Shi Deng-Lin, Wang Xiao-Li, Liu An-Kai, Hou Zai-Fen, Liang Guo-Tai
College of Agriculture, Guizhou University, Guiyang 550025, China.
Department of Agriculture and Rural Affairs of Guizhou Province, Guiyang 550001, China.
Huan Jing Ke Xue. 2021 Jan 8;42(1):443-449. doi: 10.13227/j.hjkx.202005186.
The effects of biochar combined with nitrogen fertilizer on soil microbial carbon, nitrogen (SMBC, SMBN), and rice yield and quality were investigated to provide a scientific basis for soil fertilization and nitrogen fertilizer reduction. Using a field experiment, we set up a nitrogen reduction gradient (T0-T4):0, 10%, 20%, 30%, and 40% reductions. The same amount of biochar nitrogen was used as the substitute and no nitrogen fertilizer was used as the control (CK). The yield was measured and sampled at the mature stage of rice, and the samples were analyzed in the laboratory. The results showed that the range of SMBC and SMBN was 208.42-303.16 mg·kg and 32.28-54.73 mg·kg, respectively. SMBC, SMBN, soil microbial entropy (qMB), soil microbial biomass nitrogen to total nitrogen ratio (SMBN/TN), and rice yield increased first and then decreased as the proportion of biochar and nitrogen fertilizer increased. SMBC, SMBN, and rice yield were all the highest in T2, which increased successively by 28.0%, 30.0%, and 13.4% compared with that of the T0 treatment (<0.05), while those of the T4 treatment decreased slightly (>0.05). The processing of SMBC, qMB, SMBN, and SMBN/TN showed a significantly positive relationship between the two (<0.01). Compared with that of the T0 treatment, the T2 treatment significantly increased the Milled rice, gel consistency, and amylose content. In this study, the combination of biochar (5.0 t·hm) and nitrogen reduction (20%) effectively improved soil microbial carbon and nitrogen content and increased the yield and quality of rice, which could be a good choice for reducing nitrogen fertilization and increasing the efficiency of rice in a yellow soil paddy field in Guizhou.
研究了生物炭与氮肥配施对土壤微生物碳、氮（土壤微生物量碳、土壤微生物量氮）以及水稻产量和品质的影响，旨在为土壤施肥和减氮提供科学依据。通过田间试验，设置了减氮梯度（T0 - T4）：减少0%、10%、20%、30%和40%，用等量生物炭氮替代，不施氮肥作为对照（CK）。在水稻成熟期测定产量并采样，样品在实验室进行分析。结果表明，土壤微生物量碳和土壤微生物量氮的范围分别为208.42 - 303.16 mg·kg和32.28 - 54.73 mg·kg。随着生物炭与氮肥比例增加，土壤微生物量碳、土壤微生物量氮、土壤微生物熵（qMB）、土壤微生物量氮与全氮比值（SMBN/TN）以及水稻产量均先增加后降低。土壤微生物量碳、土壤微生物量氮和水稻产量在T2处理中最高，与T0处理相比分别依次增加了28.0%、30.0%和13.4%（P<0.05），而T4处理略有下降（P>0.05）。土壤微生物量碳、qMB、土壤微生物量氮和SMBN/TN之间呈极显著正相关（P<0.01）。与T0处理相比，T2处理显著提高了精米率、胶稠度和直链淀粉含量。本研究中，生物炭（5.0 t·hm）与减氮（20%）配施有效提高了土壤微生物碳氮含量，增加了水稻产量和品质，可为贵州黄壤稻田减氮增效提供良好选择。
