Locally Available Organic Waste for Counteracting Strawberry Decline in a Mountain Specialized Cropping Area

Sebastian Soppelsa,Markus Kelderer,Massimo Zago,Luisa Maria Manici,Francesco Caputo

doi:10.3390/su13073964

Abstract

Crop decline caused by soil borne fungal pathogens affects specialized cropping systems such as fruit trees and strawberry. A study was carried out to investigate the effectiveness of pre-plant application of waste-derived biomasses in strawberry (Fragaria × ananassa) to reduce that phenomenon. A field experiment was carried out in an alpine strawberry specialized valley in South Tyrol (Italy), in a long term cultivated field selected for yield reduction over recent years. In July 2018, one month before strawberry transplanting, a field experiment with four soil treatments was set up: anaerobic digestate (solid fraction) of liquid manure, compost from anaerobic digestate of organic fraction of municipal solid waste (OFMSW), untreated control and Dazomet as chemical control. Plants were grown for two cycles (2019 and 2020). Dazomet always gave a significant (over 50%) increase in marketable yield per plant in both the years, anaerobic digestates did not improve strawberry production; compost from OFMSW gave phytotoxic effects in the first year, but improved strawberry yield like Dazomet in the second. Changes of rhizosphere bacterial populations and difference in root pathogen abundance, especially that of Dactylonectria torresensis, were correlated to the crop response to treatments. Findings suggest that waste-derived biomasses are a promising eco-friendly option for counteracting strawberry yield decline. Their positive impact was mostly linked to functional improvements induced by microbial variations. However, the use of such organic amendment requires careful evaluation of composition, doses and above all application times to reduce phytotoxic effects that in some cases can occur in the first months after application.

Highlights

Crop decline, namely the gradual reduction of plant vigor and yield, which characterizes specialized cropping systems, is linked to the loss in soil biodiversity caused by the frequent return of the crop to the same plots and the increase in nonspecific fungal pathogens that saprophytically survive on plant residue [1,2]
Once again, showed that organic wastes are promising for increasing soil fertility
Organic waste input is interesting for the possibility to increase N availability for plants and soil organic matter content in the medium-long period [48], and for its ability to induce beneficial microbial changes in the short period

Summary

Introduction

Namely the gradual reduction of plant vigor and yield, which characterizes specialized cropping systems, is linked to the loss in soil biodiversity caused by the frequent return of the crop to the same plots and the increase in nonspecific fungal pathogens that saprophytically survive on plant residue [1,2]. Strawberry is mainly produced in specialized growing areas where this high value crop shows symptoms ascribable to “crop decline” after some repeated cultivations It appears as a gradual reduction in yield and quality, reduced plant growth rate in post-transplant, collapse of plants during the fruit ripening stage, and generally reduced plant ability to counteract biotic and abiotic stress [5]. Eco-friendly alternatives for controlling specific and opportunistic soil

Methods

Results

Conclusion