Search Results (30)

Soil degradation constrains cropland productivity in Northeast China, where conservation tillage has been widely adopted to improve soil structure and sustain maize (Zea mays L.) production. However, previous studies have focused mainly on single soil types or regional-scale assessments, and the applicability of conservation tillage across contrasting cultivated soil types remains inadequately characterized. From 2021 to 2023, field experiments were conducted across geo-ecological zones within mid-temperate sub-humid and mid-temperate sub-arid climatic regions, encompassing seven typical cultivated soil types: Aeolian sandy soil, Bielic, Black soil, Chernozem, Histosol, Inceptisol, and Mollisols. A strip-tillage with straw return treatment (ST) was compared against no-tillage with straw mulching treatment (CK) to systematically evaluate the effects of strip-tillage on (i) soil physical properties (bulk density and porosity), (ii) soil chemical properties (organic matter and total nutrient contents), and (iii) maize yield components. Across the full dataset, ST significantly reduced soil bulk density and increased total porosity relative to CK; however, soil-type-specific comparisons showed that significant responses were detected only in some soil types. By contrast, soil chemical properties were significantly influenced by the treatment × soil type interaction: SOM and STN contents increased significantly in Inceptisol under ST, STP increased significantly in Mollisols, and STK increased significantly in Histosol. A PCA-derived composite physicochemical score, based on six standardized soil indicators, was higher under ST than CK in six of the seven soil types relative to CK, with the most pronounced improvements occurring in Aeolian sandy soil (+1.23), Bielic (+0.87), and Black soil (+0.65); significant maize yield increases under ST were detected in Aeolian sandy soil and Black soil, with mean increases of 7.07% and 10.94%, respectively. The associations between maize yield components and grain yield differed between ST and CK, with 1000-kernel weight showing a stronger association with grain yield under ST. Collectively, these findings indicate that ST can improve soil physical structure, but its effects on soil chemical properties, maize yield, and yield-component associations are soil-type dependent. Full article

Organic amendments can improve soil C storage, nutrient availability, and crop production, particularly in purple soils with low organic matter and weak nutrient retention. They may also alter soil micro-food web processes. However, how different amendments affect bacteria–fungi–nematode associations remains unclear. We hypothesized that, relative to mineral fertilization alone, organic amendments would improve soil nutrient conditions, reshape bacterial and fungal communities, and increase microbivorous nematode abundance, whereas combined organic–mineral inputs would increase multitrophic co-occurrence network complexity. In a long-term wheat–maize rotation, soils were sampled in both seasons in 2023 under seven treatments: no fertilization (NF), mineral fertilization (NPK), manure (OM), straw return (RSD), mineral fertilization combined with manure (OMNPK), mineral fertilization combined with straw return (RSDNPK), and mineral fertilization combined with biochar (BCNPK). Among the organic amendment treatments, only RSD reduced wheat and maize yields relative to NPK. Fertilization mainly affected microbial community composition and nematode trophic structure, while microbial α diversity changed little. Network organization differed among fertilization regimes and between crop seasons. This study provides new insights into how long-term organic amendment regimes differentially regulate crop productivity, soil resource conditions, and soil micro-food webs, and advances our understanding of belowground multitrophic responses across wheat and maize seasons. Full article

Conventional ridge tillage has triggered severe soil organic carbon depletion and soil erosion in sloping maize fields of humid northeast China, posing a persistent threat to black soil health and regional grain security. As representative conservation tillage systems integrated with full straw residue retention, no tillage and strip tillage exhibit prominent potential in soil protection, and their soil-improving benefits are inseparable from continuous straw carbon input; however, their regulatory effects on humus fractions and humic acid molecular properties in erosion-prone sloping farmlands remain largely unclarified. This study aimed to screen the optimal integrated tillage–cultivation mode for sloping farmlands in the northeast China black soil region and to reveal how tillage systems coupled with incremental agronomic practices affect maize yield, humus composition, and humic acid molecular characteristics in Albic soil, a representative degraded soil type of the regional black soil system. A 2-year field experiment was conducted in a typical sloping farmland of Jilin Province, with conventional ridge tillage set as the control. Five incremental integrated management practices (from baseline practice to fertilizer reduction, straw decomposition promotion, and 5–10% higher planting density) were arranged under both under no-tillage and strip-tillage systems. We analyzed dissolved organic matter fluorescence properties, carbon content of humus fractions, and humic acid molecular structural features, and performed principal component analysis for comprehensive performance evaluation of all treatments. This study demonstrates that optimized strip tillage, supported by full straw C input as an indispensable prerequisite, combined with straw decomposition promotion and a 10% planting density increase can synchronously boost soil fertility and maize yield, providing a scientific and practical tillage strategy for sustainable black soil conservation of sloping Albic farmlands in humid northeast China. Strip tillage achieved a 6.78% higher average maize yield than NT, and the maximum yield was recorded with ST5 (strip tillage combined with straw decomposition promotion and 10% planting density increase). Both no tillage and strip tillage significantly increased C_DOM content, humification index and autochthonous contribution, optimized humus component distribution with elevated humic acid carbon content, humic acid carbon-to-fulvic acid carbon ratio and humic acid carbon-to-total organic carbon ratio, and enhanced humic acid aromaticity, thermal stability, and hydrophobicity. The principal component analysis results indicated that ST5 ranked first in comprehensive performance, while conventional ridge tillage ranked the lowest among all treatments. Strip tillage integrated with straw decomposition promotion and 10% increased planting density effectively modulated humus fractions, improved humic acid molecular stability, and synchronously increased maize yield. This integrated management regime provides a scientific and practical tillage strategy for sustainable black soil conservation and high-efficiency maize production in sloping Albic farmlands of humid northeast China. Full article

Extracellular enzyme stoichiometry is a key indicator for assessing nutrient limitation experienced by soil microorganisms. Yet, the characteristics of enzyme-inferred microbial nutrient limitation in rhizosphere soil under the combined agricultural practices of intercropping and straw retention remain unclear. Here, we conducted a field experiment in the black soil region of Northeast China to quantify the effects of intercropping and straw retention on soil nutrients, microbial biomass, extracellular enzyme activities, and their C:N:P stoichiometry in the rhizosphere of maize and peanut. Our results showed that compared with sole cropping, intercropping increased soil organic carbon (SOC) by 6.21–13.57%, total nitrogen (TN) by 8.57–12.49%, and total phosphorus (TP) by 12.01–40.29% in the rhizosphere. The vector analysis revealed an average vector length (VL) of 1.68 and 1.57 for extracellular enzymes in the rhizosphere soil of maize and peanut, with a vector angle (VA) of 37.80° and 34.67°, respectively. These values suggest that soil microorganisms in the rhizosphere of both crops experienced C limitation, and that the degree of enzyme-inferred N limitation was modulated by microbial C acquisition strategies, with a dynamic trade-off between the two. This N limitation was more pronounced in the peanut rhizosphere. Notably, the combined treatment of intercropping and full straw retention increased the VA of peanut by 5.38%, corresponding to a partial alleviation of enzyme-inferred N limitation in the rhizosphere soil. The extracellular enzyme C:N:P stoichiometry in the rhizosphere soil of maize and peanut was 1.33:1.29:1.00 and 0.89:1.29:1.00, respectively. Microbial biomass nitrogen (MBN) was the primary factor affecting enzyme-inferred microbial nutrient limitation (explaining 54.6% of variation). The extracellular enzyme stoichiometric characteristics of rhizosphere soil differed significantly between the two crops. Intercropping had a stronger impact on rhizosphere microbial nutrient limitation than straw retention, and their synergistic effect was associated with a partial alleviation of rhizosphere enzyme-inferred N limitation by enhancing extracellular enzyme activity. These findings demonstrate that integrated intercropping and straw retention can support sustainable soil management in black soil agroecosystems. Full article

In Northeast China’s degraded croplands, nitrate (NO₃⁻-N) leaching is the dominant pathway for fertilizer-nitrogen (N) loss, which presents an increasing threat to the quality of groundwater. Conservation tillage, defined as no-tillage (NT) and straw retention, is a widely adopted management strategy to maintain cropland fertility in the black soil (BS) regions. At present, however, the impact of shifting from conventional to conservation tillage on the vertical distribution and regulatory mechanisms of NO₃⁻-N derived from applied fertilizer-N (F_NO3) remains poorly understood. Based on a 12-year field experiment, we integrated ¹⁵N-tracing field monitoring with ¹⁵N-paired-labeling incubation to quantify the vertical migration of F_NO3 into deep soil profiles, and specify the dominant processes regulating N retention and supply. Across the tested BS croplands, total NO₃⁻-N production rates (4.06–6.58 mg N kg⁻¹ soil day⁻¹) were faster than their consumption rates (0.36–0.92 mg N kg⁻¹ soil day⁻¹), leading to a net accumulation of NO₃⁻-N, and implying a potential for leaching of NO₃⁻-N, from the perspective of substrate availability. The results of the field ¹⁵N micro-plot experiment also indicated that, by maize maturity in the first growing season, an average of 7.5% of F_NO3 had migrated to the 80–100 cm soil layer. During the following two growing seasons, the maximum accumulation of F_NO3 had shifted downward to 140–160 cm and 180–220 cm, respectively. Such a pattern, particularly in light of the increased extreme precipitation in the studied regions, raises clear concerns about NO₃⁻-N leaching losses. Compared with conventional management, no-tillage with full-rate straw mulching decreased net rates of NO₃⁻-N production from 6.22 to 3.14 mg N kg⁻¹ soil day⁻¹. This reduction resulted from a decline in the gross oxidation of NH₄⁺-N to NO₃⁻-N (from 6.39 to 3.70 mg N kg⁻¹ soil day⁻¹) and an increase in DNRA (from 0.35 to 0.85 mg N kg⁻¹ soil day⁻¹), which collectively delayed the downward transport of F_NO3. Conservation tillage also increased the gross rate of heterotrophic nitrification (from 0.19 to 0.36 mg N kg⁻¹ soil day⁻¹) and its proportion relative to total nitrification (from 2.8% to 8.9%). Despite this shift, autotrophic nitrification remained the dominant process for NO₃⁻-N production in the tested BS croplands, likely due to a pH constraint on heterotrophic nitrification. With the increasingly widespread promotion of conservation tillage for soil fertility improvement, heterotrophic nitrification warrants greater attention, particularly in BS regions where pH < 6.5 and C/N contents are relatively high. Collectively, our findings provide a scientific basis for tailoring tillage practices to maintain sustainable agriculture in Northeast China. Full article

In the fragile Loess Plateau ecosystem, straw return is a key measure to improve its low soil organic matter. However, the short-term carbon retention efficacy of straw return, which depends on the initial balance between carbon mineralization and sequestration, remains unclear across different soil textures. This study investigated the short-term impacts of straw return on organic carbon fractions in three soils with varying textures via laboratory incubation. Results showed that while straw return universally increased active organic carbon pools, its accumulation in the mineral-associated organic carbon (MAOC) pool was texture-dependent. Straw incorporation, especially maize straw, effectively promoted MAOC formation in clayey soils (Phaeozems and Anthrosols) with large specific surface areas. Conversely, in Arenosols, carbon was retained in active pools, limiting long-term retention potential. The mechanism involves a combined regulation by soil physicochemical properties, where clay content and specific surface area are fundamental physical drivers for MAOC accumulation, synergistically influenced by chemical factors like pH and electrical conductivity through processes such as cation bridging. These findings provide critical scientific evidence for developing texture-specific straw return management strategies for the Loess Plateau. Full article

Ecological stoichiometry offers critical insights into nutrient dynamics and soil–plant interactions in agroecosystems. To explore the effects of long-term fertilization on soil–cotton C, N, P stoichiometry and stoichiometric homeostasis in arid gray desert soils, this study was conducted at a national gray desert soil monitoring station in Xinjiang (87°28′27″ E, 43°56′32″ N, elevation: 595 m a.s.l.)—an arid and semi-arid region with an annual mean temperature of 5–8 °C and annual precipitation of 100–200 mm. Established in 1989, the 31-year experiment adopted a wheat–maize–cotton annual rotation system with six treatments: CK (control, no fertilizer), N (nitrogen fertilizer alone), NK (nitrogen + potassium fertilizer), NP (nitrogen + phosphorus fertilizer), PK (phosphorus + potassium fertilizer), and NPK (nitrogen + phosphorus + potassium fertilizer). Key results showed that balanced NPK fertilization significantly increased soil organic carbon (SOC) by 22.7% and soil total phosphorus (STP) by 48.6% compared to CK, while the N-only treatment elevated soil N:P to 3.2 (a 68.4% increase vs. CK), indicating severe phosphorus limitation. For cotton, NPK increased seed phosphorus content by 68.2% (vs. N treatment) but reduced straw carbon content by 10.2% (vs. PK treatment), reflecting a carbon allocation trade-off from vegetative to reproductive organs under nutrient sufficiency. Stoichiometric homeostasis differed between organs: seeds maintained stricter carbon regulation (1/H = −0.40) than straw (1/H = −0.64), while straw exhibited more plastic N:P ratios (1/H = 1.95), highlighting organ-specific adaptive strategies to nutrient supply. Redundancy analysis confirmed that soil available phosphorus (AP) was the primary driver of cotton P uptake and yield formation. The seed cotton yield of NPK (5796.9 kg ha⁻¹) was 111.7% higher than CK, with NP (N-P co-application) achieving a 94.7% yield increase vs. CK—only 7.9% lower than NPK, whereas single N application showed the lowest straw yield (5995.0 kg ha⁻¹) and limited yield improvement. These findings demonstrate that long-term balanced NPK fertilization optimizes soil C-N-P stoichiometric balance by enhancing SOC sequestration and phosphorus retention, regulating cotton organ-specific stoichiometric homeostasis, and promoting efficient nutrient uptake and assimilate translocation. The study confirms that phosphorus is the key limiting factor in arid gray desert soil cotton systems, and balanced NPK supply is essential to mitigate stoichiometric imbalances and sustain soil fertility and productivity. This provides targeted practical guidance for rational fertilization management in arid agroecosystems, emphasizing the need to prioritize phosphorus supply and avoid single-nutrient application to maximize resource use efficiency. Full article

In the waxy maize production of Zhejiang Province, China, conventional straw management often causes planting difficulties and nutrient competition. Although no-till with straw retention is known to benefit soil structure, its long-term impacts on local soil health and productivity remain poorly understood. Hence, a six-year field experiment (2016–2021) was conducted with four treatments, i.e., no-till with residue retention (NTRR), no-till with residue removal (NTR0), plow tillage with residue incorporation (PTRR), and plow tillage with residue removal (PTR0), to investigate the long-term effects of tillage and residue management. The results demonstrated that plow tillage (PT) significantly improved soil physical properties, reducing soil compaction and decreasing bulk density compared to no-till (NT) practices. Meanwhile, residue retention (RR) enhanced soil chemical fertility, increasing soil organic matter by 7.8–9.8% and substantially improving available potassium levels. The PTRR treatment achieved the most favorable soil conditions with the lowest compaction and bulk density values among all treatments. PTRR consistently yielded the highest maize production, showing a 1.7–6.9% advantage over PTR0 and a substantial 15.4% yield increase in spring maize compared to residue removal (R0) treatments. Correlation analyses revealed significant relationships between soil quality and productivity, with the Soil Quality Index (SQI) showing strong positive correlations with both yield (r = 0.74, p < 0.01) and economic returns (r = 0.67, p < 0.05). These findings demonstrate that PTRR represents an optimal agricultural management strategy for simultaneously enhancing soil health and ensuring sustainable crop production in fresh maize cultivation. Full article

Enhancing chlorophyll retention in maize leaves and prolonging the grain-filling duration constitute critical strategies for yield improvement in agricultural production systems. This study investigated the mechanistic relationship between yield enhancement pathways and the leaf senescence process induced by high-input straw pellets amendment. We analyzed the impact mechanisms of green leaf area dynamics and dry matter redistribution on yield during late reproductive stages, establishing theoretical foundations for yield optimization through intensive straw pellets incorporation. The study used the maize variety Jingnongke 728 as the experimental material. Based on previous research, four treatments were set up, including no straw returning (CK), chopped straw (15 t/ha) returning to the field (FS1), a large amount of chopped straw (75 t/ha) returning to the field (FS5), and a large amount of pelletized straw (75 t/ha) returning to the field (KL5), with four replicates. A two-year experimental design systematically assessed green leaf area index (GLAI), dry matter accumulation, distribution, translocation, yield components, and grain yield to explore the differences among various treatments under different straw returning amounts and returning forms. The study detected no significant differences between FS1 and CK. Although KL5 and FS5 delayed leaf senescence, FS5 significantly depressed green leaf area index (GLAI) at the R1 stage (silking), which results in it not having more effective photosynthetic area during late phenological phases. In dry matter dynamics, KL5 exhibited 5.52–25.71% greater pre-anthesis accumulation, 2.73–60.74% higher post-anthesis accumulation, and 9.48–25.76% elevated ear dry matter allocation relative to other treatments. KL5’s post-anthesis assimilates contributed 2.43–17.02% more to grain development, concurrently increasing ear-to-total biomass ratio. Yield analysis ranked KL5 as the superior treatment with 0.68–25.15% yield advantage, driven by significantly enhanced kernel number per ear and 100-kernel mass, whereas FS5 displayed the lowest kernel count among all treatments. Returning 75 t/ha of straw pellets to the black soil area in Northeast China can significantly delay the senescence of maize leaves and increase the accumulation of dry matter after anthesis by maintaining the effective photosynthetic area of leaves in the later stage of growth, thereby achieving the goal of increasing yield. The research can offer a practical and novel approach for straw return in the black soil region of Northeast China and provide a new technological pathway for enhancing crop productivity. Full article

This study aimed to clarify the scientific quantification of fertilizer nitrogen (N) uptake and utilization, its destination, and its residual distribution in the soil at a depth of 0–30 cm after biochar application using ¹⁵N tracer technology. The purpose was to provide a theoretical basis for developing a scientific application strategy for N fertilizer and biochar in irrigated farmland areas. Two levels of N fertilizer application were set up using the ¹⁵N labeling method in microareas of large fields: the regular amount of N fertilizer (N1: 300 kg·ha⁻¹) and a reduction of N fertilizer by 15% (N2: 255 kg·ha⁻¹). Further, three levels of biochar application were set up: no biochar (B0: 0 kg·ha⁻¹), a low amount of biochar (B1: 10 × 10³ kg·ha⁻¹), and a medium amount of biochar (B2: 20 × 10³ kg·ha⁻¹). The tested biochar was derived from corn stover (maize straw). The natural abundance of ¹⁵N-labeled fertilizer N, the total N content of each aboveground organ, and the total N content of soil at a depth of 0–30 cm in a spring wheat field at maturity were determined, and the yield was measured in the corresponding plots. The proportion of ¹⁵N-labeled fertilizer N uptake by each organ of spring wheat and the soil N uptake was 20.60–35.32% and more than 64.68%, respectively. Moreover, the proportion of soil N uptake showed a decreasing trend with an increase in biochar application. The spring wheat N uptake and utilization rate, the residue rate in the soil at a depth of 0–30 cm, the total utilization rate, and the rate of loss of ¹⁵N-labeled fertilizer N ranged from 15.21% to 29.61%, 23.33% to 28.93%, 38.54% to 58.54%, and 41.46% to 61.46%, respectively. The spring wheat N fertilizer utilization rate, fertilizer N residue rate in soil, and total fertilizer N utilization rate all increased gradually with an increase in biochar application, except for the N loss rate, which decreased gradually. When N fertilizer reduction was combined with medium biochar (B2N2), the yield of spring wheat significantly improved, mainly due to an increase in the number of grains in spikes. Under this treatment, the number of grains in spikes of spring wheat was 41.9, and the yield reached 7075.54 kg·ha⁻¹, which was an increase of 9.69–28.25% and 10.91–25.35%, respectively, compared with other treatments. Yield increased by up to 25.35%, and nitrogen loss decreased by 48.24% under the B2N2 treatment. Biochar application could promote the amount and proportion of fertilizer N uptake in various organs of spring wheat as well as in the soil at a depth of 0–30 cm. In this study, a 15% reduction in N fertilizer (255 kg·ha⁻¹) combined with 20 × 10³ kg·ha⁻¹ biochar application initially helped achieve the goal of increasing spring wheat yield and N fertilizer uptake, as well as improving fertilizer N utilization, providing an optimal scientific application strategy for N fertilizer and biochar in the farmland of the irrigation area. These results substantiate the hypothesis that biochar application enhances spring wheat (Triticum aestivum L.) assimilation of fertilizer-derived nitrogen (¹⁵N) while concomitantly improving fertilizer nitrogen retention in the soil matrix, which could provide a sustainable framework for nitrogen management in irrigated farmlands. Full article

This investigation examines the effects of straw-based nitrogen fertilization on soil hydrological properties and biomass partitioning in maize under arid zone conditions. A biennial field investigation was conducted during the 2016–2017 cropping seasons, with an equal nitrogen content of 225 kg ha⁻¹, and a total of 5 treatments, 100% fertilizer nitrogen (CK), 25% straw nitrogen + 75% fertilizer nitrogen (S25), 50% straw nitrogen + 50% fertilizer nitrogen (S50), 75% straw nitrogen + 25% fertilizer nitrogen (S75), 100% straw nitrogen (S100). The data demonstrated that in 2017, in comparison with CK, the soil water storage in the 0–60 cm soil layer of S25 and S50 in the large trumpet stage (V12) increased significantly by 23.32% and 25.14% (p < 0.05), respectively. In the two-year experiment, stratified moisture reserves (0–200 cm) in different treatment groups exhibited a fluctuating pattern characterized by successive increase-decrease-increase transitions along the soil profile, and overall S25 and S50 were larger than CK. In 2016, the biomass accumulation of the S50 treatment at the maturity stage (R6) was the highest, which increased by 18.11% and 19.49% compared with the CK and S75 (p < 0.05), respectively. There was statistical parity in water use efficiency between treatments. Soil moisture retention capacity of 180–200 cm soil was positively correlated with yield at the jointing (V6) and maturity (R6) stages, and soil water storage of 160–180 cm soil was positively correlated with yield at the tasselling stage (VT). Water consumption during the presowing–to–jointing phase demonstrated the strongest correlation with final grain yield. In summary, the S25 treatment in this experiment significantly enhanced the optimization of soil hydrological properties, increasing soil moisture storage, fully utilizing soil moisture, increasing dry matter accumulation in each growth period of maize, and replacing chemical nitrogen fertilizer with 25% of straw equivalent N fertilizers was beneficial to soil moisture storage. Full article

Conservation tillage is believed to promote soil aggregate stability, carbon (C) and nitrogen (N) sequestration, but the underlying mechanisms remain unclear. In this study, soil samples from an 18-year experiment including conventional tillage with straw removal (CT), deep scarification with straw mulching (DS), and no-tillage with straw mulching (NT) were used to obtain different fractions based on a comprehensive wet-sieving method of aggregate and particle size. The results showed that NT and DS increased soil organic carbon (SOC) and N by 9.3–16.4% and 10.8–25.8%, respectively, in addition to increasing the weight proportion of macroaggregates and the contribution of macroaggregate-associated C and N to total SOC and N. The C change in the total POM accounted for 77.4% and 79.9% of the total SOC increase by NT and DS, while the MAOM only accounted for 29.2% and 25.2%, respectively. Meanwhile, microaggregates-within-macroaggregates accounted for 96.9% and 90.5% of the SOC increase by NT and DS, respectively. The total SOC and N were positively correlated with the C and N of the macroaggregates and subfractions. In conclusion, the formation of macroaggregates drives soil C and N sequestration under conservation tillage, and POM and mM were important functional pools in this process. Full article

Conservation tillage technology possesses substantial potential to enhance agricultural production efficiency and tackle issues such as wind erosion and land degradation in semi-arid regions. The integration of no-tillage and straw mulching technologies in the conventional aeolian semi-arid agricultural zones of western Liaoning, China, has led to notable improvements in crop yield and soil quality. However, a comprehensive assessment of the mechanisms and kinetics involved in soil nutrient variations is yet to be conducted. During a two-year study period, we assessed four tillage systems in the aeolian semi-arid regions of Northern China: no-tillage with full straw mulching (NTFS), no-tillage with half straw mulching (NTHS), no-tillage without straw mulching (NT), and conventional tillage (CT). The investigation focused on examining nutrient conditions, enhancing photosynthetic activity, and increasing maize yield while improving water use efficiency (WUE). Our findings emphasize the beneficial impact of combining no-tillage and straw mulching on enhancing soil water retention, resulting in a notable rise in soil moisture levels during the crucial growth phases of maize. This approach also positively influenced soil nutrient levels, particularly in the 0–20 cm layer, fostering an environment conducive to maize cultivation. In terms of ecological benefits, no-tillage with straw mulching curtailed soil sediment transport and wind erosion, notably at 30–40 cm heights, aiding in the ecological protection of the region. The yield and WUE were substantially higher under NTFS and NTHS than under CT, with NTHS demonstrating the most significant gains in yield (14.5% to 16.6%) and WUE (18.3% to 21.7%) throughout the study period. A TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) analysis confirmed NTHS as the optimal treatment, achieving the highest scores for soil water, nutrient availability, wind erosion control, maize photosynthesis, yield, and WUE, thus emerging as the most effective conservation tillage strategy for sustainable agriculture in aeolian semi-arid regions. Full article

Reducing fertilizer-N rate, applying a nitrification inhibitor (NI), and incorporating straw are widely recommended to improve N use efficiency of crops and decrease N losses. A field ¹⁵N tracer study was conducted to compare their effectiveness on fertilizer-N fates during the maize growing season in Northeast China. The following six treatments were used: (1) no N fertilization (control); (2) 200 kg urea-N ha⁻¹ (100%N); (3) 200 kg urea-N ha⁻¹ and straw (100%N + S); (4) 160 kg urea-N ha⁻¹ (80%N); (5) 160 kg urea-N ha⁻¹ and NI (Nitrapyrin in this study) (80%N + NI); and (6) 160 kg urea-N ha⁻¹, NI, and straw (80%N + NI + S). The results showed that the five N fertilization treatments yielded 16–25% more grain and 39–60% more crop N uptake than the control, but the differences among the five treatments were not statistically significant. Compared with the 100%N, 20% fertilizer-N reduction (80%N) decreased the ¹⁵N concentration in topsoil and plant pools but increased the proportion of plant ¹⁵N recovery at harvesting (NUE_15N, 60% vs. 50%). Compared with the 80%N, NI co-application (80%N + NI) delayed soil nitrification and increased soil ¹⁵N retention at harvesting (52% vs. 36%), thereby decreasing NUE_15N significantly. Straw incorporation decreased fertilizer-N retention in soil compared with NI co-application because it promoted NUE_15N significantly. In conclusion, the results demonstrate that NI and straw additions are efficient strategies for stabilizing fertilizer-N in soils and potentially minimizing N loss; however, their effects on NUE_15N vary and the related mechanism must be further clarified in long-term trials. Full article

Maize straw has been widely used for the production of energy through anaerobic digestion, but biogas production can be hindered by a lack of trace elemental nutrients. To address this issue, a lab-scale anaerobic plug flow reactor was continuously operated at 55 °C for 300 days, with a hydraulic retention time of 42 days and an organic loading rate of 2.1 g total solids/(L·day). Results from this study showed that between days 101 and 194, the methane yield slightly decreased from 0.26 ± 0.04 to 0.24 ± 0.03 L/g volatile solids (VS), but significant volatile fatty acid accumulation was observed by reaching up to 2759 ± 261 mg/L. After trace elements were added to the reactor, the methane yield increased to 0.30 ± 0.03 L/g VS, with 53% methane content. Around 62% of the total chemical oxygen demand and volatile solids were broken down into methane. Volatile fatty acid levels dropped and stabilized at around 210 ± 50 mg/L, indicating restored process stability. The addition of trace elements increased the abundance of Firmicutes and decreased Synergistetes in bacteria while simultaneously increasing the abundance of Methanosarcina in archaea. In conclusion, trace element supplementation was experimentally found to be necessary for stable thermophilic anaerobic digestion of maize straw. Full article