Effects of precision conservation agriculture in a maize-wheat-mungbean rotation on crop yield, water-use and radiation conversion under a semiarid agro-ecosystem

In recent years, water resources have decreased and water saving has become an important issue in the Indo-Gangetic Plains (IGP) of South Asia. Maize-wheat-mungbean (MWMb), is an alternate to traditional rice-wheat cropping system, can mitigate the effects of the frequency, intensity, and duration of rainfall due to climate change on food security in the semi arid-region of north-western IGP. The objective of this research was to determine the productivity, water-use efficiency (WUE) and incident radiation conversation efficiency (IRCE) of MWMb cropping system under 3 tillage practices [zero tillage (ZT), permanent beds (PB) and conventional tillage (CT) and 4 nutrient management strategies [Control (unfertilized), farmers' fertilizer practice (FFP), recommended dose of fertilizers (Ad-hoc) and a site specific nutrient management (SSNM using the Nutrient Expert (R) decision support tool). Results of multi-year trial showed that among tillage practices, ZT and PB practices reduced the system irrigation water requirement by 140-200 mm ha(-1) and 200-300mm ha(-1) respectively, compared to CT system, resulting an enhanced grain yield by 5.7-24.6%, biomass yield by 4.6-20.8%, WUE by 18.4-39.0%, and IRCE by 9.9-34.4%, respectively. Significant (P <= 0.05) improvement in system WUE, grain and biomass yield, and IRCE (by 30.6-59.9, 38.3-80.5, 34.3-64.7 and 13.5-48.5%, respectively) was observed in SSNM compared to the unfertilized plots. Significant (P <= 0.05) interactions between tillage practices and nutrient management strategies was measured with respect to water-use, WUE, grain and biomass yield, and IRCE of MWMb system. Combinations of ZT/PB practices +SSNM/Ad-hoc nutrient management strategies registered significantly (P < 0.05) higher system WUE and IRCE, grain and biomass yield compared to CT+ unfertilized/FFP. Results of present study showed that SSNM/Ad-hoc based nutrient application coupled with CA-based tillage practices.in MWMb system has complementarity to attain higher system productivity, WUE and IRCE compared to the use of these crop management practices in isolation. (C) 2017 Elsevier B.V. All rights reserved.