Although green manure crops are widely recognized for ameliorating alkaline soils, some previous studies have focused mainly on laboratory germination screenings or single yield indicators, and field validation of the synergy between high yield and soil improvement remains comparatively limited. This study evaluated 16 species/accessions with varying salt tolerance in a typical alkaline soil (initial pH 9.01, EC 306 μS·cm−1) in Heilongjiang Province during 2024–2025, based on prior laboratory screening. The experiment was conducted at a single location with three field replicates, and the same plots were monitored across both years. Plant height, fresh/dry grass yield, and soil properties (pH, EC, organic matter, nutrients) were monitored. Glycine max (L.) Merr. and Sesbania Scop. achieved dual synergy, with two-year average fresh yields of 40,733 and 35,750 kg·ha−1, respectively, while reducing soil pH by 0.28–0.29 and electrical conductivity (EC) by 42.2–46.3%. Melilotus officinalis and Vicia villosa Roth exhibited the strongest alkali reduction (pH ↓0.29, EC ↓39.0–39.7%) with moderate yields. Sorghum sudanense showed the highest salt reduction (EC ↓49.0%). Principal component analysis classified the 16 species into four functional types, revealing preliminary ecological patterns for functional differentiation. This study proposes a “laboratory screening–field validation–functional classification” evaluation framework, which requires further validation across different regions and longer time scales for the biological amelioration of alkaline soils.
Arid sandy soils are characterized by poor water retention, low nutrient availability, and limited productivity, posing major constraints to sustainable date palm cultivation under increasing water scarcity. A three-year field experiment was conducted to evaluate the combined effects of bentonite (BN), humic substances (HS), and Bacillus polymyxa (BP) under three irrigation regimes (70, 85, and 100% of crop evapotranspiration (ETc)) on soil hydro-physical properties, nutrient uptake, and fruit quality of ‘Siwi’ date palm (Phoenix dactylifera L.). Twelve treatment combinations (3 irrigation regimes × 4 soil amendment treatments) were evaluated over three consecutive growing seasons. The integrated application of BN, HS, and BP significantly improved soil hydro-physical properties by increasing field capacity and plant-available water while reducing bulk density. These improvements were associated with enhanced leaf N, P, and K concentrations and greater accumulation of total soluble solids, total and reducing sugars, phenolic compounds, flavonoids, and β-carotene compared with the untreated control. The combined application of BN (12 kg palm−1) + HS (1 L palm−1) + BP (28 mL palm−1) produced the most favorable overall responses. Moderate deficit irrigation (85% ETc) provided the best balance between fruit quality and water conservation, maintaining superior fruit biochemical quality while reducing irrigation water use by approximately 15% compared with full irrigation. Multivariate analyses further supported these findings by revealing strong positive associations among soil water availability, nutrient status, sugars, and antioxidant-related compounds, while climatic variables were closely associated with seasonal variation in fruit biochemical characteristics. Overall, the integrated application of bentonite, humic substances, and B. polymyxa under 85% ETc irrigation represents an effective management strategy for improving soil performance, enhancing fruit nutritional quality, and increasing water-use irrigation efficiency in sandy soils under arid conditions.
Nahed M. Rashed, Khairy H. Abd-El-Rahman, D. A. Elyazid et al.· Horticulturae· 0 citations
Despite maize being a staple food crop in Kenya, its productivity remains low, mainly due to inappropriate soil fertility management. The use of balanced and adequate fertilizers, while improving other soil conditions, is a prerequisite for increasing fertilizer use efficiency and maize production. This study assessed the performance of two WonderGro soil conditioner formulations (WG3 and WG21) in combination with the commonly applied DAP fertilizer on maize yield and economic returns under different soil pH conditions.
On-farm trials were conducted during the 2023 and 2024 long rains (LR) and the 2023 short rains (SR). A total of 16 study sites located in two agroecological zones (AEZs) a medium-potential zone (western Kenya) and a high-potential zone (Rift Valley) were selected for the experiments. Each AEZ comprised eight sites equally distributed across two counties. The study evaluated fertilizer performance under suboptimal (pH < 5.5) and optimal (pH ≥ 5.5) soil pH conditions for maize production. Treatments included an absolute control (0 kg DAP ha
−1
) and four fertilizer treatments: 133 kg DAP ha
−1
, 67 kg DAP ha
−1
, 67 kg DAP + 67 kg WG3 ha
−1
, and 67 kg DAP + 67 kg WG21 ha
−1
, each replicated four times.
Maize grain yield response to WonderGro application was greatest when 67 kg DAP + 67 kg WG21 ha
−1
was applied in soils with pH < 5.5 in the medium-potential zone, where grain yield reached 4.4 t ha⁻¹ during the 2023 LR season. In contrast, fertilizer treatments showed no significant differences in yield in soils with pH ≥ 5.5 in the high-potential zone, where average maize grain yields were 7.3 t ha
−1
and 6.1 t ha
−1
during the 2023 and 2024 LR seasons, respectively. From an economic perspective, the application of 67 kg DAP + 67 kg WG21 ha
−1
produced the highest value-cost ratios (VCRs) of 7.54 and 8.24 during the 2023 and 2024 LR seasons, respectively, under suboptimal pH conditions in the high-potential zone.
These results indicate that the WonderGro formulations have the potential to partially substitute for 133 kg DAP ha
−1
without yield losses, thereby improving economic returns to farmers. The findings further suggest that the benefits of WonderGro are more pronounced under suboptimal soil pH conditions, where improvements in maize productivity and profitability can be achieved.
Dishon Ogutu, Ruth Njoroge, A. Otinga et al.· Frontiers in Agronomy· 0 citations
Sandy soils are widely distributed in Egypt and are characterized by poor physical properties and a limited capacity to retain irrigation water and nutrients, which severely constrains agricultural productivity. Addressing these limitations has become increasingly critical to ensure sustainable crop production under arid and semi-arid conditions. Therefore, this study aimed to evaluate the effectiveness of biochar as a soil amendment for improving growth performance, yield, nutrient accumulation, photosynthetic pigments, and essential oil production of Mentha spicata cultivated under sandy soil conditions over two successive seasons (2024–2025). The field experiment consisted of four treatments: untreated control, NPK at 5 g L-1, biochar at 12.5 ton ha-1, and combined NPK (5 g L-1) and biochar (12.5 ton ha-1). The results showed that biochar application, either alone or in combination with mineral fertilizer, significantly improved all vegetative growth parameters, fresh and dry herbage yields, essential oil percentage and yield, leaf macronutrient content (N, P, and K), and chlorophyll b concentration. Biochar applied alone consistently outperformed mineral fertilizer alone, while the combined biochar–NPK treatment produced the highest values for all measured traits, with improvements exceeding the additive effects of individual applications. These enhancements were closely associated with increased nutrient accumulation and improved nutrient use efficiency, reflecting the ability of biochar to retain nutrients, reduce leaching losses, and synchronize nutrient availability with plant demand. The synergistic interaction between biochar and mineral fertilization highlights the potential of biochar as a sustainable soil amendment for improving productivity, quality, and resource-use efficiency of mint grown in low-fertility sandy soils.
Y. Soliman, W. Soliman· Scientific Reports· 0 citations
This study explores the sustainable optimization of Valencia orange production in Egypt's arid regions by analyzing the dual effects of deficit irrigation and biochar soil conditioning. Multi-season field experiments demonstrated that Partial Root-zone Drying (PRD) combined with 1200 kg ha⁻¹ of biochar significantly enhances the vegetative growth, physiological traits, and final yield components of Valencia orange trees in degraded sandy soils. Severe water restriction (50% Full Irrigation [FI]) constrained canopy development and chlorophyll formation. In contrast, the PRD strategy produced superior growth responses, achieving an increased canopy volume of 4.1–4.3%, an expanded leaf area of 27.0–28.3 cm², and total chlorophyll levels up to 3.0 mg g⁻¹ F.W. The application of biochar showed a significant, dose-dependent improvement in soil water-holding capacity and nutrient retention. Under the optimal interaction treatment (PRD combined with 1200 kg ha⁻¹ biochar), the trees achieved peak agronomic performance. This synergistic combination maximized canopy volume increase to 5.5–5.8%, expanded leaf area to 37.9–40.1 cm², and elevated chlorophyll content to 3.7–4.0 mg g⁻¹ F.W. Furthermore, this treatment upgraded fruit development and quality indices; fruit weight reached 231.4–240.6 g, total yield peaked at 48.5–50 ton ha⁻¹, TSS reached 13.7–14.2%, and Vitamin C maximized at 48.8–51.3 mg 100 mL⁻¹ juice, confirming that biochar effectively mitigates drought stress. Complementing these findings, the treatments were simulated using the SALTMED model software to evaluate its predictive fidelity under local Egyptian conditions. The software demonstrated exceptional accuracy, establishing a robust correlation between field-collected data and model-generated values. This alignment was statistically validated by an outstanding coefficient of determination (R² ranging from 96% to 98%). Consequently, the study strongly recommends utilizing SALTMED for managing fruit crops in Egypt to save time, labor, and costs, while providing reliable predictive data to optimize export and import operations for vital commodities like citrus.
Unknown authors· the future of agriculture· 0 citations
Sandy soils in arid regions have low fertility, poor structural stability, and limited water‐holding capacity. This study evaluated phosphogypsum (PG) as a soil amendment for improving sandy‐soil quality and wheat productivity under arid conditions.
A field experiment was conducted during the 2020/2021 winter season in West El‐Minia, Egypt. PG was applied at 0, 10, 20, and 30 t ha
−1
by surface broadcasting or soil incorporation. Soil physical, chemical, and biological properties, wheat yield, and nutrient uptake were evaluated.
Treatment performance depended on the management objective. Soil incorporation at 30 t ha
−1
(T4M4) produced the strongest overall improvement in most soil and microbial indicators, whereas surface application at 20 t ha
−1
(T3S3) produced the highest numerical grain yield and nutrient uptake. Under T4M4, bulk density decreased from 1.61 to 1.46 g cm
−3
, field capacity increased from 16.0% to 25.16%, available water rose from 11.0% to 19.65%, soil pH declined from 8.2 to 7.8, and cation exchange capacity increased from 4.22 to 9.08 cmolc kg
−1
. Microbial biomass carbon and fluorescein diacetate hydrolysis activity increased by 327.7% and 107.6%, respectively. Grain‐yield increases ranged from 29.5% to 60.3% relative to the control.
Surface application at 20 t ha
−1
was the most effective yield‐oriented treatment, whereas incorporation at 30 t ha
−1
provided broader soil and microbial improvement. PG recommendations should therefore be selected according to the intended management objective rather than a single generalized optimum.
ABSTRACT Soil acidity is a major constraint to barley production in the Southern Highlands of Ethiopia. An on-farm experiment was conducted during the 2020 and 2021 cropping seasons on strongly acidic Nitisols (pH 4.7) to evaluate the effects of integrated application of vermicompost (VC), inorganic nitrogen (N), and lime on soil chemical properties and barley productivity. Nine treatments, comprising a control, sole and combined applications of VC and N at different proportions, and integrated treatments with lime (3 t ha−1), were arranged in a randomized complete block design with three replications. Integrated application of VC, N, and lime significantly increased soil pH, available phosphorus, soil organic carbon, and total nitrogen while reducing exchangeable acidity compared with the control and sole nutrient applications. Grain yield and yield components were also significantly improved in both cropping seasons. The combined application of 50% VC + 50% N + 3 t ha−1 lime produced the greatest improvements in soil fertility and barley yield, indicating synergistic effects of integrating organic, inorganic, and liming materials for acidic soil management. The integrated application of 100 kg urea + 100 kg NPSB + 5 t vermicompost ha⁻¹ is recommended for farmers seeking to maximize barley productivity and overall profitability because it generated the highest grain yield and net benefit. However, for resource-constrained farmers with limited capital, the sole application of 100 kg urea ha⁻¹ is a practical alternative because it produced the highest marginal rate of return, indicating greater economic efficiency per unit of additional investment. Improved soil fertility and grain yield in the second cropping season demonstrated residual benefits of the integrated treatments. Overall, integrated use of vermicompost, nitrogen fertilizer, and lime was more effective than sole nutrient applications in improving soil fertility and sustaining barley production on acidic Nitisols.
Getahun Haile, M. Lemenih, G. Agegnehu· Communications in Soil Scien...· 0 citations