Long-term response of dragon fruit (Hylocereus undatus) to transformed rooting zone of a shallow soil improving yield, storage quality and profitability in a drought prone semi-arid agro-ecosystem.

Agricultural crops especially fruit trees are constrained by edaphic stresses in shallow soils with low water retention and poor fertility. Therefore, interventions of shifting to trench planting for better root anchorage and replacing the filling soil were evaluated for 8 years in dragon fruit (Hylocereus undatus) cultivated in Deccan Plateau of peninsular India. When averaged for last 5-years, 44 % higher fruit yield (18.2 ± 1.0 Mg ha-1) was harvested from trees planted in trenches filled with 1:1 mixture (T-mixed) of native soil (loamy sand with 26.7 % stones (>2mm), field capacity, FC 0.20 cm3 cm-3; organic carbon, OC 0.17 %; Av-N 54.6 kg ha-1) and a black soil (clay 54.4 %; FC 0.42 cm3 cm-3; OC 0.70 %; Av-N 157.1 kg ha-1) than the recommended pit planting (12.4 ± 1.2 Mg ha-1). Improvements in fruit yields with trenches filled with black (T-black) and native (T-native) soil were 32 and 13 %, respectively. Yield losses (total- marketable yield) were reduced by 40, 20 and 18 % over pit method with T-mixed, T-black and T-native soil, respectively. Marketable quality attributes like fruit weight, fruit size metrics and pulp/peel content were further improved under T-mixed soil. Accumulation of total soluble solids (TSS), sugar content, phenolic and flavonoid compounds were higher in fruits from T-native soil. During storage, fruits from T-native soil and pit planting exhibited minimum physiological weight loss and retained more firmness, TSS, sugars, titratable acidity, phenolic-flavonoids contents, FARP and DPPH activities. T-mixed soil provided better hydrozone and nutrients for resilience of fruit plants while protecting from aeration problems envisaged in poorly drained black soils. With B:C ratio (1.85) and lower payback period (4-years), T-mixed soil showed superior economic viability. Therefore, soil management module of planting in trenches filled-in with mixture of native and black soils can be recommended to boost productivity of fruits from shallow soils under water scarce degraded regions without penalising agro-ecosystem.