Effect of Depth of Tillage and Land Configuration on Soil Properties and Yield of Cotton Var. G.Cot.Hy.12 under South Gujarat Conditions

A field experiment was conducted on deep black soil of the Main Cotton Research Station, Surat during kharif seasons of 2005-06 and 2006-07 to study the effect of depth of tillage and land configuration on soil properties and yield of cotton var. G.Cot. Hy.12 under South Gujarat conditions. Six treatment combinations comprised of three depths of tillage viz., 10 cm (D1), 20 cm (D2) and 30 cm (D3) as main plot treatments and two land configuration techniques viz., ridge and furrow (L1) and broad bed and furrow (L2) as sub plot treatments were tested in split plot design with six replications. The experimental soil was deep black having 231.53 kg ha available N, 37.25 kg ha P2O5 and 462.30 kg ha K2O with 7.52 pH. Various growth and yield attributes viz., plant height at 120 DAS and at harvest, 50 per cent boll bursting, sympodial branches plant , dry matter accumulation plant, bolls plant and seed cotton yield (kg ha) were significantly higher with higher depth of tillage (30 cm depth), which remained statistically at par with 20 cm depth of tillage. Whereas, seed cotton yield plant was significantly higher with 30 cm depth of tillage during both the years of investigation as well as in pooled except, plant height at 60 and 90 DAS, ginning per cent and lint index. Seed index was significantly higher with 30 cm depth of tillage but, found on par with 20 cm depth of tillage in pooled results only. The treatment D3 recorded significantly the higher seed cotton yield of 2551, 2466 and 2509 kg ha over D1 during 2005-06, 2006-07 and in pooled, respectively, however, remained statistically at par with treatment D2. Treatment D3 produced higher net realization of Rs. 33888 ha but, higher BCR of 2.61 was obtained with treatment D2. The quality parameters of cotton were significantly altered due to depth of tillage except length uniformity ratio. Significantly the higher values of quality parameters were recorded with treatment D3. Weed population and dry weight of weeds at 60 and 90 DAS were also significantly reduced due to higher depth of tillage (D3), which was on par with treatment D2. Sucking pests (aphids, jassids and thrips) were significantly increased, whereas bollworms (Helicoverpa, Earias and Pectinophora) infestation were significantly decreased with increasing depth of tillage during both the years of experimentation as well as in pooled, respectively. The physical properties of soil viz., bulk density of soil was significantly reduced during 2006-07 and in pooled, whereas infiltration rate of soil was significantly increased during both the years of investigation with higher depth of tillage (D3). The chemical properties of soil at 0 22.5 cm depth viz., organic carbon was significantly higher with shallow depth of tillage (D1) but at deeper level, it was reduced, whereas pH of soil was significantly reduced with 30 cm depth of tillage during 2006-07 and in pooled. Available N and P2O5 content were significantly higher with treatment D3 in pooled only, whereas EC and available K2O at 0 22.5 cm and OC, pH, EC, available N, P2O5 and K2O did not alter significantly at 22.5 45.0 cm depth. Nitrogen, phosphorus and potassium uptake by cotton plant were significantly higher with treatment D2 and remained on par with treatment D3 during 2005-06, 2006-07 and in pooled, respectively, except, during 2006-07 in case of K uptake and N and P uptake during 2006-07 as well as in pooled. Land configuration techniques did not alter significantly most of the growth and yield attributes except, plant height at 90 DAS and lint index. Broad bed and furrow (L2) technique significantly increased plant height at 90 DAS and lint index in pooled results. Broad bed and furrow technique significantly influenced length uniformity ratio only during 2006-07, whereas other quality parameters were not improved significantly. Weed population and dry weight of weeds at 60 and 90 DAS were reduced with broad bed and furrow technique during both the years and in pooled. Ridge and furrow technique significantly reduced sucking pests (aphids, jassids and thrips) infestation, whereas broad bed and furrow technique significantly reduced bollworm (Helicoverpa, Earias) infestation during 2005-06, 2006-07 and in pooled. The physical and chemical properties of soil were also not improved significantly by land configuration except, bulk density of soil which was lowered down with ridge and furrow technique in pooled. Broad bed and furrow technique produced higher seed cotton yield with higher net realization of Rs. 32310 ha and BCR of 2.59. The treatment combination D3L1 (30 cm depth of tillage and ridge and furrow) significantly reduced the pH of the experimental soil and Pectinophora infestation, whereas treatment combination D3L2 significantly reduced the infestation of Helicoverpa and Earias population and also registered higher net realization of Rs. 35166 ha with 2.67 BCR. The higher BCR (2.69) was recorded with treatment combination D2L2 (20 cm depth of tillage and broad bed and furrow technique). Based on the results from the experimentation for two consecutive years, it seems quite logical to conclude that potential production and profit from cotton G.Cot. Hy.12 cultivated on vertisols of South Gujarat can be secured by ploughing the soil upto 20 cm depth during summer and by adopting either ridge and furrow or broad bed and furrow technique as land configuration.