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- Dynamics of Soil Carbon Average Content at Different Depths: Insights from a Global Approach to Climate Change MitigationPublication . Rodrigues, Cristina I. Dias; Brito, Luís Miguel; Nunes, Leonel J.R.This study provides an in-depth examination of the average values of gravimetric carbon content, measured in grams per kilogram (g/kg), and the organic Carbon (OC) content, quantified in kilograms per square meter (kg/m2), within various soil classifications and depths. Highlighting the relevance of such research, it delves into the intricacies of soil OC dynamics across diverse depth strata and offers a comparative analysis of different soil types, each with distinct carbon sequestration capacities. Utilizing the latest version of the world soil database, the research integrates three interconnected data sets: soil classification, density, and OC. In total, the study includes 51,507 soil profile layers to calculate the average gravimetric OC content in the fineearth fraction. In parallel, the average OC content in the fine-earth fraction was determined across 6,197 soil profile layers. This comprehensive data is organized into 34 separate soil units, each dissected across four depth categories: 0–30 cm, 0–100 cm, 0–200 cm and 0–2590 cm. The findings from this analysis reveal a consistent pattern: as depth increases, both the gravimetric content and average OC content tend to decrease. However, it is noteworthy that this trend is not universal. Certain soil units demonstrate an opposing behavior, with an increase in average OC content observed at greater depths, contradicting the prevailing trend. This divergence underscores the complexity of soil OC dynamics and the inherent variability across different soil units.
- Dynamics of Soil Carbon Average Content Insights from a Global Approach to Climate Change MitigationPublication . Rodrigues, Cristina I. Dias; Brito, Luís Miguel; Nunes, Leonel J. R.This study provides an in-depth examination of the average values of gravi- metric carbon content, measured in grams per kilogram (g/kg), and the organic Carbon (OC) content, quantified in kilograms per square meter (kg/ m2), within various soil classifications and depths. Highlighting the relevance of such research, it delves into the intricacies of soil OC dynamics across diverse depth strata and offers a comparative analysis of different soil types, each with distinct carbon sequestration capacities. Utilizing the latest version of the world soil database, the research integrates three interconnected data sets: soil classification, density, and OC. In total, the study includes 51,507 soil profile layers to calculate the average gravimetric OC content in the fine- earth fraction. In parallel, the average OC content in the fine-earth fraction was determined across 6,197 soil profile layers. This comprehensive data is organized into 34 separate soil units, each dissected across four depth categories: 0–30 cm, 0–100 cm, 0–200 cm and 0–2590 cm. The findings from this analysis reveal a consistent pattern: as depth increases, both the gravimetric content and average OC content tend to decrease. However, it is noteworthy that this trend is not universal. Certain soil units demonstrate an opposing behavior, with an increase in average OC content observed at greater depths, contradicting the prevailing trend. This divergence under- scores the complexity of soil OC dynamics and the inherent variability across different soil units.
- Effect of photo-selective nets on yield, fruit quality and Psa disease progression in a ‘hayward’ kiwifruit orchardPublication . Moura, Luísa; Pinto, Rui; Rodrigues, Raúl; Brito, Luís Miguel; Rego, Rute; Valin, Maria Isabel; Mariz-Ponte, Nuno; Santos, Conceição; Mourão, IsabelThe influence of the colour of photo-selective nets on Actinidia deliciosa yield, fruit quality and progression of the bacterial kiwifruit canker (Pseudomonas syringae pv. actinidiae, Psa) need to be characterised due to increasing use of these nets, mainly to protect from hail and storms. From May 2019 onwards, pearl (Pn), yellow (Yn) and grey (Gn) nets were installed permanently in a ‘Hayward’ kiwifruit orchard in NW Portugal and uncovered plants were used as the control. Compared to outside conditions for both seasons, the blue:red ratio and the mean air temperature were higher (mean increase of 12.7% and 0.6 °C, respectively) and the photosynthetic active radiation (PAR) was lower (10.8% less between budbreak and bloom) under the Pn. Crop yield, compared to the control, decreased by 40.3% under the three nets in 2020, and by 23.9% under the Yn and Gn in 2021. Yield and fruit grade under the Pn were similar to that of uncovered crops in 2021, and fruit grade was overall higher under the Pn compared to the Yn and Gn. Photo-selective nets did not affect the fruit quality parameters. Psa progression decreased under the Pn compared to the control during two months in both seasons, although this beneficial impact needs further evaluation.
- Valorization of kiwi waste through compostingPublication . Fernandes, Paulo; Pinto, Rui; Correia, Cláudia; Mourão, Isabel; Moura, Luísa; Brito, Luís MiguelKiwi waste from the calibration process is a major environmental problem of kiwi production due to landfill deposition. This work aims to contribute to the agronomic use of recycled kiwi waste through composting. With this objective, a composting experiment was carried out with kiwi fruit waste mixed with 5%, 10% and 20% (fresh weight) of wheat straw from bundles used to protect kiwifruit trunks from frost, as abulking agent to increase aeration, in the piles 5S, 10S and 20S, respectively. The highest temperatures for piles 5S and 10S were above 60 degrees C, whereas the temperature did not reach 40 degrees C in the pile with the highest straw content (20S) because the aeration increased heat loss in addition to increased C/N ratio of this pile. Also, the amount of organic matter mineralized decreased with increasing amount of straw because of the high C/N ratio of the straw. The highest total N (29.7 g kg(-1)) and the lowest C/N ratio (13) of the compost with 5% of straw is important from the agricultural point of view to promote N availability. In contrast, the high electrical conductivity (4.6 dS m(-1)) of this compost increases the risk of salt accumulation in the soil. Our results show that the compost with 10% straw, with high degree of maturation, absence of poor hygiene indicators as coliforms and pathogens as Salmonella sp., high organic matter content and rich in nutrients, together with the adequate compost pH and low electrical conductivity improves compost quality.
- Soil Vertical Distribution of Organic Carbon and Sequestration Potential in Ponte de Lima (Alto Minho Region, Northern Portugal)Publication . Rodrigues, Cristina I. Dias; Brito, Luís Miguel; Nunes, Leonel J.R.Understanding the vertical distributions of organic carbon (OC) is crucial for predicting and simulating the influences of soil units on the terrestrial carbon cycle. The OC in the fine earth fraction was calculated for the soil units Anthrosols, Cambisols, Fluvisols, Leptosols, and Regosols in the municipality of Ponte de Lima, Portugal, at depths of 0–30 cm, 0–100 cm, 0–200 cm, and 0–2590 cm. In the study area, over 40% of the OC is concentrated in the Regosol unit, followed by the Anthrosols with over 23% OC at all depths, and the Leptosols with over 22% OC at all depths. The soil units Cambisols and Fluvisols have a lower representation in the territory, with values below 1.5% and 6.5% respectively at all depths. The obtained results contribute to assessing the potential of the soil units present in the municipality to sequester CO2, promoting the development of carbon inventories and analyzing the distribution of OC through accurate and reliable estimates of current C reserves as an essential tool for analyzing and modeling the effects of different factors involved in the potential of soil OC sequestration.
- Impact of Kiwifruit Waste Compost on Soil Bacteriome and Lettuce GrowthPublication . Fernandes, Paulo; Pinto, Rui; Correia, Cláudia; Mourão, Isabel; Moura, Luísa; Brito, Luís MiguelComposts produced with kiwifruit waste from the calibration process (KW), mixed with 5%, 10%, and 20% wheat straw (WS), were evaluated as crop fertilizers through a pot experiment with lettuce, arranged as a randomized block design. Highest lettuce yields were achieved with 20 and 40 t·ha−1 5%WS compost and 40 t·ha−1 10%WS compost, suggesting that the physical characteristics of the composts increased soil water holding capacity and root growth, whereas chemical characteristics such as pH, organic matter, and nutrient contents contributed to improving soil reaction and nutrient availability. The type of soil amendment used influenced the development of different bacterial consortia in the bulk soil and rhizosphere, leading to increased levels of potentially beneficial bacteria and enhanced levels of relevant functions for plant growth, such as nitrogen fixation. Composted KW as an organic amendment can be used to improve soil quality and the circular economy.
- Impacts of therapeutic horticulture on happiness and loneliness in institutionalized clients with mental health conditionsPublication . Mourão, Isabel; Mouro, Cláudia V.; Brito, Luís Miguel; Costa, Sofia R.; Almeida, Telma C.Introduction: Therapeutic horticulture (TH) can be considered a non-pharmacological approach to support psychiatric treatments for the improvement of physical and mental health, but information is lacking on whether it has advantages as compared to more conventional occupational therapies (OTs). Method: The study focused on institutionalized 25 clients attending TH among other OTs and 15 clients attending OT other than TH. The measures used were the ‘Subjective Happiness Scale’ (SHS) and the ‘Social and Emotional Loneliness Scale for Adults’ (SELSA-S), along with sociodemographic and clinical data. The study design was descriptive, observational and cross-sectional. Results: Scores obtained from the SHS and SELSA-S were generally similar for both groups, although 40% of clients in the TH group perceived relaxation. These are in agreement with previous studies performed with chronic schizophrenia clients reporting that TH might effectively decrease depression/anxiety symptoms, but the feeling of hopelessness and quality of life did not change, probably due to long-term institutionalization and required medication that may limit other effects. Within the TH group, clients preferred specific horticultural tasks and more days/week attending activities decreased loneliness and increased happiness. Conclusion: TH interventions as an integrative treatment option merits further study on both process and outcome evaluation, to maximize its effectiveness.
- Lettuce response to organic and phosphate fertilizers and root mycorrhizationPublication . Brito, Luís Miguel; Sampaio, Áurea; Pinto, Rui; Mourão, Isabel; Coutinho, JoãoThe response of lettuce to production system, organic and phosphate fertilizers and root mycorrhization, was evaluated in two pot trials with factorial treatment combination of: (i) soil type (from organic and from conventional production systems) and organic fertilizer (0, 2 and 4 t ha¡1) in the first trial; and (ii) mycorrhizal inoculation (mycorrhized and nonmycorrhized plants) and Gafsa phosphate (0, 100 and 200 kg P2O5 ha¡1) in the second. Lettuce growth decreased with increasing rates of the organic fertilizer because of its very high electrical conductivity (50.1 dS m¡1) and lack of maturation. However, the fertilizer harmful effects were minimized in the soil from organic production. The application of Gafsa phosphate significantly increased lettuce yield and nutrient uptake. However, for the highest rate of phosphate, mycorrhized lettuce yield decreased compared to non-mycorrhized lettuce, suggesting that high soil available P may have harmful effects on the activity of mycorrhizal fungi.
- Evaluation of compost from seaweed and fish waste as a fertilizer for horticultural usePublication . Illera-Vives, Marta; Seoane Labandeira, S.; Brito, Luís Miguel; López-Fabal, Adolfo; López-Mosquera, M. ElviraComposting may be an effective process for treating fish waste and drift seaweed to recover organic matter and nutrient resources and to produce fertilizers for organic agriculture. The aim of this study was to evaluate the use of this type of compost as a fertilizer in a horticultural crop rotation. A greenhouse trial was carried out to test the effects of the compost on a tomato crop and its residual effects on the succeeding lettuce crop. Different compost rates (C1, C2 and C3: 40 t ha(-1), 50 t ha(-1) and 66 t ha(-1)) were compared to single rates of a mineral fertilizer (M) and of a certified organic fertilizer made from dehydrated broiler litter (BL) as well as to the control treatment, which lacked fertilization (C). Tomato yield increased significantly (5.56 kg plant(-1)) with the highest rate of compost compared to the mineral and control treatments (4.54 and 4.58 kg plant(-1), respectively). This increased yield was associated with an increase in the diameter and weight of the fruits. Moreover, the lettuce yield improved with compost rates C2 (395 g lettuce(-1)) and C3 (367 g lettuce(-1)), showing a strong residual effect of the compost. This compost is suitable as organic soil fertilizer and may be recommended for improving horticultural crop yields.
- Organic Lettuce Growth And Nutrient Uptake Response To Lime, Compost And Rock PhosphatePublication . Brito, Luís Miguel; Monteiro, José Manuel; Mourão, Isabel; Coutinho, JoãoFertilizer recommendations are needed to increase organic vegetable yields. Thus, organic lettuce growth and nutrient uptake was investigated in a randomized block pot experiment with twelve treatments from the factorial structure of three factors: (i) Gafsa phosphate [0 and 200 kg phosphorus pentoxide (P 2 O 5 ) ha -1 ], (ii) compost from source separated municipal organic waste (0, 15, and 30 t ha -1 ) and (iii) limestone [0 and 8 t ha -1 calcium carbonate (CaCO 3 ) equivalent]. Lettuce yield increased with compost application and a first order interaction between lime and phosphate was clear because lime partially replaced the need for phosphate. This was explained by the effect of liming on P availability in acid soils. Nitrogen (N), phosphorus (P), and potassium (K) accumulation increased in lettuces produced with compost or phosphate but only the accumulation of N was increased with lime. This compost is recommended to increase nutrient availability for organic lettuce whereas the need for phosphate fertilization may decrease with liming.