Abstract
In Europe, mainly due to industrial desulfurization, the supply of soil sulfur (S), an essential nutrient for crops, has been declining. One of the currently promoted sources of renewable energy is biogas production, which produces S as a waste product. In order to confirm the effect of the foliar application of waste elemental S in combination with liquid urea ammonium nitrate (UAN) fertilizer, a vegetation experiment was conducted with maize as the main crop grown for biogas production. The following treatments were included in the experiment: 1. Control (no fertilization), 2. UAN, 3. UANS1 (N:S ratio, 2:1), 4. UANS2 (1:1), 5. UANS3 (1:2). The application of UAN increased the N content in the plant and significantly affected the chlorophyll content (N-tester value). Despite the lower increase in nitrogen (N) content and uptake by the plant due to the application of UANS, these combinations had a significant effect on the quantum yield of PSII. The application of UANS significantly increased the S content of the plant. The increase in the weight of plants found on the treatment fertilized with UANS can be explained by the synergistic relationship between N and S, which contributed to the increase in crop nitrogen use efficiency. This study suggests that the foliar application of waste elemental S in combination with UAN at a 1:1 ratio could be an effective way to optimize the nutritional status of maize while reducing mineral fertilizer consumption.
Highlights
One of the principles of the European Green Deal is the proposal of greenhouse gas emissions cut by at least 55% by the year 2030, which should set Europe to a path to becoming climate-neutral by the year 2050 [1]
The application of urea ammonium nitrate (UAN) fertilizer alone and in combination with sulfur increased the chlorophyll content (N-tester value) in maize leaves compared to the unfertilized control
The increase in chlorophyll was evident at both monitoring terms (t1 and t2), while the differences between the control (N-unfertilized treatment) and the N (UAN) and NS (UANS1-3)-fertilized treatments increased over time (Table 1)
Summary
One of the principles of the European Green Deal is the proposal of greenhouse gas emissions cut by at least 55% by the year 2030, which should set Europe to a path to becoming climate-neutral by the year 2050 [1]. According to the European Biogas Association (EBA), biogas, biomethane, and other renewable gases will play a key role in helping Europe’s transition to a clean energy system [2], and the European Commission’s strategies promise targeted support for biogas in the revised Renewable Energy Directive and gas legislation. The annual production of biogas in Europe reaches 15.8 bcm and is relatively stable with a total of 18,943 biogas plants according to the EBA [3]. Biogas production is associated with the production of waste products. The utilization of waste sulfur obtained from the purification process seems to be promising from the point of view of plant nutrition and especially from the economic aspect of biogas production [7,8] and sulfur deficiency in the environment
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
