Evaluation of phosphorus runoff from sandy soils under conservation tillage with surface broadcasted recovered phosphates.

Potential new sources of phosphorus (P) fertilizer are the recovered P from livestock wastewater through chemical precipitation and the ash from combusting animal manures. Although most of the research on P losses from conservation tillage include high water-soluble P compounds from commercial fertilizer sources, information on the use of non-conventional, low water-soluble, recycled P sources is scarce. Particularly for sandy soils of the United States (US) Southeastern Coastal Plain region, research driven information on P loss into the environment is needed to determine recommendations for a direct use of new recycled P sources as crop P fertilizers.

Stochastic state-space temperature regulation of biochar production. Part I: Theoretical development.

Background: The concept of a designer biochar that targets the improvement of a specific soil property imposes the need for production processes to generate biochars with both high consistency and quality. These important production parameters can be affected by variations in process temperature that must be taken into account when controlling the pyrolysis of agricultural residues such as manures and other feedstocks.

Results: A novel stochastic state-space temperature regulator was developed to accurately match biochar batch production to a defined temperature input schedule.

Stochastic state-space temperature regulation of biochar production. Part II: Application to manure processing via pyrolysis.

Background: State-of-the-art control systems that can guarantee the pyrolytic exposure temperature are needed in the production of designer biochars. These designer biochars will have tailored characteristics that can offer improvement of specific soil properties such as water-holding capacity and cation exchange capacity.

Results: A novel stochastic state-space temperature regulator was developed for the batch production of biochar that accurately matched the pyrolytic exposure temperature to a defined temperature input schedule.