Nitrogen use by plants and nitrogen flows after application of standard and biomodified nitrogen fertilizers on barley

The aim of our study was to assess the efficiency of application of biomodified nitrogen fertilizers for barley, to reveal the sources of nitrogen used for biomass formation with the use of the 15N stable isotope, and to study nitrogen flows in the system of fertilizers–soil–plants–atmosphere. We demonstrated in a model experiment the ability of the plant growth-promoting bacteria Bacillus subtilis Ch-13 to move from the granules of mineral fertilizers to plant roots and to colonize them effectively. The effectiveness of biomodified nitrogen fertilizers for barley, Nur variety, was assessed in a microfield trial. After the application of biomodified nitrogen fertilizers, the accumulation of 15N in the plants increased by 2–5 %, its incorporation in the soil decreased and gaseous losses were decreased by 7 % as compared with the use of the usual forms of fertilizers. The application of biomodified nitrogen fertilizers can be used in agricultural practice as a novel technology to regulate nitrogen flows in the system of fertilizers–soil–plants–atmosphere.

Assessment of Reactive Nitrogen Flows in Bangladesh’s Agriculture Sector

To assess the status of and trends in agricultural nitrogen (N) flows and their wider consequences for Bangladesh, in this study, we analyzed data from national and international bodies. The increased rates of N fertilizer applied for increased food production leaves behind a huge amount of unutilized reactive N (Nr). N fertilizer use is the largest in the crop sector, an important sector, where current annual consumption is 1190 Gg. The present combined annual Nr production from crop, fishery, and livestock sectors is ~600 Gg, while emissions of nitrous oxide (N2O), a potent greenhouse gas, are ~200 Gg. Poor N management results in Nr leaking into the environment, which has increased approximately 16-fold since 1961. One potential consequence is the disruption of ecosystem functioning. The balanced tradeoff between food production and reducing Nr input needs to be achieved. One solution to reducing Nr may be a holistic approach that optimizes N application rates and incorporates waste of one subsector as an input to another applying the principle of the circular economy.

Thermal Performance of Cryogenic Micro-Pin Fin Coolers with Two-Phase Liquid Nitrogen Flows

This study experimentally explores the thermofluidic performance of a cryogenic micro-pin fin cooler with two-phase liquid nitrogen flows. The liquid nitrogen cooling system is introduced to investigate the performance of the micro-pin cooler in a cryogenic condition. The result reveals that the nominal value of the base heat transfer coefficients of the micro-pin fin cooler with liquid nitrogen flows, 240 kW/m2-K at a mass flow rate of 2.23 g/s, is an order of magnitude greater than that with FC-72 flows. The result also demonstrates that the base heat transfer coefficient of the micro-pin fin cooler is nearly three times greater than that of the micro-gap cooler, not containing any fins. This study shows the feasibility of the cryogenic micro-pin fin cooler for thermally controlling very high heat density devices such as high-power laser diode bars, of which the heat density can reach 2000 kW/m2.

Agroecosystem Stability In Spring Wheat Crops With The Application Of Fertilizers And Microbial Biological Products

The formation of spring wheat biomass on sod-podzolic soil is carried out mainly due to soil nitrogen, the share of which reaches 1/3 of the total removal of the element when using mineral fertilizers. Inoculation of spring wheat seeds with biologics of rhizosphere microorganisms increases the nitrogen content of fertilizers to 7.3%, increases its immobilization by 5.9-6.7% and reduces losses by 7.4-13.9%. The stability of the agroecosystem is characterized by nitrogen flows. During the growing season of spring wheat with a hydrothermal coefficient of 1.55-1.72, the amount of mineralized nitrogen (mineralization (M)), depending on fertilizers, reaches 9.4-11.1 g/m2, while the reimobilized nitrogen (reimobilization (RI)) – 2.2-3.1 g/m2, net-mineralized (net-mineralization (N-M)) – 6.8 - 8.0 g/m2. The use of nitrogen fertilizers and biological products leads the agroecosystem to the resistance mode (the maximum permissible level of exposure) (RI : M = 27-28%, N-M : RI = 2.5-2.7).

Fluxes of 15N, soil nitrogen in sod-podzolic soil in spring wheat crops under inoculation with Rhyzoagrin

In a microfield experiment using a labeled nitrogen 15N fertilizer on sod-podzolic light loamy soil for 11 years during the cultivation of spring wheat and the use of a biological product based on a strain belonging to the genus Agrobakterium radiobakter (strain 204), nitrogen flows in the fertilizer – soil – plant system were studied. The utilization rate of spring wheat labeled with 15N ammonium nitrate averaged 40% of the amount applied. The absolute size of the immobilization in the structure of the labeled nitrogen balance of the mineral fertilizer was 27-30%. Inoculation with Rhyzoagrin does not significantly affect the nitrogen immobilization of the mineral fertilizer. The gaseous losses of labeled nitrogen of the mineral fertilizer were 33% of those applied to the background of the phosphorus and potash fertilizers and decreased with inoculation with Rhyzoagrin to 29%. The use of an integral assessment showed that the agroecosystem functioned in the resistance mode on sod-podzolic light-loamy soil when using mineral nitrogen fertilizer. The dependence of the indicator RI: M, % of the HTC (hydrothermal coefficient) expressed by the equation y = -24, 506x2 + 43,462 x + 15,251 at R2 = 0.7416 is established.

Assessment of Nitrogen Flows at Farm and Regional Level When Developing the Manure Management System for Large-Scale Livestock Enterprises in North-West Russia

Arranging efficient manure management is the major environmental challenge in livestock farming in the Leningrad Region, with manure nitrogen being regarded as the main pollution source. The study aimed to identify the baselines for taking integrated manure management decisions towards reducing nitrogen losses applying nitrogen surplus and nitrogen use efficiency (NUE) as indicators calculated at the regional and municipal district level. At the regional level, NUE was found to be 34% and N surplus was 103 kg ha−1. Eleven “environmentally friendly” districts had a mean NUE of 59%, a mean N surplus 39.6 kg ha−1 and a mean animal density 0.89 LSU ha−1. Four districts were identified as “hot spots”, with an animal density in the range from 2.6 to 67 LSU ha−1, NUE from 1 to 37% and N surplus from 87 to 3082 kg ha−1. A scenario was suggested for the redistribution of organic fertilisers between “hot spots” and “environmentally friendly” districts, allowing each district to increase the N surplus to the regional value. Nitrogen flows and measures improving NUE at the farm level through organisational activity and advanced practices were considered with the help of the “N input − N output” diagram and the example of the nitrogen flows on a pilot dairy farm.