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In Tunisia, climate change impacts that lead to the degradation of soil resources are considered to be a major limiting factor on socio-economic development. These impacts are exacerbated by the intensive plowing and cultivation practices used by Tunisian farmers, which expedite the depletion of soil organic matter (SOM), leading to changes in the physio-chemical properties of soil and consequently promoting soil erosion. In fact, the decrease in soil organic carbon (SOC) stocks affects soil’s fertility and the ability to regulate climate change. The objective of this study, which was conducted in Le Krib in the Siliana region of northwestern Tunisia, was to evaluate the effects of two cropping systems, consisting of durum wheat (Triticum aestivum) and oats (Avena sativa), and two types of tillage, no-till (NT) and mouldboard plowing (MP), on different soil aggregate classes (>2000 µm, 2000–250 µm, 250–180 µm, 180–53 µm and

Spring barley (Hordeum vulgare L.) is an increasingly important cash crop in the province of Quebec (Canada). Soil–crop models are powerful tools for analyzing and supporting sustainable crop production. STICS model has not yet been tested for spring barley grown over several decades. This study was conducted to calibrate and evaluate the STICS model, without annual reinitialization, for predicting aboveground biomass and N nutrition attributes at harvest during 31 years of successive cropping of spring barley grown in soil (silty clay, Humic Gleysol) from the Saguenay–Lac-Saint-Jean region (northeastern Quebec, Canada). There is a good agreement between observed and predicted variables during the 31 successive barley cropping years. STICS predicted well biomass accumulation and plant N content with a low relative bias (|normalized mean error| = 0–13%) and small prediction error (normalized root mean square error = 6–25%). Overall, the STICS outputs reproduced the same trends as the field-observed data with various tillage systems and N sources. Predictions of crop attributes were more accurate in years with rainfall close to the long-term average. These ‘newly calibrated’ parameters in STICS for spring barley cropped under continental cold and humid climates require validation using independent observation datasets from other sites.

Abstract Background Continuous application of phosphorus (P) nutrient in association with its low recovery results in large amounts of P being accumulated in soil in different forms. Use of biochar can be a possible means to mobilize soil legacy P and increase its bioavailability. Therefore, the aim of this study was to identify the potential impact of a range of biochar types on P fractions in a long-term cultivated arid soil with high legacy P content. Methodology The soil was treated with biochar produced from four feedstock sources (BFS): sewage sludge (SSB), olive mill pomace (OPB), chicken manure (CMB), and date palm residues (DRB) pyrolyzed at 300, 500, or 700 °C in addition to an untreated control. The soil biochar mixture was incubated for 1 month followed by soil P fractionations using sequential chemical extraction to separate soil P into: labile (Resin-Pi, NaHCO3-Pi, NaHCO3-Po), moderately labile (NaOH-Pi, NaOH-Po), and non-labile (HCl-Pi and Residual-P) pools. Results Biochar addition clearly influenced most of the soil P fractions; however, the extent of this effect greatly varied depending on BFS and pyrolysis temperature (PT). The most evident biochar impact was observed with labile P pool, with the greatest increase being observed in NaHCO3-Pi fraction in most biochar treatments. Irrespective of PT, SSB and CMB were the most effective biochar type in increasing labile inorganic P; the SSB and CMB increased Resin-Pi by 77 and 206% and NaHCO3-Pi by 200 and 188%, respectively. In contrast, DRB made no changes in any P fraction. Differences in effects of biochar types on labile P is presumably related to the higher content of P in biowaste-based biochar compared to plant-based biochar which have much lower P content. The SSB, CMB, and OPB produced at low temperature reduced HCl-Pi content, indicating that these biochars may have stimulated organic matter decomposition and thereby dissolution of non-labile Ca-associated P to labile P forms. Conclusion Overall, biochar addition appeared to be an effective approach in enhancing legacy P availability in arid soil. However, further studies are necessary to verify these findings in the presence of plant and for a longer period. Graphic abstract

Combined paper mill biosolids (PB) and forest-derived liming by-products improve soil properties, but their residual effects following several years of application have hardly been investigated. A 13-year (2009–2021) field study was initiated at Yamachiche, QC, Canada, to assess the residual effects of PB and liming materials on the properties of a loamy soil. The PB was applied during nine consecutive years (2000–2008) at 0, 30, 60, and 90 Mg wet·ha−1, whereas the 30 Mg PB·ha−1 rate also received one of three liming materials (calcitic lime, lime mud, wood ash) at 3 Mg wet·ha−1. No amendment was applied during residual years. Past liming materials continued to increase soil pH but their effect decreased over time; meanwhile, past PB applications caused a low increase in residual soil NO3-N. Soil total C, which represented 40% of added organic C when PB applications ceased, stabilized to 15% after six years. Soil Mehlich-3-extractable contents declined over the thirteen residual years to be not significant for P, K, and Cu, while they reached half the values of the application years for Zn and Cd. Conversely, Mehlich-3 Ca was little affected by time. Therefore, land PB and liming material applications benefited soil properties several years after their cessation.

Extracellular soil enzymes play a key role in soil organic matter decomposition and nutrient cycling. However, it is not fully understood how these enzymes respond to different land use. Long-term research studies were used to evaluate how diversified management practices affect extracellular enzymes driving C cycling [phenol oxidases (PO), peroxidases (PP), α-glucosidase (AG), β-glucosidase (BG), cellobiohydrolase (CB), β-1,-4-Nacetylglucosaminidase (NAG)], N cycling [leucine aminopeptidase (LAP)], and P cycling [phosphomonoesterase (PME)]. The soil pH, contents of total organic C, total N, mehlich-3 P, soil respiration and soil nitrogen supply capacity were also measured. Different land use included tillage frequency, tillage regimes, mineral N fertilization, crop rotations and liquid dairy manure. Compared to medium or high tillage frequency, low tillage frequency increased total organic C and total N and soil respiration as well as NAG and PME activities, whereas it decreased soil nitrogen supply, mehlich-3 P, and soil pH, as well as PO, PP, AG, BG, CB, and LAP activities. Non till was associated with lower PP and PO activities than moldboard plow. Nitrogen fertilization decreased soil pH and PO activity but increased PME activity. Barley (Hordeum vulgare) in rotation with forage increased total organic C, total N, soil nitrogen supply and soil respiration by 31, 21, 44, and 33%, respectively, in comparison with barley in monoculture. The application of liquid dairy manure increased soil pH, total N and soil nitrogen supply and soil enzyme activities (AG, BG, NAG) in comparison to the mineral N fertilizer. When principal component analysis was performed, soil pH, PO, PP, CB, LAP, and PME were grouped in the first component, which explained the highest variance. This is the core group controlling the C, N, and P cycling. The activities of C, N, and P acquiring enzymes, soil nitrogen supply and soil respiration were related to changes in soil total C and N, and extractable P contents across a broad range of management practices. Increased PO and PP activities reflect total C decline.

Abstract Background Iron (Fe) is an essential plant nutrient. Its deficiency is a major constraint in crop production systems, affecting crop yield and quality. It is therefore important to elucidate the responses and adaptive mechanisms underlying Fe-deficiency symptoms in alfalfa. Materials and methods The experiment was carried out on 12-day-old alfalfa plants grown in hydroponics under Fe-sufficient and Fe-deficient conditions. Results The Fe-starved alfalfa showed decreased plant biomass, chlorophyll score, PSII efficiency, and photosynthesis performance index in young leaves under low Fe. Further, Fe shortage reduced the Fe, Zn, S and Ca concentration in root and shoot of alfalfa accompanied by the marked decrease of MsIRT1, MsZIP, MsSULTR1;1, MsSULTR1;2 and MsSULTR1;3 transcripts in root and shoot. It indicates that retardation caused by Fe-deficiency was also associated with the status of other elements, especially the reduced Fe and S may be coordinately attributed to the photosynthetic damages in Fe-deficient alfalfa. The ferric chelate reductase activity accompanied by the expression of MsFRO1 in roots showed no substantial changes, indicating the possible involvement of this Strategy I response in Fe-deficient alfalfa. However, the proton extrusion and expression of MsHAI1 were significantly induced following Fe-deficiency. In silico analysis further suggested their subcellular localization in the plasma membrane. Also, the interactome map suggested the partnership of MsFRO1 with plasma membrane H+-ATPase, transcription factor bHLH47, and nitrate reductase genes, while MsHAI1 partners include ferric reductase-like transmembrane component, plasma membrane ATPase, vacuolar-type H-pyrophosphatase, and general regulatory factor 2. In this study, SOD and APX enzymes showed a substantial increase in roots but unable to restore the oxidative damages in Fe-starved alfalfa. Conclusion These findings promote further studies for the improvement of Fe-starved alfalfa or legumes through breeding or transgenic approaches. Graphic Abstract

Sanding to bury the overgrowth of uprights and promote new growth results in alternate sand and organic sublayers in the 0–30 cm layer of cranberry soils contributing to global carbon storage. The aim of this study was to measure CO2 emission rates in cranberry soil sublayers under simulated warming. Soil samples (0–10, 10–20 and 20–30 cm) were incubated in jars for up to 105 days at 10, 20 and 30 °C. The CO2 emission rate was measured biweekly by gas chromatography. The CO2 emission rate increased with temperature and decreased in deeper soil sublayers. Linear regression relating CO2 efflux to soil sublayer and temperature returned R2 = 0.87. Sensitivity of organic matter decomposition to temperature was estimated as activation energy and as Q10 coefficient, the increase in reaction rate per 10 °C. Activation energy was 50 kJ mol−1, 59 kJ mol−1 and 71 kJ mol−1 in the in the 0–10, 10–20 and 20–30 cm sublayers, respectively, indicating higher molecular-weight compounds resisting to decomposition in deeper sublayers. The Q10 values were significantly higher (p < 0.01) in the 10–30 cm (2.79 ± 0.10) than the 0–10 cm (2.18 ± 0.07) sublayers. The 20–30 cm sublayer where less total carbon was stored was the most sensitive to higher temperature. Cranberry soils could be used as sensitive markers of global warming.

Conservation tillage, including no-tillage (NT), is being used increasingly with respect to conventional tillage (CT) to mitigate soil erosion, improve water conservation and prevent land degradation. However, NT increases soil phosphorus (P) stratification, causing P runoff and eutrophication. For sustainable P management, fertilization must be balanced between P sources and actual crop demand. To reduce P losses to the environment, it is important to better understand P spatial variability in NT fields. Little is known about tillage impacts on field-scale P spatial variabi-lity in precision agriculture. This study examines tillage impacts on spatial variability of soil-avai-lable P in a maize–soybean rotation, in two commercial fields, denoted CT (10.8 ha) and NT (9.5 ha), with the aim of improving P fertilizer recommendations in Eastern Canada. NPK fertilizers were applied to the soils (Humic Gleysols) following local recommendations. Soil samples were collected in fall 2014 in regular 35 m by 35 m grids, at 0–5 and 5–20 cm depths, providing 141 and 134 geore-ferenced points for CT and NT fields, respectively. Available P and other elements were analyzed by Mehlich-3 extraction (M3), and the P saturation index (P/Al)M3 was calculated. Variability of soil-available P in both fields ranged from moderate to very high (32% to 60%). A mean (P/Al)M3 of 3% was found in both layers under CT, compared to 8% in the 0–5 cm layer and 6% in the 5–20 cm layer under NT. Relationships between P indices and other elements differed between tillage practices. This study highlights the need to improve P fertilizer recommendations in Eastern Canada.

Wisconsin and Quebec are the world leading cranberry-producing regions. Cranberries are grown in acidic, naturally low-fertility sandy beds. Cranberry fertilization is guided by general soil and tissue nutrient tests in addition to yield target and vegetative biomass. However, other factors such as cultivar, location, and carbon and nutrient storage impact cranberry nutrition and yield. The objective of this study was to customize nutrient diagnosis and fertilizer recommendation at local scale and for next-year cranberry production after accounting for local factors and carbon and nutrient carryover effects. We collected 1768 observations from on-farm surveys and fertilizer trials in Quebec and Wisconsin to elaborate a machine learning model using minimum datasets. We tested carryover effects in a 5-year Quebec fertilizer experiment established on permanent plots. Micronutrients contributed more than macronutrients to variation in tissue compositions. Random Forest model related accurately current-year berry yield to location, cultivars, climatic indices, fertilization, and tissue and soil tests as features (classification accuracy of 0.83). Comparing compositions of defective and successful tissue compositions in the Euclidean space of tissue compositions, the general across-factor diagnosis differed from the local factor-specific diagnosis. Nutrient standards elaborated in one region could hardly be transposed to another and, within the same region, from one bed to another due to site-specific characteristics. Next-year yield and nutrient adjustment could be predicted accurately from current-year yield and tissue composition and other features, with R2 value of 0.73 in regression mode and classification accuracy of 0.85. Compositional and machine learning methods proved to be effective to customize nutrient diagnosis and predict site-specific measures for nutrient management of cranberry stands. This study emphasized the need to acquire large experimental and observational datasets to capture the numerous factor combinations impacting current and next-year cranberry yields at local scale.

Nitrate leaching is of great environmental concern, particularly with potatoes grown on sandy soils. This 3-year study evaluated the effect of three N rates (100, 150, and 200 kg ha−1) of single applications of polymer-coated urea (PCU) and a 75% PCU + 25% urea mixture, plus a conventional split application of 200 kg N ha−1 of a 50% ammonium sulfate + 50% calcium ammonium nitrate mixture (CONV) on NO3−-N leaching, potato yield, and N uptake under irrigated and non-irrigated conditions on a sandy soil in Quebec (Canada). Fertilizer N application increased growing season NO3−-N leaching only under irrigation. On average, irrigation increased seasonal NO3−-N leaching by 52%. Under irrigated conditions, PCU reduced NO3−-N leaching compared to PCU + urea. However, both PCU and PCU + urea significantly increased NO3−-N leaching compared to the CONV at the equivalent N rate of 200 kg N ha−1. This was attributed to the timing of soil N availability and deep-water percolation. Total (TY) and marketable (MY) yields in the CONV were similar to those in the PCU applied at the equivalent N rate of 200 kg N ha−1. Despite lower plant N uptake, PCU resulted in greater TY and MY compared to PCU + urea. Residual soil inorganic N was greater for PCU and PCU + urea compared to the CONV, providing evidence that PCU products have the potential to increase NO3−-N leaching after the growing season. In this study, PCU was an agronomically and environmentally better choice than PCU + urea. The results also showed that the efficiency of PCU to reduce seasonal NO3−-N leaching may vary according to the timing of precipitation and irrigation.

Industrial by-products such as paper mill biosolids (PBs) have been used as fertilizers and amendments in agriculture for many decades. However, their content of plant essential nutrients including phosphorus (P) varies largely with sources, and availability of these nutrients once applied to soil still remains unknown. Five PBs differing in their C/N ratio (12–47) were used in an incubation study to assess the P forms and availability from both PBs and PB-amended soils. Biosolids were added to three contrasting soils varying in texture and pH in 500-ml jars at the rate of 50 Mg wet ha–1, supplying between 45 and 112 kg total P ha–1. An unfertilized control and a mineral NP treatment (30 kg P ha–1) were also included. Biosolids and soil P fractions were determined by a modified Hedley fractionation method following 2 and 16 weeks of incubation. Phosphorus forms in PBs varied across type of materials with labile P ranging from 20 to 72% and organic P (Po) ranging from 28 to 66% of total P. Soil incubated with PB showed changes in all P fractions due to amendment, soil type, and duration of incubation. Resin-P and labile P, the most available forms, were significantly higher with addition of high PB–P content. Soil labile P represented up to 50% of total P added by PB. Overall, most inorganic P (Pi) fractions and labile P further increased with incubation duration. Close relationships were established between resin-P and labile P content in PB and the increases of those fractions in incubated soils, notably after 2 weeks. The P recovery as labile P represented on average 34% of total P added or 68% in terms of mineral P. We concluded that PB could be used as an efficient source of P for fertilizing crops.

In cranberry production systems, stands are covered by 1–5 cm of sand every 2–5 years to stimulate plant growth, resulting in alternate layers of sand and litter in soil upper layers. However, almost intact twigs and leaves remain in subsurface layers, indicating a slow decomposition rate. The Tea Bag Index (TBI) provides an internationally standardized methodology to compare litter decomposition rates (k) and stabilization (S) among terrestrial ecosystems. However, TBI parameters may be altered by time-dependent changes in the contact between litter and their immediate environment. The aims of this study were to determine the TBI of cranberry agroecosystems and compare it to the TBI of other terrestrial ecosystems. Litters were standardized green tea, standardized rooibos tea, and cranberry residues collected on the plantation floor. Litter decomposition was monitored during two consecutive years. Added N did not affect TBI parameters (k and S) due to possible N leaching and strong acidic soil condition. Decomposition rates (k) averaged (mean ± SD) 9.7 × 10−3 day−1 ± 1.6 × 10−3 for green tea, 3.3 × 10−3 day−1 ± 0.8 × 10−5 for rooibos tea, and 0.4 × 10−3 day−1 ± 0.86 × 10−3 for cranberry residues due to large differences in biochemical composition and tissue structure. The TBI decomposition rate (k) was 0.006 day−1 ± 0.002 in the low range among terrestrial ecosystems, and the stabilization factor (S) was 0.28 ± 0.08, indicating high potential for carbon accumulation in cranberry agroecosystems. Decomposition rates of tea litters were reduced by fractal coefficients of 0.6 for green tea and 0.4 for rooibos tea, indicating protection mechanisms building up with time in the tea bags. While the computation of the TBI stabilization factor may be biased because the green tea was not fully decomposed, fractal kinetics could be used as additional index to compare agroecosystems.

Applying higher nitrogen (N) rates than required for optimum potato (Solanum tuberosum L.) growth leads to economic and environmental losses. The extent to which the N rate associated with maximum potato yields differs from that maximizing net revenue (NR) or potato specific gravity is not fully understood. The objectives of this three-year study (2013–2015) conducted at five sites in three Canadian provinces (MB-1; MB-2; QC-1; QC-2; PEI) (15 site-years) were to: (i) assess potato marketable yield, NR, and specific gravity responses to increasing N application; (ii) calculate the N rate maximizing marketable (Nmax) yield and NR using different statistical models. The year, N fertilizer, and their interaction were significant on marketable yield and NR except at the MB-1 site where no significant effect of N was observed. No significant yield increases were observed at a N rate above 60 kg N ha−1 at four site-years and above 120 kg N ha−1 at five site-years, implying that the current recommended N rate could be reduced. All models fitted the marketable and NR data equally based on R2, mean bias error or root mean square error and resulted in comparable predicted yield and NR values. However, Nmax values were different depending on the model with higher values being predicted by the quadratic- (161.4 to 191.9 kg N ha−1) and the quadratic plateau models (60 to 191.9 kg N ha−1), while lower Nmax values were obtained with linear plateau- (60.6 to 129.8 kg N ha−1) and Mitscherlich–Baule plateau models (60.9 to 130. 9 kg N ha−1). Nitrogen rate maximizing NR was on average 4% lower than the N rate maximizing marketable yields, except at one site where it was higher by 26 kg N ha−1 when the quadratic plus plateau model was used. Specific gravity tended to decrease with the N rate. Our study confirms trade-offs between the N rate maximizing yields or NR with that maximizing specific gravity. Nitrogen rate maximizing marketable yield and NR varies depending on the selected model.

This study evaluated the effects of de-inking paper sludge (DPS) and sewage sludge (SS) application on soil properties, and durum wheat growth and yield. A pot experiment was performed on Calcaric cambisol (clCM) and Cromic Luvisol (coLV) soils. Three DPS rates (0, 30, and 60 Mg ha−1) were studied with and without nitrogen fertilizer (280 kg NH4NO3 ha−1). DPS was also mixed with SS at two rates (5 and 10 Mg ha−1) to highlight the benefits of organic nitrogen compared to mineral nitrogen. DPS improved total organic carbon and nitrogen, mineral nitrogen, and soils cation exchange capacity, the 30% rate provided the greatest improvement in both soils. DPS increased grain and root P, K, Ca, and Mg contents in both soils. It also increased wheat straw N, P, Mg, and Ca for the same soil compared to the control. Mixed DPS treatments with nitrogen fertilizer enhanced grain yield by up to 38% and increased root biomass in the studied soils. Thus, DPS is a potential source of organic matter and a liming agent for acid soils when appropriate supplemental fertilizer is provided.

For centuries, some Indigenous Peoples of the Americas have planted corn, beans and squash or pumpkins together in mounds, in an intercropping complex known as the Three Sisters. Agriculturally, nutritionally and culturally, these three crops are complementary. This literature review aims to compile historical foods prepared from the products of the Three Sisters planting system used in Indigenous communities in the region encompassing southern Quebec and Ontario in Canada, and northeastern USA. The review does not discuss cultural aspects of the Three Sisters cropping system or describe foods specific to any one Indigenous group, but rather, gives an overview of the historical foods stemming from this intercropping system, many foods of which are common or similar from one group to another. Some of the methods of food preparation used have continued over generations, some of the historical foods prepared are the foundation for foods we eat today, and some of both the methods and foods are finding revival.

Phosphorus (P) is an essential nutrient for grassland production systems. However, continuous applications of P fertilizers result in soil P accumulations, increasing the risk of P losses in runoff and erosion. This study aims to investigate the field-scale variability of soil-test P (STP) in two contrasting grassland fields using descriptive statistics and geostatistics for accurate recommendations on soil sampling strategy and sustainable approaches to P management. A young grassland (YG; 2 years) and an old grassland (OG; 10 years under permanent pasture) were classified as humo-ferric podzol and received organic fertilizers. Soil samples were collected in 16-m by 16-m triangular grids at two depths (0–5 and 5–20 cm). They were analyzed for available P and other soil elements extracted using the Mehlich-3 method (M3). The agri-environmental P saturation index (P/Al)M3 was calculated. Phosphorus accumulation was observed in OG (0–5 cm) as a result of long-term manure applications. Repeated applications of organic fertilizers can impact the long-term buildup of soil P, thus decreasing soil P va-riability and spatial dependence in permanent grasslands. A soil sampling strategy focusing on the 0–5 cm layer should be retained in permanent grasslands for sustainable P recommendations in Eastern Canada.

Agroecosystem conditions limit the productivity of lowbush blueberry. Our objectives were to investigate the effects on berry yield of agroecosystem and crop management variables, then to develop a recommendation system to adjust nutrient and soil management of lowbush blueberry to given local meteorological conditions. We collected 1504 observations from N-P-K fertilizer trials conducted in Quebec, Canada. The data set, that comprised soil, tissue, and meteorological data, was processed by Bayesian mixed models, machine learning, compositional data analysis, and Markov chains. Our investigative statistical models showed that meteorological indices had the greatest impact on yield. High mean temperature at flower bud opening and after fruit maturation, and total precipitation at flowering stage showed positive effects. Low mean temperature and low total precipitation before bud opening, at flowering, and by fruit maturity, as well as number of freezing days (−1. An in-house Markov chain algorithm optimized yields modelled by Gaussian processes from tissue test, soil test, and fertilizer dosage as conditioned to specified historical meteorological features, potentially increasing yield by a median factor of 1.5. Machine learning, compositional data analysis, and Markov chains allowed customizing nutrient management of lowbush blueberry at local scale.

The use of deinking paper sludge (DPS) as a fertilizer instead of sending it to landfill could play a role in reducing greenhouse gases and improving soil properties. The objectives of this study were (1) to evaluate the changes in the physical (permeability and structural stability), chemical (particularly soil pH), and biological (microbial metabolic quotient (qCO2), microbial biomass soil CO2 emissions) of a calcareous agricultural soil following two successive annual amendments with three treatments (0, 30, and 60 Mg DPS ha−1—control, DPS30, and DPS60, respectively); and (2) to determine whether the addition of N-fertilizer to these treatments (controlF, DPS30F, and DPS60F, respectively) causes changes to soil fertility. The DPS application increased soil organic matter (+0.80%: DPS60 vs. control; and +0.35%: controlF vs. DPS60F), available phosphorus (+23.14 mg kg−1: DPS60 vs. control; and +14.34 mg kg−1: DPS60F vs. controlF), potassium (+0.6 g kg−1: controlF vs. DPS30F), and calcium (+0.28 g kg−1: DPS60 vs. control). The 60 Mg DPS ha−1 rate improved permeability and structural stability, regardless of the presence or absence of N-fertilizer. On the other hand, the 60 Mg DPS ha−1 rate without N-fertilizer lead to a decrease in total mineralization rate and qCO2, thereby indicating a reduction in CO2 emissions. The rate of 60 Mg ha−1 DPS could be effectively used to enhance the permeability and stability (soil restoration) and mitigate CO2 emissions, whereas the 30 Mg ha−1 rate could be used as fertilizer to improve the fertility of calcareous soils.

Soil bulk density (BD), degree of compactness (DC), maximum bulk density (MBD), and critical water content (CWC) at which MBD is reached are commonly used to characterize soil compaction, and can be predicted from soil texture and organic matter content, omitting other components such as sand sub-classes and soil cementing agents and potential biases such as data redundancy and sub-compositional incoherence. Compositional data analysis is needed to account for interactions among soil components and to avoid biases. The aim of this study was to relate soil compaction indexes to the basic components of coarse-textured soils using unbiased numerical techniques. Soil samples collected in horizons A and B at 49 sites in Quebec, Canada, were analyzed for gravimetric water content, BD, particle-size distribution, MBD, CWC, organic C, total N, Si, Fe, Al, Mn, Mg, and Ca. DC was calculated as the ratio of BD to MBD. The 14 physical-chemical soil properties were expressed as isometric log-ratios balances. We conducted principal component analysis to identify the components most correlated with compaction indexes. We used regression analysis to predict MBD and CWC, and used linear mixed-effects models to predict BD and DC. The regression models accounted for up to 83% of total variation in MBD and CWC, and the linear mixed-effects models explained 58–64% of total variation in BD and DC. BD and DC were found to decrease with clay content, and increase with larger proportion of coarser particles. Organic matter content tended to reduce BD and DC, and showed little effects on MBD. Increasing evenness of sand fractions resulted in a higher MBD value. Relationships between CWC and soil texture, and between CWC and organic C were not significant. Mineral cementing agents were the major contributors to soil compaction indexes. Si, Al, Fe, and Ca oxides increased BD, DC, and CWC, but reduced MBD. The sensitivity of coarse-textured soils to compaction could be predicted to support decisions on soil resilience after ripping and on the need to implement corrective chemical, biological and physical methods such as soil amendments, structure-building crops or textural mixtures to rebalance soil compositions.