Particulate and mineral-associated organic matter in water-stable aggregates as affected by mineral fertilizer and manure applications

Abstract

Aoyama, M., Angers, D. A. and N'Dayegamiye, A. 1999. Particulate and mineral-associated organic matter in water-stable aggregates as affected by mineral fertilizer and manure applications. Can. J. Soil Sci. 79: 295-302. Application of cattle manure generally improves soil structure and organic matter (OM) content. However, changes in forms and location of OM within the aggregate structure are less well known. The effects of long-term (18-yr) applications of cattle manure (20 Mg ha -1 yr -1 ) and NPK fertilizer on the distribution of particulate and mineral-associated organic matter in water-stable aggregates were investigated in a Le Bras loam (Humic Gleysol). Soil samples from the 0-to 10-cm depth were taken from the untreated control, NPK, manure and NPK + manure treatments. They were separated into four aggregate-size fractions (>1000 µm, 250-1000 µm, 53-250 µm, and <53 µm) by slaking air-dried soil, followed by wet sieving. Particulate (>53 µm) and mineral-associated OM (<53 µm) were separated from water-stable aggregates >53 µm by sieving after mechanical dispersion. After 18 yr, manure increased the OM level of the whole soil and favored formation of slaking-resistant macroaggregates (250-1000 µm). This effect was primarily a result of the OM added by the manure. In contrast, NPK fertilizer did not affect soil OM level or macroaggregation. The increase in OM induced by manure application was observed primarily in macroaggregates, and both as mineral-associated and particulate OM. However, manure did not change OM located in the fraction <53 µm confirming that recently deposited OM preferentially accumulates within the aggregate structure and not in the finely or non-aggregated material. Since previous studies have shown that most of the C in cattle manure is composed of coarse particles, we hypothesize that manure-derived OM first enters the soil primarily as particulate material, then, during decomposition, is transformed within the aggregate structure into mineralassociated material thereby contributing to aggregate stabilization.Key words: Cattle manure, mineral fertilization, particulate organic matter, soil structure Aoyama, M., Angers, D. A. et N'Dayegamiye, A. 1999. Influence de l'application de fertilisants mineraux et de fumier sur les formes de matière organique dans les agrégats stable à l'eau. Can. J. Soil Sci. 79: 295-302. L'incorporation de fumier de bovin au sol conduit généralement à l'amélioration de sa structure et de sa teneur en matière organique (MO). Cependant, les effets sur la nature et la localisation de la MO sont moins bien connus. Nous avons étudié les conséquences à long terme (18 années) de l'application de fumier de bovin (20 Mg ha -1 année -1 ) et de fertilisants minéraux sur la distribution de la MO fine et grossière dans les agrégats d'un loam Le Bras (Gleysol humique). Des échantillons de sol ont été prélevés de l'horizon 0-10 cm des parcelles témoin (sans amendement) et des parcelles traitées soit avec des fertilisants minéraux (NPK), du fumier de bovin, ou NPK + fumier....

Protected organic matter in water-stable aggregates as affected by mineral fertilizer and manure applications

“…Thus, manure application led to the preferential accumulation of protected C and N in the macroaggregates. This physical protection could help to explain the preferential accumulation of OM in the small macroaggregates induced by the manure application as observed by Aoyama et al (1999). The effect of NPK fertilization on the amount of macroaggregate-protected N is also noteworthy and suggests that fertilizer-derived N can accumulate in a relatively labile form, which is also physically protected within the macroaggregates.…”

“…Every 5 yr, lime was applied on all plots at about 3 Mg ha -1 , based on soil analysis. Further details of the trial have been reported by N'Dayegamiye (1996) and Aoyama et al (1999).…”

“…Water-stable aggregates were separated by slaking the airdried soil followed by wet sieving (Aoyama et al 1999). Briefly, each air-dried soil sample (100 g) was directly immersed in water without pre-wetting, then fractionated into four aggregate size classes (>1000 µm, 250-1000 µm, 53-250 µm, < 53 µm) by wet sieving.…”

Influence of tillage and liquid swine manure on productivity of a soybean-barley rotation and some properties of a fine sandy loam in Prince Edward Island

“…Soil total C and N were determined for all five depths by dry combustion on soil ground and sieved at 0.5 mm. The POM was determined for all five depths using a modification of the method outlined in Aoyama et al (1999). Briefly, 25 g of air-dry soil (2 mm) was mixed with distilled water (100 mL) and 10 glass beads (5-mm diameter).…”

“…Long-term studies with organic amendments have also demonstrated the benefits to soil physical properties for both soil physical form and stability (Christensen and Johnston 1997;Haynes and Naidu 1998;Blair et al 2006). These benefits, from manure addition in particular, are often attributed to the enhancement of soil organic matter content (Aoyama et al 1999;Assefa et al 2004;Blair et al 2006). The extent and degree of change in soil properties are dependent on rate of manure application and the number of years of application (Miller et al 2002;Hao et al 2003).…”