Indian Journal of Soil Conservation

A study comprising of two densities of aonla (D₁: 6x6m and D₂: 8x8m) and four insitu live mulching options (T₁: Control; T₂: cowpea mulch; T₃: weed mulch and T₄: sunhemp mulch) was conducted in split plot design with three replications for eight years (2002 to 2009) at Selakui, Dehradun. Influence of different tree density and residue input to soil due to different live mulch options on vegetative growth and fruit yield and quality of aonla as well as soil and in-situ rain water conservation was evaluated in aonla based agri-horti system with rainfed maize-wheat/mustard sequence on 2.0% sloping land provided with multi-slot devisors. D₁(277 trees ha⁻¹) significantly enhanced tree height (15.0%), fruit yield (37.7%) and litter fall (47.8%) besides 47.0% reduction in soil loss over D₂ (156 trees ha⁻¹). D₂ also significantly improved crown spread, girth at breast height (GBH), fruit weight and TSS: acid ratio than D₁by 13.2, 9.0, 15.0 and 5.0%, respectively which may be attributed due to lower tree-tree interface on account of more space planrl that directly relates to higher availability and utilization of growth resources mainly the moisture and nutrients. Different residue inputs to soil (variable in C:N ratio and quantity) under distinct live mulch options invariably improved aonla tree growth, fruit yield and quality over the control. T₄ treatment outperformed other live mulch options and recorded maximum improvement in tree height, crown spread, GBH, fruit yield and litter yield that was equivalent to 16, 13, 9.0, 27 and 40%, respectively over unmulched control. Among interactions (DxT), D₁T₄ recorded significantly higher tree height (3.54 m), crown spread (689.73 m² ha⁻¹), fruit yield (8.14 t ha⁻¹), litter yield (3.27 t ha⁻¹) and moisture conservation (57.65%) but variations in tree height were statistically at par with D₁T₃ (3.36 m). Similarly, D₂T₄ also recorded significantly higher crown spread (2.78 m² tree⁻¹), GBH (29.3 cm), fruit yield (35.63 kg ha⁻¹), litter yield (14.74 kg tree⁻¹) and fruit weight (42.2 g) but variations were statistically at par with D₁T₂ in crown spread (2.69 m² tree⁻¹) and with D₂T₃ in litter yield (13.21 kg tree⁻¹). Significantly higher TSS: Acid ratio was produced by D₁T₂ (5.35). D₁T₄ recorded minimum soil loss (4.90 t ha⁻¹) and runoff(17.50%) and led to significantly higher moisture conservation (57.45%). The higher BC ratio (1.49) was observed in case of D₁T₄ followed byD₁T₂ witha net retum of ' 194935 and 164425 ha⁻¹ was produced due to fruits and dry woodbiomass.