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In Brazilian vineyards planted in sandy soils, nitrogen (N) should be applied at optimal rates and timing that correspond to greatest demand, thus minimizing N losses. The aim of this study was to evaluate the grapevine N distribution and recovery of urea- 15 N applied at budding and bloom. In 2009, in a vineyard ( Vitis vinifera cv. Cabernet Sauvignon) planted in Santana do Livramento, south Brazil, grapevines were treated with 10 kg N ha −1 at budding +10 kg N ha −1 at full bloom (10B + 10F); 20 kg N ha −1 at budding +20 kg N ha −1 at full bloom (20B + 20F); 20 kg N ha −1 at budding (20B); and 40 kg N ha −1 at full bloom (40F). Budding of grapevines in 2009 and 2010 was at the end of August and full bloom in November. In February 2010 and 2011, grapevine organs (leaves, berries, stem and roots) were collected, and in February 2011 soil samples were also collected in the profile. The wine-producing grapevines grown in the sandy soil took up more N derived from 20B treatment, compared with other N treatments, especially in the first crop season. The N derived from fertilizer applied at different rates and time was preferentially distributed in annual plant organs, but most N contained in the plant organs was derived from other sources than the fertilizer N. In the following season, 15 N applied in the previous year was recovered preferentially in leaves and fruits, again in low amounts. Nitrogen derived from fertilizer applied at different rates and time in a sandy soil apparently contributes little to grapevine nutrition. [ABSTRACT FROM AUTHOR]

Symbioses with arbuscular mycorrhizal fungi (AMF) may increase plant tolerance to heavy metals, in addition to the improvement in phosphorus (P) uptake by plants. This study evaluated the effects of the interaction between an increase in the soil phosphorus level and the colonization by Rhizophagus clarus on several biochemical and physiological parameters of Crotalaria juncea plants cultivated in a soil with a high copper (Cu) level. Plant growth and photosynthetic pigment fluorescence parameters, as well as the superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) enzyme activities in C. juncea plants, were analyzed. The experiment was conducted in a greenhouse, and a 3 × 2 factorial design was employed, including the natural P level, 40, and 100 mg P kg −1 , with and without R. clarus inoculation, with three replicates in a soil with a high Cu level (65 mg kg −1 ). The results demonstrate that the combination of the addition of P together with AMF inoculation improved the plant nutritional status, with consequent increases in the levels of P, K, Mg, Fe, Zn, and chlorophyll a fluorescence parameters . Furthermore, mycorrhization and phosphorus addition increased the activities of the SOD and CAT enzymes, which are responsible for the removal of reactive oxygen species when plants are exposed to high Cu levels. This synergistic effect between P application and inoculation with R. clarus could be of technological interest for achieving increased growth of C. juncea cultivated in soils with high Cu levels via the promotion of effective mechanisms for reducing Cu phytotoxicity. [ABSTRACT FROM AUTHOR]

Highlights: [•] The recovery of N by ‘Niagara Rosada’ grape from the decomposition of rye residues deposited on the soil surface was evaluated. [•] We used in the study rye residues labeled with 15N. [•] The N derived from the litter of rye added into the soil surface was accumulated at similar percentage in the annual and perennial organs of the ‘Niagara Rosada’ grape. [•] The N derived from litter of rye apparently contributed little to the ‘Niagara Rosada’ grape nutrition in the time length studied. [ABSTRACT FROM AUTHOR]

The use of organic wastes in southern Brazil is a common practice in the farms and in many of these, the criterion for defining the doses of organic wastes is to meet the N demand by crops. This may mean the accumulation of chemical elements in the soil, especially in soils managed under no-tillage systems, and enhance the transfer of these elements by surface runoff. The aim was evaluated how successive applications of organic and mineral sources of nutrients in a long-term experiment, managed under no-tillage system in a subtropical environment, influence the transfer of quantities and forms of N and P by surface runoff. The experiment was carried out in southern Brazil, in a Typic Hapludalf soil. The treatments consisted of the application of pig slurry, pig deep litter, cattle slurry, mineral fertilizer and a control, without nutrients. The doses of organic wastes were to meet the N demand by crops. Were evaluated the surface runoff and the transfers of mineral N and forms of P (soluble, particulate, and total) from 2009 to 2013 period. The amount of solution transferred by surface runoff decreased with fertilization and present a negative relationship with the soil organic matter (SOM). The transfers of mineral N increased with the increase in the contents of SOM, but decreased with the runoff. The transfers of P forms present a great relationship with the amounts of P applied and the contents of soil P extracted by Mehlich-1, and more than 55% of total P transferred by surface runoff, in the treatments that received nutrients application, is on soluble form. In addition, the transfer of soluble, particulate and total P was lower with mineral fertilizer application, when compared with organic wastes. This suggest that the use of N demand by crops as a criterium to meet the doses of organic wastes is not adequate in subtropical environment. • Use of organic wastes as a source of nutrients for plants allows to close nutrient cycles. • The use of nitrogen to set the dose of organic wastes, adds high amounts of phosphorus to the soil. • The organic wastes use increased transfers of nitrogen and phosphorus by surface runoff. • The transfers of nitrogen and phosphorus by surface runoff cause contamination of water sources. • Need to reduce the quantities of organic wastes applied, adjusting the requirements of crops. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Increased phosphorus (P) available in soil can modify the partitioning of P forms in annual and perennial organs of grapevines throughout the growing season. This study was to evaluate the distribution and redistribution of P forms in organs of grapevines grown in soils with different contents of available P. The study was conducted in two vineyards installed in the city of Santana do Livramento, state of Rio Grande do Sul (RS), in southern Brazil. The treatments were vineyard 1 (V1) with 11.8 mg kg −1 of available P in soil and vineyard 2 (V2) with 34.6 mg kg −1 . The cultivar of both vineyards is Tannat ( Vitis vinifera L.) grafted on SO4 ( Vitis berlandieri × Vitis riparia ) rootstock. Plant density per hectare was 2525 (1.2 m × 3.2 m) on a spur pruned cordon system. The grapevines were uprooted and partitioned into roots, trunks, arms, spurs, new-year shoots, leaves and clusters (when present) at flowering (F), veraison (V), harvest (H) and dormancy (D). The organs were dried, prepared and subjected to chemical fractionation of P, to estimate fractions of total acid-soluble P (P ST ), acid-soluble inorganic P (P SI ), acid-soluble organic P (P SO ) (by difference between T SP and P SI ), phospholipids P (P LIP ), P associated with RNA (P RNA ), P associated with DNA (P DNA ) and residual P (P RES ). P in grapevines of V1 and V2 accumulated mainly in the P SI fraction in leaves and clusters, which was collected at F, V and H, and in P SO fraction in roots, collected at D. Part of the root P SI was redistributed at F to the leaves and clusters in vines of V1. Vines grown in V2 accumulated more P in P SO form in roots and tended to redistribute less P SI to the leaves and clusters after F. Grapevines accumulated P in roots, both in soils with low and high available P contents, and P was subsequently redistributed and accumulated in leaves and clusters in inorganic form. [ABSTRACT FROM AUTHOR]

Long-term applications of organic amendments, such as pig slurry (PS), may represent environmental risk of soil and water pollution by trace metals (TM). Our objective was to examine different soil and manure management scenarios that enhance the long-term agricultural use of soils under repetitive PS applications while avoiding environmental risk. Firstly, we developed a new module for simulating the impacts of soil tillage frequencies in Hydrus-1D. Secondly, we used a previously validated modeling approach to predict the surface accumulation and movement of the TM during the next 100-year in the soil under different PS doses (80 and 40 m 3 ha −1 cultivation −1 ) and tillage frequencies (no-tillage and 20, 10, and 5-year tillage). No-tillage simulations revealed consistent TM surface accumulations, reaching the soil threshold value for Cu in the 0–20 cm layer after 86 years of PS amendments at high doses, but in layers 0–5, 0–10, and 5–10 cm, this concentration was already reached after 17, 38, and 75 years, respectively. While soil tillage reduced TM concentrations over the top 20 cm of the soil profile, it increased their transfer to deeper layers. Periodical soil tillage each 5, 10, and 20 years was found to allow PS applications without reaching the Cu threshold value in soil during 100 years. However, soil solution concentrations of Zn reached the threshold values for groundwater. Therefore, the best manure management practice for the long-term PS disposal with respect to Zn and Cu concentrations in soil is the application of moderate PS rates. [ABSTRACT FROM AUTHOR]

Foliar fungicide application in grapevines increases the content of heavy metals such as copper (Cu) in vineyard soils, which may reach phytotoxic levels. The application of soil amendments such as limestone and vermicompost may reduce Cu availability and phytotoxicity. The study aimed to assess growth, physiological status and changes in root morphology in young grapevines grown for 12 months in Cu-contaminated soil with and without the application of soil amendments. Samples of a Typic Hapludalf soil were collected in a vineyard with more than 30 years of cultivation. The following treatments were used: 1) control (without amendment), 2) application of organic vermicompost (86.7 g kg−1) and 3) application of limestone (3 Mg ha−1). Grapevines (Paulsen 1103 rootstock) were transplanted and grown for 12 months in PVC soil columns. We assessed parameters of growth, photosynthesis and root morphology. Grapevines grown in soil treated with limestone showed increased growth, dry matter yield and photosynthetic efficiency. The highest Cu concentrations in root tissue were found in grapevines grown in control soil. The application of vermicompost in this study did not alleviate Cu toxicity. Grapevines grown in soil treated with vermicompost showed high manganese (Mn) concentration in shoots before the winter pruning, reflecting the high Mn concentrations in soil solution that caused Mn phytotoxicity, resulting in plant death after the winter pruning. The vermicompost used in this study is not suitable for agronomic use. The use of limestone was an effective strategy to reduce Cu availability and phytotoxicity. • The use of limestone was an effective strategy to reduce Cu availability and phytotoxicity. • Cu-contaminated soil treated with limestone showed higher growth and development of young grapevines. • Vermicompost was not an effective alternative as a soil amendment. • Cu-contaminated soil treated with vermicompost showed high Mn concentration in soil solution that caused Mn phytotoxicity. [ABSTRACT FROM AUTHOR]

Peach ( Prunus persica L.) rootstock cultivars are typically selected for scion compatibility, ease of propagation, vigor, development, flowering season, yield, low need for cold temperatures, resistance to diseases, effects on the physical-chemical characteristics of the fruit, plant longevity and adaptation to adverse edaphoclimatic conditions. However, kinetic parameters related to nutrient uptake efficiency are usually not considered, such as those of nitrate (NO 3 − ) and ammonium (NH 4 + ). N is the nutrient that most impacts growth and yield. The objective of this study was to show the importance of the kinetic parameters of NO 3 − and NH 4 + uptake as additional criteria for selecting peach rootstocks. The experiment was conducted in a greenhouse. Three rootstock (‘Aldrighi’, ‘Tsukuba1’ and ‘Clone 15′) were grown for 30 days in a pot containing 0.1 mol L -1 CaSO4 solution to reduce internal reserves of N. Afterwards, the plants were placed in Hoagland nutrient solution, where periodic collections of the nutrient solution were carried out for three days and the concentrations of NO 3 − and NH 4 + were determined. After the third day of collecting the solution, the plants were collected and then separated into leaves, roots and stems. Dry matter and total N content were assessed. The kinetic parameters related to NO 3 − and NH 4 + uptake (maximum uptake rate - V max , affinity constant - K m , Minimum concentration - C min , Influx - I) were calculated using Cinética software. The most efficient rootstock for NO 3 − and NH 4 + uptake was ‘Tsukuba1’, as it showed the lowest values ​​of C min and K m and the highest values ​​of V max and I max for NO 3 − and NH 4 + . NO 3 − uptake in ‘Tsukuba1’ and ‘Aldrighi’ showed a two-phase uptake pattern, suggesting the presence of low and high affinity transport systems. On the other hand, NH 4 + uptake in the three cultivars apparently followed a one-phase uptake pattern, suggesting the presence of a high affinity transport system. The kinetic parameters of NO 3 − and NH 4 + uptake are additional criteria that can be used in selecting peach rootstocks, as they directly influence shoot and root dry matter production and N accumulation in leaves. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) improve plant ability to uptake P and tolerate heavy metals. This study aimed to evaluate the effect of available P and the inoculation of Rhizophagus clarus in a Cu-contaminated soil ( i ) on the activity of acid phosphatases (soil and plant), the presence of glomalin, and ( ii ) in the biochemical and physiological status of Mucuna cinereum . A Typic Hapludalf soil artificially contaminated by adding 60 mg kg −1 Cu was used in a 3 × 2 factorial design with three replicates. Treatments consisted of three P levels: 0, 40, and 100 mg kg −1 P. Each P treatment level was inoculated (+AMF)/non-inoculated (−AMF) with 200 spores of R. clarus per pot, and plants grown for 45 days. The addition of at least 40 mg kg −1 P and the inoculation of plants with R. clarus proved to be efficient to reduce Cu phytotoxicity and increase dry matter yield. Mycorrhization and phosphate fertilization reduced the activity of enzymes regulating oxidative stress (SOD and POD), and altered the chlorophyll a fluorescence parameters, due to the lower stress caused by available Cu. These results suggest a synergism between the application of P and the inoculation with R. clarus , favoring the growth of M. cinereum in a Cu-contaminated soil. This study shows that AMF inoculation represents an interesting alternative to P fertilization to improve plant development when exposed to excess Cu. [ABSTRACT FROM AUTHOR]

• N addition promotes the increase in the surface area of live fine roots. • Fine root production is higher in grapevine flowering stage. • N concentration in leaves is promoted by the increase in the fine roots. • Total number of dead and mortality of fine roots is increased by the addition of N. Nitrogen (N) supply to the soil via fertilization can influence important processes of the root system growth, which can increase N uptake and, consequently, the shoot growth. In this context, the study aimed to evaluate how the application of N levels can affect the dynamics of spatial and temporal growth of the root system of grapevines (Vitis vinifera L.) in sandy soil and subtropical climate. 'Alicante Bouschet' grapevines, grafted on 'Paulsen 1103' rootstock, implanted in 2011. The N addition were: Low N: control (without the N addition; 0 kg N ha−1 year−1); Medium N (40 kg N ha−1 year−1); and High N (100 kg N ha−1 year−1). The study was carried out during 2016/17 and 2017/18 crop seasons. N concentration in the leaves and morphological parameters of fine roots were evaluated using the minirhizotron technique. The addition of Medium N and High N significantly increased the values ​​of the total surface area of ​​live fine roots and the total number of live and dead fine roots, at 0-20, 20-40 and 40-60 cm soil depth, in both crop seasons evaluated. The addition of Medium N and High N also directly influenced the production rates of live fine roots, with patterns of seasonal changes, especially increased in the flowering stage of the grapevines. This occurs due to the increase in the physiological demand of growing plant tissues, such as new roots, leaves and fruits. [ABSTRACT FROM AUTHOR]