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Maize belongs to a tropical environment and is extremely sensitive to drought and chilling stress, particularly at early developmental stages. The present study investigated the individual and combined effects of drought (15% PEG-Solution) and chilling stress (15/12 °C) on morpho-physiological growth, osmolyte accumulation, production of reactive oxygen species (ROS), and activities/levels of enzymatic and non-enzymatic antioxidants in two maize hybrids (i.e., "XD889" and "XD319") and two inbred cultivars (i.e., "Yu13" and "Yu37"). Results revealed that individual and combined exposure of drought and chilling stresses hampered the morpho-physiological growth and oxidative status of maize cultivars, nevertheless, the interactive damage caused by drought + chilling was found to be more severe for all the studied traits. Between two individual stress factors, chilling-induced reductions in seedling length and biomass of maize cultivars were more compared with drought stress alone. Greater decrease in root length and biomass under chilling stress ultimately decreased the volume and surface area of the root system, and restricted the shoot growth. All the stress treatments, particularly chilling and drought + chilling, triggered the oxidative stress by higher accumulation of superoxide anion, hydrogen peroxide, hydroxyl ion, and malondialdehyde contents compared with the control. Variations in response of maize cultivars were also apparent against different stress treatments, and XD889 performed comparatively better than the rest of the cultivars. The better growth and greater stress tolerance of this cultivar was attributed to the vigorous root system architecture, as indicated by higher root biomass, root surface area, and root volume under drought and chilling stresses. Moreover, efficient antioxidant defense system in terms of higher total antioxidant capability, superoxide dismutase, peroxidase, catalase, and glutathione reductase activities also contributed in greater stress tolerance of XD889 over other cultivars. [ABSTRACT FROM AUTHOR]

Climate holds a key position in driving the agriculture of an area. The changing climatic conditions are becoming a big threat for safety of agricultural system and food security across the globe. In developing countries of Asia and Africa, declining soil fertility and drought are the major constraints in harvesting the potential yields. The average temperature around the globe is also expected to rise globally by 6°C in the coming century which is mainly due to uncontrolled emission of greenhouse gases. A prominent elevation in CO2 and CH4 concentration has been observed in the past centuries largely due to fossil burning and urbanization. Further upto 35 percent increase in the concentration of nitrous oxide is also expected due to injudicious use of nitrogenous fertilizers. According to the prediction of climate models the rise in temperature and frequent happening of severe drought are going to affect the agricultural productivity in 21st century. In order to sustain the agricultural productivity it is need of the hour to properly understand the impact of these changes on soil fertility and crop productivity. This review is aimed to highlight the potential impacts of rising temperature, shifting precipitation patterns and rising CO2 concentrations on soil health and agricultural productivity. Soil organic carbon pool is also going to get negatively affected by these changing climatic conditions. It has also been tried to shed some light on the potential of various carbon sequestration strategies conservation tillage, cover crops, Proper nutrient management, proper irrigation management and restoration of degraded soils, in combating the devastating impacts of changing climate. In addition the nitrogen management strategies are also elaborated alongwith manure management to minimize the emission of greenhouse gases. [ABSTRACT FROM AUTHOR]