Reducing Nitrogen Fertilization in Olive Growing by the Use of Natural Chabazite-Zeolitite as Soil Improver

Abstract

In order to improve the sustainability and productivity of modern agriculture, it is mandatory to enhance the efficiency of Nitrogen (N) fertilizers with low-impact and natural strategies, without impairing crop yield and plant health. To achieve these goals, the ZeOliva project conducted an experiment using a zeolite-rich tuff as a soil amendment to improve the efficiency of the N fertilizers and allow a reduction of their inputs. The results of three years of experimentation performed in three different fields in the Emilia-Romagna region (Italy) are presented. In each field, young olive trees grown on zeolite-amended soil (−50% of N-input) were compared to trees grown on unamended soil (100% N-input). Soils and leaves were collected three times every year in each area and analyzed to monitor the efficiency of the zeolite treatment compared to the control. Vegetative measurements were performed along with analysis of pH, Soil Organic Matter and soluble anions in soil samples, whereas total C and N, C discrimination factor and N isotopic signature were investigated for both soils and leaves. Besides some fluctuations of nitrogen species due to the sampling time (Pre-Fert, Post-Fertilization and Harvest), the Total Nitrogen of leaves did not highlight any difference between treatments, which suggest that plant N uptake was not affected by lower N input in the zeolite treatment. Results, including vegetative measurements, showed no significant differences between the two treatments in all the observed variables, although the control received twice the N-input from fertilization. Based on these results, it is proposed that zeolite minerals increased the N retention time in the soil, allowing a better exploitation by plants which led to the same N uptake of the control notwithstanding the reduction in the N inputs. The use of zeolite-rich tuff in olive growing thus allows a reduction in the amount of fertilizer by up to 50% and improves the N use efficiency with many environmental and economic benefits.

Short Term Effects of Chemical Fertilizer, Compost and Zeolite on Yield of Lettuce, Nutrient Composition and Soil Properties

“…Plant N uptake was also not affected by zeolite treatments. Medoro et al [97] proposed that zeolite increased the N retention time in the soil, allowing for better exploitation by plants, which led to the same N uptake as the control, notwithstanding the reduction in the N inputs.…”

Zeolite Amendment for Enhanced Onion Growth with Reduced Mineral Nitrogen Fertilization: A Promising Approach

“…It is crucial to note that these minerals' impacts on the soil are long-lasting because of their long-term structural stability under conditions of normal pressure and temperature. Furthermore, reducing the use of N fertilizers can be done frequently over many years with substantial long-term economic and environmental benefits (Medoro et al, 2022). Bio-stimulants i.e., yeast and seaweed extract led to promoting the performance and productivity of onion plants.…”

Influence of Chabazite Zeolite Foliar Applications Used for Olive Fruit Fly Control on Volatile Organic Compound Emission, Photosynthesis, and Quality of Extra Virgin Olive Oil

“…Air temperature was monitored with a sampling rate of 1 min using a Tinytag Ultra 2—TGU-4017 datalogger (Gemini Data Loggers, Chichester, UK), while rainfalls were monitored using a manual pluviometer (Raig, Barcelona, Spain). The soil analyses were collected according to Medoro et al, 2022 [ 52 ] to determine N and C content and the geochemical composition, respectively.…”

“…The total nitrogen and carbon (respectively, TN and TC) and the respective isotopic signature (δ15N and δ13C) of leaf samples were acquired with a Vario Micro Cube Elemental Analyser (EA) (Elementar, Langenselbold, Germany) connected to an Isoprime 100 Isotope Ratio Mass spectrometer (IRMS) (Isoprime, Cheadle, UK) operating in a continuous-flow mode. The EA-IRMS was calibrated with synthetic sulfanilamide (provided by Isoprime Ltd.) and Carrara Marble (cross-calibrated at the Institute of Geoscience and Georesources of the National Council of Researches of Pisa) standards [ 52 ].…”