Experimental assessment of carbon sequestration in sole and intercropping of maize (Zea mays L.) with legumes in mountain agroecosystem

Evaluation of cropping systems with respect to climate change mitigation is a need of the hour to highlight the most advantageous practice for adoption. In current research, maize (Zea mays L.) and legume intercropping has been assessed not only for biomass production, but also for its potential for carbon sequestration at various elevation sites. Research trials of maize-based sole and intercropping with mungbean (Vigna radiata L.), cowpea (Vigna sinensis S.), and soybean (Glycine max L.) were performed at three elevations (1500, 1800, and 2200 m from mean sea level) with three replications in a randomized complete block Design during three consecutive years (2015–2017). Maize economic yield (MEY), maize biological yield (MBY), aboveground biomass yield (ABY), aboveground carbon sequestered (ACS), belowground carbon sequestered (BCS), total carbon sequestered (TCS), and total carbon equivalents (TCE) were computed from experimental plots of sole and intercropped maize and legumes and for cropping systems. Research results indicated significant (p = 0.001) individual effect of cropping system and two-way interaction effects of year and elevation on MEY, MBY, ABY, ACS, BCS, TCS, and TCE. Values of MEY (10.4 t ha⁻¹) and MBY (26.6 t ha⁻¹) were significantly highest in case of sole cropping of maize, while values of ABY (47.3 t ha⁻¹), ACS (23.5 t ha⁻¹), BCS (7.97 t ha⁻¹), TCS (31.6 t ha⁻¹), and TCE (116.1 t ha⁻¹) were significantly highest in case of intercropping system of maize and mung bean.