Nitrogen dynamics in a soil-sugar cane system

Results of an organic matter management experiment of a sugar cane crop are reported for the first cropping year. Sugar cane was planted in October 1997, and labeled with a 15N fertilizer pulse to study the fate of organic matter in the soil-plant system. A nitrogen balance is presented, partitioning the system in plant components (stalk, tip and straw), soil components (five soil organic matter fractions) and evaluating leaching losses. The 15N label permitted to determine, at the end of the growing season, amounts of nitrogen derived from the fertilizer, present in the above mentioned compartments.

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Bioavailability of soil Cu, Fe, Mn and Zn from soil fractions

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n1p19 ◽

2021 ◽

Vol 42 (1) ◽

pp. 19-42

Author(s):

Renildes Lucio Ferreira Fontes ◽

◽

Gilvan Barbosa Ferreira ◽

Victor Hugo Alvarez V. ◽

Júlio Cesar Lima Neves ◽

...

Keyword(s):

Organic Matter ◽

Sequential Extraction ◽

Growth Cycle ◽

Soil Samples ◽

Growth Cycles ◽

Soil Fractions ◽

Exchangeable Fraction ◽

Soil Components ◽

Organic Matter Fractions ◽

Mn Oxides

Cationic micronutrients bioavailability depends on the chemical characteristics of soil fractions. Fourteen soils received individual doses of five micronutrients (Cu, Fe, Mn, Zn, B) arranged in seven treatments set according a Baconian Matrix. The soils incubated with treatments during 15 days had corn cultivated in greenhouse for 30 days, in three consecutive growth cycles. The cationic micronutrients were determined in the corn shoots after each growth cycle. Soil samples collected before the first and after each growth cycle had the available concentrations of Cu, Fe, Mn and Zn determined by single extractions (Mehlich-1 and DTPA-pH 7.3) and by sequential extraction. Correlation analysis was performed for the Cu, Fe, Mn and Zn concentrations determined in the corn shoots, the available concentrations of Cu, Fe, Mn and Zn in the soils (Mehlich-1 and DTPA) and the concentrations of Cu, Fe, Mn and Zn in the soil fractions (sequential extraction). The distribution of available metals forms in fractions reflected their affinity with soil components. Soil available Cu correlated with Cu bound to organic matter. The exchangeable fraction was the main source of soil available Mn and Zn. The Fe availability related mainly to the Mn oxides, Fe oxides, and exchangeable fractions. The plants absorbed Cu mainly from the Mn-oxides and organic matter fractions. Manganese absorbed by plants originated from the exchangeable and Mn-oxides fractions. The Zn absorbed by plants originated mainly from the exchangeable fraction. Correlations of single metal extractions (Mehlich-1 and DTPA) with Cu, Mn and Zn contents in plants were positive.

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Soil Organic Matter Fractions under Managed Pine Plantations of the Southeastern USA

Soil Science Society of America Journal ◽

10.2136/sssaj2004.0950 ◽

2004 ◽

Vol 68 (3) ◽

pp. 950 ◽

Cited By ~ 12

Author(s):

Marietta E. Echeverría ◽

Daniel Markewitz ◽

Lawrence A. Morris ◽

Ronald L. Hendrick

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Pine Plantations ◽

Southeastern Usa ◽

Soil Organic Matter Fractions ◽

Organic Matter Fractions

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Dating of Prehistoric Burial Mounds by 14C Analysis of Soil Organic Matter Fractions

Radiocarbon ◽

10.1017/s0033822200032434 ◽

2003 ◽

Vol 45 (1) ◽

pp. 101-112 ◽

Cited By ~ 27

Author(s):

Søren M Kristiansen ◽

Kristian Dalsgaard ◽

Mads K Holst ◽

Bent Aaby ◽

Jan Heinemeier

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Soil Science ◽

Ams Dating ◽

Buried Soil ◽

Archaeological Artifacts ◽

Burial Mounds ◽

Organic Matter Fractions ◽

Age Estimates ◽

Organic Remains

Dating of prehistoric anthropogenic earthworks requires either excavation for archaeological artifacts or macroscopic organic matter suitable for 14C analysis. Yet, the former, in many cases, is undesirable and the latter is difficult to obtain. Here we present a soil science procedure, which has the potential to overcome these problems. It includes careful sampling of buried former soil surfaces, acid-alkali-acid fractionation of soil organic matter (SOM), and subsequent 14C AMS dating. To test the procedure, soil from one of the largest known burial mounds in Scandinavia, Hohøj, and 9 other Danish burial mounds were sampled. The 14C dates from extracted SOM fractions were compared to reference ages obtained by other methods. We show that humic acid fractions in 7 of the 10 mounds had the same age as the reference, or were, at maximum, 280 yr older than the reference ages. The best age estimates were derived from an organic-rich layer from the upper cm of buried soil or sod. Differences among SOM fraction ages probably indicate the reliability of the dating. Hohøj dated to approximately 1400 BC and, thus, was up to 500 yr older than other dated Scandinavian mounds of comparable size. The remaining investigated burial mounds were dated to between 1700 and 1250 BC. We conclude that combined sampling of buried soil surfaces, SOM fractionation, and 14C analysis allows for dating of archaeological earthworks when minimal disturbance is required, or if no macroscopic organic remains are found.

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