Trifolium subterraneum cover cropping enhances soil fertility and weed seedbank dynamics in a Mediterranean apricot orchard

Abstract

The soils of Mediterranean semiarid environments are commonly characterized by low levels of organic matter and mineral elements, as well as severe weed infestations, which, taken together, cause an intensive use of auxiliary inputs (tillage, fertilizers, herbicides). Although cover crops are recognized to sustainably improve soil health, the impact of Trifolium subterraneum L. cover cropping needs specific attention. This research investigates for the first time the effects over 4 years of T. subterraneum and spontaneous flora cover crops, after either incorporating their dead mulches into the soil or leaving them on the soil surface, on soil organic matter (SOM), macroelements, mineral nitrogen, microelements, and weed seedbank dynamics as indicators of soil quality in an apricot orchard. Compared to a conventional management control, the T. subterraneum cover crop with the burying of dead mulch into the soil increased the amount of SOM (+ 15%), ammoniacal (+ 194%) and nitric (+ 308%) nitrogen, assimilable P2O5 (+ 5%), exchangeable K2O (+ 14%), exchangeable Na (+ 32%), exchangeable K (+ 16%), Fe (+ 15%), Mn (+ 28%), Zn (+ 36%), and Cu (+ 24%), while it decreased the weed seedbank size (‒ 54%) and enhanced weed biodiversity. These findings suggest that T. subterraneum cover cropping may be an environment-friendly tool to enhance soil quality and limit auxiliary input supply in Mediterranean orchards.

Wheat Response and Weed-Suppressive Ability in the Field Application of a Nanoencapsulated Disulfide (DiS-NH2) Bioherbicide Mimic

“…Interestingly, the 0.75 g m −2 dosage also suppressed weeds on a par with weed chemical control. The weed communities under study were dominated by Asteraceae members, spring-summer and annual therophytes, as expected in semi-arid agroecosystems [24]. In particular, major weeds were Centaurea napifolia L., A. fatua, Glebionis coronaria s.l., Fumaria officinalis L., Sinapis arvensis L., and L. multiflorum in location I; G. coronaria, S. arvensis, Papaver rhoeas L., Dactylis glomerata L., and Anethum graveolens L. in location II; L. perenne, and Medicago polymorpha L., A. fatua, and S. arvensis in location III.…”

Differentiated Weed-Suppressive Ability of Modern and Old Durum Wheat Cultivars after Long-Term Cultivation under Semi-Arid Climate

“…Soil samples were taken with a core sampler 10–15 cm deep along the diagonals of the central part of each sampling zone [ 34 ]. A sample was obtained by pooling 5 randomly distributed subsamples, each 0.75 dm 3 , for a total of 150 soil cores (10 farms × 3 replicates × 5 subsamples) collected.…”

“…Aside from the seedbank size for potential flora and aboveground biomass for real flora, weed species abundance was calculated under the relative density (RD), relative frequency (RF) and relative abundance index (RAI), in accordance with Scavo et al [ 34 ]: where: ∑Y i = sum of the number of individuals or seeds for a weed species, S = species richness within the plot, F i = number of sampling units in which the species i occurred and ∑F = sum of the absolute frequencies of all species. The RAI is a valuable parameter in characterising weed communities, since it takes into account both the weed density and evenness, thus overcoming the problems caused by a nonuniform weed distribution [ 35 ].…”

“…Prior to ANOVA, the normality and homogeneity of variance were respectively assessed with the Shapiro–Wilk’s and Bartlett’s tests. To meet the ANOVA assumptions, the seedbank and aboveground biomass data were log (x + 1) -transformed, the RAI data needed an arcsine–square root transformation and the H and J data were respectively square root- and logit-transformed, while the species richness showed a homogeneous variance distribution [ 34 ]. For an easier interpretation of the results, data from the five farms cultivating modern cultivars and from the other five farms cultivating old landraces were respectively pooled and presented into two groups: MOD and OLD.…”

Herbicide Use in the Era of Farm to Fork: Strengths, Weaknesses, and Future Implications

“…Under the context of each one of these axes, several different techniques and methods have been studied and evaluated within the EU, providing a wide range of management alternatives. The diversification (both in space and in time) of cropping systems includes the adoption of crop rotations, cover crops, intercropping, and landscape arrangement (Błażewicz-Woźniak et al, 2015 ; Giuliano et al, 2016 ; Kuht et al, 2017 ; Weber et al, 2017 ; Dhima et al, 2018 ; Royo-Esnal et al, 2018 ; Scavo et al, 2019 , 2021 ; Butkevičienė et al, 2021 ). Cultivar selection could be based on certain agronomic traits that enhance competitive abilities and can potentially suppress weeds more efficiently (Kokare et al, 2014 ; Karkanis et al, 2016 ; De Vita et al, 2017 ; Rasmussen et al, 2021 ).…”