The growing world population and the necessity to meet its nutritional needs despite the limited area of agricultural land pose a serious challenge for agriculture. Agriculture is responsible for 80–95% of total ammonia emissions to the atmosphere, but at the same time it has great potential to reduce them. Fertilisation with mineral nitrogen (in particular urea) is responsible for 19.0–20.3% of total ammonia emissions emitted from agriculture. Ammonia emissions have a negative impact on the environment and human health, therefore it is important to minimize the volatilization of ammonia and increase fertiliser efficiency. This is important due to the need to mitigate the negative impact of anthropopressure on the environment in terms of air pollution, negative effect on soils and waters. The application of urease inhibitors during fertilisation with nitrogen fertilisers is one method to reduce ammonia emissions from plant production. Another option to achieve this goal is to reverse the global trend toward maximizing the production of energy crops (intensive fertilisation inevitably increasing ammonia emissions to the environment) for the production of biofuels, which is growing rapidly, taking up arable land that could be used for food production. The aim of the review is to identify the impact of recently introduced technologies for reducing ammonia emissions from urea on agricultural productivity, environment, and crops. It is of importance to reconsider optimization of crop production in arable land, possible owing to the progress in the production, modification, and application of mineral fertilisers and changes in crop structure. A broad debate is necessary with policymakers and stakeholders to define new targets allowing introduction of technologies for conversion of energy crops into energy with a minimal impact on food production and environmental issue.
Plants grow in a variable environment in regard to soil water and light driving photochemical reactions. Light energy exceeding plant capability to use it for photochemical reactions must be dissipated by processes of non-photochemical quenching (NPQ). The aim of the study was to evaluate the impact of various components of NPQ on the response of Arabidopsis thaliana to fluctuating light and water availability. A laboratory experiment with Arabidopsis thaliana wild type (WT) and mutants npq1 and npq4 grown under optimum or reduced water availability was conducted. Dark-adapted plants were illuminated with fluctuating light (FL) of two intensities (55 and 530 μmol m−2 s−1) with each of the phases lasting for 20 s. The impact of water availability on the role of zeaxanthin and PsbS protein in NPQ induced at FL was analysed. The water deficit affected the dynamics of NPQ induced by FL. The lack of zeaxanthin or PsbS reduced plant capability to cope with FL. The synergy of both of these components was enhanced in regard to the amplitude of NPQ in the drought conditions. PsbS was shown as a component of primary importance in suiting plant response to FL under optimum and reduced water availability.