1,721,140 research outputs found
Nutritional implications of organic management in fruit tree productio
No full textThe most distinctive features of tree mineral nutrition in organic farming systems is related to the concepts that the target of fertilization is the soil rather than the tree. The best way to achive this goal is to increase soil organic matter (OM) content through the use of: 1. raw or stabilized manures (i. e. compost obtained from the controlled biological decomposition of organic material), 2. floor permanent grass management, 3. mulches, 4. abscised leaves, and pruned wood, etc. Fresh OM, such as raw manure (animal and green), cover crop, mulch, etc. with a C:N ratio < 20 should be tilled into the soil to achieve a net release of N. If OM with a C:N ratio > 20 is incorporated into the soil, microbes use available soil N to break down organic residues and a soil N depletion is expected as well as an increase in soil humus content. Attention must be payed when fresh OM is incorporated into the soil because it may create anoxia conditions. When nutrient deficiencies appear, fertilizers with a fast release of minerals such as blood meal (N = 5-12%), fish meal (N = 5%), natural guano (N = 16%), poultry manure (N = 3.7%) should be used. Stabilized manure and municipal solid waste (MSW) compost present a slower N release rate, but allow a complete ‘nutrient cycling’ (the breakdown of organic substances, release of energy and matter captured by life processes and their use to stimulate the new growth). In addition, by incorporating MSW composts into the soil there is a sequestration of C that otherwise would follow disposal processes with a potential release of CO2 in the atmosphere. Iron organic management of fruit trees is a major issue in calcareous soil, where prevention of leaf chlorosis might be achieved by appropriate agronomic techniques that include: introduction of tolerant rootstocks, increase in OM soil content, consociation with graminaceous such as Festuca spp. known to produce natural Fe chelators phytosiderophores (i. e. mugineic acid), use of blood meal that contains the Fe chelator heme group
Ottimizzare la concimazione del kaki valutando le asportazioni minerali.
No full textL’indagine sulle asportazioni minerali condotta in varie aree di coltivazione del kaki in Emilia-Romagna ha permesso di conoscere i valori parametrici dei vari elementi nutritivi che entrano in gioco nella definizione del piano di concimazione, in particolare nella scelta della formula NPK più idonea, al fine di rendere razionale ed ecologicamente sostenibile questa importante operazione
Carbon translocation and root respiration in potted apple trees during conditions of moderate drought
No full textThe experiment was conducted to investigate the partitioning of carbon 13 (13C) and the relationship between root C allocation and root respiration rate in 'Redcort'/M.7 and rooted cuttings of B.9. Canopies were pulsed with 13CO2 and isotopic emissions from the soil were monitored after pulse labelling. Mildly water stressed potted trees were compared with a well-watered treatment. In 'Redcort'/M.7, water stress, over a 7-day period, reduced predawn leaf water potential and root efflux rate of 13CO2 (up to 55% reduction measured 60 hours after pulse labelling). However, 13C partitioning to the roots was not reduced by low soil moisture. Evolution rate of 13C from the roots was not related to the amount of 13C allocated into the roots themselves. In B.9, 13CO2 emission from the soil was monitored for 16 days. A decrease in root respiration (up to 53% on the first day after the pulse) was the first response to soil water deficit treatment even when drought stress was not effective in reducing leaf gas exchange. These results suggest that during water deficit conditions, roots appear to use a lower proportion of their total carbon content for respiration. 13C partitioning within the tree was not affected by water supply over the duration of the experiment
Organic Fertilization of Fruit Trees as an Alternative to Mineral Fertilizers: Effect on Plant Growth, Yield and Fruit Quality
No full textSoil 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
Mineralization dynamics of different commercial organic fertilizers from agro-industry organic waste recycling: an incubation experiment
Full text linkThe mineralization process of different commercial organic fertilizers was investigated in controlled laboratory conditions. The soil was mixed with the following organic fertilizers: Emos CAP®, Organ CAP®, Sic Stal® and urea (as a control) at the rate of 300 mg N/kg dry soil. Emos CAP® is made of cattle and poultry manure, meat, bone meal and dried blood, Organ CAP® is a product made of leather and skins, while Sic Stal® contains cow and horse manure. During the incubation the concentration of NO3–-N, NH4+-N, microbial biomass and carbon dioxide, nitrous oxide and ammonia emissions were determined. All fertilizers showed a peak of NH4+-N after 7 days from the beginning of the test. The decomposition of Sic Stal® caused a rapid rise of CO2 production associated to the growth of microbial biomass while Emos CAP® promoted a release of N2O in the first 16 days. In conclusion, all the commercial organic fertilizers tested can be considered fertilizers with a fast release of N, among them Emos CAP® and Sic Stal® allow a rapid N supply to plants while Organ CAP® could be used when the N request of plants is not immediate
Effects of root-zone temperature on nitrogen accumulation by non-bearing apple trees
No full textNon-bearing, potted, apple plants were subjected to root temperature of 8 +/- I(LRT) or 23 +/- 1 degrees C (HRT) and irrigated with 100 mi of water containing 20 mg of N as NH4NO3, in which both ammonium and nitrate-N fractions were enriched in N-15 (10 atom%). The root system of each plant was pressurized (325 kPa) at day 1, 2, 4, and 8 after N-15 application to evaluate the transport of nitrogen derived from fertilizer (NDFF) through the xylem. This technique was used to investigate N absorption. LRT reduced the rate of N uptake the day after N-15 application relative to HRT. Two, 4 and 8 d after fertilization, the rate of exudation and consequently the uptake rate was similar for LRT and HRT. The total amount of N removed by plants after 8 d was not affected by root treatments. Carbon dioxide assimilation, transpiration rate and stomatal conductance were lower for trees subjected to LRT during the time course of the experiment. We suggest that the delay in N absorption was related mostly to the lower activity of root nitrate reductase detected at the lower root temperature, which increased the nitrate xylem sap concentration and diminished the rate of N uptake
Effect of agro-industry by-products on soil fertility, tree performances and fruit quality in pear (Pyrus communis L.)
Full text linkOrganic materials from agro-industry processes can be used in agriculture as a way to recycle materials that still maintain a high fertilizing value. The aim of the experiment was to evaluate the value of soil applied apple juice by-product as fertilizer for pear trees. A 3-year experiment was carried out in a mature pear orchard (cv Abbé Fétel grafted onto quince MC) in the Po valley (Italy), where the following treatments were compared: 1) unfertilized control; 2) mineral N fertilization (60 kg N ha−1 year−1 split in two spring applications); 3) apple juice by-product (1.3 t ha−1 year−1, equal to 60 kg N ha−1), fully supplied at petal drop; 4) apple juice by-product, at twice the rate of the previous treatment. Apple juice by-product soil decomposition accounted for 12% in the first 6 months. At the end of the 24-month-assay, the decomposition accounted for 24% on total dry weight that makes 28% of initial C and 36% of initial N. Soil nitrate-N concentration was increased by the mineral N fertilizer, while the application of apple juice by-product increased microbial carbon. Tree growth, yield and fruit quality were not affected by treatments, while mineral N fertilization raised leaf and fruit N concentration. In conclusion, in our conditions the use of apple juice by-product did not show negative effects on tree performances and fruit quality, with some advantages related to the recycling of organic wastes in agriculture
Nitrogen partitioning in apple trees as affected by application time
No full text15Nitrogen-ammonium nitrate was applied to four 'Mutsu' apple (Malus x domestica Borkh.) trees 40 days before harvest of 1996 (summer supplied nitrogen, SUN) and four others at full bloom in 1997 (spring supplied nitrogen, SPN) to evaluate the effect of application timing on N partitioning in mature trees. At leaf fall the largest amount of SUN was partitioned to roots and 2- to 4-year-old wood; the largest amount of SPN was partitioned to fruit and leaves and only a small amount detected in the roots. SUN did not increase N concentration in fruit or modify fruit firmness and soluble solids concentration, although it contributed to building up N reserves in the perennial woody organs. In 1997, as a result of the different timings of N supply, two sources of labeled N were distinguished and monitored in the vegetative organs: 1) the remobilized N, taken up in summer of 1996, stored in winter and then translocated to the growing tissues; 2) the newly absorbed N, taken up and moved to the canopy after the 1997 spring supply. Both fractions of remobilized and newly uptaken labeled N contributed to leaf and fruit N. Remobilized 15N was provided principally by roots which, from August to leaf fall, decreased their percentage of 15N by ≃18%, replacing the labeled with unlabeled N to maintain a constant concentration of total N
Evaluation of nutrients removed and recycled in a commercial peach orchard over a 14-years-production cycle
Full text linkUnderstanding 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
Migliorare lo stato nutrizionale delle piante con la gestione del suolo
No full textNell’ambito di un progetto finanziato dalla Regione Emilia-Romagna e coordinato da Apofruit Italia, è stato valutato l’effetto di alcune pratiche agronomiche biologiche consolidate
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