Association of Agrometeorologists

Effect of precision land levelling on microenvironment and sorghum productivity in water scarce Deccan region

G.C.WAKCHAURE, R.L. CHOUDHARY, M.J. KALEDHONKAR and S.K. BAL

Effect of favourable soil and canopy microenvironment, achieved through precision laser land levelling, on rabi sorghum (Maldandi 35-1) productivity was assessed for water deficit regions of Deccan Plateau of India. Laser levelled (0-0.1% grade) and adjoining unlevelled field plots (0.5-2% slope) located at six different experimental sites (silty clay soil) were selected for study. Germination percentage, weed control, temporal soil moisture depletion (SMD), canopy temperature depression (CTD) and water productivity were monitored. SMD ranged 0.46-0.60 for levelled plots indicated no impact of water stress at Panicle emergence stage i.e. 75 day after sowing (DAS). However, grain yield was reduced maximum by 62% when SMD increased from 0.68 to 0.88 for unlevelled plots. Lowering of CTD values by 0.7 to 3.2ºC, in levelled plots indicated the ability of plants to maintain cooler canopy compared to unlevelled plots. Grain yield was reduced by 0.47 t ha-1 with every increase in 0.5% of slope in unlevelled plots, whereas it was negatively correlated with SMD and CTD values in both cases. Laser land levelling showed significant improvement in uniform soil moisture distribution, seed germination, weed control, initial crop establishment and irrigation water productivity. Precision levelling significantly improved soil and canopy microenvironment which favoured to increase the sorghum yield by 27-73% and substantially saved irrigation water (30.9%) compared to unlevelled fields.

Laser land levelling, sorghum, water stress, soil moisture depletion, canopy temperature depression