Impact of different croplands on nutrient index, microbial diversity and
soil quality
Abstract
In the last two decades, the productivity of Rice-wheat cropping system
in the upper Indo-Gangetic Plains of India has stagnated and now in a
declining trend. As a result, farmers shifted to a different cropland
grown systems so as to achieve a higher net productivity. This study aim
to assess as how nutrient index (NI), microbial diversity and soil
quality changed after replacement of rice-wheat by vegetable (VGS),
pulse (PGS), potato (PoGS) and mustard (MGS) grown system. An analysis
of 307 soil samples from various croplands revealed a soil pH range of
6.58-8.87 with 75.3% soils under low category of mineralized N (MN)
resulting in its low NI (<1.67). The highest NI, enzymatic
activity and microbial biodiversity was recorded under PGS, which
restored 34.2, 24.1 and 10.2% greater SOC, carbon substrate oxidation
rate and MN than PoGS, respectively. The diversity indices were the
highest in PGS followed by VGS, but soil quality index was 0.783 (VGS),
0.771(PGS), 0.695 (WGS), 0.663 MGS), and 0.647 (PoGS). The silt content,
SOC, Zn, total N, acid phosphatase activity (ACP), available P and total
culturable fungi were the key soil indicators across the cropland grown
systems. Among the cropland systems, silt content, SOC, total N and ACP
were the main soil indicators for PGS, whereas, silt content, SOC, P and
Zn were the ideal indicators for VGS that affected microbial dynamics
and soil quality. Overall, it is concluded that PGS maintained higher
nutrient index, microbial and functional diversity, but VGS improve
greater soil quality.