Search Results (315)

Land use conversion to perennial cropland often degrades the soil structure and fertility, particularly under Mediterranean climatic conditions. This study assessed spatial and temporal dynamics of soil properties and tree responses to 3-year repeated mature compost additions in a citrus orchard. Digital soil mapping revealed strong baseline heterogeneity in texture, CEC, and Si pools. Compost application markedly increased total organic C and N levels, aggregate stability, and pH with noticeable changes after the first amendment, whereas a limited C storage potential was found following further additions. NDVI values of tree canopies monitored over a 3-year period showed significant time-dependent changes not correlated with the soil fertility variables, thus suggesting that multiple interrelated factors affect plant responses. The non-crystalline amorphous Si/total amorphous Si (_iSi:Si_amor) ratio is here proposed as a novel indicator of pedogenic alteration in disturbed agroecosystems. These findings highlight the importance of tailoring organic farming strategies to site-specific conditions and reinforce the value to combine C and Si pool analysis for long-term soil fertility assessment. Full article

Potassium fertilizer management is critical for achieving high yields of Korla fragrant pear, yet current practices often overlook or misuse potassium inputs. In this study, a two-year field experiment (2023–2024) was conducted with 7- to 8-year-old pear trees using four potassium levels (0, 75, 150, and 225 kg/hm²). Metagenomic sequencing was employed to assess the effects on soil microbial communities, sulfur cycle functional genes, and fruit yield. Potassium treatments significantly altered soil physicochemical properties, the abundance of sulfur cycle functional genes, and fruit yield (p < 0.05). Increasing application rates significantly elevated soil-available potassium and organic matter while reducing pH (p < 0.05). Although alpha diversity was unaffected, NMDS analysis revealed differences in microbial community composition under different treatments. Functional gene analysis showed a significant decreasing trend in betB abundance, a peak in hpsO under K150, and variable patterns for soxX and metX across treatments (p < 0.05). All potassium applications significantly increased yield relative to CK, with K150 achieving the highest yield (p < 0.05). PLS-PM analysis indicated significant positive associations between potassium rate, nutrient availability, microbial abundance, sulfur cycling, and yield, and a significant negative association with pH (p < 0.05). These results provide a foundation for optimizing potassium fertilizer strategies in Korla fragrant pear orchards. It is recommended that future studies combine metagenomic and metatranscriptomic approaches to further elucidate the mechanisms linking potassium-driven microbial functional changes to improvements in fruit quality. Full article

Based on an integrated analysis, this study summarized the current status of soil quality in Yantai apple orchards, developed a multivariate regulation model for key soil physicochemical properties, and proposed optimized fertilization strategies to improve soil quality in the region. The study analyzed the physicochemical properties of the topsoil (0–30 cm) in 19 representative apple orchards across Yantai, including indicators like pH, organic matter (OM), major nutrient ions, and salinity indicators, using standardized measurements and multivariate statistical methods, including descriptive statistics analysis, frequency distribution analysis, canonical correlation analysis, stepwise regression equation analysis, and regression fit model analysis. The results demonstrated that in apple orchards across the Yantai region, reductions in pH were significantly mitigated under the combined increased OM and exchangeable calcium (Ca). Exchangeable potassium (EK) rose in response to the joint elevation of OM and available nitrogen (AN), and AN was also positively influenced by EK, while OM also exhibited a promotive effect on Olsen phosphorus (OP). Furthermore, Ca increased with higher pH. AN and EK jointly contributed to the increases in electrical conductivity (EC) and chloride ions (Cl), while elevated exchangeable sodium (Na) and soluble salts (SS) were primarily driven by EK. Accordingly, enhancing organic and calcium source fertilizers is recommended to boost OM and Ca levels, reduce acidification, and maintain EC within optimal limits. By primarily reducing potassium’s application, followed by nitrogen and phosphorus source fertilizers, the supply of macronutrients can be optimized, and the accumulation of Na, Cl, and SS can be controlled. Collectively, the combined analysis of soil quality status and the multivariate regulation model clarified the optimized fertilization strategies, thereby establishing a solid theoretical and practical foundation for recognizing the necessity of soil testing and formula fertilization, the urgency of improving soil quality, and the scientific rationale for nutrient input management in Yantai apple orchards. Full article

Potassium (K), a critical macronutrient for the growth and development of Korla fragrant pear (Pyrus sinkiangensis Yu), plays a pivotal regulatory role in sugar-acid metabolism. Furthermore, K exhibits a highly specific response in near-infrared (NIR) spectroscopy compared to elements such as nitrogen (N) and phosphorus (P). Given its fundamental impact on fruit quality parameters, the development of rapid and non-destructive techniques for K determination is of significant importance for precision fertilization management. By measuring leaf potassium content at the fruit setting, expansion, and maturity stages (decreasing from 1.60% at fruit setting to 1.14% at maturity), this study reveals its dynamic change pattern and establishes a high-precision prediction model by combining near-infrared spectroscopy (NIRS) with machine learning algorithms. “Near-infrared spectroscopy coupled with machine learning can enable accurate, non-destructive monitoring of potassium dynamics in Korla pear leaves, with prediction accuracy (R²) exceeding 0.86 under field conditions.” We systematically collected a total of 9000 leaf samples from Korla fragrant pear orchards and acquired spectral data using a benchtop near-infrared spectrometer. After preprocessing and feature extraction, we determined the optimal modeling method for prediction accuracy through comparative analysis of multiple models. Multiplicative scatter correction (MSC) and first derivative (FD) are synergistically employed for preprocessing to eliminate scattering interference and enhance the resolution of characteristic peaks. Competitive adaptive reweighted sampling (CARS) is then utilized to screen five potassium-sensitive bands, specifically in the regions of 4003.5–4034.35 nm, 4458.62–4562.75 nm, and 5145.15–5249.29 nm, among others, which are associated with O-H stretching vibration and changes in water status. A comparison between random forest (RF) and BP neural network indicates that the MSC + FD–CARS–BP model exhibits the optimal performance, achieving coefficients of determination (R²) of 0.96% and 0.86% for the training and validation sets, respectively, root mean square errors (RMSE) of 0.098% and 0.103%, a residual predictive deviation (RPD) greater than 3, and a ratio of performance to interquartile range (RPIQ) of 4.22. Parameter optimization revealed that the BPNN model achieved optimal stability with 10 neurons in the hidden layer. The model facilitates rapid and non-destructive detection of leaf potassium content throughout the entire growth period of Korla fragrant pears, supporting precision fertilization in orchards. Moreover, it elucidates the physiological mechanism by which potassium influences spectral response through the regulation of water metabolism. Full article

In the context of agricultural green transformation, the balance between the environmental footprint and economic return is a key indicator for measuring the synergy of high yields, high efficiency, and environmental friendliness in agricultural systems. However, the pathways and mechanisms for achieving this synergy in orchard systems remain unclear. Based on a three-year field experiment in Pinghe County, Fujian Province, a comprehensive evaluation framework integrating life cycle assessment (LCA) was constructed. This framework was used to systematically analyze the differences in the net ecosystem economic benefit (EEB) and environmental impact of four fertilization regimes: the conventional farming regime with no mulching (A; 1084 kg N ha⁻¹, 914 kg P₂O₅ ha⁻¹, and 906 kg K₂O ha⁻¹), the conventional farming regime with mulching (B), the optimized fertilization regime with water–fertilizer integration (C; 250 kg N ha⁻¹, 200 kg K₂O ha⁻¹, 100 kg MgO ha⁻¹, and 400 kg CaO ha⁻¹), and the optimized fertilization regime with controlled-release fertilizers (D). The results showed that regime D performed best in terms of yield, nutrient-use efficiency, and EEB, which increased by 220.5% and 297.5% compared with regime A, and reduced the input cost by CNY 63,100~69,000 hm⁻². Moreover, compared with regime A, regimes B, C, and D significantly reduced the carbon, nitrogen, and phosphorus footprints, respectively, with the carbon footprint reduced by 6.7~21.7%, 72.4~74.8%, and 71.6~76.5%; the nitrogen footprint reduced by 2.6~19.0%, 80.7~82.2%, and 80.1~83.4%; and the phosphorus footprint reduced by 15.3%, 100%, and 100%. Furthermore, the comprehensive evaluation index (CEI) is D > C > B > A. In total, the three optimized regimes balanced high yield with environmental sustainability, with the D regime showing the best performance, offering scientific support for transitioning to low-carbon, high-value orchards in smallholder systems. Full article

Mineral nutrition management in sweet cherry orchards remains a critical challenge due to the lack of site-specific fertilization guidelines, particularly in Greece, a significant cherry-producing country. This study aimed to develop a predictive framework for total nutrient losses in sweet cherry orchards by proposing simplified estimations using fresh fruit yield as the sole input variable. Field experiments were conducted in two orchards with distinct rootstocks (MxM 14 and CAB-6P), analyzing soil properties, leaf nutrient status, and uptake patterns on different plant components. Results indicated that despite differences in soil texture and pH, nutrient availability was generally sufficient, with only Fe and Zn marginally below optimal levels in leaf tissue. Principal Component Analysis (PCA) revealed distinct nutrient distribution patterns, with N evenly distributed across fruits, peduncles, and prunings, while K was concentrated in fruits and peduncles, and Ca and Mg predominantly in fallen leaves. Notably, K was redistributed from leaves to fruits under high yields, evidenced by negative correlations between leaf biomass and K uptake. Strong relationships (r² > 0.8) were found between fresh fruit yield and uptake of N, P, K, Mg, B, and Cu, enabling reliable predictions of total nutrient losses. Estimated annual nutrient removals were 85.6 kg ha⁻¹ N, 8.94 kg ha⁻¹ P, 42.7 kg ha⁻¹ K, and 12.0 kg ha⁻¹ Mg, with significant fractions retained in prunings and fallen leaves (e.g., 51.8 kg ha⁻¹ N, 6.2 kg ha⁻¹ P). The developed yield-based models provide a practical tool for optimizing fertilization strategies, while our findings highlight the potential for nutrient recycling through sustainable residue management. Full article

Soil fertility has an important impact on orchard yield and quality, and sandy soil limits the economic yield of orchards due to its low water and fertilizer retention capacity. Although biochar and alfalfa planting have been widely utilized separately in soil improvement, few studies have examined the effects of combined alfalfa planting and biochar application on jujube orchard soils. This study investigates the effects of alfalfa planting alone and alfalfa planting combined with different levels of biocarbon addition on soil properties. A field experiment was conducted in a jujube orchard in Yanchuan County, Shaanxi Province, with four treatments: clear tillage control (CK), alfalfa planting only (B1), alfalfa planting + 1.5 kg·m⁻² biocarbon (B2), and alfalfa planting + 3 kg·m⁻² biocarbon (B3). The results show that planting alfalfa significantly increased soil moisture content (SMC) and soil organic matter (SOM) content by 27.79% and 17.65%, respectively, and biochar addition significantly increased soil carbon, nitrogen, and phosphorus content by 8.11–37.7%, enhanced the soil moisture content (SMC) by 98.13–100.22%, promoted the growth of alfalfa, and increased vegetation cover (p < 0.05). The combination of biochar and alfalfa improves soil fertility more effectively than alfalfa alone. It can increase the soil N and P nutrient contents, improve soil available nutrients, promote alfalfa growth in a short period, and provide a feasible solution for soil improvement in the future. Full article

The Soil and Water Assessment Tool (SWAT) was utilized to analyze the spatiotemporal distribution patterns of composite non-point source pollution in the Yapu Port Basin, China, and to quantify the pollutant load contributions from various sources. Scenario-based simulations were designed to assess the effectiveness of different mitigation strategies, focusing on both agricultural and urban non-point source pollution control. The watershed was divided into 39 sub-watersheds and 106 hydrologic response units (HRUs). Model calibration and validation were conducted using the observed data on runoff, total phosphorus (TP), and total nitrogen (TN). The results demonstrate good model performance, with coefficients of determination (R²) ≥ 0.85 and Nash–Sutcliffe efficiencies (NSEs) ≥ 0.84, indicating its applicability to the study area. Temporally, pollutant loads exhibited a positive correlation with precipitation, with peak values observed during the annual flood season. Spatially, pollution intensity increased from upstream to downstream, with the western region of the watershed showing higher loss intensity. Pollution was predominantly concentrated in the downstream region. Based on the composite source analysis, a series of management measures were designed targeting both agricultural and urban non-point source pollution. Among individual measures, fertilizer reduction in agricultural fields and the establishment of vegetative buffer strips demonstrated the highest effectiveness. Combined management strategies significantly enhanced pollution control, with average TN and TP load reductions of 22.18% and 22.70%, respectively. The most effective scenario combined fertilizer reduction, improved urban stormwater utilization, vegetative buffer strips, and grassed swales in both farmland and orchards, resulting in TN and TP reductions of 67.2% and 56.2%, respectively. Full article

Establishing critical levels (CLs) and sufficiency ranges (SRs) for nutrients improves fertilizer recommendations and supports citrus yield and fruit quality. The objective of this study was to establish CLs, soil fertility classes, and leaf nutrient SRs for citrus. This study used data on the yield and nutrients of the soil and leaves, collected from 2016 to 2021, of commercial orange (Citrus sinensis) and tangerine (Citrus deliciosa) orchards in the Southwest and Metropolitan regions of the state of Rio Grande do Sul, in southern Brazil. The yield data were related to the soil attributes/leaf nutrient contents. From the models obtained from this relationship, soil fertility classes and leaf sufficiency ranges were established using the boundary line (BL) method. The appropriate classes are 5.1–5.6 for pH, 1.0–1.4% for OM, 65.8–129.0 mg dm⁻³ for P, 161.4–326.0 mg dm⁻³ for K, 0.9–1.4 cmol_c dm⁻³ for Ca, 0.22–0.34, cmol_c dm⁻³ for Mg, 1.9–2.9 cmol_c dm⁻³ for SB, 4.5–5.8 cmol_c dm⁻³ for CEC, and 40.6–53.2% for V. The appropriate ranges of leaf contents were as follows: 19.1–22.7 g kg⁻¹ of N, 0.8–1.3 g kg⁻¹ of P, 7.8–11.3 g kg⁻¹ of K, 20.9–28.4 g kg⁻¹ of Ca, 2.0–3.3 g kg⁻¹ of Mg, 2.0–3.0 g kg⁻¹ of S, 88.8–127.5 mg kg⁻¹ of B, 28.3–73.6 mg kg⁻¹ of Cu, 74.3–122.5 mg kg⁻¹ of Fe, 55.7–89.3 mg kg⁻¹ of Mn, and 10.9–15.6 mg kg⁻¹ of Zn. The BL method made it possible to establish nutrient CLs using data from commercial orchards, which is not possible when using conventional approaches. The established norms will allow for a more precise definition of the real need for fertilizer application in citrus orchards. Full article

In specialized orchards, approximately 6–10 tons/hectare of cactus pear pruning waste and 60 million tons of spent coffee grounds are estimated to be produced each year worldwide. Composting is a process that produces stable organic matter useful in agriculture. The aim of this work was to explore the potential of Opuntia ficus-indica (OFI) cladodes and spent coffee ground (SCG) mixtures for compost production and to assess their benefits for agricultural applications. Three composting campaigns were carried out using rotating composters. Feedstock for these campaigns was formulated with different ratios of OFI and SCGs, and the compost obtained were characterized by their chemical and physical proprieties. To assess these composts, basil was grown in plots using growing substrate as a blank and comparing it with substrate mixed with 10% of each compost. All plants sprouted and grew up. While no significant differences were detected in polyphenol content among the grown plants, the yields with compost at OFI–SCG (3.3:1) were differentiated for longer shoots and there was greater biomass compared to the control. Compost obtained from cladode mixed with spent coffee grounds proved to be a good soil improver with the characteristics of being able to ameliorate soil fertility and plant growth. Full article

Orchard cover crops enhance the local microclimate and soil fertility, serving as an eco-friendly, efficient management practice. However, the effects of different cultivated species and planting patterns on plant growth and soil properties remain unclear. In this study, we hypothesized that different cultivated species and planting patterns would differently affect root growth and soil biochemistry. Therefore, the root growth, soil nutrients, and soil metabolites in an orchard planted with Vulpia myuros, Vicia villosa, Orychophragmus violaceus, and Brassica campestris in either a tree-disk or inter-row patterns were conducted. The results indicated that the tree-disk pattern promoted root development. This increase in below-ground biomass contributed to changes in soil nutrient dynamics, with a significant biomass accumulation observed for Orychophragmus violaceus. While the inter-row pattern improved soil aeration and was conducive to aboveground plant growth. The tree-disk pattern with Vicia villosa and Brassica campestris increased the total phosphorus (TP) and total potassium (TK) in the 0–10 cm layer. The soil NH₄⁺-N and NO₃⁻-N contents were higher under the tree-disk pattern than under the inter-row pattern with Brassica campestris, whereas the opposite effect was seen with Vulpia myuros. Overall, we recommend planting Orychophragmus violaceus in a tree-disk pattern and Vulpia myuros in an inter-row pattern to promote plant biomass accumulation and soil nutrient increases in orchards. Our study provides a basis for the selection of orchard-cultivated species and planting patterns to promote the sustainable development of the fruit industry. Full article

The production of fruit crops plays a vital role in the agricultural sector, contributing significantly to the social and economic development of rural communities. In Brazil, fruit production is diverse due to favorable edaphoclimatic conditions, with avocado (Persea americana Mill.) emerging as an important crop. Its production continues to expand in both cultivated areas and yield, making it a key export to non-producing countries. However, despite its importance, nutritional management information, crucial for achieving high yields, remains limited. Current guidelines on nutrition monitoring are outdated, general, and based on data from other countries with different edaphoclimatic conditions, making them not directly applicable to Brazilian orchards. Furthermore, outdated nutritional information becomes less reliable over time, as climate change alters soil conditions and crop nutrient concentrations and requirements, reinforcing the need for the establishment of up-to-date and specific nutritional information. This study aimed to establish nutritional standards for ‘Hass’ avocado production using the Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND) methodologies, and to define sufficiency ranges (SRs) and Critical Levels (CLs) for both macronutrients (N, P, K, Ca, Mg, and S) and micronutrients (B, Cu, Fe, Mn, and Zn). The analyses were based on yield (t ha⁻¹) and leaf nutrient content data from commercial orchards, with datasets divided into younger (4–9 years) and older (10–26 years) plant groups. The DRIS effectively established nutritional standards for younger plants, explaining 11% of yield variation through nutritional balance. CND, in turn, was effective for both groups, accounting for 14% of yield variation and outperforming DRIS in associating nutritional status with productivity. SRs and CLs for ‘Hass’ avocado production were defined using both DRIS and CND. Together, these indices and diagnostic parameters offer valuable tools for enhancing nutritional monitoring and fertilization strategies in Brazil. Notably, SRs and CLs varied according to plant age. Full article

Background: Soil degradation and nutrient depletion critically impact pecan (Carya illinoinensis) production, reducing yield and soil fertility. Colloidal nutrition, a novel approach involving nano-scale nutrient formulations, could offer potential for soil restoration. Aim: This study aimed to assess the impact of colloidal nutrition on key physical, chemical, and biological soil health parameters in pecan tree cultivation. Methods: Soil from two orchards with 30-year-old pecan trees was used where different nutrition treatments were applied: conventional and colloidal. The variables considered included physical, chemical, and biological properties for the assessment of soil health indicators. Results: The colloidal treatment showed low salinity (2020: 2.04; 2021: 0.88 dS/m) and higher levels of humic acids (1.52 g C/100 g soil), available water depth (2020: 305.11, 2021: 350.00 m³/ha), and soil organic matter (2020: 2.10%; 2021: 2.11%). Furthermore, 6 of the 17 phytopathogens that were examined were not detected in the colloidal treatment. Conclusions: This study enhanced our understanding of the improvements that colloidal treatment could potentially provide to the physical, chemical, and biological aspects of soil health in pecan orchards. Full article

Farmer differentiation has led to significant differences in input behaviors, presenting new challenges for agricultural environmental governance. However, previous studies evaluating agricultural production systems often overlook the impact of farmer heterogeneity, and the relationship between farmer differentiation and environmental impacts remains unclear. This study takes the apple production system as a case and employs life cycle assessment (LCA) using the IMPACT2002+ model to establish environmental impact evaluation indicators for agricultural products. The environmental impacts of different types of farmers are analyzed. The findings are as follows: Overall, orchard systems under Type II part-time farmer (PTF(II)) management show the highest environmental impacts, whereas Type I part-time farmer (PTF(I)) systems exhibit the lowest, with pure farmer (PF) systems falling in between. Endpoint assessments reveal that human health is the most affected, with resource impacts being the least significant. Further analysis reveals that fertilizers are the primary environmental hotspot in the apple production system. For PFs and PTFs(I), the second-largest source of pollution in the orchard system is the purchase of storage services, whereas for PTFs(II), it is irrigation. Therefore, the government should strengthen the management of fertilizers and irrigation, and promote measures such as eco-friendly fertilizers and water-saving technologies, thereby reducing the environmental burden of production. Full article

Excessive phosphorus (P) fertilization has led to high soil P accumulation in pear orchards across China, increasing the risk of P loss while limiting economic returns. Orchard grassing has been proposed as a strategy to optimize soil P content and reduce P loss; however, its limited economic benefits have hindered widespread adoption. To address this, we developed a novel planting and mowing ryegrass (MF) system, integrating P loss mitigation with improved economic returns. A two-year field experiment was conducted in the Yangtze River Basin to assess the effects of this system on soil P fractions, P loss risk, and pear production. The results showed that soil available nitrogen (N), available potassium (K), and total P content were significantly lower in the MF treatment compared to natural grassing (NG) at different growth stages. Moreover, the MF treatment increased pear yield by 14.7–16.7% and reduced titratable acidity by 23.5–47.1%, with these improvements primarily driven by changes in phosphorus-related indicators (NaOH-Pi, NaHCO₃-Pi, and intermediate P) across different years. Additionally, the reduction in NaHCO₃-Pi in the MF treatment contributed to a decline in P leaching risk indicators, including Olsen-P and CaCl₂-P. These findings highlight the potential of the MF system as a sustainable orchard management strategy, effectively optimizing soil P dynamics, mitigating P leaching risks, and enhancing pear yield and quality under high P conditions. Full article