Remote sensing (RS) has been widely applied to map soil salinity in landscapes where salinity exhibits strong spatial contrasts, characterized by high electrical conductivity (EC) values. However, its effectiveness in regions dominated by low EC values remains less understood, particularly in irrigated agroecosystems where salinization processes differ from natural dryland settings. This study evaluated RS-based models within the Riverhurst Irrigation District, Saskatchewan, where both irrigation induced salinity and naturally occurring salinity occur, and where the majority of EC values fall within the 0-2 dS/m range. Vegetation and salinity indices derived from 30 m Landsat 8 imagery, together with geomorphometric variables from a 5 m LiDAR-derived digital elevation model, were used to model soil salinity for three depth intervals (0–30, 30–60, and 60–90 cm) using Random Forest (RF) and Support Vector Machine (SVM). Model evaluation on independent test dataset showed that the SVM outperformed RF, achieving a higher coefficient of determination (R2) of 0.77 and a lower root mean square error (RMSE) of 0.48, compared to RF (R2=0.66, RMSE=0.51) .

Balancing high yield, nitrogen use efficiency, and environmental sustainability is a central challenge around the world. A ¹⁵N tracing and a gradient nitrogen application experiment was taken at 12 runoff plots with four treatments, i.e. 0, 90, 120, and 150 kg ha⁻¹ on subtropical sloping red soils of southern China. Effects of N rate on peanut yield, N losses, and soil N balance were systematically evaluated in different growth stages. Results showed that an appropriate N rate (90 kg ha⁻¹) effectively synchronized N supply with crop demand across growth stages: it met early-stage N requirements for vigorous growth while preserving rhizobial N fixation capacity, thereby maintaining a stable N source during pod-filling and achieving a pod yield of 3,866 kg ha⁻¹. In contrast, excessive N application (150 kg ha⁻¹) disrupted this balance, leading to early-stage N surplus, excessive vegetative growth, suppressed nodulation, and a late-season N shortfall, which reduced the harvest index without increasing yield. Environmentally, deep leaching was the primary pathway of N loss, accounting for 67.5% of the total loss. The 90 kg ha⁻¹ treatment significantly reduced N loss while maintaining soil N balance, whereas the high N treatment increased loss by 93.8%. These findings demonstrate that effective N management in peanut systems on sloping red soils should tailor N supply to crop demand patterns rather than simply increasing input. The 90 kg ha⁻¹ rate is recommended to sustain productivity while minimizing environmental risk, providing a scientific basis for sustainable peanut production in the region.

Soil pH is a key component of soil health, influencing chemical, biological and related processes such as nutrient cycling. Globally, it has been recognized for decades that fertilization with ammonium fertilizers (including ammonium nitrate, urea and ammonium phosphate) at high rates and/or over long time periods can decrease soil pH, and is of particular concern in soils with naturally neutral pH (6.5-7.0) due to reduced buffering capacity. To investigate acidification in Canadian agriculture, soils were sampled from the 0-5, 5-10 and 10-20 cm depths from long-term research plots in historically neutral-pH soils in Saskatchewan (SK) and Quebec (QC), and a shorter-term N fertilization trial in SK and Manitoba (MB), under a range of fertilization practices including with and without chemical N fertilization, organic management with no fertilizers (chemical or animal manure), and a range of management practices, including tillage and crop rotations. Soil pH ranged from 5.0 to 7.3 in SK and QC soils and up to 8.4 in MB soils, and was consistently lower in plots with long-term ammonium fertilization. For all fertilized plots, soil pH was lowest at the depth of fertilizer placement (5-10 cm) and highest at 10-20 cm, with the greatest pH differences between these depths in no-till plots. Acidification altered exchangeable cation concentrations, decreasing exchangeable calcium and increasing exchangeable aluminum; this indicates that buffering capacity was reduced in many of the studied soils. These results show that acidification is a concern for neutral-pH Canadian soils, warranting further investigation.

Shifting precipitation patterns in British Columbia (BC), Canada, are increasing the challenge of effective overwinter cover cropping in organic vegetable production and driving the need for alternative soil cover options. As an alternative soil cover, farmers are using plastic silage tarps. There is, however, limited understanding about the impact of overwintered tarps on soil conditions or subsequent cash crops. This study compared the impacts of overwinter plastic tarping with cover cropping or no-tarp conditions on plant available nitrogen (PAN), electrical conductivity (EC), volumetric water content (VWC), and crop yield on organic practicing vegetable farms. Between 2019 and 2021, our study spanned three agricultural regions of BC, with replicated field experiments on two farms and unreplicated plots on 12 additional farms. Plant available nitrogen, EC, and VWC were measured in the spring after tarp removal at all farms. Additional measurements were taken at the experimental farms, including PAN throughout the growing season and crop yield. Spring PAN was 1.8 to 7.8 times greater, and EC was 2.6 times greater under the tarps. Spring VWC varied and was likely related to tarp removal timing. Crop yield was not significantly impacted by overwinter treatment. Data indicate that tarps created lower VWC conditions over the winter until early spring after which time VWC under tarped conditions was higher than soil under cover crops. Our findings indicate that overwintered tarps are an effective soil cover strategy for small-scale organic farmers to conserve soil PAN and influence early spring soil water content under changing precipitation regimes.

Phosphorus (P) loss from soils via snowmelt runoff is a major contributor to eutrophication in water bodies across the Canadian Prairies. Reductions in P losses are often achieved using single-component soil amendments. Blended amendments have been shown to stabilize P more effectively than single amendments; however, their effectiveness in reducing P loss with snowmelt flooding is not well understood. This laboratory incubation study, conducted under simulated snowmelt flooding, compared the effectiveness of blended soil amendments with single amendments in reducing P release from six agricultural soils from southern Manitoba. The treatments were unamended (control), single amendment of alum [KAl(SO4)2·12H2O], or ferric chloride (FeCl3) at 2.5 Mg ha-1, single amendment of gypsum (CaSO4·2H2O) or magnesium sulfate (MgSO4) at 2.5 Mg ha-1 or 5 Mg ha-1, and eight amendment blends of gypsum/magnesium sulfate with alum/ferric chloride at different combinations. Treated soils were packed in vessels, flooded, and incubated at 4°C for 56 days. Floodwater samples were collected bi-weekly and analyzed for dissolved reactive P (DRP) concentrations. Blended amendments typically led to greater DRP reductions in floodwater, achieving maximum decreases of 51-89%, compared to 38-64% reductions observed with individual amendments. The gypsum and ferric chloride blend (1:1 ratio at 2.5 Mg ha-1) demonstrated consistent effectiveness across all soil types, whereas ferric chloride was the most effective when applied individually. Single amendment of ferric chloride was only slightly inferior to blended amendments, suggesting it would be a viable option to reduce floodwater DRP in most soils.

Brassicaceae oilseed crop residues contain diverse chemical compounds that have the potential to influence nitrogen (N) mineralization and hence recovery from crop residues. This study investigated how glucosinolate (GLS), carbon (C), N, lignin contents, and associated ratios (C:N and lignin:N) in selected Brassicaceae [Argentine canola (Brassica napus L.), industrial mustard (B. carinata L.), Oriental mustard (B. juncea L.), camelina (Camelina sativa L. Crantz), and yellow mustard (Sinapis alba L.] and non-Brassicaceae (spring wheat, Triticum aestivum L.) crop residues affect N recovery potential and soil N availability. A 120-d laboratory incubation was performed using 15N-labeled residues of these crops. Yellow mustard contained the highest GLS concentration (6.49 µmol g-1 of tissue) and Argentine canola contained the least (0.02 µmol g-1 of tissue). Argentine canola (17.8:1) and Oriental mustard (19.5:1) residues had the lowest lignin:N due to their high N concentrations. After 120-d, 47.1-53.7% of residue N was mineralized and recovered as ammonium-N and nitrate-N. Nitrogen mineralization from the Brassicaceae residues was initially lower than wheat, likely due to inhibitory effects of GLS degradation products on soil microbes. Strong negative correlations were found between N recovery and both GLS concentration (r = –0.737 to –0.846, days 3-28, P=0.04) and lignin:N ratio (r = –0.631 to –0.552, days 3–56, P=0.02), indicating that these biochemical properties likely delayed N availability from crop residues at the early-stage. These findings suggest that the biochemical composition of Brassicaceae residues, particularly their GLS content, can delay short-term N cycling and affect nutrient availability for subsequent crops.

Crop production in Canada demands consistent use of nitrogen (N) fertilizer, which produces substantial nitrous oxide (N2O) emissions. It may be reduced through scientifically supported N management practices, including applying right sources at right time, right rate and right place (i.e., 4R practices). One promising 4R practice is use of enhanced efficiency fertilizers (EEFs). However, there is a lack of research synthesis quantifying their effectiveness. To address this gap, we conducted a Canada-wide meta-analysis of field research studies to measure the effectiveness of EEFs and their effects when compared to, or combined with other 4R management practices. Here we present the results of two analyses, i) comparison of EEFs to conventional N fertilizers (21 studies, 291 observations) using the natural-log-of-the-response-ratio as the effect size, and ii) the comparison of different 4R practices (31 studies, 561 observations) using emission factor (EF) as the effect size. Mean effect sizes were calculated using a generic-inverse-variance, random effect multilevel model. Overall, EEFs reduced N2O emissions by 11% compared to conventional fertilizers. EEF types had 23, 15, 6, and -9 % N2O reductions (with negative values implying an increase) from nitrification inhibitors, dual inhibitors, slow-release, and urease inhibitors, respectively. The most influential moderators for EEF performance were air temperature at fertilization and soil silt content. The best 4R practices were split application (EF = 0.78%) and EEFs (EF = 0.75%), followed by organic fertilizers (EF = 0.8%). The most influential moderators of EFs were annual relative humidity, percent of soil sand, and crop type.

This study examines how wind speed affects soil respiration in Pinus koraiensis plantations in eastern Liaoning's mountains, using high-frequency monitoring data to improve carbon cycle models and soil carbon management. The correlation analysis, XGBoost models, and structural equation modeling were employed to disentangle the direct physical effects and indirect microenvironmental regulation of understory wind speed on soil respiration, as well as nonlinear interactions with soil moisture. The results demonstrated that soil respiration exhibited significant diurnal variation, showing a humped relationship, and declined markedly from late summer to early winter. The wind speed showed a strong negative correlation with soil respiration rate, with a path coefficient of -0.198, independently explaining 7.9% of environmental factor variation. The wind speed-soil moisture interaction significantly altered respiration patterns: under high wind speeds (>0.8 m/s), soil moisture’s promotive effect on respiration weakened by ~14.5%. Wind speed suppressed respiration via dual pathways: directly enhancing soil CO₂ ventilation (path coefficient: -0.127) and indirectly reducing microbial activity by lowering soil moisture (path coefficient: -0.071). This study establishes a multi-path respiration model incorporating wind speed for temperate plantations, demonstrating that wind speed inhibits soil carbon release through synergistic physical transport and biological effects. Global wind speed decline may enhance annual carbon accumulation in plantation soils. These findings provide a scientific basis for developing wind speed-regulated forest carbon sequestration technologies.

Manure application in agriculture risks phosphorus (P) runoff. This incubation study evaluated the effect of manure treatments with alum, gypsum, and Epsom salt (300 mg L −1 ) prior to soil application in reducing labile phosphorus in swine manure and manured soils. The manure treated with alum had significantly lower water-extractable P (20% and 36% decrease) than the Epsom salt-treated and untreated manure after 7-day incubation. However, when the treated manure was applied to soils, there was no significant difference in water-extractable P or Olsen P compared with untreated manure. Increased amendment rates and multiple applications can be explored in future research.

This study investigated the impacts of long-term application of mineral and organic fertilizers on soil organic carbon (SOC) fractions and carbon management index (CMI) under a faba bean cropping system. The experiment was established in 1996 at the Çukurova University Research Centre in Adana/Türkiye and is still ongoing. Since establishment, five fertilizer treatments have been applied each cropping season, including control (no fertilizer), mineral fertilizer (100N–26P–83K kg ha −1 ), animal manure (25 t ha −1 ), compost 25 (25 t ha −1 ), and compost 10 (10 t ha −1 ) with mycorrhizal fungi. In the present study, faba beans were grown and harvested in 2022 cropping season. At harvest, soil samples were collected to a depth of 0–20 cm and analyzed for SOC and its fractions, such as permanganate oxidizable “labile” (POXC) and particulate organic carbon (POC). The soil CMI and carbon sensitivity index were also estimated. Animal manure and compost 25 increased bulk SOC and its fractions relative to other treatments. Manure increased bulk SOC, POC, and POXC concentrations by 74%, 226%, and 85%, respectively, relative to the control, while compost 25 increased these fractions by 57%, 54%, and 59%. The CMI was also increased by 87% and 57% over the control under manure and compost 25 , respectively. Cumulative soil CO 2 flux did not differ among treatments. In conclusion, long-term manure and compost 25 use increased CMI and the labile and particulate SOC pools. The POC fraction showed the highest sensitivity compared to POXC, particularly under manure, indicating its potential as an early indicator of SOC change.