A comparative study of fifteen cover crop species for orchard soil management: water uptake, root density traits and soil aggregate stability

Abstract

Increasing the use of cover crops (CCs) is a necessity in sustainable viticulture, although it might clash with possible excessive competition towards vines. Especially in a climate-change scenario, the latter feature should be minimized while maintaining ecosystem services. Aimed at identifying CCs for vineyard floor management, the trial characterized several species according to their evapotranspiration (ET) rates, root growth patterns, and soil aggregate stability potential. The study was performed in 2020 in Piacenza (Northern Italy) on 15 CC species grown in pots kept outdoor and classified as grasses (GR), legumes (LE) and creeping (CR). Together with bare soil (control), they were arranged in a complete randomized block design. CCs ET was assessed through a gravimetric method, starting before mowing and then repeated 2, 8, 17 and 25 days thereafter. Above-ground dry biomass (ADW), root length density (RLD), root dry weight (RDW) and root diameter class length (DCL) were measured, and mean weight diameter (MWD) was calculated within 0–20 cm depth. Before mowing, ET was the highest in LE (18.6 mm day−1) and the lowest in CR (8.1 mm day−1) the latter being even lower than the control (8.5 mm day−1). The high ET rates shown by LE were mainly related to very fast development after sowing, rather than to a higher transpiration per unit of leaf area. After mowing, the 15 species’ ET reduction (%) plotted vs leaf area index (LAI, m2 m−2) yielded a very close fit (R2 = 0.94), suggesting that (i) a linear decrease in water use is expected anytime starting with an initial LAI of 5–6, (ii) a saturation effect seems to be reached beyond this limit. Selection of cover crop species to be used in the vineyard was mainly based on diurnal and seasonal water use rates as well as dynamic and extent of root growth patterns. Among GR, Festuca ovina stood out as the one with the lowest ET due to its “dwarfing” characteristics, making it suitable for a permanent inter-row covering. CR species confirmed their potential for under-vine grassing, assuring rapid soil coverage, lowest ET rates, and shallow root colonization.

The Health of Vineyard Soils: Towards a Sustainable Viticulture

“…Cover crops and living mulches, defined as any crop or crop mixture planted or allowed to spontaneously blossom into or after a main crop and then, respectively, killed or maintained alive, offer numerous advantages in grape production [213]. Despite their competition for water and nutrients, especially in the upper soil layers, where most of the annual vine roots are active [214], cover crops should be adopted, as soil and water conservation are becoming even more important in the face of climate change [215]. Regarding both synthetic and organic mulching, these have proven highly effective in conserving water around grapevine roots, a critical factor for viticulture in arid to dry sub-humid regions, thereby enhancing water use efficiency amid changing climate patterns [216,217].…”

“…Selecting the appropriate type of cover crops poses a challenge in vineyard soil management. Several characteristics should be considered when choosing cover crops [215]: (i) establishment capacity and resistance to repeated trampling; (ii) homogeneity and duration; (iii) ability for effective weed control; (iv) perennial habit to reduce the need for reseeding, that is to reduce costs; (v) reduced aerial development to minimize maintenance and vineyard interventions; (vi) seasonal growth pattern: featuring a lag in summer growth followed by autumn recovery; (vii) low evapotranspiration rates; (viii) deepening root growth patterns; and (ix) soil aggregate stability potential. Moreover, cover crop management, including the frequency and timing of maintenance operations and the choice of plant species, must be tailored to local climate and weather conditions, striking a balance between wine production, biodiversity, and ecosystem service provision [187].…”

Enhancing estimation of cover crop biomass using field-based high-throughput phenotyping and machine learning models

“…Conventionally, cover crop AGB has been measured through destructive sampling of a specific subarea in the plot. This sampling process is time-consuming and labor-intensive, and poses a challenge in experiments constrained by plot size due to the need to balance treatment levels and field size ( O'Brien et al., 2022 ; Zhang et al., 2022 ; Capri et al., 2023 ). Nevertheless, understanding the dynamic nature of cover crop biomass accumulation at high temporal resolution could offer insights for researchers seeking to develop or refine predictive models for cover crop research.…”

Do Living Mulches or Environmental Conditions Have a Greater Impact on the External Quality of the Apple Fruit ‘Chopin’ Cultivar?

“…In addition to weed control [11][12][13][14], living mulch offers other benefits for the orchard agroecosystem, including an increase in flora biodiversity [8] and organic matter in the soil [15][16][17], and it also affects the chemical [15,17,18] and biological [19,20] properties of soil. Species of the Poaceae family are often used as cover plants in perennial fruit crops [21]. Among grasses, species of the Festuca genus deserve special attention, especially blue fescue (F. ovina L.) [7,22] and red fescue (F. rubra L.) [23][24][25][26].…”