Water footprint, runoff and soil loss assessment of cotton production in central India

Abstract

Cotton the major crop grown on the Vertisols of central India is dependent on the monsoonal rains. Most often the high intensity rains are received in short spells and most of it is lost through runoff. Information on runoff, soil loss and water footprint (WF) of cotton grown under rainfed conditions is meagre. We determined the water runoff, soil loss, and the water footprint in a field study conducted during 2019–2022. During the study period, of the total mean annual rainfall, 47 % was effective rainfall (541 mm), and 51 % was lost through runoff. The soil loss was highest (11.5 Mg ha⁻¹) in the year 2022. The average annual soil loss was 8.81 Mg ha⁻¹. It was observed that the mean crop water use was 541 mm and 624 mm under rainfed and drip irrigated conditions, respectively. The WF of rainfed cotton was 11,339 m³ to produce 1Mg of lint. The green (WF_green) and grey (WF_grey) WF values were 9424 and 1915 m³ Mg⁻¹, respectively, corresponding to 83 % and 17 % of the total WF (WF_total).The values obtained for WF_green, WF_blue, WF_grey and WF_total under drip irrigated cotton production were 7227, 842, 1891 and 9959 m³ Mg⁻¹, respectively. These values correspond to 73 %, 8 % and 19 % of the WF_total, respectively. The blue water use in drip irrigated cotton was 50–120 mm during non-monsoon months (October to November), which resulted in 0.18 Mg ha⁻¹ (28 %) lint yield enhancement and 13 % WF reduction compared to rainfed cotton. Our study indicates scope for enhancing rainfed cotton production by adopting appropriate water and crop management practices making it not only profitable but also addressing the sustainable development goals.