Biochar and organic substitution improved net ecosystem economic benefit in intensive vegetable production

Abstract

Biochar amendment and substituting chemical fertilizers with organic manure (organic substitution) have been widely reported to increase crop production and decrease reactive nitrogen (Nr) loss including nitrous oxide (N2O), nitric oxide (NO), and ammonia (NH3) emissions, and N runoff and leaching. However, few comprehensive evaluations have been performed on the environmental and economic aspects of biochar amendment or organic substitution. Here, we studied the comprehensive effects of biochar amendment, organic substitution, and biochar amendment combined with organic substitution on crop production, Nr loss, and net ecosystem economic benefit (NEEB) in intensive vegetable production by integrating life-cycle assessment for Nr footprints, empirical models for NH3 volatilization and N runoff and leaching derived from peer-reviewed publications and validated by the current measurements and direct field measurement for N2O and NO emissions during 5 consecutive years of vegetable crop rotations. Five fertilization treatments were applied (SN: synthetic fertilizer application; SNB: SN plus 20 t ha−1 biochar amendment; SNM: substituting 50% of chemical N fertilizer with organic manure; SNMB: SNM plus 20 t ha−1 biochar amendment; and CK: no fertilizer or biochar addition). Compared with the SN, the SNB increased vegetable yield (28.4%, p < 0.05; interannually varying from − 10 to 74.9%) and nitrogen use efficiency (29.2%, interannually varying from − 39.7 to 150.4%), and decreased field Nr loss (45.4%, p < 0.01; interannually varying from − 40.3 to 78.4%), and thus improved NEEB by 7.1%; meanwhile, the SNM increased vegetable yield (11.6%, interannually varying from − 5.4 to 27.1%) and nitrogen use efficiency (45.7%, p < 0.05; interannually varying from 2.3 to 154%), reduced field Nr loss (34.9%, p < 0.01; interannually varying from 8.4–39.0%), and thus improved NEEB by 17.8% (p < 0.05) compared to the SN, being 56.0 × 103 Chinese Yuan (CNY) ha−1 crop−1. Due to the high foreground Nr loss during organic manure production and high input costs of biochar production, the SNMB decreased the NEEB by 8.0% as compared to the SN. Moreover, the SNB and SNM improved vegetable qualities by increasing protein, soluble sugar, and vitamin C contents while decreasing nitrate content (p < 0.05). Therefore, single application of biochar amendment or organic substitution would achieve better NEEB and product quality in vegetable production. Graphical Abstract

Trade‐off between soil carbon sequestration and net ecosystem economic benefits for paddy fields under long‐term application of biochar

“…On the one hand, due to the current high price of biochar (110 $ Mg −1 ) and the low international C price (35 $ Mg −1 CO 2 eq), the economic return is low, so the application of biochar in some agricultural ecosystems is restricted. On the other hand, due to the dominance of yield gains in NEEB (Li et al., 2015), when biochar was combined with N fertilizer, vegetable yield increased by 28%, resulting in a 7.1% increase in NEEB (Bi et al., 2022). However, the increase in bulk crop yield was not as high as that of vegetables.…”

“…Besides GHG emissions, CF and GHGI, another concern is to improve the economic profits of rice production (Bi et al., 2022), namely the NEEB. NEEB consists of crop yield gains minus input cost and carbon cost (Cai et al., 2018).…”

“…Although biochar combined with N fertilizer significantly increased vegetable yield by 28%, NEEB increased by only 7.1%. However, NEEB reduced by 8.0% when vegetable yield rose by just 12% (Bi et al., 2022). Due to the prevalence of yield improvements in NEEB, biochar alone enhanced yield by 11% in rice ecosystems (Liu et al., 2022; Liu et al., 2022).…”

Biochar from animal manure: A critical assessment on technical feasibility, economic viability, and ecological impact

“…This or similar approaches would help to get the most accurate picture when comparing manure versus manure biochar applications to support the decision‐making of, for example, a farmer who needs to optimize the on‐farm nutrient recycling with a given amount of manure available. Such information will facilitate an accurate estimation of net ecosystem and economic benefits (often referred to as NEEB) between manure and manure biochar‐based farming systems as, for example, performed to quantitatively compare mineral fertilization with biochar‐based organic fertilization (Bi et al, 2022; Li et al, 2015). In addition, further mechanistic information can be obtained, for example, from experiments with normalized carbon or nutrient contents of the organic amendments.…”

Hydrogen, Ammonia and Symbiotic/Smart Fertilizer Production Using Renewable Feedstock and CO2 Utilization through Catalytic Processes and Nonthermal Plasma with Novel Catalysts and In Situ Reactive Separation: A Roadmap for Sustainable and Innovation-Based Technology

“…Several novel fertilizer systems, known as "smart fertilizers" are available [7][8][9][10][11][12][13]. They are mainly based on hydrophilic super-absorbing polymers (SAPs) or biochar.…”