Subsoiling Affecting Soil Quality Parameters and Sugarcane Yield in Multiratooning System in Subtropical India

ABSTRACT

Soil compaction in the plow layer of soils is becoming a serious concern because of conventional tillage practices adopted by sugarcane growers utilizing a rotavator, particularly in medium to heavy textured soils. Continuous use of machinery causes compaction in the plow layer; thus strategic tillage practices have become an essential component in intensive agriculture. Keeping these points in view, a field experiment was conducted in split plot design considering four pre-plant tillage treatments, i.e., (i) one subsoiling (SS) followed by two harrowings (H) (ii) subsoiling alone and direct planting through Sugarcane Cutter Planter (SS) (iii) one plowing through moldboard (MB) plow and two harrowings (MB+H) (iv) and conventional practice (CP) in main plots and three ratoon management treatments viz., (i) HW:Three hand weedings (HW) (ii) integrated weed management (IWM), trash mulching at the time of ratoon initiation and application of microbial consortia (TM +MC) in subplots. Results on bulk density in surface and subsurface layers indicated a significant reduction due to subsoiling. Higher availability of N (252 to 310.2 kg ha⁻¹) was analyzed with adoption of subsoiling as compared to conventional practice (218.4 to 224 kg N ha⁻¹). Subsoiling improved soil microbial biomass carbon (SMBC) by 39% to 73% and 32.20% to 46% as compared to conventional practice in 0–15 cm and 15–30 cm depth, respectively. Among all the primary tillage treatments, sub soiling enhanced SMBC at the highest level (1574 mg C/kg soil/day in 0–15 cm soil depth). Sugarcane (97.26 t ha⁻¹) and sugar (11.87 t ha⁻¹) yields also improved significantly under subsoiling as compared to other pre-plant tillage treatments. Subsoiling before planting also increased mean ratoon cane (117.6 t ha⁻¹) and sugar yields (14.48 t/ha). In addition to trash mulching and application of microbial consortia in ratoon crop proved effective for sustaining higher ratoon yields in sugarcane.

Short title: Minimum tillage affecting soil quality parameters and sugarcane yield

KEYWORDS:

• Available n
• bulk density
• ratoon cane
• soil microbial biomass carbon