Biochar, wood vinegar, and poultry litter are waste streams that can be utilized as soil amendments and fertilizers. However, poultry litter releases several pollutants through nutrient leaching and carries heavy microbial loads, including potential human pathogens. Improving nutrient retention and reducing microbial load in poultry litter may help protect environmental and human health and improve its value as a soil amendment. The objectives of this study were to determine how blending varying proportions of loblolly pine (Pinus taeda L.) biochar, wood vinegar, and poultry litter affected nutrient profiles and microbial abundance over time. Biochar inclusion rates were 0%, 5%, 10%, and 20%, and wood vinegar was applied at 2% w/w. Samples were taken at Day 0, 57, and 112 to measure nitrogen, phosphorus, potassium, pH, total fungi, and total bacteria. Nutrient levels generally decreased with increasing biochar level; however, biochar inclusion rates of 10% and 20% retained nitrogen and phosphorus and exhibited improved physical properties. Overall, adding wood vinegar decreased nutrient concentrations and showed a biocidal effect for bacteria and fungi. Bacteria and fungi showed different relationships with biochar inclusion rates, with fungi preferring higher biochar inclusion rates and bacteria flourishing at lower biochar inclusion rates.

The effect of various inclusion rates of pine biochar (PBC), miscanthus biochar (MCB) and starting moisture contents on the water activity (A_w) of broiler litter/biochar mixtures was examined. Suitable models for the resulting moisture sorption isotherms were also evaluated. For poultry mixed with PBC and MBC, higher starting moisture contents led to increased A_w. A_w generally increased at high inclusion rates of PBC and MBC, which may be explained by the porous nature and general hydrophobicity of BC. Of the five models examined, the exponential rise to maximum was considered to be the most useful due to its accuracy at moisture contents similar to those commonly found in commercial poultry houses (10–30 % wet basis). Accuracy of models was determined using R², mean squared prediction error (MSPE), and mean absolute percent error (MAPE). In general, higher inclusion rates of biochar resulted in less overall prediction accuracy. Results from this paper indicate that several moisture isotherm models can be used to effectively model the relationship between moisture content and A_w in broiler litter and biochar mixtures.

Compost and Arbuscular mycorrhizal fungi are environmentally sustainable and low-cost materials that can benefit tropical soils with high phosphorus fixation and low organic matter content. This study investigated the effects of Arbuscular mycorrhizal fungi (AMF) and compost on the growth and nutrient uptake efficiency of sugarcane (Saccharum officinarum) seedlings. The experimental design was a completely randomized factorial design, where factor A (n = 5) was the compost doses (0, 15, 30, 60 and 120 t ha-1) and B (n = 3) the AMF inoculum (Rhizophagus clarus, Gigaspora margarita, and non-inoculated). At 30 and 90 d, seedlings’ diameter and height were measured. Mycorrhizal colonization rate, biomass production, nutrient uptake (P and N), and mycorrhizal dependency were assessed at the end of the experiment. The AMF and compost doses affected the colonization rate, initial growth, biomass production, and nutrient uptake of sugarcane seedlings. Overall, the AMF benefited plant growth at lower doses of compost. R. clarus had a higher impact on the shoot diameter of sugarcane seedlings. Mycorrhizal colonization increased with compost addition only in seedlings inoculated with G. margarita. There was no clear trend among AMF treatments for nutrient uptake. In general, sugarcane seedlings dependency on mycorrhizal condition to produce growth was higher at lower compost doses.