Long-term effect of fertilizers and amendments on soil aggregate stability and carbon dynamics in an acid Alfisol
Loading...
Date
2021-10-28
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Palampur
Abstract
The present investigation was carried out in an on-going long-term fertilizer
experiment, initiated during 1972 at experimental farm of Department of Soil Science, CSK
HPKV Palampur, to study the long-term effect of fertilizers and amendments on soil
aggregate stability and carbon dynamics in an acid Alfisol under maize-wheat cropping
system. The experiment consisted of eleven treatments. The soil of the experimental site was
silt loam and classified taxonomically as “Typic Hapludalf” (Subgroup). Soil samples were
collected from surface (0 - 0.15 m) layer after the harvest of wheat (rabi, 2019-20) and were
analyzed for different physical and chemical soil parameters. Long-term use of integrated
nutrient management practices significantly improved the available N, P and K as compared
to control. Effect of long-term application of inorganic fertilizers and amendments on soil
aggregate distribution, aggregate stability and aggregate associated different carbon pools
were studied. Application of inorganic fertilizers along with FYM increased the WSA, MWD
and GMD over control thus, enhanced aggregate stability of soil. MWD and GMD were
higher in FYM amended plots than unfertilized control plots. The addition of FYM enhanced
the macroaggregates (>0.25 mm) as compared to microaggregates (<0.25 mm). Incorporation
of FYM alone or in combination with chemical fertilizers enhanced the accumulation of
different C pools in all aggregate fractions over unfertilized control. Among the
macroaggregates, 1-0.5 mm fraction had the higher TOC, OC, LC and NLC as compared to
microaggregates. 100 per cent NPK + FYM amended plots recorded highest productivity of
wheat. Different aggregate fractions of TOC, OC, LC and NLC were found to be positively
and significantly correlated with available N, P and K and negatively and significantly
correlated with BD whereas, positively and non-significantly correlated with soil pH and EC.
Different aggregate fraction of TOC, OC, LC and NLC were positively and significantly
correlated with grain and straw yield of wheat.