. In the first five harvests, the period of use and rest was fixed with each paddock being occupied for 5 days followed by 35 days of rest (i.e., 40-day grazing cycle). In the subsequent harvests, the timing for moving animals in and out of each paddock was based on pasture height, with entry set at 0.90 m and exit at 0.40 m. Grazing intensification levels (IL) consisted of different animal stocking rates, grazing cycles, and forage biomass, which varied depending on the nitrogen application doses: 0 (IL-0), 150 (IL-150), 300 (IL-300), and 450 (IL-450) kg of N ha−1 year−1. Undisturbed soil samples were taken at four depths (0–0.10, 0.10–0.20, 0.20–0.30, and 0.30–0.40 m) in two sampling positions (under plants vs. between plants) and used to measure several soil physical properties (e.g., bulk density, macroporosity, mesoporosity, microporosity, water and air storage capacity, available water, pore size distribution, and water retention curve). The impact of grazing intensification on soil physical quality was minor, occurring only between plants and at the 0–0.10 m depth, where an increase in soil bulk density and a decrease in microporosity was observed. Grazing intensification also increased the water retention capacity between plants. Regardless of the sampling position and the grazing IL, water and air storage capacity was not detrimental to plant development. Overall, the increased animal stocking rate resulting from the greater pasture biomass production due to improved nitrogen fertilization does not degrade soil physical quality.

Effect of Moisture Depletion Rate and Irrigation Water Depth on the Productivity and Water Use Efficiency of Soybean Crop (Glycine max L.) Merr. under Drip Irrigation and Fixed Sprinkler Irrigation Systems

Background: Water management and its appropriate use are priorities in arid and semi-arid areas across the globe. Methods: A field experiment was carried out at Hisar in Al-Tunkopry district, Kirkuk Governorate, during 2023 summer season. Split-split plot design was adopted to implement the experiment, using randomized complete blocks design (RCBD). The main plots included irrigation method factor (sprinkler and drip) and the moisture depletion rate was placed in the sub plots (60 and 70% of the available water) while varing irrigation depth were placed in the sub-sub plots (50, 75 and 100)% of the net irrigation depth. Result: Results of the study revealed that the water requirement of the soybean crop under the sprinkler irrigation system reached 1275.9 and 1272.9 mm season-1 at 100% of net irrigation depth and at moisture depletion rates of 60 and 70%, respectively and in drip irrigation system it reached 1170.6 and 1201 mm season-1 for an irrigation level of 100% of the net irrigation depth and at a moisture depletion rate of 60 and 70%, respectively. The yield coefficient values (0.52, 0.90, 1.01, 0.90) and (0.44, 0.85, 0.96, 0.52) at a moisture depletion of 60% for the two methods (drip and sprinkler irrigation). The highest seed yield was 4.094 Mg ha-1 for the sprinkler irrigation treatment with a moisture depletion rate of 60% and an irrigation water level of 50% of the net irrigation depth, while the lowest yield was 2.41800 Mg ha-1 for the drip irrigation treatment with a moisture depletion rate of 60 and a level of 75% of the net depth. The drip irrigation achieved the highest water use efficiency 0.607072 kg m-3, in comparison to the sprinkler irrigation 0.362063 kg m-3.