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Correct water management of yellow kiwifruit vines is essential for reaching high yield and fruit quality, to keep plants healthy and avoid useless water loss. The aim of the present experiment was to evaluate the physiological responses of potted Zezy002 (Actinidia chinensis var chinensis) plants to decrease of soil moisture to the wilting point, and to assess the retention curves of 5 typical soil substrates for the kiwifruit production in Italy. The 5 soils were collected from 4 Italian regions named: Basilicata, Calabria, Emilia-Romagna and Lazio (2 soils: Folie and Rosini). Plants from each soil were divided in three groups: 3 plants were irrigated maintaining soil moisture at field capacity (CONTROL); 4 plants were subjected to water stress (STRESS plants), after 48 h of water suspension, two of the four plants were irrigated as for the control plants (RECOVERY). Each pot was provided with a chalk potentiometric probe to monitor soil matric potential (Ym). In addition, soil moisture was evaluated by weight of a soil sample oven-dried, finally daily pot evapotranspiration rate was evaluated gravimetrically by pot weight at 24-h-interval. Leaf gas exchange and stem water potential (Yw) were measured daily. After irrigation suspension, plants rapidly (48 h) reached the wilting point evidenced by the stop of CO2 fixation. This corresponded to stem Yw lower than -1.75 MPa in all soils but the one from Emilia-Romagna which had the higher percentage of loam (42%) that also maintained a positive CO2 assimilation rate longer than the other soils. In this lapse of time, the rate of leaf CO2 assimilation, stomatal conductance and transpiration sharply decreased while intercellular CO2 concentration increased. Similarly stem Yw responded quickly to the suspension and re-start of irrigation, reaching values as low as – 1,9 MPa 2 days after the quit of irrigation. At wilting points soil Ym was: -0.96 MPa for Emilia-Romagna, -0.5 MPa for Basilicata, -1.6 MPa for Calabria, -1.8 MPa for Lazio Folie and -2.3 MPa for Lazio Rosini. CO2 assimilation was better correlated to stem Yw than soil Ym.Key words: soil water moisture, chalk potentiometric probe, leaf gas exchange, stem water potential, soil matric potential

Cover crop nitrogen (N) cycling has an important role in agricultural production and contributes to peach [Prunus persica (L.) Batsch] N nutrition. This study evaluated black oat (Avena strigosa Schreb) and ryegrass (Lolium multiflorum L.) residue decomposition dynamics, N recovery from cover crop residues, and N compartmentalization in peach tree organs. A 2-year field trial was developed with labeled (3.6?4.0 atom% 15N excess) cover crop shoot biomass application in a 5-year-old peach orchard. The region?s climate is warm temperate (Cfb), and the soil is classified as a Typic Hapludalf. Litter bags with unlabeled shoot residues were also deposited in the orchard to assess biomass, carbon (C), N, lignin, cellulose, and non-structural biomass decomposition dynamics. After 13 months, the leaves, trunk, and roots showed the greatest proportion of N derived from residues (Ndfr) (35.4, 25.1, and 22.4%, respectively) while the greatest concentrations of 15N and Ndfr occurred in roots

Made available in DSpace on 2021-06-25T15:06:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-27 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundacao de Amparo `a Pesquisa do Rio Grande do Sul (FAPERGS) Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA) Nitrogen (N) fertilizers such as urea are applied to peach orchards worldwide whenever the soil cannot meet plants' N demand. However, the actual nutritional contribution of different N supply modes applied to peach crops, or the contribution of residual N in the subsequent cycle, is yet to be fully known. The current study aims to assess the annual and residual urea N contribution to the nutrition of peach trees grown under subtropical climate. Forty kilograms of N per hectare supplied as enriched urea (3.0 at. % N-15), were applied to peach in full production at a single rate (100 % at budding) or split in two rates (50 % at budding and 50 % at flowering). Total N-15 and N concentrations in the application year and in the year after treatments were assessed in peach leaves throughout the cycle, in fruits (pulp and stone) at harvest and in stratified soil samples. Total N-15, N concentrations and total dry mass were measured in annual and perennial tree organs in the year after treatment application. Peach trees evidenced higher N deriving from fertilizer (NDFF) in leaves and fruits (pulp and stone) in the year N was applied to the soil, as well as in the following year when N application was split into two rates. The highest NDFF amounts recorded in the year following N application were observed in leaves and fruits (annual organs) and thick roots (perennial organ), mainly when N was splitted. However, mainly in the year following its application, due to the small residual N, the N found in trees derived from sources other than N fertilizer; this justifies annual N applications, whenever necessary. The cultivation of cover crops and the preservation of organic matter could help N peach nutrition that seems to take advantage more of residual N in soil than on fertilizers. Univ Fed Santa Maria, Ctr Rural Sci, Dept Soil Sci, Av Roraima 1000, BR-97105900 Santa Maria, RS, Brazil Univ Fed Santa Catarina, Ctr Agr Sci, Dept Rural Engn, Rod Admar Gonzaga 1346, BR-88034000 Florianopolis, SC, Brazil Fed Inst Educ Sci & Technol Rio Grande Sul, Rua Alberto Hoffmann 285, BR-91791508 Porto Alegre, RS, Brazil Embrapa Uva & Vinho, Rua Livramento 515, BR-95701008 Bento Goncalves, RS, Brazil Univ Bologna, Dept Agr & Food Sci, Viale Fanin 44, I-40127 Bologna, Italy Sao Paulo State Univ Julio de Mesquita Filho, Registro Campus,Rua Nelson Brihi Badur 430, BR-13900000 Registro, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Registro Campus,Rua Nelson Brihi Badur 430, BR-13900000 Registro, SP, Brazil

Bergamot (Citrus × bergamia) is mainly cultivated in Calabria area (Italy) for its essential oil that is widely used in cosmetics, food and medicine. The harvest season (November to February) affects the quality of essential oil, consequently the aim of our study was to evaluate the composition of volatile fractions at different harvesting stages. Two different cultivars, Femminello and Fantastico, were collected in November, December and January and their volatile compounds composition was determined by SPME GC/MS. Fourty‐two compounds were identified. Monoterpenes were the preponderant group; limonene was the most representative compound with similar concentrations in the varieties and at the three harvesting times. β‐Ocimene, β‐mircene and α‐terpinene showed higher concentration in Femminello than Fantastico, while trans‐α‐bergamotene, α‐pinene and citronellal were mostly concentrated in Fantastico. The concentration of β‐pinene in Fantastico and Femminello was higher in December and January, respectively, and γ‐terpinene concentration was higher in Femminello in November and January and in Fantastico in December. Linalool was the most preponderant monoterpene alcohol with a significantly higher concentration in Femminello than in Fantastico, but without significant differences during ripening. cis‐γ‐Bisabolene was the most preponderant sesquiterpene; it was more concentrated in Fantastico than in Femminello and showed a significantly higher concentration in December and January than in November. Linalyl and neryl acetate were the most abundant esters, with a significantly higher concentration in Fantastico. Fantastico seems to be the variety that produces higher volatile organic compounds in essential oil; moreover, the volatile compound concentration was higher at the second and third harvest time.

Rapid analyses methods for the assessment of soil microbiota are lacking. In a commercial farm tomato plants were subjected to different fertilization strategies: 1. mineral Control (C); 2. Organic amendment (O); 3. Organic amendment + Micosat F © biofertilizer (OM). A first rapid method (Litterbag-NIRS) concerned hay litterbags coupled with a smart SCiOTM device. A second method (Foliar-NIRS) used the same device on the leaves. The plants showed positive responses to the amendment and biofertilization in the yield: C 60.5.1 t ha-1vs. 70.8 in O (+17%) and 74.2 in OM (+23% from C and + 5% (P 0.08) from O). The use of Litterbag-NIRS fingerprinting, completed with litterbags phenotyping and elaborated with a multivariate support vector machine classifier provided a similar knowledge to that obtained from microbial and chemical analyses of the soil. The reason for this response is that the analyses were embedded in the Litterbag-NIRS at medium-high precision. A polydromic function was hypothesized in order to disentangle the activities of different soil microbial populations from each other. The organic amendment delayed the functionality of the rapid r-strategist microbial populations, but at the same time activated slow k-strategists to intake the walls of the hay inside the litterbags. In this sense, the Litterbag-NIRS test can provide an effective “swamp” of the microbial fertility of the soil. Briefly, the Litterbag-NIRS coupled with Foliar-NIRS accounted for 95% of the average yield results, and both are therefore recommended for a rational assessment of microbial soil fertility.

Phosphorus (P) availability in subtropical soils does not often meet the nutritional demand of native tree species such as the ipê-roxo tree (Handroanthus heptaphyllus), therefore, it is necessary to supply P at planting. However, the impact of P on root system growth remains unknown. The aim of the current study was to investigate the effect of P application on root morphology of H. heptaphyllus plants over a 36-month period in a subtropical climate region. During the experiment, the plants subjected to fertilization with 40 kg P ha−1 were compared to untreated control. Plant roots were scanned through minirhizotron system 18 and 36 months after transplant (MAT), and generated images were used to determine total root length, mean root diameter and total root volume. Plant height and leaf P concentrations were also evaluated. Phosphorus application enhanced root and whole plant growth with a more evident effect at 36 MAT, when soil P availability decreased. The results give important information on the cultivation of H. heptaphyllus plants in soils presenting low P availability.

Soil analysis is used to estimate nutrient availability, but nutrient concentrations are not always related to yield in most fruit plants, including grapevines. Thus, additional multivariate mathematical models, such as the compositional nutrient diagnosis (CND), which takes into account leaves nutrient concentration, and yield, can contribute to estimating critical levels or sufficiency bands of elements, as well as to detect deficiency and/or excess of nutrients. The aim of the present study was to establish CND standards, and the critical level and sufficiency band of nutrients, in the grapevine Vitis vinifera L., grown in a subtropical climate region. Leaves were collected in 81 vineyards in the Campanha Ga&uacute, cha do Rio Grande do Sul region, Southern Brazil, and analyzed for macro- and micro-nutrient concentration. The yield of each vineyard was assessed. Grapevine nutritional status was calculated through the CND method. CND-r2 indices were effective in establishing the nutritional status of grapevines for macro- and micro-nutrients as sub-optimal, excessive, or balanced. The CND methodology established the critical level and sufficiency bands of nutrients more accurately than the current recommendations for grapevines. Multi-nutrient associations were more effective than the single nutrient determination in defining the threshold of a given nutrient that can reduce grapevine yield.

Dato il crescente interesse che il biochar ottiene come prodotto di risulta di diverse filiere di trattamento di sottoprodotti, residui – e in generale biomasse – appare necessario avviare una sperimentazione volta a confermarne gli effetti agronomici in condizioni di campo e in ambiente temperato. Un crescente numero di lavori scientifici tratta la sperimentazione agronomica del biochar ma, generalmente, per esperimenti di breve termine o per test in vaso e con biochar molto diversificati, che portano spesso a risultati contrastanti e incerti. Il progetto Enochar intende valutare gli effetti dell’applicazione al suolo di biochar – da solo o in miscela con ammendanti prodotti da impianto di compostaggio che tratta scarti agroalimentari di origine naturale (Enomondo, Società del gruppo Caviro) –, sulla fertilità e sulle proprietà fisiche del suolo, sulla risposta vegeto-produttiva della vite in condizioni di campo nel medio-lungo termine (5-7 anni), nonché sul prodotto finale: il vino. Il programma di monitoraggio e lo studio degli effetti dell’applicazione del biochar e delle sue miscele hanno lo scopo di: - acquisire conoscenze agronomiche specifiche per orientare le scelte degli utilizzatori finali e offrire un campo visita agli agricoltori e agli operatori della filiera viti-vinicola - fornire prove ed evidenze scientifiche per i decisori - stimolare un’economia del biochar e quindi collaborare con tutti gli stakeholder chiave coinvolti nel ciclo di vita. La scelta della filiera vitivinicola è legata all’importanza della viticultura in Emilia-Romagna e alla conseguente abbondanza dei suoi residui (Greggio et al., 2019). In particolare, Enochar si pone l’obiettivo di ottenere: - evidenze scientifiche circa l’efficacia dell’applicazione del biochar in viticoltura a medio-lungo termine - il know-how specifico circa le tecniche di produzione del biochar, le modalità e le dosi di somministrazione in campo, nonché i metodi e macchinari per la distribuzione - la promozione della conoscenza del biochar al fine di predisporre le basi per una produzione sistematica e di qualità di biochar, partendo dai residui di potatura della vite.

Wastewater may represent an alternative source for irrigation and mineral nutrients in intensive agriculture, offering potential agronomical and environmental advantages. This work investigates the effect of STW (secondary treated wastewater) used for irrigation, on the nutritional and physiological response of 3-year-old nectarine trees. To this end, trees ('Big Top'/'GF 677') were individually grown on 40-L pots filled with a sandy-loamy soil and drip irrigated with: a) Tap water (U) (unfertilized trees); b) Tap water (M) (mineral fertilized trees) and c) Secondary treated wastewater (W) (trees did not receive mineral fertilizers). Each treatment was applied to five individual trees. Regardless of the water source, trees received 360 L tree‑1 season‑1 and only M-trees received 14.2, 2.35, 8.96, and 0.72 g tree‑1 season‑1 of N, P, K and Mg, respectively, from commercial fertilizers throughout the season. Shoot length and photosynthetic daily assimilation rates were promoted by STW, compared to U trees, although M trees showed the highest values. This response is likely related to the amount of nutrients supplied to the trees along the season. Although STW provided a “fertigation-like” effect, results suggest that this strategy did not completely fulfill the tree nutrient demand. On the other hand, the STW recycling as irrigation water was not detrimental to plant growth. Treatments affected mainly leaf rather than fruit mineral concentration. Mineral concentration resulted mostly in the optimal range for all the treatments, except the U, which showed nutritional deficiencies. Heavy metal concentration both in leaves and fruit tissues was unaffected by treatments, with concentrations within international limits imposed for the human consumption. Results indicate how STW may be conveniently recycled as water source in the irrigation strategies of perennial species grown in temperate environments although this strategy may only contribute to partial fulfilment of plant nutrient requirements.

The continuous use of copper (Cu)-based fungicides in viticulture to counteract fungal diseases has resulted in an accumulation of Cu in the topsoil, sometimes reaching toxic levels that can cause plant stress and reduce soil fertility. A possible strategy to mitigate the negative effects of Cu could include its incorporation into chemical compounds with phosphorous (P). The aim of this study was to evaluate the effectiveness of soil P addition on alleviating the toxic effect of Cu when applied in excess to potted grapevines plants. Micro-propagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu (4 levels: 0, 100, 200 and 300 mg kg-1 dw) and P (2 levels: 0 and 100 mg kg-1 dw) and three replicates. Sixty days after transplant, P was not effective in preventing the accumulation of Cu in vines. The total plant biomass was not influenced by soil Cu addition, while P increased plant growth by enhancing plant nutritional status. In addition, Cu reduced nutrient (P, K and Zn) content in plants. Net photosynthesis and efficiency of photosystem II decreased as a consequence of the increase of Cu concentration in soil. The effect of P in mitigating Cu toxicity was mainly related to the ability of plants to restore nutrient uptake.

Understanding nutrient dynamics within a peach orchard is fundamental to the development of accurate nutrient management practices. The present study investigated the nutrient uptake and redistribution in a 14-years-old commercial orchard in the Po valley. At the end of the experiment, trees were harvested, biomass and organ nutrient concentration were determined. Skeleton and roots accounted for the highest plant biomass, followed by fruits at harvest, pruned wood and abscised leaves; thinned fruits were less than 1 kg tree-1. The difference between the amounts of nutrients in leaves sampled in summer and in autumn (at abscission) was used to estimate the fraction of nutrients remobilized during the vegetative season inside the tree. The decrease of N, P, S, Cu, Mn and Zn concentration in abscised, compared to summer-sampled leaves was the result of the translocation of nutrients into fruits and storage organs. Nutrient circulation in a commercial nectarine orchard was calculated by determination of the fractions of each nutrient recycled (sum of nutrients in abscised leaves, thinned fruits and pruned wood) and remobilized (sum of nutrients in fruits at harvest, roots and skeleton). In our experimental conditions, on average, nectarine Stark RedGold showed an annual request of (in kg ha-1) 100, 17, 73, 129, 16, and 6 of N, P, K, Ca, Mg and S, respectively. More than half of these quantities were recycled in the orchard and returned back to the soil; consequently, if the nutrient use efficiency is maximized, the fertilization of nectarine requires only small amount of external inputs.

Agricultural land abandonment is an emerging problem in European Union (EU), and about 11% of agricultural EU land is at high risk of abandonment in the coming 10 years. Land abandonment may have both positive and negative effects in ecosystems. Due to the potential for land abandonment to increase soil fertility, the study of vegetation succession effects on soil quality is of great importance. In this study, we investigated an abandoned vineyard where, after a period of 30 years, rows and alleys were characterized by two different forms of vegetation succession: natural recolonization by trees along the rows and by herbaceous vegetation in the alleys. No-tilled alleys covered by herbaceous vegetation of a neighboring conventionally cultivated vineyard were used as a comparison. Soil samples were chemically characterized (pH, extractable element, and available and total metals), and analyzed for the determination of carbon (C) and nitrogen (N) pools, hydrolytic and phenol oxidizing (PO) enzyme activities involved in C, N, and phosphorus (P) cycles, and the enzyme ratios. Results highlighted that natural recolonization by trees increased the organic C and N soil pools by 58% and 34%, respectively, compared to the natural recolonization by herbaceous vegetation. Moreover, natural recolonization by trees reduced β-glucosidase by 79%, urease by 100%, alkaline phosphastase by 98%, acid phosphatase specific hydrolytic activities by 50%, and catechol oxidase and laccase specific oxidative activities by 127% and 119%, respectively, compared to the renaturalization by herbaceous vegetation. In addition, the natural recolonization by trees reduced the C (βglu):C (PO) enzymes ratio by 16% compared to that of the conventional vineyard. Comparing the natural recolonization by herbaceous vegetation with that of the conventional vineyard revealed little significant difference (15% of the measured and calculated parameters), in particular, PO activities significantly decreased in the renaturalized vineyard with herbaceous vegetation by 49% (catechol oxidase) and 52% (laccase), and the C (βglu):C (PO) enzyme ratio showed a reduction (−11%) in the vineyard naturally recolonized by herbaceous vegetation compared to the conventional vineyard. This highlights that the type of vegetation succession that takes place after land abandonment may have a significant impact in terms of soil fertility and C accrual potential. These results help to focus attention on the practices used in agro-forestry that should be adopted in abandoned agro-ecosystems to increase their biodiversity, soil C stock, and soil quality, because these indicators are affected by the type of vegetative coverage.

Soil application of fresh organic matter is a way to increase soil organic matter and provide nutrients to trees. The effect of application of organic matter depends on the interaction among soil, root and microbial biomass. The aim of this research was to evaluate the potential release of N for hybrid GF677 (P. persica x P. dulcis) uptake, of 6 neemcakes available on the Italian market compared with fresh leaves of Melia azedarach, an ornamental tree that grows in the area of investigation. The release of N, and consequently root uptake was related to C:N ratio, the lower the ratio the higher the N concentration in plant tissues and plant growth. Using the 15N isotope technique, we found that up to 30% of the N applied with fresh Melia leaves, was accumulated in the tree, however the mineral N concentration in soil and plant and plant growth was not affected by the application of plant derivatives.

Soil is an essential non-renewable resource for plant growth and yield; it undergoes rapid degradation rates in intensive agricultural areas but it has extremely slow formation and regeneration processes. Consequently, soils from agroecosystems are severely depleted of their nutrients and organic matter pools. The excessive use of mineral fertilizers to supply tree with macro- (N, P, K, Ca, Mg, S) and micronutrients (Cu, Fe, Mn, Zn, B) may raise a concern since they may contain potentially toxic elements, are often expensive and can have a negative impact on the environment. Furthermore, the production of urban and industrial organic wastes is increasing worldwide and environmental friendly strategies for their disposal, for example, compost production, have been developed. Consequently, the necessity to reconcile economic and ecological issues has led to the increase of the use of recycled waste organic fertilizers that can synchronize plant need with nutrient release and, at the same time, improve soil fertility. The enhancement of soil organic matter provides storage of nutrients and water, stimulates soil biological activity and improves C sequestration. Several authors reported benefcial effects of organic matter on orchard soil quality and tree performance. In the present chapter, we will discuss the use of organic matter as an alternative to mineral fertilizers evaluating the effect on plant growth, nutritional status and yield performances.

The decline of soil fertility due to intensification of agricultural practice can lead to reduced plant performances; the use of organic amendments could be a valuable strategy to overcome this this problem. The aim of the present study was to verify that the application of organic fertilizers may promote root growth to the detriment of the canopy by evaluating the effects of application of organic fertilizer on CO2 fixation, C partitioning, and plant growth. The experiment was carried out on strawberry (Fragaria × ananassa) plants, potted in 10 L pots. The following treatments were compared, in a complete randomized block design: (1) unfertilized control; (2) mineral fertilization; (3) cow manure (20 g kg−1 soil); (4) compost low rate (20 g kg−1 soil); (5) compost high rate (60 g kg−1 soil). Two months after their application, fertilizers did not affect plant growth; however, the application of compost at the high rate stimulated the 13CO2 assimilation. In the following 2 weeks, plants treated with compost at 60 g kg−1 soil showed a higher amount of 13C than the other treatments; however, the 13C relative partitioning was not affected by fertilization. Root:canopy ratio was decreased by mineral and compost high rate fertilizations, in response to the increase of root N concentration, indicating that root growth was stimulated by low soil N.

Sustainability of food production is a major concern today. This study assessed the environmental impact of fruit production and discussed business implications for sustainability. Data were collected from three agricultural enterprises growing six species of fruit, extending over a total of 34 hectares, and producing roughly one thousand tons of fruit per year. The results of the life-cycle assessment (LCA) showed that several production activities heavily impact the environment: in descending order of absolute terms, fruit refrigeration, agronomic operations, irrigation, and fertilizer use were recognized as the most impacting. Other activities, including agrochemical applications, planting, and plastic use for harvesting and packaging, showed overall lower impacts. The high environmental impact associated with most of the production activities emphasizes the need to make the primary food production cleaner, more resource-efficient, and less energy-intensive. Affordable incremental innovations able to reshape the way business is conducted in the context of primary food production are proposed, mainly relying on process rationalization and digital switchover. The analysis of the business path toward increased sustainability involves strategic issues, ranging from the reshaping of production processes to relationships with consumers, affecting value proposition, creation, and capture.

The search for sustainable source of N, the need of soil organic matter restoration, along with the call for recycling of organic wastes has led to a rise of the use of organic fertilizers. The aim of the present experiment was to evaluate: the effectiveness of compost application as a N fertilizer, the impact on N distribution in soil and plant and on tree performances, in a long-term experiment (14 years). The study was carried out in the Po valley, Italy and, since orchard planting (2001), the following treatments were applied: 1. unfertilized control; 2. mineral fertilization; 3. compost at a rate of 5 t DW ha −1 yr −1 ; 4. compost at a rate of 10 t DW ha −1 yr −1 . Soil total N, potentially mineralizable, microbial and extractable N were higher in compost in comparison to mineral (fertilizer). The effect was found both in the row and in the inter-row and the rise of N fractions was evident in the shallowest soil layer of the row. Soil mineral, potentially mineralizable N was increased by mineral (11.1 mg kg −1 ) and compost 10 (12.4 mg kg −1 ) fertilization compared with control (6.7 mg kg −1 ). Vegetative growth and yield were increased in trees treated with mineral and compost 10; moreover, these plants were able to recycle (66.1 and 70.5 kg ha −1 yr −1 , respectively) and remobilize (41.5 and 48.7 kg ha −1 yr −1 , respectively) a higher amount of N than those of control and compost 5. In conclusion, organic fertilization strategy promoted the buildup of soil N reserve, meaning a capacity of the ecosystem to sequestrate N. The application of compost 10 showed a similar effect on plant growth and production as mineral fertilization, but introduced the advantage of the use of a cheap, renewable waste material, providing a new insight on N fertilization management.

The aim of the present experiment was to evaluate the effectiveness of soil electrical conductivity (EC) measurement as a fast tool to assess mineral nitrogen (N) in orchards, in order to define precise N inputs that can help farmers to reduce useless fertilizer application. During one vegetative season, seven orchards of different species, supplied with mineral or organic fertilization, were monitored. Nitrate soil concentration was measured monthly by laboratory analyses, while soil EC and moisture were recorded continuously by soil probes. Nitrate and EC were positively correlated, laying the foundation for the identification of a fast and reliable index. However, while some dates showed a high Pearson correlation coefficient, no correlation was found for others. The correlation was not affected by type of fertilizer, and was higher in silty-clay-loam than in loam soils. Pooling all of the data, a significant correlation with a Pearson coefficient of 0.75 was found. The soil optimal nitrate N availability was defined by an EC in the range of 0.3 to 0.6 mS cm&minus, 1. Although these are only preliminary results, our data are promising, showing a good suitability of soil EC measurement as a means to monitor soil mineral N availability.

The objective of this experiment was to valuate, after 14 years, the impact of annual compost applications on micronutrient and potentially toxic trace elements on nectarine tree uptake and soil fertility. The study was performed in the Po valley, Italy, on the variety Stark RedGold (grafted on GF677). Since orchard planting, the following treatments were applied, in a randomized complete block design, with four replicates: 1. unfertilized control; 2. mineral fertilization (N was supplied as NO3NH4 at 70–130 kg ha−1 year−1); 3. compost at 5 t DW ha−1 year−1; 4. compost at 10 t DW ha−1 year−1. The actual rate of application was 12.5 (LOW) and 25 (HIGH) t ha−1, since compost was concentrated in the tree row. Compost was made from domestic organic wastes mixed with pruning material from urban ornamental trees and garden management and stabilized for 3 months. The supply of compost HIGH induced an enrichment of soil total Cu, Zn and Cd, and a decrease of Fe and Co concentration; with values always below the European threshold limits for heavy metals in the soil. In addition, compost (at both rates) increased availability (DTPA-extractable) of Fe, Mn and Zn, Cd, Ni, and Pb in the top soil (0–0.15 m). Total micronutrient and trace element tree content was not affected by fertilization treatments; however, the recycled fraction returned to the soil at the end of the season through abscised leaves and pruned wood of Cu, Fe, Mn and Zn was increased by mineral fertilization; Fe and Zn also by compost HIGH. Our data show that the introduction of compost at both 12.5 and 25 t ha−1 year−1 in the row did not increase the risk of pollution related to potentially toxic trace elements and at the same time increased the bioavailability of Fe, Mn and Zn.

Study’s objective was to evaluate spatial variability of herbaceous cover species community in vineyards cultivated in soil with increasing Cu levels in Pampa biome. Three vineyards, with increasing soil Cu available contents and a natural field area (NF), were selected. In each experimental area, soil Cu content, botanical composition, cumulative aerial biomass, and aerial part Cu concentration, in most frequent species, were evaluated. In total, 39 vascular plant species were identified, including four exotic species. Biodiversity indicators did not significantly correlate with soil Cu. However, botanical composition variation could be observed. In NF, Poaceae and Asteraceae families presented greater dry mass contribution, while this contribution decreased in higher soil Cu concentration areas. The Cu concentration and accumulation in plant aerial part were higher in older vineyards, as plant aerial part accumulated, in average, 13.8mg Cu m−2. Among species found in experimental fields, Ageratum conyzoides, a species known to form Cu-tolerant populations, occurred in most areas, especially in vineyards, presenting higher aerial Cu concentrations, with a mean of 126.47mgkg−1. Soil enrichment with Cu did not alter the vegetation’s biodiversity, but may have contributed to the botanical composition modification. The native species, P. plicatulum and A. conyzoides, presented a high bio-accumulation factor and are potential candidates for phytoremediation techniques.

The effectiveness of post-harvest foliar-applied Fe(II)-sulfate was assessed and indices were tested for precocious prognosis of Fe-chlorosis in field-grown pear trees. In a commercial pear (Abbé Fétel/BA 29) orchard, Fe-induced chlorotic trees were sprayed in early autumn with a Fe(II)-sulfate heptahydrate solution and compared with water-sprayed control trees. Leaf Fe concentration was higher in senescent and abscised leaves of Fe-sprayed trees, indicating that Fe was taken up. However, phytotoxic symptoms occurred and leaves fell earlier than in untreated trees. Fe(II)-sulfate spray increased Fe concentration of flower buds and fruiting spur leaves as well as leaf Chl values. Yield was increased in sprayed trees by about 13%, mostly associated with a higher fruit number per tree rather than fruit size, indicating an improved fruit set. We hypothesize that a fraction of the absorbed Fe contributed to sustain Fe requirements of the newly formed organs as from growth resumption. Summer leaf SPAD readings were positively correlated with Fe concentration of flower buds, fruiting spur leaves and, in particular, with senescent and abscised leaves. Our findings suggest the effectiveness of the post-harvest foliarly applied Fe(II)-sulfate to improve Fe nutrition of pear trees the following season. Rather than inducing a temporary re-greening, our approach is based on the fact that high Fe-rates sprayed before leaf fall may contribute to increase Fe pools within perennial organs. We propose utilizing leaf Fe concentration of senesced and abscised leaves as a predictive tool for the diagnosis of the Fe-chlorosis occurrence in pear trees.

The sustainable approach to fruit crop fertilization focuses on the increasing and maintaining of soil fertility. The utmost parameter that defines soil fertility is its content in organic matter (OM) that can be increased by temporary or permanent intercropping, mulching, and adoption of amendments originated by the recycling of organic by products. To increase nutrient use efficiency, the release of nutrients, as a consequence of the mineralization of OM, and root uptake timing should be synchronized, particularly for those nutrients (i.e., mineral N) that are not hold by soil nutrient holding capacity. The rate of nutrient application is the result of tree requirement and soil availability. The former is estimated by the amount of nutrient found in the different tree organs during orchard lifetime. Soil fertility is measured, during the growing season, by soil analysis, and it is recommended particularly for nutrients that are easily leached out with the excess of water.

The continuous use of copper-based fungicides in viticulture to contrast fungal diseases may result into an accumulation of Cu in the topsoil, reaching toxicity levels for plants and soil biota. A possible strategy to mitigate the negative effects of excess of Cu could involve the formation of insoluble molecules by the application of P to the soil. The aim of this study was to evaluate the effectiveness P soil application as a strategy to alleviate the toxic effect of excess of Cu on potted grapevines plants, with particular emphasis on the physiological response of plants. Micropropagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu (4 levels: 0, 100, 200, 300 mg kg−1 dw) and P (2 levels: 0 and 100 mg kg−1 dw) and three replicates. Net photosynthesis, efficiency of PSII photochemistry and linear electron transport rate decreased as soil Cu concentration increased. The addition of P increased net photosynthesis, improved the efficiency of PSII photochemistry and linear electron transport rate, but decreased stomatal conductance. As a consequence, shoot and root biomass declined with the increase of Cu concentration in soil, while the increment of P tackled this decline and improved nutritional status. CuEDTA extractable fraction in soil was increased by both the supply of Cu and P; this because the addition of P in combination with the highest Cu soil concentration determined a decrease of soil pH. In conclusion, the addition of P to the soil mitigated Cu excess toxicity symptoms in grape through a preservation of photosynthetic apparatus efficiency and an improvement of nutrient uptake.

The aim of the present study was to evaluate the effectiveness of P soil addition to mitigate the toxic effect of excess of Cu on grapevine on sandy non-calcareous soil. Micro-propagated plants of 1103 Paulsen rootstock were grown according to a factorial experimental design with two factors: Cu addition (0, 100, 200 and 300 mg kg −1 dw) and P addition (0, 50 and 100 mg kg −1 soil dw). The experiment was conducted in the greenhouse and plants were grown on a sandy soil in rhizoboxes. At the end of the trial, plants were destructively harvested, the biomass and the nutrient concentration of organs were determined. Root growth was evaluated during the trial and the concentration of organic acid in root tissue and exudates was determined. Shoot length and plant biomass declined as Cu concentration in soil increased; the application of P enhanced plant growth and nutritional status. Root biomass decreased at Cu > 100 mg kg −1 and increased in P at 100 mg kg −1 . Phosphorous stimulated root length, diameter and the number of apexes. Root citric acid increased as a response of Cu at 300 mg kg −1 , root ascorbic acid decreased with the increase of Cu (200 and 300 mg kg −1 ) and P at 100 mg kg −1 . The concentration of citric acid from root exudations was higher in Cu at 300 mg kg −1 and Cu at 200 mg kg −1 (compared to control) and P at 100 mg kg −1 soils. The application of P fertilization seems to be a valuable strategy to overcome the toxicity of high concentration of Cu in soil.

Made available in DSpace on 2020-12-10T19:37:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-12-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Mineralized nitrogen (N) from organic matter and decomposing residues in most soils are not always taken into account. Little is known about the correct N application dose for pear trees to promote yield and fruit quality, without increase the risk of N loss into the environment. The study aimed to evaluate the effect of N doses application on N soil content, tree yield and fruit quality. The treatments consisted of the application of 0, 40, 80, 120 and 160 kg N ha(-1) year(-1), whereas urea was applied on the soil surface in September and February for 5 seasons (2011/12 to 2015/16). Leaves were collected, prepared and submitted to nutrient analysis. Fruit weight, number and yield were evaluated. Soil samples were collected at 0-0.20 m for 3 seasons (2013/2014 to 2015/2016), prepared and submitted to NH4+-N and NO3-N analysis, and then mineral N content was calculated. Peel color, ethylene production, and respiration rate were analyzed in the 2015/2016 crop season after 90 days inside the controlled atmosphere storage chamber. The fruits were kept at ambient conditions for 7 days and evaluated again for peel color, ethylene production and respiration rate, as well as destructive parameters such as titratable acidity, soluble solids and pulp firmness. The doses of N application affect the fruit number and yield, but did not affect leaf nutrient concentration. The highest N levels in the soil were observed in the 2014/2015 and 2015/2016 crops. The most economical doses were 122.0, 66.4, 22.5 and 96.0 kg N ha(-1) in the crops of 2011/2012, 2012/2013, 2013/2014 and 2015/2016 respectively. Univ Fed Santa Catarina, Rodovia Admar Gonzaga 1346, BR-88034001 Florianopolis, SC, Brazil Expt Stn Epagr Sao Joaquim, Rua Joao Araujo Lima,103, BR-88600000 Sao Joaquim, SC, Brazil Univ Fed Santa Maria, Ave Roraima 1000,CP 221, BR-97105900 Santa Maria, RS, Brazil Univ Bologna, Viale Fanin 46, Bologna, Italy Embrapa Temperate Climate, CP 403,Rodovia BR 392 Km 78, BR-96010971 Pelotas, RS, Brazil Estate Univ Paulista Julio de Mesquita Filho, Campus Registro,BR 116,Km 449, BR-11900000 Registro, SP, Brazil Estate Univ Paulista Julio de Mesquita Filho, Campus Registro,BR 116,Km 449, BR-11900000 Registro, SP, Brazil CAPES: 001