Extracellular soil enzymes play a key role in organic matter decomposition and nutrient cycling. However, it is not fully understood how these respond to different land use. Long-term research studies were used evaluate diversified management practices affect extracellular driving C cycling [phenol oxidases (PO), peroxidases (PP), α-glucosidase (AG), β-glucosidase (BG), cellobiohydrolase (CB), β-1,-4-Nacetylglucosaminidase (NAG)], N [leucine aminopeptidase (LAP)], P [phosphomonoesterase...

Tissue analysis is commonly used in ecology and agronomy to portray plant nutrient signatures. Nutrient concentration data, or ionomes, belongs the compositional data class, i.e. multivariate that are proportions of some whole, hence carrying important numerical properties. Statistics computed across raw ordinary log-transformed intrinsically biased, possibly leading wrong inferences. Our objective was present a sound robust approach based on novel balance concept classify ionomes. We...

Abstract Phosphorus (P) is one of the most limiting essential nutrients for agricultural production and its availability to crops assessed by various methods. Mehlich‐3, however, remains used method worldwide. For decades, colorimetric blue ascorbic acid‐molybdate reaction has been determine soil P concentration following Mehlich‐3 extraction. Since early 1990s, use automated methods quantify including expanded rapidly, inductively coupled plasma (ICP) emission spectroscopy becoming popular...

The in situ use of anion exchange membranes (AEMs) as a soil-testing procedure may provide more precise evaluation N availability to forages than standard methods. main objective this study was evaluate the potential AEMs predict soil NO 3 –N for forage production western part province Quebec, Canada. In 1995 and 1996, were buried (0–15 cm) soils at four sites. fertilizer treatments consisted five NH 4 rates (0, 60, 120, 180, 240 kg ha –1 ). At all sites, − sorbed on (NO 3AEMs ) increased...

The development of sustainable farming systems depends on our ability to predict and manage the response weed communities changes in cropping practices. A study was established at Normandin, Québec, Canada, investigate influence liquid dairy manure mineral fertilizer, as well chisel moldboard plow tillage systems, a spring barley monoculture 3-yr barley-forage rotation that included red clover timothy. Weed species richness (Margalef's D MG ), evenness (Shannon's E), diversity H') were...

The knowledge of P transformations is essential to understand the behaviour in soils. Organic (P o ) and inorganic i fractions were obtained from 0‐ 30‐ 90‐cm layers a Labarre silty clay (fine, mixed, frigid, Humic Cryaquept) by sequential extraction. Barley ( Hordeum vulgare L.) monoculture 3‐yr barley‐forage rotation as main plots, two nutrient sources (mineral fertilizer liquid dairy manure) subplots studied. Path analysis was used describe soil between falls 1989 1997. Nutrient source...

Clubroot, a disease caused by Plasmodiophora brassicae, first appeared in canola fields Quebec 1997. The objective of this project was to assess the impact soil infested with P. brassicae on productivity and grain quality canola. In 1998 1999, 31 cultivars total (23 Brassica napus or 25 B. 1999 6 rapa) were evaluated. 2000, two lines (70584 et 70585) rapa tested. These sown where had been prevalent for few years another which never cruciferous crop before. reduced productivity. Grain yield...

Information about the dynamics of soil P fractions is useful to predict their bioavailability and risk transfer from soils surface waters. The objective this study was assess effects cropping systems nutrient sources on in a Labarre silty clay (Humic Gleysol). Soil samples (0-15 cm) were collected 1989, 1994 1997 field with four systems, combining two crop rotations, barley (Hordeum vulgare L.) monoculture 3-yr barley-forage rotation, tillage operations (chisel moldboard plowing) as main...

Critical nutrient concentrations are required for assessing the level of crop nutrition. Our objectives were to validate an existing model critical phosphorus concentration ( P c = 0.94 + 0.107 N ) in shoot biomass (SB) wheat Triticum aestivum L.) and assess alternative approach expressing as a function SB rather than ). We applied four rates fertilizer (0, 10, 20, 30 kg ha −1 on soils with low medium available at locations three countries (Normandin [Canada; 2010, 2011, 2012], Brandon...

Understanding how plant allometry, architecture and phenology contribute to fruit production can identify those traits that maximize yield. In this study, we compared these variables yield for two shrub species, Vaccinium angustifolium myrtilloides, test the hypothesis is linked plants' allometric traits, which are predictors of production.We measured leaf flower above-ground biomass both species in a commercial wild lowbush blueberry field (Quebec, Canada) over 2-year crop cycle; 1 year...

Abstract Effects of management practices on crop growth and yields may or not be mediated through crop‐weed interactions. Our objective was to detect confirm a relationship between the influence factors spring barley ( Hordeum vulgare L.) potential occurrence interference. A field study established Normandin clay (fine, mixed, frigid Humic Cryaquept) at in Québec investigate effects rotation, tillage (chisel plow, CP; moldboard MP), nutrient source midseason aboveground dry weight seed yield...

Knowledge of phosphorus (P) dynamics in soil is essential for predicting its bioavailability and the risk P transfer from to bodies water. A comparative study was conducted assess changes fractions pathways transformation measured after 10 annual applications mineral fertilizers (MIN) liquid dairy manure (LDM). Fractionation path analyses were performed quantify inorganic (Pi) organic (Po) forms relationships between pools 0 15-cm layer a Labarre silty clay (fine, mixed, frigid, Humic...

Crop responses to increasing P fertilization are often variable and poorly related soil test. Our objectives were determine the influence of fertilizer on growth seed yield canola ( Brassica napus L.) develop a first approximation its critical phosphorus concentration (P c ) in shoot biomass. An experiment with four rates (0, 20, 40, 80 kg ha −1 was conducted soils low available content at 5 site‐years [Normandin (QC; 2010, 2011, 2012) Brandon (MB; 2012)] Canada. Dry matter (DM) yield, N...

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 production. STICS model has not yet been tested spring grown over several decades. This study was conducted to calibrate evaluate model, without annual reinitialization, predicting aboveground biomass N nutrition attributes at harvest during 31 years successive cropping soil (silty clay, Humic Gleysol) from...

In many soils, the content and quality of organic matter (OM) control water-stable aggregation, which in turn preserves soil surface integrity. The effects management practices on OM aggregation remain to be determined for certain soils climatic conditions. We assessed eight systems involving two crop sequences: [barley ( Hordeum vulgare L.) monoculture (M) barley rotation (R) with a forage mix red clover Trifolium pratense timothy Phleum L. ‘Champ’)], fall tillage [moldboard plowing (MP)...

To evaluate the nutritional status of wild lowbush blueberry (Vaccinium angustifolium Ait.), optimum leaf nutrient concentrations were developed in earlier studies conducted Canada's Maritime Provinces and Maine. However, these have not been validated under climatic edaphic conditions Saguenay-Lac-Saint-Jean region Quebec (Canada). These may be necessarily correlated with high productivity levels recorded this recent years. The objective study was therefore to determine minimum maximum...

Lafond, J. et Ziadi, N. 2011. Fertilisation azotee phosphatee dans la production du bleuet nain sauvage au Quebec. Can. Plant Sci. 91: 535–544. Peu d’etudes ont evalue les interactions entre l'azote (N) le phosphore (P) (Vaccinium angustifolium Ait.). Ainsi, l'objectif de cette etude a ete determiner reponse fertilisation en N P sous conditions climatiques edaphiques Saguenay-Lac-Saint-Jean, Quebec, Canada. Les traitements consiste quatre doses (0, 30, 60 90 kg ha−1) P2O5 ha−1). rendements...

The knowledge of P transformations is essential to understand the behaviour in soils. Organic (Po) and inorganic (Pi) fractions were obtained from 0- 30- 90-cm layers a Labarre silty clay (fine, mixed, frigid, Humic Cryaquept) by sequential extraction. Barley (Hordeum vulgare L.) monoculture 3-yr barley-forage rotation as main plots, two nutrient sources (mineral fertilizer liquid dairy manure) subplots studied. Path analysis was used describe soil between falls 1989 1997. Nutrient source...

Combined primary and secondary papermill sludge (PS) is a good potential source of C other nutrients to restore low organic matter sandy soils supporting native lowbush blueberry (Vaccinium angustifolium Ait.). A 3-yr field study was conducted compare the effect PS with mineral fertilizers (MF) on yield soil chemical properties enzyme activities l’Afrique sand (Humo-Ferric Podzol) in Saguenay-Lac Saint-Jean area (Quebec, Canada). The applied spring sprout year at 0, 8.5, 17 34 Mg ha -1 MF...