Search Results (1,089)

The performance of lettuce, pepper, and chili pepper, and the biological soil quality, in a ground-mounted PV system under cultivation conditions typical of the Mediterranean environment of the Puglia region were evaluated. Microclimatic parameters, plant growth and yield response, soil quality assessed using the QBS-ar index, and land equivalent ratio (LER) were determined in three different cultivation areas: a cultivation area outside the photovoltaic plant but immediately adjacent to it (‘Control’); the inter-row area closest to the row of panels exposed to sunlight (‘Area close PV structure’); the inter-row area distant from the row of panels (‘Area distant PV structure’). Cumulated solar radiation, in particular during the summer growing cycles, was only slightly affected in the Area distant PV structure (1616 and 2130 MJ m⁻² for pepper and chili pepper, respectively, in the control area, in comparison to 1630 and 2044 MJ m⁻², in the Area distant PV structure), while it was strongly reduced in the Area close PV structure (883 and 1091 MJ m⁻² for pepper and chili pepper, respectively). In general, a reduction in air temperature and wind speed, as well as an increase in relative air humidity, was observed under PV conditions. On average, the evapotranspirative demand was reduced in the PV growing conditions compared to open field, with a more relevant effect in the sub-zone close to the photovoltaic structures, where cumulative ET0 was 28% and 34% lower than the Control in the pepper and chili pepper growing cycle, respectively. Lettuce growth was impaired by PV cultivation conditions, with an average reduction of 15% in plant height and 37% in marketable yield per plant, with no significant differences between the two sub-zones in the PV system. For pepper, the best growing conditions were observed in open field control compared to PV, but with differences related to the PV sub-zone. The plants grown in the Area distant PV structure were more negatively affected by the modified growing conditions, showing the lowest shoot and fruit fresh weight, the latter reduced by 51% compared to the Control; intermediate values were observed for these parameters in the Area close PV structure, with a less severe tendency to yield reduction. For chili pepper, both shoot and fruit fresh weight were lower in PV conditions, regardless of the sub-zone, with a reduction of 82% in yield per plant compared to the Control. However, despite the yield reductions, the LER was improved (1.60 and 1.40 in case of a lettuce + pepper or lettuce + chili pepper annual cropping program, respectively), highlighting a more efficient use of land, without negative or even ameliorative impacts on biological soil quality and biodiversity in terms of QBS-ar and microarthropods taxa abundance. Knowledge of the response of different crops under cultivation conditions typical of specific environments is necessary to define optimal cropping programs aimed at maximizing resource-use efficiency and land use. Full article

The APSIM (Agricultural Production Systems Simulator)-Wheat model has been widely used to simulate wheat growth, but the sensitivity characteristics of the model parameters at different soil moisture levels in arid regions are unknown. Based on 2023~2025 winter wheat field data from the Changji Experimental Site, Xinjiang, China, this study conducted a global sensitivity analysis of the APSIM-Wheat model using Morris and EFAST methods. Twenty-one selected parameters were perturbed at ±50% of their baseline values to quantify the sensitivity of the aboveground total dry matter (WAGT) and yield to parameter variations. Parameters exhibiting significant effects on yield were identified. The calibrated APSIM model performance was evaluated against field observations. The results indicated that the order of influential parameters varied slightly across different soil moisture levels. However, the WAGT output was notably sensitive to accumulated temperature from seedling to jointing stage (T1), accumulated temperature from the jointing to the flowering period (T2), accumulated temperature from grain filling to maturity (T4), and crop water demand (E1). Meanwhile, yield output showed greater sensitivity to number of grains per stem (G1), accumulated temperature from flowering to grain filling (T3), potential daily grain filling rate during the grain filling period (P1), extinction coefficient (K), T1, T2, T4, and E1. The sensitivity indices of different soil moisture levels under Morris and EFAST methods showed highly significant consistency. After optimization, the coefficient of determination (R²) was 0.877~0.974, the index of agreement (d-index) was 0.941~0.995, the root mean square error (RMSE) was 319.45~642.69 kg·ha^–1, the mean absolute error (MAE) was 314.69~473.21 kg·ha^–1, the residual standard deviation ratio (RSR) was 0.68~0.93, and the Nash–Sutcliffe efficiency (NSE) was 0.26~0.57, thereby enhancing the performance of the model. This study highlights the need for more careful calibration of these influential parameters to reduce the uncertainty associated with the model. Full article

The impact of long-term organic (ECO) versus conventional (CON) agricultural management on subsurface soil microbiota diversity and soil physicochemical properties remains unclear in Mediterranean vineyards. This study evaluated long-term ECO and CON effects in the Alt Penedès terroir (Spain), focusing on subsurface soil microbial diversity and soil characteristics. ECO increased the fungal-to-bacterial ratio and ammonium-oxidizing bacteria but reduced total subsurface soil bacterial populations and soil organic carbon. While ECO did not enhance annual yield production in the vineyard, fungal abundance, and ammonium-oxidizing archaea, it slightly increased the overall alpha diversity (Shannon and Inverse Simpson indexes) and significantly altered taxa composition in subsurface soil with a more robust and modular community. Crop management, soil texture, training system, and rootstock, but not vine variety, significantly influenced beta diversity in subsurface soil. The Mantel test revealed subsurface soil texture, Ca²⁺/Mg²⁺ ratio, and salinity as the main key soil drivers shifting the microbial community (beta diversity), while C/N and topsoil organic matter significantly correlated with bacterial abundance; NH₄⁺ correlated with fungal abundance; and N-Kjeldahl, pH, and Mg²⁺/K⁺ correlated with alpha diversity. Integrating soil microbiota and physicochemical monitoring allowed us to confirm the positive effect of long-term agroecological practices on subsurface soil health and to identify the critical factors shaping their microbial communities in Mediterranean vineyards. Full article

Agro-photovoltaics (APV) or agrivoltaic systems integrate crop cultivation with solar energy production, offering a promising solution through the dual-use of land. This two-year study (2023 and 2024) examined the effects of an APV system on rice production. The results indicated that APV arrays created spatially variable light environments, with shadow lengths following predictable solar azimuth patterns and cloudy conditions mitigating shading effects through enhanced diffuse light. Compared with CK (non-shadow area), inter-panel plots (BP) maintained 77% photosynthetic efficiency and 85.4% plant height, whereas the areas beneath the panel showed a significant decrease in the relative chlorophyll content (SPAD values), photosynthesis rates, and yield. BP plots preserved a 78% fruiting rate through adaptive stomatal regulation, whereas LP zones (directly under the low eave) exhibited 35% higher intercellular CO₂ because of the limited assimilation in shading. Rice yield losses were correlated with shading intensity, driven by reduced panicles and grain filling. Moreover, the APV system achieved a high land equivalent ratio of 148–149% by combining 65–66% rice yield with 82.5% photovoltaics output. Based on the microenvironment created by the APV system, optimal crop types and fertilisation are essential for enhancing agricultural yields and improving land use efficiency. Full article

While irrigation is generally required for most summer crops in the Mediterranean region, increasingly scarce water supplies are leading to a demand for more efficient irrigation infrastructure. Here, we assess how three irrigation volumes—100 mm/week (simulating excess water), 55 mm twice per week (moderate supply), and a variable amount adjusted on a weekly basis according to crop water demand (AMP) applied once or twice weekly via drip irrigation—impacted the growth, yield, and ear traits of a local maize variety under low-input farming in central Portugal. We found that irrigation management significantly influenced grain yield and irrigation water use efficiency (IWUE), with the 55 mm treatment applied twice weekly achieving the highest yield (3504 kg ha⁻¹) and IWUE (7.2 kg ha⁻¹ mm⁻¹). The highest irrigation treatment (100 mm/weekly) impaired yield (996 kg ha⁻¹ and 1973 kg ha⁻¹, when water was applied in one or two events), likely due to nutrient leaching, and resulted in the lowest IWRU (1.2 kg ha⁻¹ mm⁻¹ and 2.5 kg ha⁻¹ mm⁻¹, respectively). Biweekly applications tended to increase crop height. Irrigation rate and frequency significantly affected kernel number and size, but not total ear weight or cob-to-ear weight ratio. These findings highlight the importance of irrigation frequency based on crop water demand over blanket approaches based on volume alone. Full article

The efficiency of water use in irrigated agriculture is a global priority to address water scarcity. A comprehensive meta-analysis was conducted to evaluate the effects of irrigation practices on potato yield, crop evapotranspiration (ETc), water productivity (WP), and irrigation water productivity (IWP) across diverse growing conditions, including soil texture, fertilizer application rates, annual precipitation, and soil organic carbon (SOC). The results revealed that supplementary irrigation increased potato yield by 55% and ETc by 39% while maintaining WP comparable to non-irrigated conditions. The greatest yield and WP improvements from supplementary irrigation occurred under drip irrigation with moderate N, P, and K application rates (150–250 kg ha⁻¹) and irrigation amounts below 150 mm. This practice was particularly effective in sandy soils with 1.5–2.0% SOC and annual rainfall of 200–400 mm. Conversely, deficit irrigation reduced potato yield and ETc by 25% and 24%, respectively, but significantly enhanced WP and IWP by 9% and 28% compared to full irrigation. When a water-saving ratio of 10–20% was implemented under drip irrigation with optimal fertilizer rates (240–360 kg N ha⁻¹, >104 kg P₂O₅ ha⁻¹, 150–200 kg K₂O ha⁻¹), deficit irrigation improved WP without yield loss in sandy soils with annual rainfall of 600–800 mm when compared to full irrigation. The IWP increased with rising SOC levels, indicating that SOC improvement in low-carbon soils enhances water productivity in irrigated potato systems. These findings demonstrate that tailored irrigation strategies can simultaneously reduce water inputs and achieve higher yield and WP in potato production systems. Full article

Excessive or improper fertilization not only salinizes soil but also reduces crop yield and quality. The objective of this study was to determine the optimum N, P, and K levels capable of improving tomato fruit quality and reducing environmental pollution for tomato plants under brackish water irrigation conditions. The ‘Jingcai 8’ tomato was used as the research object, and an orthogonal experimental design was used to set up three nutritional factors of N, P, and K. Each factor was set at three levels: N (mmol·L⁻¹): 2.00 (N1), 4.00 (N2), and 8.00 (N3); P (mmol·L⁻¹): 0.67 (P1), 1.33 (P2), and 2.00 (P3); K (mmol·L⁻¹): 8.00 (K1), 12.00 (K2), and 16.00 (K3). The effects of different levels of N, P, and K on plant growth indexes, root vigor and antistress enzymes, biomass and nutrients of plants and fruits, yield, quality, soil nutrients, and soil enzymes were investigated, and metabolomic measurements were performed on treatments ranked first (N:P:K ratio was 2:1.33:12) and ninth (N:P:K ratio was 8:1.33:8) for overall quality. In general, a N concentration of 8 mmol·L⁻¹ promoted plant vegetative growth and plant biomass accumulation by promoting the accumulation of aboveground nitrogen content, but it reduced the weight of single fruit and tomato quality due to an increase in soil EC and pH. In contrast, 0.67 mmol·L⁻¹ of P and 12 mmol·L⁻¹ of K were able to promote both plant vegetative growth and tomato quality formation. In addition, 0.67 mmol·L⁻¹ of P enhanced soil nutrient availability and enzyme activity, while 16 mmol·L⁻¹ of K reduced nutrient availability and enzyme activity and increased soil EC. The concentrations of ferulic acid, cinnamic acid, caffeic acid, coumarin, and (-)-epigallocatechin were generally higher in tomatoes from the T2 treatment (N:P:K ratio was 2:1.33:12) than in those from other treatments. Together, the optimum N:P:K ratio (2:1.33:12) of fertilization enhances tomato yield and quality under brackish water irrigation. Full article

Early-season sugarcane identification plays a pivotal role in precision agriculture, enabling timely yield forecasting and informed policy-making. Compared to post-season crop identification, early-season identification faces unique challenges, including incomplete temporal observations and spectral ambiguity among crop types in early seasons. Previous studies have not systematically investigated the capability of optical and synthetic aperture radar (SAR) data for early-season sugarcane identification, which may result in suboptimal accuracy and delayed identification timelines. Both the timing for reliable identification (≥90% accuracy) and the earliest achievable timepoint matching post-season level remain undetermined, and which features are effective in the early-season identification is still unknown. To address these questions, this study integrated Sentinel-1 and Sentinel-2 data, extracted 10 spectral indices and 8 SAR features, and employed a random forest classifier for early-season sugarcane identification by means of progressive temporal analysis. It was found that LSWI (Land Surface Water Index) performed best among 18 individual features. Through the feature set accumulation, the seven-dimensional feature set (LSWI, IRECI (Inverted Red-Edge Chlorophyll Index), EVI (Enhanced Vegetation Index), PSSRa (Pigment Specific Simple Ratio a), NDVI (Normalized Difference Vegetation Index), VH backscatter coefficient, and REIP (Red-Edge Inflection Point Index)) achieved the earliest attainment of 90% accuracy by 30 June (early-elongation stage), with peak accuracy (92.80% F1-score) comparable to post-season accuracy reached by 19 August (mid-elongation stage). The early-season sugarcane maps demonstrated high agreement with post-season maps. The 30 June map achieved 88.01% field-level and 90.22% area-level consistency, while the 19 August map reached 91.58% and 93.11%, respectively. The results demonstrate that sugarcane can be reliably identified with accuracy comparable to post-season mapping as early as six months prior to harvest through the integration of optical and SAR data. This study develops a robust approach for early-season sugarcane identification, which could fundamentally enhance precision agriculture operations through timely crop status assessment. Full article

Protected structures with drip fertigation systems have allowed many countries around the world to grow high-value vegetables, such as tomatoes and bell peppers year round, particularly under adverse edaphoclimatic conditions. This paper evaluates the feasibility of tomato and bell pepper cultivation in Sunshine Pacific Limited. Farm in Tanumalala, a commercial farm in Samoa, under a protected cultivation system with drip fertigation. The yield, water use efficiency, establishment and maintenance costs, and the average return per hectare of production were analyzed. Additionally, economic feasibility indicators were estimated using the discount factors of 6.5% and 11%. Results showed that the annual yield of tomatoes (163,500 kg/ha) was higher than bell peppers (103,500 kg/ha). The water use efficiency (WUE) and product water use (PWU) of these two crops in this study were less efficient compared to what was observed in other countries, as indicated by the value of the respective WUE and PWU: 8.38 kg/m³ and 0.12 m³/kg for tomatoes while 5.31 kg/m³ and 0.19 m³/kg for capsicum. Despite the high initial establishment cost, all economic feasibility parameters indicated that the system is profitable, having a BCR ratio of more than 2, and feasible under Samoa conditions, mostly due to the high market price. Thus, this system of cultivation could be an option for growing high-value vegetables in Samoa. However, further research is needed to improve the yield and water use efficiency. Full article

China ranks as the world’s leading potato (Solanum tuberosum L.) producer, while the poor seeding machinery performance limited a higher input–output ratio in potato cultivation and impeded sustainable development. We developed an advanced air-suction mulai-arm potato planter (ASPP) that incorporated integrated side-deep fertilization, automated seed feeding, negative-pressure seed filling, seed transportation, positive-pressure seed delivery, soil covering, and compaction. The study proposes a Negative-pressure seed extraction mechanism that minimizes seed damage by precisely controlling suction pressure, and the near-zero-speed seed delivery mechanism synchronizes seed release with ground speed, reducing bounce-induced spacing errors. Furthermore, the structural configuration and operation principle of ASPP were systematically elucidated, and key performance parameters and optimal values were identified. We conducted a randomized complete block design plot trial comparing the spoon-belt potato planter (SBPP) and spoon-chain potato planter (SCPP), evaluating sowing quality, seedling emergence rate (ER), potato yield (PY), and comprehensive economic benefits. The results revealed that plant spacing index (PSI), missed-seeding index (MI), re-seeding index (RI), and coefficient of variation (CV) of ASPP were 90.05%, 3.78%, 2.32%, and 7.93%, respectively. The mean ER values for ASPP, SBPP, and SCPP were 94.76%, 85.42%, and 83.46%, respectively, with the ASPP showing improvements of 10.93% and 13.54% over SBPP and SCPP. However, the SBPP and SCPP exhibited greater emergence uniformity than ASPP. The mean PY value was 37,205.25, 32,973.75, and 34,620 kg·ha⁻¹ for ASPP, SBPP, and SCPP. The ASPP outperformed the SBPP and SCPP by 12.83% and 7.47%. Overall, ASPP demonstrated balanced and superior performance across the above-mentioned indicators, demonstrating its potential to enable precision agriculture in tuber crop cultivation. Full article

The sustainable utilization of saline water resources represents an effective strategy for alleviating water scarcity in arid regions. However, the mechanisms by which prolonged saline water irrigation influences soil salinization and dryland crop growth are not yet fully understood. This study examined the effects of six irrigation water salinity levels (CK: 0.87 g·L⁻¹, S1: 2 g·L⁻¹, S2: 4 g·L⁻¹, S3: 6 g·L⁻¹, S4: 8 g·L⁻¹, S5: 10 g·L⁻¹) on soil salinization dynamics and jujube growth during a three-year field experiment (2020–2022). The results showed that soil salinity within the 0–1 m profile significantly increased with rising irrigation water salinity and prolonged irrigation duration, with the 0–0.4 m layer accounting for 50.27–74.95% of the total salt accumulation. A distinct unimodal salt distribution was observed in the 0.3–0.6 m soil zone, with the salinity peak shifting downward from 0.4 to 0.5 m over time. Meanwhile, soil pH and sodium adsorption ratio (SAR) increased steadily over the study period. The dominant hydrochemical type shifted from SO₄²⁻-Ca²⁺·Mg²⁺ to Cl⁻-Na⁺·Mg²⁺. Crop performance exhibited a nonlinear response to irrigation salinity levels. Low salinity (2 g·L⁻¹) significantly enhanced plant height, stem diameter, leaf area index (LAI), vitamin C content, and yield, with improvements of up to 12.11%, 3.96%, 16.67%, 16.24%, and 16.52% in the early years. However, prolonged exposure to saline irrigation led to significant declines in both plant growth and water productivity (WP) by 2022. Under high-salinity conditions (S5), yield decreased by 16.75%, while WP declined by more than 30%. To comprehensively evaluate the trade-off between economic effects and soil environment, the entropy weight TOPSIS method was employed to identify S1 as the optimal irrigation treatment for the 2020–2021 period and control (CK) as the optimal treatment for 2022. Through fitting analysis, the optimal irrigation water salinity levels over 3 years were determined to be 2.75 g·L⁻¹, 2.49 g·L⁻¹, and 0.87 g·L⁻¹, respectively. These findings suggest that short-term irrigation of jujube trees with saline water at concentrations ≤ 3 g·L⁻¹ is agronomically feasible. Full article

Interest in the wine sector focusing on no- or low-alcohol wines is growing. De-alcoholation, typically a post-fermentation process, faces restrictions in some countries and is often quite costly. Using raw materials like low-sugar grapes suitable for this purpose seems logical, yet the literature currently lacks contributions in this area. In this review paper, we outline an ideal ripening process where the goal of producing “low-sugar grapes” can be achieved through various methodologies applied at (i) the whole-canopy level (minimal pruning, hedge mechanical pruning with or without hand finishing, cane pruning combined with high bud load and no cluster thinning, applications of exogenous hormones, late irrigation, and double cropping); (ii) the canopy microclimate level, involving changes in the leaf area-to-fruit ratios (netting, apical or basal leaf removal, late shoot trimming, use of antitranspirants); and (iii) through new technologies (high-yield plots from vigor maps and the adoption of agrivoltaics). However, the efforts in this survey extend beyond merely achieving the production of low-sugar grapes in the vineyard, which is indeed primary but not exhaustive. Therefore, we also explore solutions for obtaining low-sugar grapes while simultaneously enhancing features such as lower acidity, increased phenolics, and aroma potential, which might boost consumer appreciation. The review emphasizes that (i) grapes intended for low-alcohol wine production should not be viewed as a low-quality sector but rather as an alternative endeavour, where the concept of grape quality remains firmly intact and (ii) viticulture for low sugar concentration is a primary strategy, rather than merely a support to dealcoholization techniques. Full article

Nitrogen (N) and potassium (K) are essential macronutrients for plants whose functions and interactions profoundly influence plant physiological metabolism, environmental adaptation, and agricultural production efficiency. This review summarizes research advances in plant N and K nutrition and their interaction mechanisms, elucidating the key physiological functions of N and K individually and their respective absorption and transport mechanisms involving transporters such as NRTs and HAKs/KUPs. The review discusses the types of nutrient interactions (synergism and antagonism), with a primary focus on the physiological basis of N–K interactions and their interplay in root absorption and transport (e.g., K⁺-NO₃⁻ co-transport; NH₄⁺ inhibition of K⁺ uptake), photosynthesis (jointly optimizing CO₂ conductance, mesophyll conductance, and N allocation within photosynthetic machinery to enhance photosynthetic N use efficiency, PNUE), as well as sensing, signaling, co-regulation, and metabolism. This review emphasizes that N–K balance is crucial for improving crop yield and quality, enhancing fertilizer use efficiency (NUE/KUE), and reducing environmental pollution. Consequently, developing effective N–K management strategies based on these interaction mechanisms and implementing Balanced Fertilization Techniques (BFT) to optimize N–K ratios and application strategies in agricultural production represent vital pathways for ensuring food security, addressing resource constraints, and advancing green, low-carbon agriculture, including through coordinated management of greenhouse gas emissions. Full article

High nighttime temperature (HNT) due to asymmetric diurnal warming threatens wheat productivity. This study evaluated the effect of HNT on wheat phenology, physiology, and yield through field and controlled environment experiments in Central Queensland, Australia. Two wheat genotypes, Faraday and AVT#6, were assessed under three sowing dates—1 May (Early), 15 June (Mid), and 1 August (Late)—within the recommended sowing window for the region. In a parallel growth chamber study, the plants were exposed to two nighttime temperature regimes, of 15 °C (normal) and 20 °C (high), with consistent daytime conditions from booting to maturity. Late sowing resulted in shortened vegetative growth and grain filling periods and increased exposure to HNT during the reproductive phase. This resulted in elevated floret sterility, lower grain weight, and up to 40% yield loss. AVT#6 exhibited greater sensitivity to HNT despite maturing earlier. Leaf gas exchange analysis revealed increased nighttime respiration (Rn) and reduced assimilation (A), resulting in higher Rn/A ratio for late-sown crops. The results from controlled environment chambers resembled trends of the field experiment, producing lower grain yield and biomass under HNT. Cumulative nighttime hours above 20 °C correlated more strongly with yield losses than daytime heat. These findings highlight the need for HNT-tolerant genotypes and optimized sowing schedules under future climate scenarios. Full article

Slow-release nitrogen fertilizers enhance crop production and reduce environmental pollution, but their slow nitrogen release may cause insufficient nitrogen supply in the early stages of crop growth. Mixed nitrogen fertilization (MNF), combining slow-release nitrogen fertilizer with urea, is an effective way to increase yield and income and improve nitrogen fertilizer efficiency. This study used urea alone (Urea) and slow-release nitrogen fertilizer alone (C/SRF) as controls and employed meta-analysis and a random forest model to assess MNF effects on crop yield and nitrogen partial factor productivity (PFPN), and to identify key influencing factors. Results showed that compared with urea, MNF increased crop yield by 7.42% and PFPN by 8.20%, with higher improvement rates in Northwest China, regions with an average annual temperature ≤ 20 °C, and elevations of 750–1050 m; in soils with a pH of 5.5–6.5, where 150–240 kg·ha⁻¹ nitrogen with 25–35% content and an 80–100 day release period was applied, and the blending ratio was ≥0.3; and when planting rapeseed, maize, and cotton for 1–2 years. The top three influencing factors were crop type, nitrogen rate, and soil pH. Compared with C/SRF, MNF increased crop yield by 2.44% and had a non-significant increase in PFPN, with higher improvement rates in Northwest China, regions with an average annual temperature ≤ 5 °C, average annual precipitation ≤ 400 mm, and elevations of 300–900 m; in sandy soils with pH > 7.5, where 150–270 kg·ha⁻¹ nitrogen with 25–30% content and a 40–80 day release period was applied, and the blending ratio was 0.4–0.7; and when planting potatoes and rapeseed for 3 years. The top three influencing factors were nitrogen rate, crop type, and average annual precipitation. In conclusion, MNF should comprehensively consider crops, regions, soil, and management. This study provides a scientific basis for optimizing slow-release nitrogen fertilizers and promoting the large-scale application of MNF in farmland. Full article