Innovative Soil Management and Micro-Climate Modulation for Saving Water in Peach Orchards

Abstract

Microclimatic and soil management studies emphasize that roofing above the canopy or soil mulching contributes to reduce water losses from horticultural cropping systems and, at the same time, to increase water use efficiency. The aim of this 2-year on-farm study, carried out on a late ripening peach (cv. California) orchard, was to investigate the combined effect of water supply (full or deficit irrigation, DI), incoming light (hail or shading net), and soil management (tilling or mulching) on: microclimate; fruit growth; yield; irrigation water use productivity (WP_I); and soil water stress coefficient (Ks). Shading hail net reduced air temperature (-1°C), wind speed (-57%), solar radiation (-32%), while increased relative air humidity (+9.5%). Compared to the control treatment (hail net coverage, soil tillage, and full irrigation), the innovative management (DI + shading hail net + mulching) reduced seasonal volumes of irrigation water (-25%) and increased both final yield (+36%) and WP_I (+53%). Saving water resources without losing yield is an achievable goal by peach orchards growing under the Mediterranean climate if the DI agro-technique is adopted conjointly with shading hail net and soil mulching.

Keywords: deficit irrigation; irrigation water productivity; mulching; shading hail net; soil stress coefficient.

Figure 1

Soil management (T, tillage; M, mulching) and vegetation roofing (H, ail net; S, shading net) at the experimental site.

Figure 2

Field capacity (fc) and wilting point (wp) detected in each treatment. Each bar represents the average of 3 samples + s.e. No letter indicates no significant differences according to Duncan test (P < 0.05).

Figure 3

Trend of air temperature (min, max, and avg) and rain during two experimental seasons (2017–2018).

Figure 4

Trend of daily agrometeorological data (T. air, air temperature; u, wind speed; RH, air relative humidity; Rs, solar radiation) measured from the weather station (out), under Hail (H) and Shading hail (S) nets during two seasons (2017 and 2018).

Figure 5

Trends of daily soil water content (SWC) during 2017 (A–D) and 2018 (E–H) observed on HMFI and HMDI (A–E), HTFI and HTDI (B–F), SMFI and SMDI (C–G), STFI and STDI (D–H) crop managements. The values of the field capacity (continuous line), readily available water threshold (dashed line), wilting point (dense dashed line) are also shown.

Figure 6

Daily variations of soil water content (SWC) during 2017 season at three depths (−0.1, −0.3 and −0.5 m) for HMFI (A) and HMDI (B) managements. The values of the field capacity (continuous line), readily available water threshold (dashed line), wilting point (dense dashed line) are also shown.

Figure 7

Trends of daily soil water stress coefficients (Ks) during 2017 (A–D) and 2018 (E–H) observed on HMFI and HMDI (A–E), HTFI and HTDI (B–F), SMFI and SMDI (C–G), STFI and STDI (D–H) crop managements.

Figure 8

Combined effects of Light regimes (H and S), Soil managements (T and M), Irrigation regimes (FI and DI) on standardized soil water stress coefficient (Ks_st) for each season (2017 and 2018). Different letters indicate significant differences according to the Duncan’s test (P < 0.05).

Figure 9

Fruit volume (cm³; A, B) and Absolute Growth Rate (AGR, cm³ d⁻¹; C, D) under Light regimes (H, gray line; S, black line) during fruit development (DAFB, days after full bloom) in 2017 and 2018. ** and * indicate a significant difference at P < 0.01 and P < 0.05, respectively.

Figure 10

Yield (t ha⁻¹; A) and fresh weight (g; B) under the two light regimes (Shading hail net vs Hail net); Irrigation Water Productivity (WP_I, kg m⁻³) under the two light regimes (C) and the two water regimes (Deficit Irrigation vs Full Irrigation; D) in 2017 and 2018. Different letters indicate a significant difference at P < 0.05.

Figure 11

Relationship between yield and standardized soil water stress coefficient (Ks_st) calculated for all treatments in two seasons (2017 and 2018).