ABSTRACT The decomposition of senescent leaf litter in silvopastoral systems (SPSs) is regulated by biotic and abiotic factors and plays a key role in nutrient cycling and soil carbon dynamics. The litter bag method is widely used to assess litter decomposition (LD), but it requires a long incubation period and a specific nylon mesh. Therefore, alternative approaches are needed. This study compared three methodologies for assessing LD of senescent leaves of Gliricidia sepium (gliricidia) and Urochloa decumbens (signalgrass) in an SPS. For two of the methods, soil was incubated in litter bags made of nylon or non-woven textile (NWT) for 256 days. In the third method, NWT bags were ruminally incubated for 144 h. The loss of organic matter, carbon, nitrogen, and lignin was evaluated. For gliricidia, no differences in the decomposition rate (k) of organic matter, carbon, or nitrogen were observed among methods. For signalgrass, ruminal incubation resulted in a higher k. Decomposition of senescent gliricidia litter can be reliably assessed using either nylon or NWT incubation methods, while signalgrass litter is more sensitive to textile type. Ruminal incubation with NWT is a viable alternative, and incubation times beyond 144 h are recommended to better capture late-stage decomposition, especially in grasses.

ABSTRACT Composting is an effective way to recycle perishable waste (e.g. food, vegetable and fruit waste), while the effects of varying compost application rates on soil properties and bacterial communities are not well understood. Soil samples were taken from pot experiments that included an unfertilized control, a mineral NPK-only treatment and four compost-amended mineral fertilizer treatments at 0.7%, 2.1%, 3.5% and 4.9% w/w. Soil analysis included pH, electrical conductivity (EC), soil organic carbon, total nitrogen, total soluble salt, and assessment of diversity and community of soil bacteria. Results showed that perishable waste compost application enhanced soil salinity by significantly increasing soil total soluble salt content (67–174%) and EC (24–152%) compared with mineral fertilizer. Perishable waste compost addition affected soil bacterial community composition by increasing Cyanobacteria and decreasing Firmicutes relative abundance, which reflected changes in soil salinity. Soil bacterial community stability and potential biological activity, together with soil phosphorus availability and rice yield (increased by 41% and 36% compared to mineral fertilizer) were promoted under the 2.1% perishable waste compost addition, which suggested this rate was recommended for optimal productivity in paddy soil. These findings advanced our understanding of the soil salinity risk for perishable waste compost use as organic fertilizer.

ABSTRACT Fertilizer salt injury and ammonia toxicity are major constraints to seedling emergence and early plant development. This study evaluated the ecotoxicological effects of varying rates of subsurface-applied starter nitrogen (N) and potassium (K) fertilizers on maize emergence across different soil types. Fertilizer treatments included 45, 55, 65, and 75 kg N ha−1 and 74, 95, 107, and 120 kg K ha−1, with a control. Significant interactions among soil type, fertilizer source, and application rate influenced maize emergence and seedling development. Key factors such as fertilizer salinity, ammonium-N (NH4 + -N), and soil pH significantly affected seed ecotoxicology (p < 0.05). Soil-specific toxicity thresholds were established: in silt-clay soil, 75 kg N ha−1 was the critical threshold for all N sources, while in silt-loam soil, thresholds were 25 kg N ha−1 for DAP and urea, and 75 kg N ha−1 for MAP. Both silt-clay and silt-loam soils tolerated up to 105 kg K ha−1 irrespective of K source. In sandy soil, subsurface application of urea and KCl negatively impacted 90% relative seed emergence. Observed toxicity symptoms included delayed emergence and leaf chlorosis. Strong correlations between emergence and early biophysical traits indicate that this research offers practical diagnostic guidelines for managing fertilizer toxicity in maize production.

ABSTRACT Cattle manure (CM) and biochar are rich sources of plant nutrients, and serve as soil conditioners to improve soil properties, but their low solubility may slow nutrient release. The experiment aimed to evaluate the impact of CM, biochar and K fertilizer on maize growth and yield, and on soil properties. The experiment was conducted for two consecutive years. CM and biochar application along with K fertilizer significantly increased the growth and yield parameters. The highest grain yield of 3455 kg ha−1 was recorded in plots receiving CM along with K at 120 kg ha−1. Moreover, CM and biochar application with K fertilizers increased distribution of the K content, which was higher for CM than biochar. The highest K content of soil was 221 kg ha−1 when K was applied at 120 kg ha−1 with CM. Also, extractable P, total N and organic matter were significantly increased during both years. Application of CM or biochar along with K fertilizers also significantly reduced the soil sodium adsorption ratio, electrical conductivity and bulk density. Hence, K fertilization combined with organic amendments like CM or biochar may enhance maize growth and yield, compared to organic amendment alone.

ABSTRACT Soil fungi tolerate drought better than bacteria, making them vital for climate-related soil studies. This study examined the responses of the two most abundant fungal phyla in topsoil, Ascomycota and Basidiomycota, to extreme temperature and moisture conditions under controlled conditions. Two soils from the same geographic region but with contrasting land-use histories (ploughed vs. unploughed) were analysed. Initial fungal and bacterial biomass quantifications in terms of rRNA gene copy number showed that fungi were more stable than bacterial biomass under the imposed abiotic stress, highlighting their key role in soil microbial resilience. Further analysis using phylum-specific primers and digital PCR revealed that the Ascomycota phylum experienced stable growth under simulated extreme fluctuations in soil moisture. In contrast, the biomass of Basidiomycota doubled under water-stressed conditions compared to optimal field conditions. However, under flooding and abnormally hot conditions, it halved. Ascomycota, which is largely composed of spore-dispersed fungi that prevail in ploughed soils, contributes to microbial stability during extreme events. Basidiomycota, on the other hand, has an underestimated capacity to sustain microbial biomass through prolonged drought. The findings highlight the crucial role of forest and conservation-oriented land uses where Basidiomycetes thrive, in enhancing soil microbial stability as drought progressively increases.

ABSTRACT Waterlogging is a major abiotic stress limiting sesame (Sesamum indicum L.) production in low-lying areas of Bangladesh, primarily due to excessive rainfall and poor drainage. To identify tolerant genotypes and understand their physiological responses, a two-year field study (February 2023–June 2024) was conducted at the Stress Research Site, Department of Agronomy, Gazipur Agricultural University, Bangladesh. In the first experiment, 89 local and exotic sesame genotypes were evaluated under control and 3-d waterlogging imposed at 14 d after sowing (DAS). Based on the total dry matter accumulation, five tolerant genotypes (BD-7005, BD-6961, BD-6998, BD-7004, and BD-7001) were selected. In the second experiment, these genotypes were further tested under 3-d waterlogging at the flowering stage (35 DAS) and under well-watered conditions, following a randomized complete block design (RCBD) with three replications. Waterlogging stress significantly reduced stomatal conductance, transpiration, chlorophyll, and photosynthesis, while increasing intercellular CO2 concentration and malondialdehyde content. In contrast, proline and total sugar contents increased, indicating osmotic adjustment. Among the genotypes, BD-7005 exhibited superior tolerance by maintaining higher leaf water content, chlorophyll, photosynthetic efficiency, membrane stability, and seed yield. These findings suggest BD-7005 as a promising candidate for breeding waterlogging-tolerant sesame suitable for flood-prone regions of Bangladesh.

ABSTRACT The semi-arid grasslands of northwestern China are characterized by fragile ecosystems, limited water resources, and significant degradation. This study investigates the effects of different land-use practices, such as fencing, grazing, and tourism, on soil preferential flow in the semi-arid grasslands of central Inner Mongolia. The preferential flow process was observed using the dye tracer method and quantitatively analyzed via image processing to determine morphological features. Results indicated that preferential flow was observed in all areas, but the extent varied significantly: fenced areas exhibited the most pronounced preferential flow at both 25 mm and 50 mm infiltration volumes. Preferential flow mainly occurred in the top 30 cm, with a decreasing ratio of dyed area at greater depths. At 25 mm infiltration, the preferential flow ratio exceeded 50% in fenced areas. Increasing the volume to 50 mm resulted in peak values for infiltration depth and stained area ratio, although the proportion of preferential flow decreased. Key factors influencing preferential flow included soil bulk density, texture, and root nutrient characteristics. This study provides essential insights for effective grassland management and water resource conservation, contributing to the governance of semi-arid ecosystems by prioritizing fencing to improve soil health.

ABSTRACT Accurate prediction of nitrogen (N) mineralization following the termination of grass-clover is essential for improving N efficiency in agricultural systems. In this study, short-term N mineralization after fall termination of grass-clover, followed by a winter rye cover crop, was evaluated over winter in comparison to intact grass-clover (control). Soil samples of a Plaggic Anthrosol were collected after fall termination and in the subsequent spring in two consecutive years (2021–2023) from a field trial with grass-clover in North-West Germany. Nitrogen mineralization was assessed through laboratory incubation experiments and modeling using rate coefficients and pedotransfer functions from the literature. Laboratory results indicated a high short-term N mineralization potential immediately after grass-clover termination in fall and in the following spring. While the potential net N release in the fall-terminated treatment decreased from fall to spring, the control treatment increased. Modeled N mineralization in fall aligned well with the fall-terminated treatment but overestimated the N release for the control. By applying the model under field conditions from fall to spring, grass-clover termination resulted in the mineralization of 61.62 kg N ha−1. This prediction of mineralizable N could be further used to assess the risk of environmentally significant N losses and to optimize N fertilization.

ABSTRACT Limited varieties along with planting position are among the major factors that limit cassava production in Ethiopia. Therefore, a field experiment was conducted in the Mela and Bodi sub-districts of Gena Bosa district in Dawro Zone during 2017 cropping seasons, to determine the response of cassava varieties to different planting positions. The treatments consisted of four varieties (Local, Variety, Kello and Awassa-04 varieties) and three planting positions (inclined at an angle of about 45°, 90° and 180°). The experiment was laid out as a randomized complete block design (RCBD) and replicated three times per treatment. Data were collected on phenology, growth, yield components and yield. The data were subjected to analysis of variance. The results indicated that interaction effects of variety and planting position significantly affected all parameters. Kello variety planted slant planting position both at Mela and Bodi sub-districts significantly improved the phenology, growth, root morphology, yield components, and root yield of cassava. The highest mean net benefit (210,544 ETB ha−1) with an acceptable marginal rate of return of 12,493% was obtained from Kello variety planted slant planting position. Thus, planting Kello variety in slant planting position is suggested for maximizing agronomic and economic returns of cassava farmers.

ABSTRACT Co-inoculation with beneficial microbiology has become important in different hydroponic crops. Cannabis sativa L. is a plant rich in products of secondary metabolism. Phenolic compounds and flavonoids act as anti-inflammatory, anti-aging, and anti-cancer agents due to their antioxidant properties. However, the interactions between microbiota and their effect on the synthesis of antioxidant compounds during the vegetative stage have not been studied in depth. Therefore, this research focus to evaluate the impact of Pseudomonas fluorescens and Trichoderma spp. on the dynamics of the nutrient environment, physiological development and the production of antioxidant compounds. Five treatments were evaluated: without inoculation; 3.33 × 104; 6.67 × 104; 1.00 × 105; 1.33 × 105 CFU L−1 of P. fluorescens and Trichoderma spp. in a divided plot design under controlled conditions. The results showed that 6.67 × 104 CFU L−1 stimulated the best development in terms of height (51.24 cm), stem diameter (9.83 mm) and aboveground biomass, as well as increased production of antioxidant compounds, specifically quercetin (353.64 mg) and gallic acid (51.25 mg) in the plant. Finally, high densities of microorganisms in the rhizosphere inhibited vegetative growth. Co-inoculation in the hydroponic system is a biotechnological alternative for the production of antioxidant metabolites.