Water Productivity of Sugarcane Influenced by Planting Techniques, Mulching and Irrigation Scheduling in Indo-Gangetic Plains of India

Abstract

Sugarcane is one of the most suitable alternative crops to predominant rice–wheat cropping system in indo-Gangetic plains of India. However, grand growth period of this crop coincides with hot and dry summer months having higher evaporative demands which raise the crop water requirement during this period, thus narrowing its scope of being an alternative to rice–wheat cropping system. To enhance water productivity of sugarcane field, experiments were conducted at Punjab Agricultural University, Regional Research Stations, Faridkot and Kapurthala during spring 2016, 2017 and 2018 on planting methods and irrigation scheduling. Four planting methods comprised of P₁: conventional flat (75 cm apart) with mulching @ 6 ha⁻¹, P₂: conventional flat without mulch, P₃: paired row trench planting (30:120 cm) with mulch and P₄: paired row trench planting without mulch as main plots and three irrigation schedules, i.e., irrigation at 0.60, 0.80 and 1.00 IW/CPE as subplots factors in split plot design. The results revealed that paired row trench planting (30:120 cm) with mulch @ 6 t ha⁻¹ resulted into 162% and 123% higher apparent water productivity than conventional flat planted crop without mulch at Faridkot and Kapurthala, respectively. In paired row trench planting, irrigation water application was 58.4% and 52.0% lesser than conventional flat planted crop at Faridkot and Kapurthala, respectively, as water was applied only in trenches which actually curtailed the wettable area to 40%. Mulching in conventional flat planted crop improved the cane yield by 10.3% over non-mulch flat planted crop at Kapurthala, but this difference was only 6.1% in paired row trench planted crop at Faridkot. At Kapurthala, mulching in paired row trench planted crop enhanced the cane yield by 8.8%, but in conventional flat planted crop, this increase was up to 6.9%. On the basis of these results, it can be concluded that the planting sugarcane in paired row trench planting system with mulch @ 6 t ha⁻¹ is the most viable planting system in sugarcane to attain higher crop and water productivity. Based on the availability of irrigation water, crop can either be irrigated at 0.6 or 0.8 IW/CPE for higher total and apparent water productivity and higher water-use efficiency. Higher benefit/cost ratio (mean over locations) is obtained under paired row trench planting with mulch and irrigation scheduling at 0.8 IW/CPE.