ABSTRACT
The high input of nitrogen is often required in today's agriculture, especially for the most cultivated crops largely involved in human and animal nutrition, such as winter wheat. Nitrogen is a mobile nutrient in the soil, and the high doses of N are often associated with possible losses through volatilization or leaching. One of the possible options to increase nitrogen use efficiency is the application of fertilizers with inhibitors. The main objective of the presented three-year experiment established under the field conditions at the two experimental sites was to examine the effect of nitrogen-sulphur fertilizer (ammonium nitrate sulphate) with the inhibitors of nitrification (IN) (dicyandiamide and 1,2,4 triazole). In addition to the nitrogen content in two forms, this fertilizer also contains sulphur, which can possibly enhance the utilization of nitrogen due to their well-known synergy. The treatments included in the experiment were: 1. Unfertilized, 2. N technology 3. N + S technology and 4. N + S + IN. The total dose of applied N for every fertilized treatment was 159 kg/ha. Treatments 2 and 3 were fertilized with three split doses of N, treatment 4 was fertilized only two times due to the addition of IN (a higher dose of fertilizer in the second application). The results obtained from the three-year experiment showed a significantly higher yield of grain (8.18 t/ha) after the fertilization with N + S + IN in comparison with N + S (7.67 t/ha) and N (7.61 t/ha), which proved the positive effect of IN on nitrogen use efficiency during the vegetation. The differences between qualitative parameters of wheat grain (hectolitre weight, protein and gluten content) were evaluated as statistically insignificant for each fertilized treatment. This similar result is likely due to the IN application, which provided a continuous nitrogen supply during vegetation comparable to the three split nitrogen applications. Thus, our results showed, that the addition of IN to the higher dose of fertilizer applied earlier in the vegetation can provide comparable results in terms of quality to the technologies based on three split fertilizations. The three-year experiment established at two experimental sites has proved, that the application of ammonium sulphate nitrate fertilizers with IN in a higher dose is a better option to the commonly used nitrogen technology, which was also supported by the economic evaluation and the highest net profit.
ABSTRACT
Maize (Zea mays L.) is one of the most widely grown cereals in the world. Its cultivation is affected by abiotic stress caused by climate change, in particular, drought. Zinc (Zn) supplied by foliar nutrition can increase plant resistance to water stress by enhancing physiological and enzymatic antioxidant defence mechanisms. One of the possibilities to reduce the effect of drought on plant production is also the utilization of trehalose. In order to confirm the effect of the foliar application of selected forms of Zn (0.1% w/v solution)-zinc oxide micro- (ZnO) and nanoparticles (ZnONP), zinc sulphate (ZnSO4) and zinc chelate (ZnEDTA)-a pot experiment in controlled conditions was conducted in combination with trehalose (1% w/v solution) on selected growth parameters of maize exposed to the drought stress. A significant effect of coapplication of Zn and trehalose on chlorophyll content, chlorophyll fluorescence parameters, root electrical capacity, weight of maize aboveground biomass (AGB) and Zn content in AGB was found. At the same time, the hypothesis of a positive effect of carbohydrates on increasing the uptake of foliar-applied Zn was confirmed, especially for the ZnEDTA and ZnSO4. This paper presents the first empirical evidence of the trehalose addition to sprays for zinc foliar fertilization of maize proving to be an effective way of increasing the resistance of maize grown under drought stress conditions.
ABSTRACT
The use of mineral nitrogen (N) fertilizers is associated with significant nitrogen loss through the volatilization. Ammonia (NH3) emissions are common from fertilizers with amide (NH2) and ammonium (NH4) nitrogen forms applied to the soil surface without incorporation. The objective of the laboratory and greenhouse pot experiments was to verify the hypothesis that liquid mineral fertilizers and fertilizer solutions containing N-NH2 and N-NH4 applied to the soil surface in combination with natural hydroabsorbents (NHAs) will reduce the volatilization of nitrogen. The effect of NHAs addition to urea ammonium nitrate (UAN) fertilizer and urea, ammonium nitrate (AN) and ammonium sulphate (AS) solutions was evaluated in a laboratory experiment. The effect of the two types of NHAs (acidic and neutral) was compared with the control (UAN) and its mixture with the commercially used urease inhibitor N-(n-butyl) thiophosphoric triamide (NBPT). The proportion of volatilized NH3 of the total N from the examined fertilizers applied to the soil surface was determined by the titration method. Subsequently, the effect of fertilization with UAN and its mixture with NHAs and NBPT on the growth of maize under the drought conditions was verified in a greenhouse pot experiment. While the addition of NBPT resulted in a reduction of NH3 emission for the fertilizers containing NH2 (UAN, urea solution), a decrease in volatilization after the addition of both acidic and neutral NHA was observed especially for UAN. A reduction in ammonia emission was also observed for AS after the addition of acidic NHA. The addition of both NHAs and NBPT to UAN increased the utilization of nitrogen from the applied fertilizer, which was reflected by an increase in chlorophyll content and increased CO2 assimilation by maize plants grown under the drought stress. UAN fertilizer combined with acidic NHA and NBPT significantly increased aboveground biomass production and root system capacity of maize. Significant increases in UAN nitrogen recovery were observed for all examined additives (UI and both types of NHAs). In addition to the known effects of hydroabsorbents, especially their influence on soil physical and biological properties and soil water retention, the effect of NHAs application in combination with UAN and AS solutions on the reduction of gaseous N loss, maize plant growth and fertilizer nitrogen recovery was found.
ABSTRACT
Fertilizers play an essential role in agriculture due to the rising food demand. However, high input fertilizer concentration and the non-controlled leaching of nutrients cause an unwanted increase in reactive, unassimilated nitrogen and induce environmental pollution. This paper investigates the preparation and properties of slow-release fertilizer with fully biodegradable poly(3-hydroxybutyrate) coating that releases nitrogen gradually and is not a pollutant for soil. Nitrogen fertilizer (calcium ammonium nitrate) was pelletized with selected filler materials (poly(3-hydroxybutyrate), struvite, dried biomass). Pellets were coated with a solution of poly(3-hydroxybutyrate) in dioxolane that formed a high-quality and thin polymer coating. Coated pellets were tested in aqueous and soil environments. Some coated pellets showed excellent resistance even after 76 days in water, where only 20% of the ammonium nitrate was released. Pot experiments in Mitscherlich vegetation vessels monitored the effect of the application of coated fertilizers on the development and growth of maize and the dynamics of N release in the soil. We found that the use of our coated fertilizers in maize nutrition is a suitable way to supply nutrients to plants concerning their needs and that the poly(3-hydroxybutyrate) that was used for the coating does not adversely affect the growth of maize plants.
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.
ABSTRACT
Fertilizer coating can increase the efficiency of N fertilizers and reduce their negative impact on the environment. This may be achieved by the utilization of biodegradable natural coating materials instead of polyurethane-based polymers. The aim of this study was to detect the effect of calcium ammonium nitrate (CAN) fertilizer coated with modified conventional polyurethane enhanced with vegetable oils on the yield and quality of Brassica napus L. compared to CAN fertilizer with a vegetable oil-based polymer and to assess the risks of nitrogen loss. Three types of treatments were tested for both coated fertilizers: divided application (CAN, coated CAN), a single application of coated CAN, and a single application of CAN with coated CAN (1:2). A single application of coated CAN with both types of coating in the growth stage of the 9th true leaf significantly increased the yield, the thousand seed weight, and oil production compared to the uncoated CAN. The potential of using coated CAN may be seen in a slow nitrogen release ensuring the nitrogen demand for rapeseed plants throughout vegetation and eliminating the risk of its loss. The increased potential of NH4+ volatilization and NO3- leaching were determined using the uncoated CAN fertilizer compared to the coated variants. Oil-based polymer coatings on CAN fertilizer can be considered as an adequate replacement for partially modified conventional polyurethane.
ABSTRACT
Phosphorus (P) is an important nutrient in plant nutrition. Its absorption by plants from the soil is influenced by many factors. Therefore, a foliar application of this nutrient could be utilized for the optimal nutrition state of plants. The premise of the study is that foliar application of phosphorus will increase the yield of normal-phytate (npa) cultivars (CDC Bronco a Cutlass) and low-phytate (lpa) lines (1-2347-144, 1-150-81) grown in soils with low phosphorus supply and affect seed quality depending on the ability of the pea to produce phytate. A graded application of phosphorus (H3PO4) in four doses: without P (P0), 27.3 mg P (P1), 54.5 mg P (P2), and 81.8 mg P/pot (P3) realized at the development stages of the 6th true leaf led to a significant increase of chlorophyll contents, and fluorescence parameters of chlorophyll expressing the CO2 assimilation velocity. The P fertilization increased the yield of seeds significantly, except the highest dose of phosphorus (P3) at which the yield of the npa cultivars was reduced. The line 1-2347-144 was the most sensible to the P application when the dose P3 increased the seed production by 42.1%. Only the lpa line 1-150-81 showed a decreased tendency in the phytate content at the stepped application of the P nutrition. Foliar application of phosphorus significantly increased ash material in seed, but did not tend to affect the protein and mineral content of seeds. Only the zinc content in seeds was significantly reduced by foliar application of P in npa and lpa pea genotypes. It is concluded from the present study that foliar phosphorus application could be an effective way to enhance the pea growth in P-deficient condition with a direct effect on seed yield and quality.
