Impact of Agroecological Practices on Greenhouse Vegetable Production: Comparison among Organic Production Systems

Corrado Ciaccia,Suzana Madžarić,Fabio Tittarelli,Francesco Giovanni Ceglie,Giovanni Burgio,Enrico Muzzi,Elena Testani,Giancarlo Mimiola

doi:10.3390/agronomy9070372

Abstract

In greenhouses, where intensive systems are widely used for organic production, the differences between “conventionalized” and agroecological approaches are especially evident. Among the agronomic practices, green manure from agroecological service crops (ASCs) and organic amendments represent the main tools for soil fertility management with respect to the substitution of synthetic fertilizer with organic ones (the input substitution approach). Over a two-year organic rotation, we compared a conventionalized system (SB) and two agroecological systems, characterized by ASC introduction combined with the use of manure (AM) and compost (AC) amendments. A system approach was utilized for the comparison assessment. For this purpose, agronomic performance, soil fertility and the density of soil arthropod activity were monitored for the entire rotation. The comprehensive evaluation of the parameters measured provided evidence that clearly differentiated SB from AM and AC. The drivers of discrimination were soil parameters referring to long term fertility and soil arthropod dynamics. The study confirmed the higher productivity of SB but also no positive impact on soil fertility and soil arthropods, as highlighted by AM and AC. Based on the results, a trade-off between productivity and the promotion of long-term ecosystem diversity and functioning is needed for the assessment of systems of organic production.

Highlights

The issue of intensive organic production systems has been the subject of debate during the last decade, since the concept of “conventionalization” of organic production was introduced [1,2].“Conventionalized” organic production, called as “input-substitution” system, is characterized by the substitution of synthetic inputs with those allowed by organic regulations [3]
Soil mineral nitrogen (NO3 − -N + NH4 + -N as soil mineral nitrogen (SMN)) parameters showed the lowest dynamics in SB and first crop year rotation, whereas the highest were recorded in the same year by AC, recording the highest NO3 − -N content during the lettuce cycle (179 ppm), with a similar trend shown by AM
The analysis of the results in terms of soil fertility are further supported by the evidence shown in Figure 2, where the increasing amount of organic matter incorporated into the soil in the AC and AM systems is graphically represented in canonical discriminant analysis (CDA) by the shifting of agroecological systems in the second year of the trial under the Soil total organic carbon (TOC) and Soil total nitrogen (TN) drivers

Summary

Introduction

“Conventionalized” organic production, called as “input-substitution” system, is characterized by the substitution of synthetic inputs with those allowed by organic regulations [3] Despite their conformity to organic regulations, these systems are, in general terms, very similar to conventional and integrated ones for the high yield per unit area and the potential environmentally negative externalities, such as degradation of soil, high greenhouse gases (GHG) emissions and biodiversity losses [4]. Agronomy 2019, 9, 372 amendments, long-term rotation and cover crop cultivation are more introduced. Recently have such alternative organic systems of production been tested in protected conditions [10]. Among the many criteria involved in the definition of the price premium for organic vegetables, the potential environmental impact of the production system is considered one of the more influential among consumers of organic food [11,12,13]

Methods

Results

Discussion

Conclusion