In:
International Agrophysics, Institute of Agrophysics Polish Academy of Sciences, Vol. 28, No. 2 ( 2014-04-1), p. 163-168
Abstract:
The study aims to elucidate the impact of organic inputs on strength and structural stability of aggregates in a sandy loam soil. Tensile strength, friability and water stability of aggregates, and the carbon contents in bulk soil and in large macro ( 〉 2 mm), small macro (0.25-2 mm), micro (0.053-0.25 mm) and silt+clay size ( 〈 0.053) aggregates were evaluated in soils from a long-term experiment with rice-wheat rotation at Modipuram, India, with different sources and amounts of organic C inputs as partial substitution of N fertilizer. Addition of organic substrates significantly improved soil organic C contents, but the type and source of inputs had different impacts. Tensile strength of aggregates decreased and friability increased through organic inputs, with a maximum effect under green gram residue (rice)-farmyard manure (wheat) substitution. Higher macroaggregates in the crop residue- and farmyard manure-treated soils resulted in a higher aggregate mean weight diameter, which also had higher soil organic C contents. The bulk soil organic C had a strong relation with the mean weight diameter of aggregates, but the soil organic C content in all aggregate fractions was not necessarily effective for aggregate stability. The soil organic C content in large macroaggregates (2-8 mm) had a significant positive effect on aggregate stability, although a reverse effect was observed for aggregates 〈 0.25 mm. Partial substitution of nitrogen by organic substrates improved aggregate properties and the soil organic C content in bulk soil and aggregate fractions, although the relative effect varied with the source and amount of the organic inputs.
Type of Medium:
Online Resource
ISSN:
0236-8722
DOI:
10.2478/intag-2014-0004
Language:
Unknown
Publisher:
Institute of Agrophysics Polish Academy of Sciences
Publication Date:
2014
detail.hit.zdb_id:
2235638-1
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