Biofermentation of organic waste from a pig-breeding complex in a drum-type installa-tion

Relevance. In modern pig-breeding complexes, manure is processed by separation producing the liquid and solid manure fractions. The complexes also generate other types of organic waste. Testing the process of producing the organic fertilizer based on the solid organic waste of a pig-breeding complex in a drum-type biofermenter.Material and methods. The processing of a mixture of two types of solid fractions of pig slurry and the waste from mechanical cleaning of grain into an organic fertilizer in a drum-type biofermentation unit was tested. The tested material was produced on the pig-breeding complex with the closed production cycle located in Leningrad Region. The optimization criterion was the temperature of the mixture in the installation. The controlling factors were the aeration frequency, the air supply rate to the biofermenter, and the rotation interval of the drum. Assumed values of the tested factors were: the moisture content of the mixture of 55–65% and the density of the mixture of 400– 600 kg/m3. The standard methods for statistical and experimental data analysis were applied.Results. Four operation modes of the biofermenter were tested, of which only one allowed to achieve the heating of the mixture above 55 °C and a stable course of the biofermentation process. Under this mode, the aeration rate was 5 min/h; the air supply rate to the biofermenter was 10 m/s; and the drum rotation interval was every 12 hours. The significance of the factors in a multivariate experiment was considered; the mathematical model was analyzed using the steepest ascent method. Considering the identified operation mode, 12 drum-type biofermenters with the working volume of 31.3 m3 each will be needed to process the solid fraction of manure produced on the pig-breeding complex with the animal stock of 107,000 head and the output of the solid fraction of manure of 90 tons per day. A building with a floor area of 1000 m2 will be required to place these biofermenters. This area is 113.4 times smaller than the area of the watertight pad for clamps to process the manure by the passive composting technology. Nitrogen emissions will be reduced by 6.3% owing to the intense mineralization of nitrogen in the fermented mixture.

Cotton tolerance to halauxifen-methyl applied preplant

Auxin herbicides are used in combinations to control glyphosate-resistant horseweed preplant burndown. Herbicide labels for 2,4-D–containing products require a 30-d rotation interval for planting cotton cultivars not resistant to 2,4-D. Dicamba labels require an accumulation of 2.5 cm of rain plus 21 d per 280 g ae ha–1 rotation interval for planting cotton cultivars not resistant to dicamba. Previous research has shown that cotton injury caused by dicamba applied 14 d before planting was transient with little effect on cotton yield, whereas 2,4-D has little effect on cotton when applied 7 d prior to planting. Injury caused by dicamba and 2,4-D is inversely related to rainfall received between herbicide application and cotton planting. Experiments were conducted to evaluate cotton tolerance to halauxifen-methyl, a new Group 4 herbicide, applied at intervals shorter than labeled requirements. Experiments were established near Painter and Suffolk, VA, and Belvidere, Clayton, Eure, Lewiston, and Rocky Mount, NC, during the 2017 and 2018 growing seasons. Herbicide treatments included halauxifen, dicamba, and 2,4-D applied 4, 3, 2, 1, and 0 wk before planting (WBP). Visible estimates of cotton growth reduction and total injury were collected 1, 2, and 4 wk after cotton emergence (WAE). Cotton stand and percentage of plants with distorted leaves were recorded 2 and 4 WAE. Cotton plant heights were recorded 4 and 8 WAE. Halauxifen was less injurious (9%) than dicamba (26%) or 2,4-D (21%) 2 WAE when herbicides were applied 0 WBP. Cotton stand reduction 2 WAE by halauxifen was less than 2,4-D and dicamba when applied 0 WBP. Injury observed from herbicides applied 1, 2, 3, and 4 WBP was minor, and no significant differences in cotton stand were observed. Early-season cotton injury was transient, and seed cotton yield was unaffected by any treatment.

Non-monotone periodic orbits of a rotational horseshoe

In this paper, we present results for the forcing relation on the set of braid types of periodic orbits of a rotational horseshoe on the annulus. Precisely, we are concerned with a family of periodic orbits, called the Boyland family, and we prove that for each pair $(r,s)$ of rational numbers with $r<s$ in $(0,1)$, there exists a non-monotone orbit $B_{r,s}$ in this family which has pseudo-Anosov type and rotation interval $[r,s]$. Furthermore, the forcing relation among these orbits is given by the inclusion order on their rotation sets. It is also proved that the Markov partition associated to each Boyland orbit comes from a pruning map which projects to a bimodal circle map. This family also contains the Holmes orbits $H_{p/q}$, which are the largest for the forcing order among all the $(p,q)$-orbits of the rotational horseshoe.

Ergodic properties of bimodal circle maps

We give conditions that characterize the existence of an absolutely continuous invariant probability measure for a degree one $C^{2}$ endomorphism of the circle which is bimodal, such that all its periodic orbits are repelling, and such that both boundaries of its rotation interval are irrational numbers. Those conditions are satisfied when the boundary points of the rotation interval belong to a Diophantine class. In particular, they hold for Lebesgue almost every rotation interval. By standard results, the measure obtained is a global physical measure and it is hyperbolic.

Prescribed-burning vs. wildfire: management implications for annual carbon emissions along a latitudinal gradient of <i>Calluna vulgaris</i>-dominated vegetation

A~present challenge in fire ecology is to optimize management techniques so that ecological services are maximized and C emissions minimized. Here, we model the effects of different prescribed-burning rotation intervals and wildfires on carbon emissions (present and future) in British moorlands. Biomass-accumulation curves from four Calluna-dominated ecosystems along a north–south, climatic gradient in Great Britain were calculated and used within a matrix-model based on Markov Chains to calculate above-ground biomass-loads, and annual C losses under different prescribed-burning rotation intervals. Additionally, we assessed the interaction of these parameters with an increasing wildfire return interval. We observed that litter accumulation patterns varied along the latitudinal gradient, with differences between northern (colder and wetter) and southern sites (hotter and drier). The accumulation patterns of the living vegetation dominated by Calluna were determined by site-specific conditions. The optimal prescribed-burning rotation interval for minimizing annual carbon losses also differed between sites: the rotation interval for northern sites was between 30 and 50 years, whereas for southern sites a hump-backed relationship was found with the optimal interval either between 8 to 10 years or between 30 to 50 years. Increasing wildfire frequency interacted with prescribed-burning rotation intervals by both increasing C emissions and modifying the optimum prescribed-burning interval for C minimum emission. This highlights the importance of studying site-specific biomass accumulation patterns with respect to environmental conditions for identifying suitable fire-rotation intervals to minimize C losses.