Abstract
Abstract Organic fertilization in orchards aims at increasing soil fertility, at impacting plant productivity and environmental sustainability. This study aimed at verifying the effects of organic fertilization and fruit load on two nectarine cultivars with high and low fruit loads. The experiment was carried out in an orchard under organic management in Fratta Terme, Po valley, in northeastern Italy. Nectarine cultivars Big Top and Carene, implemented in 2017 and grafted onto GF677, were used. Three levels of compost (0, 20 and 40 t dw ha-1) were combined with two fruit loads (low and high) to set up a factorial experimental design with two factors and four randomized replicates. Compost was incorporated at 20 cm depth. The following parameters were evaluated: nitrate- and ammonium- N concentrations in soil at 20 - 40 cm depth, macro and micronutrients in leaves, tree yield, number of fruits, fruit mass and diameter, soluble solids and pulp firmness. The supply of compost enhanced nitrate-N release in soil. In both cultivars, macro- and micronutrient concentrations in leaves were not affected by organic fertilization or fruit load, except for iron, which increased as a consequence of the compost supply. Low crop load induced higher fruit size in both varieties, a fact that was observed after pit hardening. However, the organic fertilization rate did not influence tree yield, fruit mass and soluble solids.
Highlights
Adequate management of soil organic matter (SOM) and nutrients availability are factors that ensure nutritional balance in orchards and, fruit productivity and quality
Concentration was higher in control than in amended plots; in July the supply of compost at 40 t ha-1 induced an increase of soil nitrate in comparison to control, while compost 20 t ha-1 induced intermediate values (Table 2)
Ammonium-N concentration in soil was lower than the nitrate-N (Tables 2 and 3), because in well-drained soil it is quickly transformed into nitrate by microbial activity
Summary
Adequate management of soil organic matter (SOM) and nutrients availability are factors that ensure nutritional balance in orchards and, fruit productivity and quality. In traditional fruit tree cultivation, excessive use of mineral-based fertilizers in the long run may affect the ecosystem due to risks of leaching and/or emission of nitrogen (N) into the atmosphere. Sustainable alternatives, such as the use of organic fertilizers, should be employed to carry out nutrient management in plants (BALDI; TOSELLI, 2014; BALDI et al, 2016; TOSELLI et al, 2019a). Compost can be obtained from several organic sources and has been extensively applied to fruit orchards thanks to its positive effects on soil properties (DIACONO; MONTEMURRO, 2010; BALDI et al, 2016; SORRENTI; TOSELLI, 2016) and fruit production in comparison to mineral fertilizers (ROUSSOS et al, 2017). There are studies in the literature on the effect of compost of nectarine orchard (BALDI et al, 2016), the increasing interest on sustainable management techniques and on organic production, more research should be carried out with different cultivars, types of compost and doses
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
