Heavy Clay Soil Research Articles

Growth and yield of eight sweet potato accessions in red yellow podsolic soil

Sweet potatoes are included in the group of tubers that have considerable potential as a source of substitution food. This is because sweet potatoes contain a number of minerals and nutrients that are no less important than rice and corn and which are quite potential as food diversification and agro-industry materials. Sweet potatoes include plants that have high diversity, judging from the leaves and tubers. Each genetic variety has its own specific character of each variety. The development of tubers will be hampered when planted on heavy clay soils and poor soil physical properties, so that it can reduce yields and the shape of the tubers is often lumpy - lumps and high fiber content.The purpose of this study is to obtain sweet potato accession that provides the best growth potential and yield on red yellow podzolic soils.The research has been carried out in the Experimental Garden of the Faculty of Agriculture, Tanjungpura University Pontianak which lasted for 3 months. This study used a Complete Randomized Design (RAL) consisting of 8 treatments with 3 repeats and 3 samples in each treatment so that 72 experimental units were obtained. There were eight sweet potato accessions, namely A1= (ARF 01 accession), A2= (ARF 02 accession), A3= (ARF 03 accession), A4= (ARF 05 accession), A5= (ARF 06 accession), A6= (ARF 08 accession), A7= (ARF 09 accession), and A8= (ARF 10 accession). The variables observed in this study were the length of the main vine, the number of branches, the fresh weight of the top of the plant, the dry weight of the plant, the number of tubers per plant, the diameter of the tubers, the length of the bulbs, the weight of the tubers per plant and the sugar content. The variables observed in this study were the length of the main vine, the number of branches, the fresh weight of the top of the plant, the dry weight of the plant, the number of tubers per plant, the diameter of the tubers, the length of the bulbs, the weight of the tubers per plant and the sugar content. The results showed that ARF-08 accession had the longest tendril length (132.44 cm), ARF-10 accession has the heaviest plant top weight (458.89 g) and heaviest plant dry weight (65.27 g), ARF-08 accession has the largest tuber diameter (43.09 mm) and heaviest tuber weight per plant (598.01 g).

Physiological, biochemical and soil microbial responses of green gram (Vigna radiata L.) to foliar nutrition of nano- fertilizers

A field experiment was conducted at Tamil Nadu Agricultural University, Coimbatore, during the summer of 2024 to determine the physiological, biochemical, and microbial responses of green gram to foliar nutrition of nano-fertilizers. The experiment was carried out in black heavy clay soil (Vertisol). Treatments included recommended doses of fertilizer (RDF) at 100%, 75%, and 50%, each combined with two rounds of foliar sprays using nano urea and nano DAP (first spray and a second spray 15 days later), along with conventional urea and DAP sprays, and a TNAU Pulse Wonder spray. Ten treatments were tested, each replicated three times in a randomized block design (RBD). Physiological (chlorophyll content), biochemical (soluble proteins, nitrate reductase activity), and microbiological (nodule number, microbial population) parameters were recorded at critical growth stages. The combination of 100% RDF with two nano DAP sprays resulted in significantly higher total chlorophyll concentration (increases of 21.4%, 10.7%), soluble protein content (increases of 30.5%, 15.7%), and nitrate reductase activity (increases of 30.1%, 14.7%), with values at par with 75% RDF + nano DAP foliar sprays twice, as well as 100% RDF + TNAU Pulse Wonder in comparison to 100% RDF with conventional DAP sprays, respectively observed after 1st spray. Notably, the 50% RDF + nano DAP significantly increased nodule number and microbial population at critical stages. Overall, the data demonstrated that 75% RDF + foliar spray of nano DAP (twice) has improved physiological and biochemical changes in green gram plants, indicating a potential saving of phosphorus fertilizers by up to 25%. Physiological responses were more pronounced with nano DAP than conventional DAP, likely due to its rapid absorption, quick assimilation and improved use efficiency.

Germination ecology, emergence dynamics, and competition in feathertop Rhodes grass (Chloris virgata Sw.): Implications for effective control strategies

Feathertop Rhodes grass (Chloris virgata Sw.) is a summer growing grass weed that is invading farming land in southern Australia, being favoured by conservation farming systems and weed management using a narrow range of herbicides. Improved understanding of the biology of this species will be important for its effective management. A series of experiments on seed germination, dormancy release and emergence pattern were conducted under laboratory, glasshouse, and field conditions at Wagga Wagga Agricultural Institute. Seed of feathertop Rhodes grass exhibited post-harvest dormancy but germinated after a 3-month after-ripening period. Soil moisture was critical for the emergence of feathertop Rhodes grass in both a sandy loam and heavy clay soil. Higher emergence levels occurred in the sandy loam, but seedling survival was higher in the heavy clay soil. Seeds buried at shallower depths had a high probability of emergence and emerged within 1–3 days, with more than 70% of seed emerging within 7 days from burial at depths of 0- and 2-cm. Seed of feathertop Rhodes grass can germinate early in spring in southern NSW but compete poorly when emerging in an established cereal crop. In a fallow situation, there can be staggered emergence of feathertop Rhodes grass, triggered by the rainfall events. Our results indicate that feathertop Rhodes grass might not be a problem in cereal cropping in southern NSW. Effective management should focus on winter and summer fallows. Strategic cultivation could be a useful control tactic for feathertop Rhodes grass management. Exposure to either paraquat or glufosinate herbicides reduced seed viability, depending on the application timing. Our study provides important information on the growth, development, and seed biology of feathertop Rhodes grass that will contribute to the development of a more effective management program for this weed in southern Australia.

Risk for nitrogen leaching after application of solid manure in autumn differs between manure types

Manure application performed in autumn requires regulation due to the risk of nitrogen (N) leaching during winter. On the other hand, application of manure in spring can pose some practical problems depending on the risk for N immobilization and the difficulty in ploughing heavy clay soils during this time of year. The risk for leaching is likely to differ between different soil texture and manure characteristics. In this study, we sought to estimate the risk for nitrogen leaching depending on the carbon/nitrogen ratio (C/N) of the manure, time for manure application, and soil type. We combined 3-year lysimeter experiments with 2-year field plot experiments and laboratory soil incubations and compared results with those from an empirical model. We compared effects of manure application on two soils (silty clay and loamy sand) and solid manures with different representing C/N ratios. In incubations, only manure with a C/N-ratio below 14 contributed with significant amounts of leachable N during the first months after application. In the lysimeter study, N leaching was unaffected by the timing of the application of the manure with C/N-ratio 18. However, regarding manure with C/N-ratio 10, N leaching was elevated with 10–15 kg N per ha after manure application in October compared to November and March on both soil types. The mineral N analyses from soil profiles in the field experiments showed a similar pattern, however, the increase was higher on the loamy sand compared to the silty clay. The ammonia emissions did not differ between manure types, but were on average 24% of applied NH4-N after application in October when air temperature was on average 12°C compared to only 3% of applied NH4-N in November and March when air temperature was on average 5°C. Similar to lysimeter results, the modelled N leaching was higher the earlier the manure application occurred in autumn. However, the model also predicted increased leaching for the manure with a high C/N-ratio, and a smaller effect on leaching on clay soil. Considering this, the model calculations overestimated the leaching effects from manure with a high C/N-ratio and underestimated the leaching effects on clay soil.

Using stem water potential derived from continuous reading sensors for irrigation scheduling: nectarine as a test case

AbstractWe investigated on-site soil and plant based sensors translated to stem water potential for nectarine orchard irrigation control on heavy clay soil. Irrigation targeted predetermined stem water potential (SWP) thresholds for each phenological stage. Sensors were compared to SWP in six trees in a drying and wetting plot where irrigation was withheld periodically, allowing SWP to reach moderate water stress. Other sensor readings were regressed on SWP for those times, and the regressions were used for irrigation scheduling. The latter kept stage I and III SWP at ~ − 0.9 MPa, and moderate water stress in stage II (SWP ~ − 1.5 MPa). Weekly adjustments were made according to the thresholds. Results showed that tensiometers could be used for stages I and III, as they were very sensitive. However, when stress was applied soil water tension exceeded tensiometer range at 30 cm depth.Soil water content sensors had slower responses than the others, so they might be difficult to use for precise irrigation in heavy soils. Dendrometers responded quickly and therefore might be more useful for management even in moderate water stress, even with their sensitivity to climatic conditions. Analysis showed to maintain SWP within ± 0.1 MPa, 2 tensiometers, 10 soil water content sensors and 7 dendrometers stations are needed. Signal-to-noise (SNR) ranks were SWP > 30 cm tensiometers > 60 cm tensiometers > dendrometers > 30 cm soil water content > 60 cm soil water content sensors for the full season. Nonetheless, in some stages tensiometer SNR was greater than that of SWP.

Effect of Tile Drain Spacing on Nitrate Losses, Heavy Clay Soil Properties and Wheat Crop Productivity in Egypt

Effect of Tile Drain Spacing on Nitrate Losses, Heavy Clay Soil Properties and Wheat Crop Productivity in Egypt

Impact of soil spatial variability on young almond trees: A case study on heavy clay soils

AbstractThe viability of modern horticulture heavily relies on adopting sustainable practices. Understanding soil spatial variability on heavy clay soils and its impact on young trees is crucial to design suitable soil and water management strategies that guarantee the sustainability of orchards. The objective of this study was to assess in an orchard with heavy clay soils of the Riverine Plain, NSW, the impact of soil spatial variability on the development of young almond (Prunus dulcis (Mill.) D. A. Webb) trees and evaluate the use of remote and proximal sensing tools for identifying threatening factors for the sustainability of the crop. Soil and aerial surveys were used to assess the soil and crop spatial variability in an 8.3‐ha irrigation block. The site was divided into five areas based on apparent electrical conductivity (ECa) measurements where soil samples were collected. Tree growth, soil, and plant water status were monitored in two contrasting areas in ECa. In the first year of study, a significant and positive correlation was found between ECa and percentage of ground canopy cover. Soil analysis and soil moisture monitoring revealed that high values of exchangeable sodium percentage, which are indicative of sodic soils prone to dispersion, and limited water infiltration were the cause of the reduced tree growth in areas with low ECa. The impact of soil spatial variability on tree growth decreased in the second growing season due to weather and water management factors that influenced soil water content. This study showcases the usefulness of remote and proximal sensing in assessing potential soil‐spatial‐related issues in newly established orchards as well as the impact soil spatial variability can have on tree development in the first years after planting.

Impact of Stress Induced by Unfavorable Soil Conditions on the Germination, Seedling Developmentand Stress Tolerance Indices of Browntop Millet (Brachiaria ramosa L.)

Background: Browntop millet, a traditionally cultivated yet underutilized millet, is abundant in iron, zincand fiber. It can thrive in diverse soils and climates, adapting well to a broad spectrum of ecological conditions. Assessing the performance of Brown top millet in various challenging soils prevalent across Tamil Nadu could provide valuable insights into its adaptability and potential for cultivation in different soil conditions. The evaluation focuses on its germination, seedling growthand stress tolerance indices in these diverse soil environments. Methods: The pot experiment was carried out in the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore during Kharif 2023 season. Six soil types were collected from different zones in Tamil Nadu and tested in a completely randomized design with four replications. Germination, seedling growth and stress tolerance indices were calculated by using standard formula. Result: Results of the investigation revealed that the treatment with sandy clay loam soils of Eastern Block 37B TNAU, Coimbatore (T1) recorded higher germination and seedling growth indices. The lowest values were recorded with the sodic soils of ADAC and RI, Trichy (T6). The higher stress tolerance indices were recorded with the heavy clay soils of Cotton Research Station (CRS), Veppanthattai, Perambalur district (T2)and acidic soils of Anaikatti, Coimbatore district (T3).

Maintaining favourable carbon balance in boreal clay soil is challenging even under no-till and crop diversification

We explored the carbon balance, including both gaseous and waterborne carbon, of a long-term experimental site in 2019 and 2020. Additionally, we assessed earthworm abundance and soil aggregation, aiming to uncover potential factors influencing the decomposition and stabilization capacity of organic carbon in the soil. The heavy clay soil site in southern Finland was under long-term cereal monocropping with conventional tillage (CT) and no-till (NT) treatments. Short-term diversification with cover crop and winter rapeseed as a break crop were applied on parts of the site, and the effects of climate, carbon input and soil conditions on the carbon balance were assessed. Net ecosystem exchange (NEE) ranged from −0.32 to 1.91 Mg CO2-C ha−1 yr−1 in CT and from 0.22 to 2.40 Mg CO2-C ha−1 yr−1 in NT. Net ecosystem carbon balance ranged from 1.49 to 3.27 Mg C ha−1 yr−1 and 1.51 to 3.67 Mg C ha−1 yr−1 in CT and NT, respectively, indicating carbon loss from soil. The differences in NEE or carbon balance between CT and NT were not statistically discernible. Earthworm abundance was higher in NT than in CT and increased vastly in the NT management after diversification of the rotation with winter rapeseed. Soil erosion measurements showed remarkably lower carbon loss (44%) for NT compared to CT, however, the role of erosion in the carbon balance was minor, ranging from 50 to 120 kg C ha−1 yr−1. The mean size of soil aggregates decreased during the study period, and soil aggregates tended to enlarge in the summer and diminish in the winter. The results highlight the difficulty of maintaining a positive carbon balance in boreal agricultural soils with limited productivity. Furthermore, future climatic conditions may worsen the situation by promoting decomposition and restricting carbon protection in soil aggregates.

Optimizing water management in young almond orchards with heavy clay soils in southeastern Australia using proximal and remote sensors

Optimizing water management in young almond orchards with heavy clay soils in southeastern Australia using proximal and remote sensors

Performance of surface, subsurface and trench‐type drainage systems in paddy fields for non‐rice farming

AbstractEffective drainage is a crucial factor in paddy fields, especially in regions with waterlogging or heavy clay soils. Identifying an effective drainage system is essential for the successful removal of excess soil water from paddy fields to prepare them for subsequent crops. This study aimed to evaluate three different drainage systems, shallow surface drainage (shallow ditch), conventional subsurface pipe drainage and trench‐type subsurface drainage (French drain), in paddy fields in terms of drainage water volume, water table depth, drainage intensity, soil moisture and cracks. Experiments were carried out in a physical model capable of simulation with a 7.5 m drain spacing. The findings indicated that trench‐type drainage was more effective in reducing soil moisture due to its higher drainage water volume compared to other systems. The time required for the topsoil to reach its lower plastic limit in the subsurface, trench‐type and shallow surface drainage systems was 14, 11 and 15 h after the depletion of excess water over the soil surface, respectively. Although shallow surface drainage represented faster depletion of excess water, trench‐type drainage eventually proved to be the most effective alternative for providing appropriate qualifications for secondary cultivation. Crack areas on the soil surface were twice as extensive in trench‐type and subsurface drainage systems as in shallow surface drainage systems, indicating their superior performance.

The organic carbon‐to‐clay ratio as an indicator of soil structure vulnerability, a metric focused on the condition of soil structure

AbstractThe soil organic carbon to clay ratio (SOC:clay) is a metric used in soil quality management. In Switzerland and the United Kingdom, for example, threshold values for SOC:clay ratios have been determined to indicate very good (>1:8) to degraded (<1:13) soil structures. A recent article in Soil Use and Management by Poeplau and Don, however, suggested that this metric is ‘strongly biased and misleading’, based on their observation that German sandy soils and heavy clay soils tend to show very high and very low SOC:clay ratios, respectively. An alternative metric was proposed based on the ratio of actual SOC to expected SOC level for a considered area. We offer a commentary on the proposal, arguing that because soil structure quality is overlooked by the approach, it fails to provide appropriate SOC levels for soil health and could lead to soils with highly depleted SOC being classified ‘good’. The SOC:clay ratio, on the other hand, does address soil structure condition, providing a structure vulnerability index, a key function independent of local soil management conditions. When soils are found to have high structure vulnerability, as indicated by the SOC:clay ratio, the cropping practices at the site should be investigated and ways to increase the SOC content considered. Structure condition threshold values may only need to be reassessed if it is shown that the average structure quality observed is not in conformity with the present thresholds, which would be expected for some soils, such as Andosols.

Assessing nitrous oxide emissions and productivity of cropping systems for biogas production using digestate and mineral fertilisation in a coastal marsh site

Significant greenhouse gas emissions during substrate cultivation reduces the potential environmental benefits of biogas production. This study investigates the productivity of different cropping systems and their environmental impact in terms of nitrous oxide (N2O) emissions under the environmental conditions of the coastal marsh regions (Northern Germany) with heavy clay soils, in a 2-year field trial (April 2009-March 2011). Treatments included four cropping systems (perennial ryegrass (Lolium perenne, PR) ley, continuous maize (Zea mays), a rotation (CR1) of spring wheat (Triticum aestivum), Italian ryegrass (Lolium multiflorum, IR) and maize, and a rotation (CR2) of maize, winter wheat and IR; two sources of N (nitrogen) fertilizers (calcium ammonium nitrate, and biogas residue (BR)), and three levels of N fertilizer applications (control, moderate, high). Nitrous oxide emissions were determined for the unfertilized and highly fertilized cropping systems comprising PR ley, CR1 and CR2. Cumulative annual N2O emissions varied across the treatments, ranging from 0.82 to 3.4 kg N2O-N ha−1 year−1. Under high N fertilizer applications, PR ley incurred higher N2O-N losses compared to other tested cropping systems, and IR cover crop caused relatively high N2O-N emissions in a short vegetation period. The study observed wide range of yield-scaled emissions (0.00–5.60 kg N2O-N (Mg DM)−1) for different crops, emphasizing the variability in N2O emissions linked to cropping systems. The N2O-N emission factors for the three cropping systems were found to be low to moderate for all treatments, ranging from 0.03% to 0.53% compared to IPCC default Tier 1 N2O-N EFs. The lower emissions in the study were associated with prolonged high soil moisture conditions (water filled pore space >70%.), indicated by its negative correlation with N2O-N fluxes. Low dry matter and N yield of PR and of the wheat-IR sequence after BR application compared to other crops indicated a low N use efficiency. The estimation of N2O-N emissions based on N surplus was not promising specifically for the coastal study site where high groundwater level and organic matter in the soils were the predominant drivers for N2O-N emissions.

Quantitative detection of the Ralstonia solanacearum species complex in soil by qPCR combined with a recombinant internal control strain

ABSTRACT The detection of soil-borne pathogens by quantitative PCR (qPCR) has been challenging due to the pronounced influence of soil type on DNA extraction and PCR reactions. In the present study, we developed a novel qPCR system and an internal sample process control (ISPC) strain, RsPC, for the detection of Ralstonia solanacearum species complex (RSSC), the pathogens causing bacterial wilt. Specific primers and TaqMan probe were designed based on analyses of 16S rRNA gene sequences from 581 Ralstonia genomes, and the RsPC was constructed by insertion of an artificial fragment, which consisted of two fragments from the kanamycin-resistant gene and the gfp gene, into the chromosome of a phylogenetically closely related strain, Ralstonia pickettii JCM 5969. The qPCR target sequences of RSSC and RsPC shared primers; however, different TaqMan probes were used to distinguish them from each other. The interaction assay between ISPC and target DNA showed no influence on sensitivity when their difference in concentration was <10 4 -fold. We tested 10 different soils with co-spiked RsPC and R. pseudosolanacearum LMG 9673 and found comparable recovery efficiencies (REs) of two strains in most samples, and the REs of LMG 9673 after correction by RsPC were closer to theoretical values. The RE of LMG 9673 improved most (2.98-fold) in a heavy clay soil. Similar results were obtained in three representative soils co-spiked with RsPC and LMG 9673 (at three concentrations), R. solanacearum NCPPB 325, and R. syzygii LLRS-1, respectively . The qPCR system and ISPC strain developed in this study could be applied for the accurate detection of RSSC in soil, and similar ISPCs can be developed in the future for other soil-borne animal and plant pathogens. IMPORTANCE DNA-based detection and quantification of soil-borne pathogens, such as the Ralstonia solanacearum species complex (RSSC), plays a vital role in risk assessment, but meanwhile, precise quantification is difficult due to the poor purity and yield of the soil DNA retrieved. The internal sample process control (ISPC) strain RsPC we developed solved this problem and significantly improved the accuracy of quantification of RSSC in different soils. ISPC-based quantitative PCR detection is a method especially suitable for the quantitative detection of microbes in complex matrices (such as soil and sludge) containing various PCR inhibitors and for those not easy to lyse (like Gram-positive bacteria, fungi, and thick-wall cells like resting spores). In addition, the use of ISPC strains removes additional workload on the preparation of high-quality template DNA and facilitates the development of high-throughput quantitative detection techniques for soil microbes.

Growth and Yield Response of Masakwa Sorghum (Sorghum bicolor (L.) Moench) Cultivars to Supplementary Irrigation in a Nigeria Sahel Savanna Vertisols

Masakwa sorghum, a post-rainy season crop is commonly grown using residual moisture without supplementary irrigation on heavy clay soils or Vertisols during cool harmattan period. Field experiments were conducted to determine response of masakwa sorghum cultivars to supplementary irrigation during 2020/2021 and 2021/2022 dry seasons in sahel savanna vertisols in Monguno Local Government Area of Borno State NE Nigeria. Four irrigation treatments applied at 0.3, 0.6, 0.9 and 1.2 liters/stand constituted the irrigation treatments, while Adja’ama and Tumbuna constituted the cultivars. The treatments were replicated three times in a Randomized Complete Block Design. Plant heights were significantly higher for 0.3, 0.6 or 0.9 liters (P<0.01) than 1.2 liters at 4 WAT, 0.6 and 0.9 liters (P<0.05) than 0.3 or 1.2 liters at 8 WAT, and 0.3 liter (P<0.01) than 0.6 or 1.2 liters at 10 WAT. Panicle length was significantly (P<0.01) greater for 0.6 and 0.9 liters, while grain yield per plant was significantly (P<0.01) greater for 0.3 liter than the other irrigation levels. Grain yield per hectare was significantly (P<0.01) greater when irrigation was applied at flower inception (0.9 liter), while the cultivar Tumbuna significantly (P<0.01) produced superior grain yield than Adja’ama. Straw yield per plant was significantly (P<0.01) greater for 1.2 liters, but harvest index was significantly (P<0.01) greater for 0.3 liter than the other treatments. The economic returns from the irrigation levels were negative as the marginal rate of returns: – N2.64, – N 0.82 and – N 0.23 for 1.2, 0.9 and 0.6 liters per stand, respectively, however, the farmer practice (0.3 liters at transplanting only) realized the net benefit of N 42,960.00 per hectare. It is apparent therefore that the flower inception is the most critical stage for moisture stress in masakwa sorghum; however, there is no economic benefit of supplementary irrigation of the sorghum cultivars after transplanting as observed from the current study.

Effects of organic carbon and clay contents on structure‐related properties of arable soils with high clay content

AbstractUnderstanding of factors governing soil structural features is necessary for managing key processes affecting crop productivity and environmental impacts of agriculture, for example, soil water balance, aeration, and root penetration. Organic matter is known to act as a major binding agent in soil aggregation and thus constitutes a central pillar in soil structure formation. However, knowledge of the structural role of organic matter or carbon (OC) in soils highly rich in clay‐sized particles (<0.002 mm) is limited. In this study, the effects of clay and OC contents on aggregate stability, water holding capacity, near‐saturated hydraulic conductivity, total porosity, and pore size distribution were assessed in cultivated fields with high clay content located in private crop production farms in southern Finland. Significant positive correlations were found between OC content and proportion of water stable aggregates and specific pore sizes from the range of 30 μm up to 1 mm diameter determined by image analysis. Porosities on a smaller size range derived from water retention measurements likewise showed a positive correlation with OC in <0.2 μm sizes. On the range of 0.2–1 μm, a negative relationship was observed, which induced a negative effect of OC on soil plant available water reserves. In line with the positive correlation between OC and larger soil pores, free water, representing the amount of water that can be drained by gravity, exhibited a positive relationship with OC suggesting that OC content can enhance aeration of soils with high clay content. Compared to OC, clay content tended to have an adverse effect on soil structural properties. Clay correlated negatively with pores larger than 30 μm, free water content, and extrapolated field saturated hydraulic conductivity. Further, our imaging results showed how saturated hydraulic conductivity was controlled by pore morphology, and there was a power law relationship between the conductivity and critical pore diameter. in agreement with the percolation theory. Overall, the structural impacts and hydrological implications of OC and clay in heavy clay soils vary by pore size ranges and their emergent practical impacts are thus not straightforward.

Morphology and Floral Biology of Twelve Water Lily Genotypes

An experiment was conducted at the east nursery of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur from July 2020 to June 2021 with a view to characterizing twelve water lily (Nymphaea nouchali) germplasm for cultivation in Bangladesh. The experiment was set up in a Randomized Complete Block Design with three replications. Rhizomes of each germplasm were planted in earthen tub of around 95 cm upper diameter and 40 cm depth was half filled with heavy clay soils. Characterization of the germplasm was then started at vegetative stage after 30 days of planting on the basis of flower color and thirty other traits. Results indicated that the number of leaves/plant at different days after planting varied significantly and counted the highest in NN 002 (26.0 at 30 DAP, 32.0 at 60 DAP and 29.7 at 90 DAP) and the lowest in NN 012 at 30 DAP (3.0) and 60 DAP (12.7); while at 90 DAP, the lowest was recorded in NN 010 (7.3). Leaf length varied from 8.2 cm (NN 007) to 31.4 cm (NN 008); while, leaf width varied from 7.5 cm (NN 007) to 28.6 cm (NN 002). The shortest time (36 days) to flowering was found in NN 008, conversely NN 011 took the maximum number of days (46) to flowering. Flower diameter ranged from 7.1 to 16.7 cm with the minimum in NN 007 and the maximum in NN 002. In NN 001, flowers were opened at night and closed in the morning; while in others, flower were opened in the early morning and closed either in the afternoon or in the evening. The duration of flowering in the genotypes ranged from 3-4 days. The genotypes NN 007 produced the maximum suckers per plant (13.3); and NN 003, NN 005, NN 008 and NN 009 did not produce any sucker. Flowers with shorter stalk from the base (< 30 cm) in NN 006, NN 007, NN 010, NN 011 and NN 012 can be used for producing flowers in small tub or urn. The genotypes NN 001, NN 002, NN 003, NN 004, NN 007, NN 008, NN 009 and NN 001 produced abundant pollen and they can be used in breeding program for developing more variation through crossing. All the genotypes should be maintained for further evaluation and next year use. Ann. Bangladesh Agric. (2022) 26 (2) : 97-111

Satureja montana L. Cultivated under Polypropylene Woven Fabric on Clay-Textured Soil in Dry Farming Conditions

During a five-year field trial established with Satureja montana L. under polypropylene woven fabric (PPWF) on clay-textured soil in dry farming conditions in South Banat, Serbia, the influence of a single basal application of compost and mineral fertilizers at different planting densities (3.6 and 5 plants m−2) on the yield was investigated. Single-dose fertilization positively influenced the yields of S. montana in both applied fertilization models. In the third production year, the dry herb yield achieved by applying organic fertilizers in dense cultivation (1016 g m−1) was comparable with that obtained in the mineral plot (961 g m−1). Furthermore, the plants were optimally supplied with N, P, and K macronutrients, with equal amounts removed by yield, in both tested fertilization plots. The use of PPWF proved beneficial to cultivated plants in terms of water-use efficiency and weed suppression. However, severe yield loss was observed in the fourth and fifth production years as a result of the extreme rainfall conditions; the excess moisture retained by PPWF applied to heavy clay soil favored the development of soil-borne pathogens. Other mulch materials should be further investigated for the production of S. montana on heavy clay soil.

ОСОБЕННОСТИ ЭКОЛОГИЧЕСКИХ ТРЕБОВАНИЙ ХЛОПЧАТНИКА К УСЛОВИЯМ ПРОИЗРАСТАНИЯ

Purpose: to determine the features of the ecological requirements of cotton to growth conditions. Discussion. To expand the area of cotton growing in Russia, it is necessary to solve the problems of acclimatization and zoning of cotton, since this crop has its own specific agro-requirements for growth conditions. The main factors influencing the development and productivity of a crop are temperature, moisture, light, soil, nutrient regime, and terrain. It has been determined that the minimum soil temperature at which cotton seeds germinate is 10–12 °C, the optimum air temperature for plant development is approximately 25–30 °C, but not higher than 36 °C, since cotton is depressed. It is drought tolerant but requires irrigation to increase yield. Cotton needs evenly diffused sunlight. The light regime is regulated by the seeding rate, the seeding method and the direction of rows. The best soils are loamy; heavy clay soils are suitable, but costly to improve water-physical properties; soils with a close occurrence of groundwater are of little use. Saline soils are suitable for chloride-sulfate salinization with a salt content of no more than 0.4 %, and for sodium sulfate – no more than 0.8 %. The content of exchangeable sodium in soil should not exceed 5 % of the total soil absorption complex. To form 1 ton of raw cotton, 50–60 kg of nitrogen, 10–15 kg of phosphorus, 50–60 kg of potassium and 50 kg of calcium are required. The flat surface is the most favorable for cotton cultivation. Conclusions. Knowledge of the ecological requirements for cotton will make it possible to assess the feasibility of cultivating this crop in a particular area.

Evaluation of Current Farm Machinery Selection Practices of Wonji Shoa Sugar Factory

The Government of Ethiopia is trying to improve sugar industry sector by establishing new factories, expansion projects and rehabilitation of existing ones. The main input in this process is agricultural mechanization; however it has been resulted in a huge number of farm machinery of various types and sizes, without consideration of proper selection and matching between tractors and their attachments (implements). This approach had led to high cost of agricultural operation, resulted in an unbalanced distribution of machinery and the agricultural operations throughout the years. Wonji Shoa Sugar factory is one of the victims of the aforementioned problem. The present study was conducted to evaluate the current farm machinery selection practices of Wonji Shoa Sugar Factory. Three soil types namely; heavy clay, vertisol and sandy loam were selected with four field activities (subsoiling, ploughing, harrowing and furrowing). For subsoiling, ploughing and harrowing, 9410-R John Deer tractor with implements of 5 shank and 3.2 m wide mounted subsoiler, 2.8 m wide double gang offset disc plough, and 3.5 m wide semi mounted four gangs double offset were used respectively. For furrowing YTO-1804 tractor and a four bottom fully mounted 4.5 m wide rider was used. For each experiment, the draft force requirement of the implements, the drawbar power, fuel consumption, overall energy efficiency and power utilization ratio were determined at different tractor travel speeds. Subsoiling, ploughing and harrowing were activities were evaluated at the travel speed of w 3, 4, 5 and 6 km/hr. And a travel speed of 4, 5, 6 and 7 km/hr were used for furrowing operation. Linear regression tests were run to examine the interactions between the factors and determine their significant impact. The results of this study noted for furrowing operation as lowest draft force, drawbar power, fuel consumption and energy efficiency of 14 kN, 12.65kW, 13 lit/hr and 8.7 % respectively in sandy loam soil type. The maximum Draft force of 79.8 kW and drawbar power of 131 kW was noted for subsoiling operation in Heavy clay soil. Moreover the results of all operation in all soil type, as indicated by both overall energy efficiency and power utilization factor shows the mismatch between the tractor and implements, as the tractors were overpowered. That means a less amount of the available power from the tractor is being used to operate the implement. If the tractor had been matched with a bigger and compatible implement a better efficiency and higher productivity of the tractor implement combination could have been achieved.