Potential of Composted Macrophytes as a Sustainable Organic Fertilizer: Environmental and Agronomic Insights

Soil-specific effects of biobased fertilizers and struvite on phosphorus dynamics and wheat growth

Biobased fertilizers are increasingly considered viable alternatives to mineral phosphorus (P) fertilizers, however their agronomic performance in calcareous soils remains insufficiently documented. This study aimed to assess the effectiveness of composted organic waste (olive mill pomace, OMP; solid urban residue, SUR, and sewage sludge, SWS), applied individually or in combination with struvite (STR) to increase soil fertility, enhance plant growth and promote crop biofortification. A pot experiment was conducted using wheat as a model crop in three Mediterranean soils (Entisol, Inceptisol, and Vertisol) differing in carbonate content and P phytoavailability. All treatments supplied 50 mg P per kg of soil, including the application of diammonium phosphate (DAP), while unamended soils received no P (CON). Soil type modulated the performance of the biobased fertilizers. SUR and SWS, applied alone in the Entisol and Vertisol or combined with STR in all soils, increased plant-available soil P (74-238%) relative to CON. SWS, applied alone or with STR, achieved wheat yields comparable to those of DAP in the Entisol and Vertisol and exceeded DAP yields in the Inceptisol. The combination of SUR or SWS with STR resulted in plant P use efficiencies comparable to or higher than those obtained with DAP. SUR and SUR+STR enhanced wheat biofortification in the Inceptisol. By contrast, OMP showed limited effectiveness as a biobased fertilizer due to insufficient stabilization during the composting process, although its performance improved when combined with STR. Overall, while SUR and SWS alone or in combination with STR, can substitute mineral P fertilizers, their effectiveness depends on soil type and compost stabilization.

Agronomic, Biochemical and Metabolic Responses of Tomato to Vermicompost and Mineral Fertilization in Loam and Clay Soils

The intensive use of mineral fertilizers in horticultural systems has improved crop productivity but also increased concerns regarding soil degradation and environmental sustainability. In this context, vermicompost derived from buffalo manure may represent a sustainable alternative for nutrient management and organic waste valorization. This study evaluated the effects of four fertilization strategies on tomato (Solanum lycopersicum L.) grown in loam and clay soils: unfertilized control, mineral fertilization, vermicompost applied at an equivalent nitrogen rate, and the residual effect of vermicompost from a previous cauliflower crop. Agronomic performance, fruit quality, carbon and nitrogen metabolism, and antioxidant-related traits were assessed. Mineral fertilization produced the highest marketable yield, reaching 9.68 and 7.69 kg m−2 in loam and clay soils, respectively, mainly through increased fruit number. Direct vermicompost application maintained substantial productivity, with yields of 7.55 and 5.18 kg m−2 in the two soils. The fertilization strategies also induced distinct changes in fruit composition. Mineral fertilization increased total free amino acids to approximately 160 mg g−1 DW, mainly through the accumulation of glutamine, glutamate, asparagine and γ-aminobutyric acid, but was associated with lower soluble solids and antioxidant activity. Vermicompost promoted the highest lycopene concentration, approximately 2.1 mg g−1 DW, in clay soil and maintained intermediate antioxidant activity and amino acid concentrations. Soil texture also influenced carbohydrate partitioning, with greater fructose accumulation in clay soil and greater starch accumulation in loam soil. The residual vermicompost treatment alone did not adequately sustain tomato productivity or metabolic activity, particularly in clay soil. Overall, vermicompost partially replaced mineral fertilization while maintaining satisfactory yield and modulating fruit metabolic quality, although its effectiveness depended strongly on soil texture.

Nutrient Management Interventions for Sustainable Maize Production in Rainfed Vertisols

A field experiment was conducted at the Regional Agricultural Research Station, Nandyal, Andhra Pradesh, during the kharif season of 2025 to evaluate nutrient management interventions for sustainable maize production under rainfed Vertisols. The experiment was laid out in a Randomised Block Design with seven treatments and three replications. The initial soil was alkaline (pH 8.12), with an electrical conductivity of 0.16 dS m⁻¹, organic carbon of 0.41%, and available N, P and K contents of 184, 56.25 and 345 kg ha⁻¹, respectively. Growth, yield attributes, grain and stover yield, nutrient uptake and post-harvest soil fertility were assessed. The 100% recommended dose of fertilisers (RDF) produced the highest grain yield (6800 kg ha⁻¹), stover yield (8770 kg ha⁻¹), and N, P and K uptake (130.6, 38.05 and 127.5 kg ha⁻¹, respectively). The 75% RDF + FYM at 10 t ha⁻¹ treatment produced 6452 kg ha⁻¹ grain yield, which was statistically comparable with 100% RDF because the difference was lower than the critical difference. Post-harvest available N, P and K were highest under 100% RDF, while organic carbon was numerically higher under treatments receiving organic inputs. Under the conditions of this single-season experiment, 75% RDF + FYM at 10 t ha⁻¹ provided a promising integrated nutrient-management option for maintaining maize productivity while reducing mineral fertiliser input.

Exogenous Nutrient Bag Formulations Affect Soil Fertility and Microbial Communities in Morchella sextelata Cultivation

Simple Summary This study evaluated organic waste-based nutrient supplements for morel mushroom cultivation, focusing on yield, nutritional quality, and soil ecological responses. The wa-60 formulation increased yield by 28.6% while sustaining high amino acid levels, positioning it as a viable option for balancing productivity and fruit-body quality. Although wr-60 did not enhance yield, it substantially enriched soil bacterial diversity, indicating its potential for substrate amelioration and microecological restoration. Both treatments dynamically regulated soil organic matter, pH, macronutrients, microbial biomass, and enzyme activities, exhibiting a biphasic pattern of rapid initial changes followed by stabilization. Collectively, wa-60 emerged as a promising organic amendment strategy for morel production. Future research should incorporate field-scale trials and functional genomic approaches to clarify the causal roles of key microbial taxa in nutrient release and crop performance.

Mitigation of Fungicide-altered Soil Physicochemical Properties and Nutrient Dynamics through Organic Ameliorants in Temperate Apple Orchard Soil

Repeated fungicide application in apple orchards may influence soil physicochemical properties and nutrient cycling. This study evaluated four organic amendments—vermicompost (VC), farmyard manure (FYM), spent mushroom compost (SMC), and Trichoderma-fortified compost (CFT)—alone and in combination with captan, propanib, flusilazole and difenoconazole during a 60-day laboratory incubation of temperate apple orchard soil collected from Shalimar, Kashmir, India. Twenty-five treatments were arranged in a completely randomised design with three replications. Soil pH, electrical conductivity (EC), organic carbon (OC), and available nitrogen (N), phosphorus (P) and potassium (K) were measured at 0, 30, 45 and 60 days after treatment. At 60 days, vermicompost recorded a pH of 6.11, OC of 1.238%, available N of 484.7 kg ha⁻¹, P of 31.0 kg ha⁻¹ and K of 177.8 kg ha⁻¹, compared with 6.85, 1.000%, 449.5 kg ha⁻¹, 24.6 kg ha⁻¹ and 146.7 kg ha⁻¹, respectively, in the control. The other organic amendments also increased OC and available macronutrients over the incubation period, whereas fungicide-only treatments generally showed smaller changes. Fungicide–amendment combinations generally maintained higher nutrient and OC values than the corresponding fungicide-only treatments. Among the amendments, vermicompost produced the most pronounced numerical response in the measured soil properties. These findings support further field evaluation of organic amendments as components of integrated soil-fertility and disease-management strategies in temperate apple orchards.

Biochar and hydrochar for saline soil amelioration and rice seedling growth promotion