Management and Crop Residue Influence Soil Aggregate Stability

Abstract

Soil management is one of the most important factors influencing the structure of soils. The interaction of management (including tillage and crop rotation history) with soil biochemistry, soil aggregation, and soil humus composition was determined in a native prairie and a producer field situation in 1997. A comparison of a native prairie and an adjacent conventional corn (Zea mays L.)-soybean [Glycine max (L.) Merr. 1 rotation on the same soil type found that the Webster soil (fine-loamy, mixed, superactive, mesic Typic Endoaquoll) after soybean (C 3 plant) was lower in monosaccharide content and protein content as determined by ion chromatography, and lower in phenolic acid content than the Webster soil after corn (C 4 plant) or in native prairie as determined by gas chromatography. A wet, nested sieve aggregate stability measurement determined that the prairie soil had a higher mean aggregate size (1.85 mm) when compared with the soil in the presence of decomposing corn (1.0 mm) or soybean (0.34 mm) residues. Mean aggregate size was found to be correlated with soil monosaccharide content (r = 0.75), total soil protein content (r = 0.995***), total soil phenolic acid content (r = 0.997***), and alkaline extractable humic substance content (r = 0.98**). Alkaline extractable humic substances were correlated with the phenolic acid content of the humic substances (r = 0.996***). The results suggest that the decrease in soil stability after soybean growth was due to a decrease in the content of soil humic substances caused by the substantially lower phenolic acids content (humic acid precursors) in the soybean residue.

Effets de boues mixtes de papetières fraîches et compostées sur l’agrégation du sol, l’inclusion et la minéralisation du C dans les macro-agrégats stables à l’eau

“…à l'eau suite aux apports des composts de boues mixtes pourraient donc être reliées aux effets liants des substances humiques (Chaney et Swift 1986;Fortun et al 1989;Piccolo et Mbagwu 1989;Dinel et al 1991;Gu et Doner 1993) qui sont relativement résistantes à la dégradation microbienne. Martens (2000) a observé une diminution du DMP des agré-gats stables à l'eau dans un sol cultivé en soya, attribuant cet effet à une réduction de la teneur du sol en substances humiques. Swift (2001) rapporte que les substances humiques adsorbées sur le complexe argilo-humique sont efficaces dans la stabilisation des agrégats de sol, même en absence de polysaccharides.…”

“…Par contre, des recherches ont démontré que les substances humiques pouvaient augmenter la stabilité des macro-agrégats (Chaney et Swift 1986;Fortun et al 1989;Piccolo et Mbagwu 1999). En effet, certaines études ont mis en évidence une corrélation positive de la proportion des agrégats stables du sol avec la teneur en précurseurs des acides humiques, en l'occurrence les polyphénols des résidus végétaux (Monreal et al 1995) ou la teneur en acides phénoliques du sol (Martens 2000).…”

Application of Compost and Vermicompost as Substitutes for Mineral Fertilizers to Produce Green Beans

“…Compost is an aerobically decomposed organic material derived from plants and animal sources by mesophilic and thermophilic microorganisms (Martens, 2000 andInsam &de Bertoldi, 2007). Vermicompost is product of organic S USTAINABLE agricultural development need to provide alternatives of mineral fertilizers to produce safe food for humans, maintain of soil fertility and preserve of environment from pollution.…”

Effect of Long-Term Double Rice Cultivation with Different Management Practices on C Sequestration and Economics under Hot Semi-Arid Climate in India

“…Crop species play important roles in C sequestration because their residues vary in quantity and quality (e.g. lignin, phenolic content, C/N), which affect their decomposition and turnover rates in soil (Martens 2000). In contrast, numerous reports show that C stock in soils has declined with intensive cultivation using modern inputs (Swarup et al, 2000;Lal, 2004a).…”