In Winter Wheat (Triticum Aestivum L.), No-Till Improves Photosynthetic Nitrogen and Water-Use Efficiency

Abstract

To evaluate the combined effect of different agricultural practices on photosynthetic nitrogen and water-use efficiency, winter wheat was grown in the field under tillage and no-till conditions, with and without cover crops under low and high nitrogen fertilization inputs. Leaf physiological traits, such as the rate of photosynthesis, stomatal conductance, the rate of transpiration, the chlorophyll content index, the leaf area ratio, and specific leaf area were used as indicators representative of nitrogen and water-use efficiency. Six years after conversion to no-till, in the presence and in the absence of cover crops, significant increases in photosynthetic water-use efficiency and soil water content were observed both under low and high nitrogen fertilization input. Moreover, we observed that photosynthetic nitrogen-use efficiency, the rate of photosynthesis and specific leaf area were higher in the absence of tilling than in the presence of tilling. Thus, agronomic practices based on continuous no-till appear to be promising for increasing both photosynthetic nitrogen- and water-use efficiency in winter wheat.