Alternative poultry litter storage for improved transportation and use as a soil amendment

The social networks of manureshed management

Manureshed management-the strategic use of manure nutrients that prioritizes recycling between livestock systems and cropping systems-provides a comprehensive framework for sustainable nutrient management that necessitates the collaboration of many actors. Understanding the social dimensions of collaboration is critical to implement the strategic and technological requirements of functional manuresheds. To improve this understanding, we identified aspirational networks of actors involved in manureshed management across local, regional, and national scales, principally in the United States, elucidating key relationships and highlighting the breadth of interactions essential to successful manureshed management. We concluded that, although the social networks vary with scale, the involvement of a common core set of actors and relationships appears to be universal to the successful integration of modern livestock and crop production systems necessary for functional manuresheds. Our analysis also reveals that, in addition to agricultural producers, local actors in extension and advisory services and private and public sectors ensure optimal outcomes at all scales. For manureshed management to successfully integrate crop and livestock production and sustainably manage manure nutrient resources at each scale, the full complement of actors identified in these social networks is critical to generate innovation and ensure collaboration continuity.

Biological and thermochemical conversion of human solid waste to soil amendments

Biological and thermochemical sanitization of source-separated human solid waste (HSW) are effective technologies for unsewered communities. While both methods are capable of fecal pathogen sterilization, the agronomically-beneficial properties of waste sanitized between methods remains unclear. Therefore, this study compared recovery and quality of soil amendments produced by compostation, torrefaction, and pyrolysis of HSW, established their financial value, and quantified tradeoffs between product value and conversion efficiency. Temperature and associated mass losses significantly affected the physical and chemical properties of thermochemically-treated HSW. Thermophilic composting, a biological sanitation method practiced in informal settlements in Nairobi, Kenya, produced an amendment that contained between 16 and 858-fold more plant-available nitrogen (N; 214.5 mg N/kg) than HSW pyrolyzed between 300 and 700 °C (0.2-15.2 mg N/kg). Conversely, HSW pyrolyzed at 600 °C had four-fold higher plant-available phosphorus (P; 3117 mg P/kg) and five-fold higher plant-available potassium (K; 7403 mg K/kg) than composted HSW (716 mg P/kg and 1462 mg K/kg). Wide variation between international fertilizer prices on the low end and regional East African prices on the high end resulted in broad-spaced quantiles for the value of agronomic components in HSW amendments. Phosphorus and K comprised a disproportionate amount of the value, 52-87%, compared to plant-available N, which contributed less than 2%. The total value of treated HSW, summed across all agronomic components per unit weight amendment, was greatest for thermochemically-treated HSW at 600 °C, averaging 220 USD/Mg, more than four-fold that of composted HSW, 53 USD/Mg. In contrast, torrefaction provided the highest monetary value per unit weight feedstock, 144 USD/Mg, as low heating temperatures engender minimal mass loss and higher nutrient densities per unit weight feedstock, compared to composted or pyrolyzed HSW. When benchmarked against total N, P, and K of eight commonly-applied organic amendments, including sewage-sludge (Milorganite), compost, and alfalfa meal, HSW pyrolyzed at 700 °C was of greatest value per unit weight of amendment, 365 USD/Mg, compared to 89 USD/Mg for composted HSW, and contained 2.9% total N (0.5 mg available N/kg), 3.1% total P (7640 mg available P/kg), 3.5% total K (17,671 mg available K/kg).

Copper and Zinc Runoff from Land Application of Composted Poultry Litter

Regions with long-term animal manure applications based on nitrogen (N) requirements have concerns regarding elevated nutrient levels. Most attention has focused on phosphorus (P), but heavy metal accumulation has received attention due to perceived environmental concerns. Composting is a potential management practice that can reduce total manure mass and volume while creating a stabilized product that has less odor and fewer pathogens. However, composting animal manures can lead to high N loss via ammonia volatilization and increased concentrations of nonvolatile nutrients. The objective of this study was to measure copper (Cu) and zinc (Zn) concentrations in runoff water from plots fertilized with composted and fresh poultry litter. Seven treatments were evaluated in the first year: (i) unfertilized control, (ii) fresh poultry litter, (iii) normal compost (no amendment), (iv) composted litter with alum, (v) composted litter with phosphoric acid, (vi) composted litter with a microbial mixture, and (vii) composted litter with alum + microbial mixture. Six of these treatments were evaluated in Year 2 (alum + microbial mixture was not evaluated in Year 2). Rainfall simulators were used to produce a 5 cm h storm event sufficient in length to cause 30 min of continuous runoff. Concentrations of Cu and Zn were elevated in compost compared with fresh poultry litter. However, metal concentrations in compost did not correlate well with metal concentrations in runoff water and may have been affected by compost maturity and amendment. Total Cu and Zn concentrations in runoff water did not differ between alum-amended compost and fresh poultry litter in each year.

Application of poultry processing industry waste: a strategy for vegetation growth in degraded soil

The disposal of poultry processing industry waste into the environment without proper care, can cause contamination. Agricultural monitored application is an alternative for disposal, considering its high amount of organic matter and its potential as a soil fertilizer. This study aimed to evaluate the potential of poultry processing industry waste to improve the conditions of a degraded soil from a desertification hotspot, contributing to leguminous tree seedlings growth. The study was carried out under greenhouse conditions in a randomized blocks design and a 4 × 2 factorial scheme with five replicates. The treatments featured four amounts of poultry processing industry waste (D1 = control 0 kg ha(-1); D2 = 1020.41 kg ha(-1); D3 = 2040.82 kg ha(-1); D4 = 4081.63 kg ha(-1)) and two leguminous tree species (Mimosa caesalpiniaefolia Benth and Leucaena leucocephala (Lam.) de Wit). The poultry processing industry waste was composed of poultry blood, grease, excrements and substances from the digestive system. Plant height, biomass production, plant nutrient accumulation and soil organic carbon were measured forty days after waste application. Leguminous tree seedlings growth was increased by waste amounts, especially M. caesalpiniaefolia Benth, with height increment of 29.5 cm for the waste amount of 1625 kg ha(-1), and L. leucocephala (Lam.) de Wit, with maximum height increment of 20 cm for the waste amount of 3814.3 kg ha(-1). M. caesalpiniaefolia Benth had greater initial growth, as well as greater biomass and nutrient accumulation compared with L. leucocephala (Lam.) de Wit. However, belowground biomass was similar between the evaluated species, resulting in higher root/shoot ratio for L. leucocephala (Lam.) de Wit. Soil organic carbon did not show significant response to waste amounts, but it did to leguminous tree seedlings growth, especially L. leucocephala (Lam.) de Wit. Poultry processing industry waste contributes to leguminous tree seedlings growth, indicating that it can be part of a long-term strategy to increase soil organic carbon in degraded soil from a desertification hotspot.