In:
Journal of Plant Nutrition and Soil Science, Wiley, Vol. 179, No. 1 ( 2016-02), p. 94-103
Abstract:
Soil test indicators are needed to predict the contribution of soil organic N to crop N requirements. Labile organic matter (OM) fractions containing C and N are readily metabolized by soil microorganisms, which leads to N mineralization and contributes to the soil N supply to crops. The objective of this study was to identify labile OM fractions that could be indicators of the soil N supply by evaluating the relationship between the soil N supply, the C and N concentrations, and C/N ratios of water extractable OM, hot‐water extractable OM, particulate OM, microbial biomass, and salt extractable OM. Labile OM fractions were measured before planting spring wheat ( Triticum aestivum L.) in fertilized soils and the soil N supply was determined from the wheat N uptake and soil mineral N concentration after 6 weeks. Prior to the study, fertilized sandy loam and silty clay soils received three annual applications of 90 kg available N (ha · y) −1 from mineral fertilizer, liquid dairy cattle manure, liquid swine manure or solid poultry litter, and there was a zero‐N control. Water extractable organic N was the only labile OM fraction to be affected by fertilization in both soil types ( P 〈 0.01). Across both test soils, the soil N supply was significantly correlated with the particulate OM N ( r = 0.87, P 〈 0.001), the particulate OM C ( r = 0.83, P 〈 0.001), and hot‐water extractable organic N ( r = 0.81, P 〈 0.001). We conclude that pre‐planting concentrations of particulate OM and hot‐water extractable organic N could be early season indicators of the soil N supply in fertilized soils of the Saint Lawrence River Lowlands in Quebec, Canada. The suitability of these pre‐planting indicators to predict the soil N supply under field conditions and in fertilized soils from other regions remains to be determined.
Type of Medium:
Online Resource
ISSN:
1436-8730
,
1522-2624
DOI:
10.1002/jpln.201400532
Language:
English
Publisher:
Wiley
Publication Date:
2016
detail.hit.zdb_id:
1481142-X
detail.hit.zdb_id:
1470765-2
detail.hit.zdb_id:
200063-5
SSG:
12
SSG:
13
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