RESUMO
There is currently a limited understanding of the complex response of fungal microbiota diversity to organic fertigation. In this work, a 2-year field trial with organic tomato crops in a soil previously amended with fresh sheep manure was conducted. Two hypotheses were compared: (i) fertigation with organic liquid fertilizers versus (ii) irrigation with water. At the end of both years, soils were analyzed for physical-chemical parameters and mycobiome variables. Plate culture and DNA metabarcoding methods were performed in order to obtain a detailed understanding of soil fungal communities. Fertigation did not increase any of the physical-chemical parameters. Concerning soil fungal communities, differences were only found regarding the identification of biomarkers. The class Leotiomycetes and the family Myxotrichaceae were identified as biomarkers in the soil fungal community analyzed by means of DNA metabarcoding of the "fertigation" treatment at the end of Year 1. The Mortierella genus was detected as a biomarker in the "water" treatment, and Mucor was identified in the "fertigation" treatment in the cultivable soil fungi at the end of Year 2. In both years, tomato yield and fruit quality did not consistently differ between treatments, despite the high cost of the fertilizers added through fertigation.
RESUMO
Pisum sativum L. ssp. arvense, is colloquially called tirabeque or mangetout because it is eaten whole; its pods are recognized as a delicatessen in cooking due to its crunch on the palate and high sweetness. Furthermore, this legume is an important source of protein and antioxidant compounds. Quality control in this species requires the analysis of a large number of samples using costly and laborious conventional methods. For this reason, a non-chemical and rapid technique as near-infrared reflectance spectroscopy (NIRS) was explored to determine its physicochemical quality (color, firmness, total soluble solids, pH, total polyphenols, ascorbic acid and protein content). Pod samples from different cultivars and grown under different fertigation treatments were added to the NIRS analysis to increase spectral and chemical variability in the calibration set. Modified partial least squares regression was used for obtaining the calibration models of these parameters. The coefficients of determination in the external validation ranged from 0.50 to 0.88. The RPD (standard deviation to standard error of prediction ratio) and RER (standard deviation to range) were variable for quality parameters and showed values that were characteristic of equations suitable for quantitative prediction and screening purposes, except for the total soluble solid calibration model.
