Compost mineralization in soil as a function of composting process conditions

Abstract

Compost has been shown to have a range of positive impacts on soil quality and can provide an important source of nutrients for plants. While these benefits have been documented for many finished composts, there is presently little understanding of the impact of composting process conditions and the extent of compost decomposition on soil C and N mineralization after compost incorporation. This study evaluated the impact of composting process conditions and the extent of compost decomposition on soil C and N mineralization after compost incorporation. Dried, ground composts were blended with equal parts of quartz sand and soil and incubated aerobically for 28 d at 30 °C. Cumulative respired CO 2 -C and net mineralized N were quantified. Results indicate that (1) organic substrates that did not degrade due to sub-optimal conditions during the composting process can readily mineralize after incorporation in soil; (2) C and N cycling dynamics in soil after compost incorporation can be affected by compost feedstock, processing conditions, and time; and (3) denitrification after compost incorporation in soil can limit N availability from compost. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. AbstractCompost has been shown to have a range of positive impacts on soil quality and can provide an important source of nutrients for plants. While these benefits have been documented for many finished composts, there is presently little understanding of the impact of composting process conditions and the extent of compost decomposition on soil C and N mineralization after compost incorporation. This study evaluated the impact of composting process conditions and the extent of compost decomposition on soil C and N mineralization after compost incorporation. Dried, ground composts were blended with equal parts of quartz sand and soil and incubated aerobically for 28 d at 30°C. Cumulative respired CO 2 -C and net mineralized N were quantified. Results indicate that (1) organic substrates that did not degrade due to sub-optimal conditions during the composting process can readily mineralize after incorporation in soil; (2) C and N cycling dynamics in soil after compost incorporation can be affected by compost feedstock, processing conditions, and time; and (3) denitrification after compost incorporation in soil can limit N availability from compost.

Composts Produced From Pig Slurry Solids: Nutrient Efficiency and N-Leaching Risks in Amended Soils

“…The low N losses by leaching during the two rain events (Figure 3) indicate that the N applied in excess accumulated in the soil, as losses by denitrification may have been irrelevant at a soil moisture content of <70% WHC. According to Estavillo et al (1996), N losses by denitrification from mineral fertilizers can be 9-17% during spring/autumn, reaching 2% from mature composts (Cambardella et al, 2003). In fact, the TN accumulation in the soil with the compost and mineral fertilizer treatments occurred as organic N ( Table 5).…”

Humusica 2, article 16: Techno humus systems and recycling of waste

“…Grinding woody material in pieces < 2 cm speeds up the process. Out of these optimal conditions, biodegradation slows down or is arrested (Mustin, 1987;Cambardella et al, 2003;McDowell and Clark-McDowell, 2008;Gerbier, 2015); • Real systems are always more complicated than expected (Jones and Martin, 2003;Uzun, 2004;Jones and Saison et al, 2006;Thummes et al, 2007;Farrell and Jones, 2009;Vogel and Dussutour, 2016). However, by selecting/mixing good organic remains (absence of pollutants and good C/N balance) and maintaining the right aeration/temperature level in the core of the pile, even a child may use the decomposing power of a techno humus system.…”

Effects of Organic Amendment Application on Soil Quality and Garlic Yield in Central-Western Argentina

“…Chicken litter had low water content, high proportion of cellulosic matter (from rice bran) and high soluble N content, characteristic of faeces of birds fed on protein-enhanced diets [33,18]. Vermicompost exhibited the typical characteristics of stable, good quality products (high humus and ash content) obtained from animal manures [13,14,34,35].…”

“…Likewise, the high chemical fertilizer doses applied with CL have favoured microbial growth and the consequent fast organic C consume and N release [4,44]. Thus, one of the objectives of amendment use is not met: gradual release of nitrates from organic N to improve synchronization with crop requirements [34,33,45].…”