Leguminous green manure (LGM) has a reputation for improving crop productivity. However, little is known about the beneficial interactions with straw on crop yield and nutrient (N, P, K) use efficiency. Herein, a 9-year field experiment (from 2015 to 2023) containing three treatments—(1) chemical fertilizer as the control (CK), (2) NPK + straw return (Straw) and (3) NPK + straw return with LGM (Straw + LGM)—was conducted to investigate whether the combined application of LGM and straw can increase productivity and nutrient use efficiency in the wheat–maize–sunflower diversified cropping rotation. The results showed that in the third rotation (2021–2023), Straw + LGM significantly increased wheat yield by 10.2% and maize yield by 19.9% compared to CK. The total equivalent yield under Straw + LGM was the highest (26.09 Mg ha⁻¹), exceeding Straw and CK treatments by 2.7% and 12.3%, respectively. For each 2 Mg ha⁻¹ increase in straw returned to the field, sunflower yield increased by 0.2 Mg ha⁻¹, whereas for each 1 Mg ha⁻¹ increase in LGM yield from the previous crop, sunflower yield increased by 0.45 Mg ha⁻¹. Compared to CK, the co-application of LGM and straw increased the N use efficiency of maize in the first and third rotation cycle by 70.6% and 55.8%, respectively, and the P use efficiency by 147.8% in the third rotation cycle. Moreover, Straw treatment led to an increase of net income from wheat and sunflower by 14.5% and 44.6%, while Straw + LGM increased the net income from maize by 15.8% in the third rotation cycle. Combining leguminous green manure with a diversified cropping rotation has greater potential to improve nutrient use efficiency, crop productivity and net income, which can be recommended as a sustainable agronomic practice in the Hetao District, Northwest China.

The two major concerns of sustainable agriculture are safeguarding food security and reducing greenhouse gas emissions. Studies on the performance of strip-till with controlled-release blended fertilizer on rainfed maize grain yield, greenhouse gas emissions, and net ecosystem economic budget are scarce in the hilly region of northeast China. In this study, the differences between strip-till (RST) and conventional ridge cropping (CP), straw off-field no-tillage (NT), and no-tillage with straw mulching (RNT) were comparatively investigated in the conventional fertilizer (Sd) mode. And meanwhile, four fertilization modes were also set up under strip-till (RST): conventional fertilization (Sd), controlled-release nitrogen fertilizer blended with normal urea 3:7 (30%Cr), controlled-release nitrogen fertilizer blended with normal urea 5:5 (50%Cr), and no-nitrogen fertilization. We analyzed maize yield, greenhouse gas emissions (GHG), greenhouse gas intensity (GHGI), net income and net ecosystem economic budget (NEEB) for different treatments. The results showed that, under conventional fertilizer (Sd) mode, the maize yield of RST increased by 4.2%, 6.0% and 7.2% compared with NT, CP and RNT and the net income increased by 7.0%, 9.7% and 10.0%, respectively. Compared with CP and NT, although RST increased CO₂ and N₂O emissions, the GHGI of RST was not significantly different from CP and NT, and was 8.0% lower than that of RNT. The NEEB of RST increased by 6.8%, 9.7% and 11.0%, respectively, compared with NT, CP and RNT. Under strip-till, compared with 30%Cr and Sd, the yield of 50%Cr increased by 4.0% and 9.2% and the net income increased by 3.5% and 6.9%, respectively. There was no significant difference in GHGI between 50%Cr and 30%Cr, and 50%Cr decreased by 10.4% compared with Sd. The NEEB of 50%Cr increased by 3.8% and 7.4% compared to 30%Cr and Sd. Strip-till combines controlled-release nitrogen fertilizer blended with normal urea 5:5 (50%Cr) and can be applied as a sustainable strategy to improve the economic efficiency of maize and reduce environmental costs in the hilly region of northeast China.

To address the critical challenges of wind erosion mitigation and sustainable soil management in the fragile agroecosystem of the black soil region in the foothills of the Daxing’anling Mountains, this study evaluated five tillage practices—conventional ridge tillage (CP), no tillage with straw removal (NT), no tillage with straw mulching (R+NT), autumn strip tillage with straw mulching (R+ST_A), and spring strip tillage with straw mulching (R+ST_S)—across two landforms: gently sloped uplands and flat depressions. The results demonstrated that R+ST_S achieved superior performance across both landscapes, exhibiting a 42.99% reduction in the wind erosion rate, a 48.88% decrease in soil sediment discharge, and a 52.26% reduction in the soil creep amount compared to CP. These improvements were mechanistically linked to the enhanced surface microtopography (aerodynamic roughness increased by 1.8–2.3 fold) and optimized straw coverage (68–72%). R+ST_S also enhanced the topsoil fertility, increasing the total nitrogen (TN), soil organic carbon (SOC), alkaline nitrogen (AN), available phosphorus (AP), and rapidly available potassium (AK) by 22.07%, 12.94%, 14.92%, 32.94%, and 9.52%, respectively. Furthermore, it improved maize emergence and its yield by 10.04% and 9.99% compared to R+NT. Mantel tests and SEM revealed strong negative correlations between erosion and nutrients, identifying nitrogen availability as the key yield driver. R+STS offers a sustainable strategy for erosion control and productivity improvement in the black soil region.

As the third-largest maize-producing province in China and a typical arid and semi-arid region, quantitatively evaluating the carbon and nitrogen footprints of maize production and their dominant factors is of great significance in guiding the high-yield, low-carbon, and sustainable development of maize production in the Inner Mongolia Autonomous Region. This study quantitatively evaluated the interannual evolution characteristics of the carbon and nitrogen footprints in maize production and their dominant factors in Inner Mongolia from 2003 to 2022 based on statistical yearbook data and emission parameter models. The results showed that from 2003 to 2022, the maize planting area, yield, and total yield in Inner Mongolia all increased, with an average annual increase of 97 kg ha⁻¹ in yield and 1.23 × 10⁶ Mg in total yield. The carbon and nitrogen footprints of Inner Mongolia maize production over the past 20 years had overall decreasing trends, while the nitrogen fertilizer bias productivity, net ecosystem carbon balance, and sustainability index had increasing trends. Carbon footprint reduced by an average of 5.2 kg CO₂ eq Mg⁻¹ per year, and nitrogen footprint reduced by an average of 0.21 g N eq kg⁻¹ per year. Currently, the transportation and production of fertilizer and field application of N fertilizer are the main controlling factors of GHG emissions from maize production. NO₃⁻-N, NH₄⁺-N leaching, and NH₃ volatilization from field application of N fertilizer are the main sources of reactive N losses. The application of simplified processes, such as phased regulation of nitrogen and controlled-release fertilizers, as well as conservation tillage, have broad prospects for emission reduction in maize production in Inner Mongolia.

Long-term irrational farming practices and low return of organic materials to the fields in the black soil area have led to reduced soil carbon and nitrogen stability and nutrient imbalance, which in turn affect soil fertility and crop yields. Straw return is an effective way to enhance soil organic matter and crop productivity, but the effects of long-term straw return under tilling practices on carbon and nitrogen sequestration and soil microbial stoichiometric equilibrium in black soil need to be further investigated. This study investigated the physical, chemical and biological properties of the 0–60 cm soil layer under deep tillage with straw return to the field (DTS), deep harrow with straw return to the field (DHS), rotary tillage with straw return to the field (RTS), no tillage with straw return to the field (NTS), and conventional tillage with straw removal (CT) on the basis of seven consecutive years of tillage pattern location trials in the black soil area of eastern Inner Mongolia. The results showed that DTS and NTS significantly increased the soil organic carbon (SOC), soil total nitrogen (TN), soil microbial biomass carbon (MBC), soil microbial biomass nitrogen (MBN) contents, and the SOC/TN ratio in the 0–40 cm soil layer, enhancing soil carbon and nitrogen sequestration capacity, while the concomitant increase in the average MBC/MBN ratio in the plow layer from 6.8 to 8.2. The soil microbial quotient increased by 29.0% and 26.2%, respectively, and the stoichiometric imbalance ratio decreased by 7.9% and 5.7%, respectively. Meanwhile, in terms of maize yield from 2018 to 2024, DTS showed the most stable and significant yield increase with 41.53%. Whereas NTS showed a higher yield increase potential with a 27.36% increase in yield as the number of years of straw return increased. Therefore, DTS and NTS are superior tillage methods to improve the quality of the black soil tillage layer, to promote soil microbial carbon and nitrogen balance, and to increase crop yields.

Maize, as a major cereal crop in China, is vital for national food security, and appropriate nitrogen fertilization is essential for its growth and yield. Avoiding excessive nitrogen fertilizer application while maintaining productivity remains a critical challenge for sustainable agriculture. Although straw returning is widely adopted to reduce chemical fertilizer inputs, its effectiveness is often regionally constrained. In the West Liaohe Plain, low temperature and spring drought limit straw decomposition and nutrient release, making it difficult to reduce nitrogen fertilizer input and improve fertilizer use efficiency. Therefore, this study examined the effects of different nitrogen management modes on straw decomposition, nutrient release, mineral fertilizer substitution potential, soil available nutrients, and maize yield under shallow buried drip irrigation with integrated water and fertilizer management. A field experiment was conducted with five nitrogen (N) fertilizer management treatments: a conventional fertilization treatment (CK), in which 15% of total N was applied as starter fertilizer; two increased starter N treatments, in which 30% (30%N) and 45% (45%N) of total N were applied as starter fertilizer; and two organic substitution treatments, in which 30% (30%ON) and 45% (45%ON) of mineral N fertilizer were substituted with decomposed sheep manure based on equivalent total N input. Straw decomposition and nutrient release were measured using the nylon mesh bag method and fitted with an exponential decay model. The mineral fertilizer substitution potential was estimated based on straw nutrient release, while soil available nutrient dynamics in the 0–40 cm soil layer were analyzed, and the Mantel test and PCA were used to assess their relationships. Organic substitution promoted straw decomposition. The 30%ON treatment showed the highest rate at 70.91%, which was 19.2% higher than that of CK, and it exhibited a higher theoretical maximum decomposition rate (a), higher decomposition rate constant (k), and a shorter half-life. All treatments increased nutrient release and soil available nutrients, and organic substitution demonstrated stronger temporal persistence and more uniform vertical distribution among soil layers. The 30%ON treatment increased straw nutrient release by 4.8% to 18.2% and enhanced mineral fertilizer substitution potential. Although the 30%ON treatment did not increase yield in the first experimental year, it showed a significant yield advantage in the second year, which coincided with greater straw nutrient release and higher soil available nutrient levels under this treatment. Substituting 30% of mineral N fertilizer with organic fertilizer under shallow buried drip irrigation (300 kg N ha⁻¹) optimized the C/N balance of the input system and facilitated straw decomposition and nutrient release. The continuous accumulation of soil available nutrients under this treatment, together with sustained straw nutrient release, was associated with a significant yield advantage in the second experimental year. Therefore, the 30%ON treatment may represent an appropriate management strategy for coordinating straw resource utilization, soil fertility maintenance, and stable maize production in the West Liaohe Plain.