The effects of bovine urine application on two soil nitrogen compounds and growth of three forage grasses in the Colombian Piedmont plains

The effects of application of bovine urine on biomass and nitrogen (N) accumulation in 3 tropical grasses (Urochloa decumbens cv. Basilisk, U. humidicola cv. Humidicola and Megathyrsus maximus cv. Mombasa), and on available N concentrations in soil (NH4+-N, NO3--N) were studied using a randomized complete block design with 3 replicates. There were significant interactions between species and urine application over time in terms of herbage accumulation and N concentration (P<0.01), with significant differences in the concentrations of N available in the soil (P<0.01). Soil temperature and precipitation had important effects on the concentrations of both soil ions. Application of bovine urine increased dry matter accumulation of all grasses in the short term and of U. decumbens over the whole year. Application of urine increased soil N levels, but for U. humidicola and M. maximus the effects were transient. It is necessary to continue with longer-term studies in the Piedmont plains to determine the effects of livestock grazing on the biogeochemical cycles, environmental impacts and natural mitigation options that the ecosystem offers, e.g. CO2 sequestration, biological nitrification inhibitors and organic matter decomposition.

Quantification and Stereochemical Composition of R-(−) and S-(+)-Clenbuterol Enantiomers in Bovine Urine by Liquid Chromatography–Tandem Mass Spectrometry

Clenbuterol (4-amino-α-[(tert-butylamino)methyl]-3,5-dichlorobenzylalcohol) is a β2-adrenergic agonist. The consumption of meat contaminated with clenbuterol can lead to increased heart rate, blood pressure, anxiety, palpitations and skeletal muscle tremors. Several analytical methods have been developed to identify and quantify clenbuterol in different biological matrices. In this report, we have developed a specific and sensitive analytical method for quantifying clenbuterol and performed an in-depth enantiomeric analysis in bovine urine. The method was evaluated in accordance with international guidelines, and we used an isotopically labeled analog as an internal standard. The extraction efficiency for clenbuterol in bovine urine was &gt; 98%, the limit of detection was 0.05 ng/mL and the limit of quantification was 0.10 ng/mL. Our assay showed high specificity, no carryover was observed and the assay was linear in the range 0.10–8.0 ng/mL. Fifteen bovine urine samples were analyzed (containing clenbuterol), and an enantiomeric analysis was performed. The clenbuterol concentration range was 0.10–10.56 ng/mL across these samples. The levorotatory enantiomer was detected at greater concentrations than the dextrorotatory enantiomer, the ratio being 1.7 ± 0.6 (n = 15), and a statistical difference was observed (P &lt; 0.05) using the Wilcoxon test.

Application of Biofertilizers in Cover of and Its Effects on Organic Maize

The objective of the present study was to verify the effect of two doses of the biofertilizer ‘Supermagro’ applied in cover, in the presence and absence of cured bovine urine in the maize crop, and in the soil penetration resistance, as well as the effect in the application of biofertilizer ‘Fert Bokashi’. The experimental design used was of randomized blocks with four replicates. The treatments constituted of cover application of ‘Supermagro’ in the dose of 6% (recommended dose) (T1); cover application of ‘Supermagro’ in the dose of 12% (T2); cover application of ‘Supermagro’ in the dose of 6% + cured bovine urine 3% (T3); cover application of ‘Supermagro’ in the dose of 12% + cured bovine urine 3% (T4); cover application of cured bovine urine 3% (T5); use of the biofertilizer ‘Fert Bokashi’ in the dose of 0,5% of dilution) (T6); and control (T7). The results obtained were tabulated and submitted to analysis of variance and the comparison of means by the Dunnett test at 5% of probability, with the aid of the statistical analysis software SAS. For the parameters: thousand grain mass, the treatment ‘Fert Bokashi’ alone presented the highest thousand grain mass (375,00 g) being it superior to the control (p<0,05) with 360,94 g. For the yield parameter, the treatments ‘Supermagro’ 12% + urine, bovine urine alone and ‘Fert Bokashi’ presented the highest averages, (5961 kg ha-1, 5512 kg ha-1 and 5808 kg ha-1, respectively) which differed statistically from the control (5500 kg ha-1) (p<0,05). The biofertilizers are an alternative to increase the yield of maize in the organic system with an average increase of 20% in the maize production in relation to the area without application. The biofertilizer ‘Fer Bokashi’ is an alternative to increase maize yield in the organic production system. The application of biofertilizers did not influence in the soil penetration resistance.