Optimization of Blended Biochar Pellet by the Use of Nutrient Releasing Model

Abstract

For the recycling of biomass conversion materials, this experiment was conducted to investigate plant nutrient releasing characteristics, and to determine an optimum blended ratio of biochar for producing a biochar pellet based on a column leaching study. The treatments consisted of only pig manure compost (PMC) as a control, pig manure compost pellets (PMCP), and biochar pellets (BCP) blended with biochar and pig manure compost with the following ratios: 9:1, 8:2, 4:6, and 2:8. Results showed that the accumulated amount of ammonium nitrogen (NH4-N) was in order of PMC > PMCP > BCP (2:8) > BCP (4:6) > BCP (8:2) > BCP (9:1) ratios. The highest accumulated amounts of phosphate phosphorus (PO4-P) and potassium (K) were 1953 and 1917 mg L−1 in the PMC and PMCP, but the lowest in the BCP (9:1) were 223 and 1078 mg L−1, respectively. It was shown that the highest accumulated amount of silicon dioxide (SiO2) was 2329 mg L−1 in the BCP (8:2), but the lowest in the PMC was 985 mg L−1. The estimations for accumulated NH4-N, PO4-P, K, and SiO2 releasing amounts in all the treatments were significantly fitted with a modified Hyperbola model. The optimum mixing rate was estimated to be BCP (2:8). Therefore, biochar pellets might be useful in obtaining basic information on slow-release fertilizer for sustainable agriculture.

Role of Biochar in Improving Sandy Soil Water Retention and Resilience to Drought

“…The loss of labile aliphatic compounds in biochar samples derived from pig manure, crop residues, and municipal solid waste has been reported to cause the disappearance of hydrophobicity when the pyrolysis temperature is over 500 °C [53]. Omondi et al showed in their review that for a Other studies have also reported that biochar produced from cellulosic biomass such as grain husk [14], pig manure compost [45,46], cattle manure [47], cattle manure mixed with straw [47], chicken manure [47], chicken manure mixed with sawdust [47] and pig slurry (PC) [47], red oak (Quercus rubra) [15,22], ground wheat straw and wood pellets (69% Norway Spruce, 19% Beech plus other wood species) [25], North European grassland species [34], Picea abies (70%) and deciduous wood shavings of Fagus sylvatica (30%) [27], wheat and maize straws [33], mesquite feedstock/mesquite wood (Prosopis sp.) [32,48], and Pseudotsuga menziesii [24] have large portions of the volume of pores that are 1 (or smaller) to 10 µm in diameter, because the biochar inherited the architecture of the biomass [9,[48][49][50].…”

“…The drawbacks of fine particulate biochar are significant weight loss of biochar during handling and transport to fields and potential chronic damage to the human respiration system [57][58][59]. Densified biochar pellets were then developed to alleviate the loss of fine biochar particles and reduce the costs of storage, transport, and handling [17,45,46,61,62]. Moreover, biochar pellets can function as a nutrient carrier to increase nutrient use efficiency by reducing the nutrient release rate.…”

Growth Responses and Changes of Soil Chemical Properties with Application Rate of Supplemented Biochar pellet as Slow Release Fertilizer during Tomato Cultivation

“…‡ TN: Total nitrogen. § TC: Total carbon.25%가량은 집중 호우 시 유거수에 의해 손실된다(Shin and Park, 2018). 특히 시비할 때 비산에 의해 사람의 코나 입 으로 들어가게 되면 호흡기 관련 문제를 일으키는 단점도 있다(Shin and Park, 2018).…”

“…§ TC: Total carbon.25%가량은 집중 호우 시 유거수에 의해 손실된다(Shin and Park, 2018). 특히 시비할 때 비산에 의해 사람의 코나 입 으로 들어가게 되면 호흡기 관련 문제를 일으키는 단점도 있다(Shin and Park, 2018). 이러한 문제점에 대해 돈분 퇴 비와 바이오차를 혼합하여 만든 돈분 바이오차 펠렛 형태는 바람에 의한 손실을 줄일 뿐만 아니라, 돈분 퇴비보다 펠 렛형 돈분 퇴비가 NH 4 + -N를 더 천천히 용출 시킨다고 하였다.…”

“…이러한 문제점에 대해 돈분 퇴 비와 바이오차를 혼합하여 만든 돈분 바이오차 펠렛 형태는 바람에 의한 손실을 줄일 뿐만 아니라, 돈분 퇴비보다 펠 렛형 돈분 퇴비가 NH 4 + -N를 더 천천히 용출 시킨다고 하였다. 따라서 혼합형 바이오차 펠렛을 이용 한 결과 작물을 재배하는 동안 양분을 이용할 수 있도록 서서히 방출하기 때문에 손실을 최소화한다고 하였고(Shin and Park, 2018), 바이오차와 돈분 퇴비 혼합비에 따른 작물 생육에 관한 연구 결과 돈분과 바이오차 혼합비 (6:4) 처 리구에서 상추 수량이 11% 증수되었다. 이와 비슷한 연구로 배추 재배 시 돈분 퇴비와 바이오차의 혼합비 (6:4)로 바이오차 펠렛 완효성 비료를 제조하여 추천 질소 시용량 기준으로 60%로 시비하였을 때, 바이오차 펠렛 처리구에서 대조구보다 토양 중의 NO 3 -N의 농도는 천천히 감소하였고, 배추 수량은 대조구와 비교하여 유의한 차이가 없었다고 발표하였다 (Kim et al, 2019).…”