Organic fertilizers reduce negative effect of drought in barely (C3) and millet (C4) under warmed climate conditions

Abstract

ABSTRACT The aim of this research was to assess the effect of different fertilization on barley and millet resistance to drought stress under current and warmed climates. Barley grown with organic fertilizers showed 3.8% and 5.6% lower losses of photosynthetic rate than plants grown with mineral fertilizers, at current and warmed climates, respectively. Enrichment with organic fertilizers also resulted in lower and insignificant trapped energy flux losses of barley due to drought in warmed climate compared to losses in fertilization with mineral when the negative drought effect was significant. Production of enzymatic antioxidants in barley, in warmed climate and drought conditions, increased by 44% more due to organic fertilization than due to mineral fertilization. Aforementioned changes in indicators resulted in different drought resistance under different fertilization, as drought resistance index of barley fertilized with organic fertilizers was statistically significantly higher, compared to plants fertilized with mineral fertilizers in both investigated climates. Meanwhile, a statistically significant difference between the changes in millet resistance was found only under current climatic conditions. Study reveals that different fertilization changed the physiological and biochemical response of barley and millet to drought stress, and that organic fertilizers were more effective for plants resistance to drought.