ABSTRACT

Composts are an attractive organic-farming alternative to chemical fertilizers and are used for carbon sequestration to increase soil carbon storage. In Japan, a new type of mixed compost fertilizer called compost-compound fertilizer mixture (CCFM) has been registered. It exhibits several merits for organic farming; that is, it is odorless, easy to handle, and has a controllable nutrient content. CCFM consists of compost mixed with chemical fertilizer, such that nutrient content can be effectively adjusted. Although it has been pointed out that pellet composts generate more greenhouse gas emissions (GHGEs), such as carbon dioxide (CO₂) and nitrous oxide (N₂O), the mechanism involved is not clearly understood. To investigate the effect of CCFM on GHGEs, soil microbial properties and plant growth, incubation and pot experiments were conducted in a Hungarian Chernozem and a Japanese Andosol. Both soils were incubated with 1) CCFM prepared using pig manure mixed with chemical fertilizer, 2) chemical fertilizer only, or 3) no fertilizer. A pot experiment was conducted using Komatsuna (Brassica rapa). In the Chernozem, the maximum N₂O production rate was observed after chemical fertilizer treatment. The emission factors of chemical fertilizer and CCFM were 0.25% and 0.19%, respectively. In contrast, N₂O production was not detected in the Andosol. Meanwhile, CO₂ production was higher (P < 0.05) in the Chernozem than in the Andosol; furthermore, it was higher under CCFM than under chemical fertilizer treatment, with 7.5% of amended carbon changing to CO₂, thus suggesting that dominant carbon remained in the soil. Microbial biomass increased faster in the Andosol than in the Chernozem and the change was faster under the CCFM than under the chemical fertilizer or control treatments. In the pot experiment, CCFM tended to enhance plant growth in both soils. These experiments showed that CCFM has a soil-carbon storage effect with less resultant GHGEs, especially in Andosols, thereby leading to a more sustainable agriculture. Nonetheless, further studies are required for long-term experiments with other crops.

摘要

堆肥是一种有吸引力的有机农业替代化肥，用于固碳以增加土壤碳储存。在日本，一种称为堆肥-复合肥料混合物（CCFM）的新型混合堆肥已被注册。它展示了有机农业的几个优点；即无味、易处理、营养成分可控。CCFM由堆肥与化肥混合而成，可有效调节养分含量。尽管有人指出颗粒堆肥会产生更多的温室气体排放 (GHGE)，例如二氧化碳 (CO₂) 和一氧化二氮 (N₂O)，但其机制尚不清楚。为了研究 CCFM 对 GHGEs、土壤微生物特性和植物生长的影响，孵化和盆栽实验在匈牙利黑钙土和日本安多溶胶中进行。两种土壤均使用 1) CCFM 与化肥混合制备的 CCFM，2) 仅使用化肥，或 3) 不使用化肥进行培养。使用 Komatsuna (芸苔）。在黑钙土中，在化肥处理后观察到最大的 N2O 生成率。化肥和CCFM的排放因子分别为0.25%和0.19%。相反，在 Andosol 中没有检测到 N2O 的产生。同时，二氧化碳产量更高（P< 0.05）在黑钙土中比在安多溶胶中；此外，CCFM 处理高于化肥处理，7.5% 的修正碳转化为 CO2，表明主要碳保留在土壤中。Andosol 中微生物生物量的增加速度比黑钙土中快，CCFM 下的变化比化肥或对照处理下更快。在盆栽试验中，CCFM 倾向于促进两种土壤中的植物生长。这些实验表明 CCFM 具有土壤碳储存效应，产生的温室气体较少，尤其是在 Andosols 中，从而导致更可持续的农业。尽管如此，还需要进一步研究其他作物的长期试验。