关键词: 黑土区, 秸秆覆盖春条耕, 土壤氮素周转, 玉米, 干物质积累, 氮素积累, 籽粒产量

Abstract: 【Objective】 To clarify the effects of different tillage methods on maize growth and nitrogen use in the black soil region along the foothills of Daxing′anling Mountains,providing a theoretical basis for the synergistic improvement of black soil conservation and grain production capacity.【Methods】 Field comparative experiments were conducted in Jalaid Banner of Hinggan League and Arun Banner of Hulun Buir City,Inner Mongolia,during 2023 to 2024. A randomized block design was adopted with five tillage methods：conventional plowing（CP）,residue-covered no-tillage（RNT）,residue-removed no-tillage（NT）,residue-covered autumn strip tillage（RST_A）,and residue-covered spring strip tillage（RST_S）. Soil nitrogen dynamic changes in the 0-20 cm soil layer throughout the whole maize growth period were measured. Dry matter accumulation,dry matter transport volume,nitrogen accumulation,and nitrogen transport volume of maize at the silking and maturity stages were determined. Grain yield was measured at harvest,and apparent soil nitrogen loss was calculated.【Results】 Compared with CP,the RST_S tillage method increased the average soil total nitrogen content in the 0-20 cm soil layer throughout the whole maize growth period by 6.5% and 4.9% in Jalaid Banner and Arun Banner,respectively,over the two years. At critical maize growth stages（V6,V12,and R1）,soil ammonium nitrogen accumulation increased by an average of 17.9%,18.0%,and 11.1%,and by 18.3%,27.3%,and 18.6%,while soil nitrate nitrogen accumulation decreased by an average of 4.9%,3.5%,and 10.0% and by 5.3%,10.0%,and 13.3%,respectively. During the two years,maize dry matter accumulation at the silking stage under the RST_S tillage method increased by an average of 8.2% and 23.4% compared with CP in Jalaid Banner and Arun Banner,respectively. At mature stage,stem and leaf dry matter transport volume increased by an average of 30.5%,62.5% and 32.6%,87.8%,respectively,compared with CP. Stem and leaf nitrogen accumulation at the silking stage increased by an average of 12.8%,19.9% and 8.2%,10.3%,respectively,compared with cp,while nitrogen transport volume increased by an average of 11.9% and 13.7%,compared with CP. Under the RST_S tillage method,maize grain yield increased by an average of 8.6% and 9.7%,and nitrogen use efficiency increased by an average of 30.1% and 43.3% in Jalaid Banner and Arun Banner,respectively,compared with CP. Apparent soil nitrogen loss and nitrogen surplus in Jalaid Banner were reduced by 0.8%-36.6% and 5.3%-21.1%,respectively,compared with other tillage methods,while those in Arun Banner were reduced by 10.3%-28.9% and 7.0%-21.4%,respectively.【Conclusion】 Residue-covered spring strip tillage increased soil nitrogen content at key maize growth stages,promoted dry matter and nitrogen accumulation and transport,and significantly improved maize grain yield and nitrogen use efficiency. This tillage method is one of the effective approaches for achieving grain yield improvement and efficiency enhancement of maize production in the black soil region along the foothill of Daxing′anling Mountains.

Key words: Black soil region, Residue-covered spring strip tillage, Soil nitrogen turnover, Maize, Dry matter accumulation, Nitrogen accumulation, Grain yield