Abstract: Worldwide, about two-thirds of industrial and domestic wastewater effluent is discharged without treatment, which can cause contamination and eutrophication of the water. In particular, for Mediterranean countries, irrigation with treated wastewater would mitigate the water stress and support the agricultural sector. Changing global weather patterns will make the situation worse, due to increased susceptibility to drought, which can cause major environmental, social, and economic problems. The study was carried out in open field in an intensive agricultural area of the Apulian region in Southern Italy where freshwater resources are often scarce. As well as providing a water resource, irrigation with treated wastewater represents a significant source of nutrients for soil–plant systems. However, the use of wastewater might have further effects on soil. This study thus investigated the long-term impact of irrigation with reclaimed agro-industrial wastewater on the chemical characteristics of the soil. Two crops (processing tomato and broccoli) were cultivated in succession in Stornarella (Foggia) over four years from 2012 to 2016 using two types of irrigation water: groundwater and tertiary treated agro-industrial wastewater that had undergone an activated sludge process, sedimentation filtration, and UV radiation. Chemical analyses were performed on the irrigation waters and soil samples. The treated wastewater was characterised by high levels of several chemical parameters including TSS, EC, COD, BOD5, Na+, Ca2+, Mg2+, NH4-N, PO4-P, K+, SAR and CaCO3, as compared with the groundwater. However, despite these higher levels, the mean content of several chemical parameters in the soil did not show relevant differences between the irrigation treatments, in terms of the chemical features of the soil.
Abstract: The experimental trial was carried out in open field at Foggia district (Apulia Region, Southern Italy), during the spring-summer season 2014, in order to evaluate the effect of four biostimulant products (RadiconÒ, Viormon plusÒ, LysodinÒ and SiaptonÒ 10L), compared with a control (no biostimulant), on the infestation of processing tomato crop (cv Dres) by the chlorophyll-lacking root parasite Phelipanche ramosa. Biostimulants consist in different categories of products (microbial inoculants, humic and fulvic acids, hydrolyzed proteins and aminoacids, seaweed extracts) which play various roles in plant growing, including the improvement of crop resistance and quali-quantitative characteristics of yield. The experimental trial was arranged according to a complete randomized block design with five treatments, each of one replicated three times. The processing tomato seedlings were transplanted on 5 May 2014. Throughout the crop cycle, P. ramosa infestation was assessed according to the number of emerged shoots (branched plants) counted in each plot, at 66, 78 and 92 day after transplanting. The tomato fruits were harvested at full-stage of maturity on 8 August 2014. From each plot, the marketable yield was measured and the quali-quantitative yield parameters (mean weight, dry matter content, colour coordinate, colour index and soluble solids content of the fruits) were determined. The whole dataset was tested according to the basic assumptions for the analysis of variance (ANOVA) and the differences between the means were determined using Tukey’s tests at the 5% probability level. The results of the study showed that none of the applied biostimulants provided a whole control of Phelipanche, although some positive effects were obtained from their application. To this respect, the RadiconÒ appeared to be the most effective in reducing the infestation of this root-parasite in tomato crop. This treatment also gave the higher tomato yield.
Abstract: Nowadays, the main goal for modern horticultural
production is an increase the quality. In recent years, the use of
organic fertilizers or biostimulants that can be applied in agriculture
to improve quali-quantitative crop yields has encountered increasing
interest. Biostimulants are gaining importance also for their possible
use in organic and sustainable agriculture, to avoid excessive
fertilizer applications. Consecutive experimental trials were carried
out in the Apulia region (southern Italy) on three herbaceous crops
(cauliflower, pepper, fennel) grown in pots under conventional and
organic fertilization systems without and with biostimulants. The aim
was to determine the effects of three biostimulants (Siapton®10L,
Micotech L, Lysodin Alga-Fert) on quali-quantitative yield
characteristics. At harvest, the quali-quantitative yield characteristics
of each crop were determined. All of the experimental data were
subjected to analysis of variance (ANOVA), and when significant
effects were detected, the means were compared using Tukey’s tests.
These data show large differences in these yield characteristics
between conventional and organic crops, particularly highlighting
higher yields for the conventional crops, while variable results were
generally observed when the biostimulants were applied. In this
context, there were no effects of the biostimulants on the quantitative
yield, whereas there were low positive effects on the qualitative
characteristics, as related to higher dry matter content of cauliflower,
and higher soluble solids content of pepper. Moreover, there were
evident positive effects of the biostimulants with fennel, due to the
lower nitrate content. These latter data are in line with most of the
published literature obtained for other herbaceous crops.