Changes in phosphorus fractions of a Humic Gleysol as influenced by cropping systems and nutrient sources

Carefoot, J. P. and Whalen, J. K. 2003. Phosphorus concentrations in subsurface water as influenced by cropping systems and fertilizer sources. Can. J. Soil Sci. 83: 203-212. Over-fertilization of agricultural soils with P has been linked to water pollution, and it is becoming apparent that subsurface P losses can be substantial. The silty-loam Gleysol chosen for this study contained 146 mg Mehlich-3 P kg -1 , which exceeds the critical limit (66 mg Mehlich-3 P kg -1 ) for Québec. Equal quantities of fertilizer P (45 kg P ha -1 ) were applied from inorganic (triple superphosphate) and organic (composted cattle manure) sources to corn-corn and corn-soybean rotations. We evaluated crop production, the Mehlich-3 P and degree of soil P saturation levels, and the P concentration in subsurface water. Crop yields were unaffected by the fertilizer source, and only 31 to 67% of the P applied over a 2-yr period was exported, suggesting that the P fertilizer rate, chosen to match the P requirements of the corn crop, was excessive. After 2 yr, surface (0 to 15 cm) soils contained 149 to 199 mg Mehlich-3 P kg -1 and the Mehlich-3 (P/Al) saturation ratio (DSPS M3 ) ranged from 0.10 to 0.14. Subsurface water from piezometers installed to a 60-cm depth contained between 0.3 and 1.7 mg total P L -1 , and particulate P was the dominant P form at most sampling dates. Mehlich-3 P was positively correlated with dissolved reactive P, whereas the DSPS M3 was positively correlated with the total P and particulate P concentrations in subsurface water. We conclude that these soil test parameters could be useful indicators of subsurface P losses from Québec soils.Key words: Soil test P, degree of soil P saturation, composted cattle manure, triple superphosphate, P leaching Il existe un lien évident entre la sur-fertilisation des sols agricoles en phosphore (P) et la pollution des eaux. Le Gleysol limoneau choisi pour cette etude contiennait 146 mg kg -1 du P selon la méthode Mehlich-3 (Mehlich-3 P), excédant ainsi la limite critique (66 mg Mehlich-3 P kg -1 ) du Québec. Les quantités égaux d'engrais phosphorique (45 kg P ha -1 ) ont été appliqué en forme inorganique (superphosphate triple) et organique (fumier de bétail composté) sur les cultures en rotation maïs-maïs et maïs-soya. Nous avons evalué la récolte des cultures, la quantité du Mehlich-3 P, le degré de saturation du sol en P (DSSP), et la concentration du P dans l'eau sous-terrain. Les récoltes ont été nullement affecté par la source de fertilisant. Seulement 31 à 67% du P appliqué sur un period du deux ans a été exporté, ceci nous laissons à croire que la taux de fertilisation du P, recommendait au Québec, est excessif. Après deux ans, le sols du surface (0 à 15 cm) contiennait 149 à 199 mg Mehlich-3 P kg -1 puis la ratio du saturation en P (P/Al) selon la méthode Mehlich-3 (DSSP M3 ) a été entre 0.10 et 0.14. L'eau collectait d'un profondeur de 60 cm avec l'utilisation d'un pieometre contiennait entre 0.3 et 1.7 mg P totale L -1 . Le P en particules était la forme dominant du...

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Phosphorus concentrations in subsurface water as influenced by cropping systems and fertilizer sources

Carefoot¹,

Whalen²

2003

“…(Zheng et al 2001), because the NaHCO 3 -P o acted as a transitory pool rather than as a sink or source of P in P transformations (Zheng et al 2002). According to O'Halloran et al (1987), the NaOH-P o is primarily derived from humic compounds generated from plant-residue decomposition.…”

Section: Labile P O Fractionsmentioning

confidence: 99%

Influence of soil texture on fertilizer and soil phosphorus transformations in Gleysolic soils

Parent¹,

MacLeod²

2003

Influence of soil texture on fertilizer and soil phosphorus transformations in Gleysolic soils. Can. J. Soil Sci. 83: 395-403. The P dynamics in soils should be quantified in agricultural soils to improve fertilizer P (FP) efficiency while limiting the risk of P transfer from soils to water bodies. This study assessed P transformations following FP addition to Gleysolic soils. A pot experiment was conducted with five soils varying in texture from sandy loam to heavy clay, and receiving four FP rates under barley (Hordeum vulgare L.)-soybean (Glycine max L.) rotations. A modified Hedley procedure was used for soil P fractionation. Soil resin-P and NaHCO 3 -P i contents were interactively affected by texture and FP. The NaHCO 3 -P o , NaOH-P o , HCl-P and H 2 SO 4 -P were only affected by soil texture. Proportions of 78 and 90% of the variation in labile and total P were, respectively, related to soil clay content. The FP addition increased resin-P, NaHCO 3 -P i and NaOH-P i and -P o contents in coarse-textured soils, but the amount added was not sufficient to mask the initial influence of soil texture on the sizes of soil P pools. Plant P uptake was proportional to FP rate but less closely linked to clay content. The average increase in labile P per unit of total FP added in excess of plant exports was 0.85, 0.82, 0.73, 0.55 and 0.24 for the sandy loam, loam, clay loam, clay and heavy clay soil, respectively. The results of this study stress the important of considering soil texture in Gleysolic soils when assessing P accumulation and transformations in soils, due to commercial fertilizers applied in excess of crop removal.Key words: P fractions, clay content, fertilizer P, plant P uptake, soil texture Zheng, Z., Parent, L. E. et MacLeod, J. A. 2003. Influence de la texture du sol sur les transformations du p des engrais et du p dans les sols Gleysoliques. Can. J. Soil Sci. 83: 395-403. Il est de première importance de comprendre la dynamique du P dans les sols agricoles pour un meilleur usage des fertilisants phosphatés (FP ) tout en limitant le risque de transfert de P vers les eaux. Cette étude vise à déterminer les transformations du P après l'ajout de FP à des sols Gleysoliques de teneurs croissantes en argile. Un essai en serre a été mené avec cinq sols recevant quatre doses de FP sous une rotation orge (Hordeum vulgare L.)-soja (Glycine max L.). Une méthode de fractionnement séquentiel du P du sol de type Hedley a été utilisée. Les fractions P-résine, et P i -NaHCO 3 furent influencées par la texture du sol et le FP. Les fractions P o -NaHCO 3 , P o -NaOH, P-HCl et P-H 2 SO 4 dépendaient uniquement de la texture du sol. Des proportions de 78% des variations du P labile et de 90% du P total étaient attribuables à la teneur en argile du sol. L'ajout de FP a augmenté les teneurs en P-résine, P i -NaHCO 3 et P i /P o -NaOH dans les sols de texture grossière. Cependant, les doses de FP utilisées ne suffisaient pas à masquer l'influence de la texture du sol sur les tailles des fractions du P. Le prélève-ment du ...

“…Soils were air-dried, sieved through a 2-mm screen, and ground to 0.2 mm. Soil samples (0.5 g) were sequentially extracted by the Hedley procedure described by Tiessen and Moir (2007), with a modification consisting in soil digestion by an acidified potassium persulphate oxidation (Zheng et al 2001), to determine the P distribution in the different pools as a function of used reagents, according to the following scheme:…”

Section: Soil P Fractionationmentioning

confidence: 99%

Soil phosphorus fractions following annual paper mill biosolids and liming materials application

Fan¹,

Ziadi²,

Gagnon³

et al. 2010

Soil phosphorus fractions following annual paper mill biosolids and liming materials application. Can. J. Soil Sci. 90: 467Á479. Industrial by-products such as paper mill biosolids (PB) and different liming materials have been used as fertilizers and amendments in agricultural soils for many decades. However, little is known about the effects of their repeated application on soil nutrient availability, particularly phosphorus (P). A 6-yr field study (2000Á2005) was conducted in the province of Quebec to investigate the effect of repeated annual applications of different PB and industrial by-products on selected soil chemical properties, especially soil P fractions. Different PB rates (0 to 90 Mg wet ha(1 ) and several liming products (lime mud, wood ash, calcitic lime, and Mg by-products) were annually applied to field crops after seeding. Soils were sampled before seeding in May 2003 and at harvest in October 2005. Results showed that HCl-P was the largest P pool, accounting for about 64% of the total P fraction, and that the repeated applications of liming products significantly increased this pool and decreased the organic P pools. The NaOH-Po and residual-P were significantly lower in 2005 than in 2003, indicating that PB application without supplemental P fertilizer inputs enhanced the mobility and/or mineralization of NaOH-Po and the transformation of recalcitrant P to more labile forms with time. Lime mud (LM) was found to be the best liming material owing to its high neutralization capacity and positive effect on soil P availability over time.Key words: Paper mill biosolids, alkaline residuals, lime, wood ash, soil P fractions Fan, J. L., Ziadi, N., Gagnon, B. et Hu, Z. Y. 2010. Fractions du phosphore du sol suite a`l'application annuelle de biosolides papetiers et de re´sidus alcalins. Can. J. Soil Sci. 90: 467Á479. Les sous-produits industriels tel que les biosolides papetiers (BP) et les diffe´rents re´sidus alcalins ont e´te´utilise´s comme fertilisants et amendements en agriculture depuis plusieurs de´cennies. Toutefois, l'effet de leur application re´pe´te´e sur la disponibilite´des nutriments du sol, en particulier le phosphore (P), est encore mal connu. Une e´tude au champ de six ans (2000Á2005) a e´te´conduite dans la province de Que´bec pour e´valuer l'effet d'applications re´pe´te´es de diffe´rents BP et de re´sidus alcalins sur certaines proprie´te´s chimiques du sol, notamment les diffe´rentes fractions du P. Diffe´rents taux de BP (0 a`90 Mg humide ha (1 ) et quelques re´sidus alcalins (boues de chaux, cendres de bois, chaux calcique, sous-produit-magne´siens) ont e´te´applique´s annuellement en post-leve´e a`diffe´rentes cultures. Les sols ont e´te´e´chantillonne´s avant le semis en mai 2003 et a`la re´colte en octobre 2005. Les re´sultats ont indique´que le HCl-P est la fraction la plus importante repre´sentant environ 64% de toutes les fractions totales de P. Les applications re´pe´te´es de re´sidus alcalins ont significativement augmente´ce pool mais diminueć eux de la fraction organiqu...