SOIL ORGANIC CARBON FRACTIONS, MINERAL N AND HYDRO-PHYSICAL PROPERTIES UNDER DIFFERENT NUTRIENT MANAGEMENT PRACTICES IN PIGEONPEAWHEAT SEQUENCE
KrishiKosh
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Title |
SOIL ORGANIC CARBON FRACTIONS, MINERAL N AND HYDRO-PHYSICAL PROPERTIES UNDER DIFFERENT NUTRIENT MANAGEMENT PRACTICES IN PIGEONPEAWHEAT SEQUENCE
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Creator |
NINTU MANDAL
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Contributor |
B.S. Dwivedi
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Subject |
carbon, crops, fertilizers, organic fertilizers, fractionation, farmyard manure, nutrients, economic resources, organic matter, yields
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Description |
T-8276
Decline in soil organic carbon (SOC), deterioration in physical properties and widespread nutrient deficiencies are considered major threats to the sustainable agriculture. The severity of these problems is greater in intensively-cropped areas of the Indo-Gangetic Plain region. Management strategies like integrated nutrient supply and crop diversification with inclusion of legumes may have potential to restore the soil health. Hence, in the present investigation an attempt has been made to study the effect of different nutrient management practices involving sole or conjoint use of fertilizers and manures on SOC fractions, mineral N and hydro-physical properties in a pigeonpea-wheat sequence, using a field experiment that continued for five years (2004- 05 to 2008-09) on a Typic Haplustept at IARI Research Farm, New Delhi. In addition to fertilizer NPK and two manures i.e. FYM and sulphitation pressmud (SPM), effect of induced defoliation (ID) imposed in pigeonpea by foliar spray of 10% (w/v) urea solution at physiological maturity was also evaluated. Soil samples from surface (0-15 cm) and sub-surface (15-30 cm) layers were collected after completion of five crop cycles, and analysed for different SOC fractions, mineral N and hydro-physical properties. Conjoint use of soil test-based fertilizer NPK and organics increased significantly different SOC fractions, macro-aggregate associated C, and mineral N compared with sole NPK or unfertilized-control, although the extent of increase varied in accordance with the nature of organic inputs. Whereas FYM and SPM used along with NPK brought significant increase in relatively stabilized SOC fractions like Walkley and Black C (WBC) and particulate organic C (POC), the magnitude of increase in microbial biomass C (MBC) and labile C (LBC) was greater under ID. By and large, highest values of different SOC fractions were obtained under NPK+FYM+ID treatment. The proportion of WBC, MBC and LBC towards TOC in 0- 15 cm soil varied from 17 to 22, 1.0 to 1.8 and 6.7 to 11.8 %, respectively. The 65 corresponding figures for 15-30 cm soil depth were relatively lower. The SOC fractions were significantly correlated with each other, particularly in 0-15 cm soil depth, and also with mineral N and wheat yield. Use of organic manures, especially FYM, with fertilizer NPK improved soil aggregation, as evident by a significant increase in macro-aggregates, mean weight diameter, geometric mean diameter and water-stable aggregates, over NPK or control. The treatment effect was generally consistent in sub-surface (15-30 cm) soil also. Compared with NPK, soil bulk density was reduced significantly with the conjoint use of organics and NPK. The bulk density was lowest under NPK+FYM+ID. The hydrophysical properties showed a positive and significant relationship with crop yields, except bulk density (0-15 cm) which had negative relationship with yield. |
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Date |
2016-10-13T12:02:47Z
2016-10-13T12:02:47Z 2010 |
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Type |
Thesis
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Identifier |
http://krishikosh.egranth.ac.in/handle/1/80482
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Format |
application/pdf
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Publisher |
IARI, DIVISION OF SOIL SCIENCE AND AGRICULTURAL CHEMISTRY
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