Assessing Nitrogen Availability in Biobased Fertilizers: Effect of Vegetation on Mineralization Patterns

Biobased nitrogen (N) fertilizers derived from animal manure can substitute synthetic mineral N fertilizer and contribute to more sustainable agriculture. Practitioners need to obtain a reliable estimation of the biobased fertilizers’ N value. This study compared the estimates for pig slurry (PS) and liquid fraction of digestate (LFD) using laboratory incubation and plant-growing experiments. A no-N treatment was used as control and calcium ammonium nitrate (CAN) as synthetic mineral fertilizer. After 100 days of incubation, the addition of PS and LFD resulted in a net N mineralization rate of 10.6 ± 0.3% and 20.6 ± 0.4% of the total applied N, respectively. The addition of CAN showed no significant net mineralization or immobilization (net N release 96 ± 6%). In the pot experiment under vegetation, all fertilized treatments caused N immobilization with a negative net N mineralization rate of −51 ± 11%, −9 ± 4%, and −27 ± 10% of the total applied N in CAN, PS, and LFD treatments, respectively. Compared to the pot experiment, the laboratory incubation without vegetation may have overestimated the N value of biobased fertilizers. Vegetation resulted in a lower estimation of available N from fertilizers, probably due to intensified competition with soil microbes or increased N loss via denitrification.

Effect of urea modified hydroxyapatite nano fertilizer on nitrogen release pattern in red soil

A laboratory incubation study was conducted during 2018 at College of Agriculture V.C. Farm, Mandya using CRD design with eight treatments and three replication. Treatments included were T1:100% Nitrogen-Urea (NU), T2 to T4: NU: UHA @ 75:25, 50:50 and 25:75 per cent, respectively and T5 to T7: UHA @ 50, 75 and 100%, respectively, T8: Absolute control. Results revealed that application of 100 per cent N through nano UHA increased the content of ammonical-N at 5 DAI (653.3 μg g-1) but the content decreased at 10 DAI (583.3 μg g-1) and increased to 716.7 μg g-1 at 15 DAI and maintained it upto 20 DAI while, it decreased at 45 DAI. The nitrate –N release was highest (596.7 μg g-1) at 10 DAI in T7 treatment and maintained it upto 20 DAI and decreased at 45 DAI. Similar pattern was observed with the application of 75 and 50 per cent N-UHA treatments (T6 and T5, respectively). The amount of release of ammonical and nitrate N was proportional to the amount N added through UHA at any sampling interval.

Draft Genome Sequences of Nine Environmental Bacterial Isolates Colonizing Plastic

ABSTRACT Here, we report the draft genome sequences of nine bacterial isolates obtained after laboratory incubation of seawater, soil, and wastewater samples with polylactic acid, polyethylene, or polyethylene terephthalate film for 2 weeks. Assuming colonization as a prerequisite of degradation, these strains could contribute to a solution to the global plastic waste problem.

Derivation of pesticide aged sorption parameters from laboratory incubation data

The results of the incubation laboratory experiment showed that the decomposition of cyantraniliprole is bi-phasic and the rapid decomposition in the period after the application of the pesticide is accompanied by a subsequent slowdown of this process. The use of the biexponential equation increased the accuracy of the description of the dynamics of decomposition of cyantraniliprole, as evidenced by the static indices. The bi-exponential equation coefficients were used to calculate the parameters of non-equilibrium sorption. The obtained parameters served as input data for the PEARL model. Modelling the migration of cyantraniliprole with considering aged sorption, showed a significant decrease in the predicted concentrations of the pesticide in percolate.

Soil nitrous oxide emissions most sensitive to fertilization history during a laboratory incubation

A 12 wk laboratory incubation examined the effects of application of various nitrogen (N) and sulfur (S) fertilizers on soil plant-available nutrient levels and nitrous oxide (N2O) gas emissions with respect to soil fertilization history using soils sampled from the University of Alberta Breton Classical Plots. Fertilization history and added fertilizer treatments showed significant effects on N2O emissions and NO3−-N and SO4−-S recovered on ion-exchange resins over the 12 wk. Mean cumulative N2O emissions ranged from 0.43 to 1.18 kg N2O-N ha−1. The relationship between observed total resin-recovered NO3−-N and N2O emissions was not consistent for soils receiving long-term applications of various combinations of N, phosphorus, potassium, and S fertilizers. The N2O emission from two soils with a history of long-term N fertilizer applications but different S fertilization histories was significantly different even though resin-recovered NO3−-N levels were similar. When grouped according to added fertilizer treatments, mean cumulative N2O emissions showed a strong linear relationship with mean resin-adsorbed NO3−-N production. We hypothesize that the differences in the relationship between NO3−-N production and N2O-N emissions for soils with different long-term fertilization histories may be a result of the interaction of N and S oxidation processes. Further, soil fertilization history may significantly influence soil N2O emissions in response to N fertilizers added within the growing season of observation but isn’t often considered in short-term experiments, and this may be a significant source of uncertainty in the estimation of greenhouse gases inventories from agricultural soils.