College of Water Resources and Architectural Engineering, Northwest A&F University, Weihui Road 23, 712100 Yangling, Shaanxi, China; Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China; Department of Agroecology, Aarhus University, Blichers Allé 20, Postboks 50, DK-8830, Tjele, Denmark.
College of Water Resources and Architectural Engineering, Northwest A&F University, Weihui Road 23, 712100 Yangling, Shaanxi, China; Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, Shaanxi 712100, China.
Sci Total Environ. 2021 May 20;770:144769. doi: 10.1016/j.scitotenv.2020.144769. Epub 2021 Jan 25.
Biochar has shown beneficial effects in agricultural production, yet the combined effects of biochar and reduced irrigation on crop growth and water-use efficiency (WUE) in diverse soil types have not been fully explored. A split-root pot experiment was conducted to investigate the effects of addition of 2% softwood (SWB) and wheat straw biochar (WSB) on growth, physiology, WUE and nutrients uptake of tobacco (Nicotiana tabacum L.) plants grown in a Ferrosol and an Anthrosol, respectively, under three irrigation treatments. The plants were either irrigated daily to 90% of water-holding capacity (FI), or irrigated with 70% volume of water used for FI to the whole root-zone (DI) or alternately to half root-zone (PRD). The results showed that plants grown in Anthrosol possessed greater leaf gas exchange rates, dry biomass and WUE while lower nutrients content compared to those grown in Ferrosol. Despite a negative effect on plant N content and WUE, WSB addition increased water-holding capacity, consequently improved leaf gas exchange, water uptake, biomass and K content resulting in an improved in the leaf quality of tobacco as exemplified by an increased leaf K content and a more appropriate N to K stoichiometric ratio. However, these effects were not evident upon SWB addition. Moreover, these responses to biochar addition were stronger in Ferrosol than in Anthrosol might be associated with its lower pH. Compared to FI, PRD slightly reduced photosynthetic rate but significantly decreased stomatal conductance, transpiration rate and leaf area, leading to a significant increase in intrinsic, instantaneous and plant WUE. Additionally, PRD was superior over DI in improving yield, WUE, N uptake under a same irrigation volume. It was concluded that WSB combined with PRD could be a promising practice to synergistically improve tobacco yield, quality and WUE by improving soil hydro-physical properties and nutrients bioavailability.
生物炭在农业生产中表现出有益的效果，但生物炭和减少灌溉对不同土壤类型中作物生长和水分利用效率（WUE）的综合影响尚未得到充分探索。采用分根盆栽试验，研究了在三种灌溉处理下，分别向铁铝土和人为土中添加 2%软木（SWB）和小麦秸秆生物炭（WSB）对烟草（Nicotiana tabacum L.）生长、生理、WUE 和养分吸收的影响。这些植物要么每天灌溉至持水量的 90%（FI），要么用 FI 用水量的 70%灌溉整个根区（DI），要么交替灌溉一半根区（PRD）。结果表明，与 Ferrosol 相比，在 Anthrosol 中生长的植物具有更高的叶片气体交换速率、干生物量和 WUE，而养分含量较低。尽管 WSB 对植物 N 含量和 WUE 有负面影响，但它增加了持水量，从而改善了叶片气体交换、水分吸收、生物量和 K 含量，从而提高了烟草叶片的质量，例如增加了叶片 K 含量和更合适的 N 到 K 化学计量比。然而，在添加 SWB 时，这些效果并不明显。此外，这些对生物炭添加的响应在 Ferrosol 中比在 Anthrosol 中更强，这可能与 Ferrosol 较低的 pH 值有关。与 FI 相比，PRD 略降低了光合速率，但显著降低了气孔导度、蒸腾速率和叶面积，导致内在、瞬时和植物 WUE 显著增加。此外，在相同灌溉量下，PRD 优于 DI，可提高产量、WUE 和 N 吸收。综上所述，WSB 与 PRD 相结合，可以通过改善土壤水物理性质和养分生物有效性，协同提高烟草产量、品质和 WUE，是一种很有前途的实践。
