Wang Lei, Leghari Shah Jahan, Wu Jiajun, Wang Na, Pang Min, Jin Liang
Institute of Plant Nutrition, Resources and Environment, Beijing Academy of Agricultural and Forestry Sciences, Beijing, China.
College of Mechanical and Electronical Engineering, Northwest A&F University, Yangling, Shaanxi, China.
Front Plant Sci. 2023 Sep 6;14:1230023. doi: 10.3389/fpls.2023.1230023. eCollection 2023.
Long-term application of nitrogen (N) fertilizer adversely degrades soil and decreases crop yield. Biochar amendment with N fertilizer not only can increase yield but also can improve the soil. A 3-year field experiment was conducted to determine the effect of biochar doses with N fertilizer on maize yield and soil N and water dynamics under border irrigation (BI) and drip irrigation (DI) methods. Treatments were 260 kg N ha without biochar addition and combined with low, medium, and high doses of biochar, namely, 15.5 t ha, 30.7 t ha, and 45.3 t ha (NB, NB, NB, and NB), respectively. The biochar doses and irrigation methods significantly ( < 0.05) increased maize growth and yield characteristics, irrigation water use efficiency (IWUE), and fertilizer N use efficiency (FNUE) and enhanced the soil properties. In the BI and DI method, the NB, NB, and NB treatments increased yield by 4.96%-6.10%, 8.36%-9.85%, and 9.65%-11.41%, respectively, compared to NB. In terms of IWUE and FNUE, the non-biochar treatment had lower IWUE and FNUE compared to biochar combined with N fertilizer treatments under both BI and DI methods. In the BI method, the IWUE in NB and NB ranged from 3.36 to 3.43 kg kg, and in DI, it was maximum, ranging from 5.70 to 5.94 kg kg. Similarly, these medium and high doses of biochar increased the FNUE of maize. The FNUEs in NB and NB under BI ranged from 38.72 to 38.95 kg kg and from 38.89 to 39.58 kg kg, while FNUEs of these same treatments under DI ranged from 48.26 to 49.58 kg kg and from 48.92 to 50.28 kg kg. The effect of biochar was more obvious in DI as compared to the BI method because soil water content (SWC) and soil N concentrations (SNCs) were higher at rhizosphere soil layers under DI. Biochar improved SWC and SNC at 0-20 cm and 20-40 cm soil layers and decreased below 60-cm soil layers. In contrast, despite biochar-controlled SWC and SNCs, still, values of these parameters were higher in deeper soil layers. In the BI method, the SNCs were higher at 60-80 cm and 80-100 cm compared to the top and middle soil layers. Depth-wise results of SNC demonstrated that the biochar's ability to store SNC was further enhanced in the DI method. Moreover, biochar increased soil organic matter (OM) and soil aggregate stability and maintained pH. The NB treatment increased soil OM by 11.11%-14.60%, NB by 14.29%-19.42%, and NB by 21.98%-23.78% in both irrigation methods. This increased OM resulted in improved average soil aggregates stability by 2.45%-11.71% and 4.52%-14.66% in the BI and DI method, respectively. The results of our study revealed that combined application of N fertilizer with a medium dose of biochar under the DI method would be the best management practice, which will significantly increase crop yield, improve SWC, enrich SNC and OM, improve soil structure, and maintain pH.
长期施用氮肥会对土壤产生不利影响，导致土壤退化并降低作物产量。氮肥与生物炭配施不仅可以提高产量，还能改善土壤。为此开展了一项为期3年的田间试验，以确定在畦灌（BI）和滴灌（DI）方式下，氮肥与不同剂量生物炭配施对玉米产量以及土壤氮素和水分动态的影响。试验处理包括不添加生物炭的260 kg N·ha，以及分别与低、中、高剂量生物炭（即15.5 t·ha、30.7 t·ha和45.3 t·ha，分别记为NB、NB、NB）配施的氮肥。生物炭剂量和灌溉方式显著（<0.05）提高了玉米的生长和产量特性、灌溉水利用效率（IWUE）和肥料氮利用效率（FNUE），并改善了土壤性质。在畦灌和滴灌方式下，与NB处理相比，NB、NB和NB处理的玉米产量分别提高了4.96% - 6.10%、8.36% - 9.85%和9.65% - 11.41%。在IWUE和FNUE方面，与氮肥配施生物炭的处理相比，不施生物炭处理在畦灌和滴灌方式下的IWUE和FNUE均较低。在畦灌方式下，NB和NB处理的IWUE为3.36 - 3.43 kg·kg，在滴灌方式下最高，为5.70 - 5.9 kg·kg。同样，这些中高剂量生物炭提高了玉米的FNUE。畦灌方式下NB和NB处理的FNUE分别为38.72 - 38.95 kg·kg和38.89 - 39.58 kg·kg，而相同处理在滴灌方式下的FNUE分别为48.26 - 49.58 kg·kg和48.92 - 50.28 kg·kg。与畦灌方式相比，生物炭在滴灌方式下的效果更明显，因为滴灌方式下根际土壤层的土壤含水量（SWC）和土壤氮浓度（SNC）更高。生物炭提高了0 - 20 cm和20 - 40 cm土层的SWC和SNC，而在60 cm以下土层则降低。相比之下，尽管生物炭能调控SWC和SNC，但这些参数在较深土层中的值仍然较高。在畦灌方式下，60 - 80 cm和80 - 100 cm土层的SNC高于表层和中层土壤。SNC的垂直分布结果表明，滴灌方式进一步增强了生物炭储存SNC的能力。此外，生物炭增加了土壤有机质（OM）和土壤团聚体稳定性，并维持了土壤pH值。在两种灌溉方式下，NB处理使土壤OM增加了11.11% - 14.60%，NB处理增加了14.29% - 19.42%，NB处理增加了21.98% - 23.78%。OM的增加分别使畦灌和滴灌方式下的平均土壤团聚体稳定性提高了2.45% - 11.71%和4.52% - 14.66%。本研究结果表明，滴灌方式下氮肥与中剂量生物炭配施是最佳管理措施，可显著提高作物产量，改善SWC，增加SNC和OM，改善土壤结构并维持土壤pH值。
