3.1. Soil characteristics of different sugarcane zones
Sampling adequacy of 131, 198 and 122 soil samples collected from different cane producing zones of Uttar Pradesh were measured using Kaiser-Meyer-Olkin and Bartlett’s test to assess the goodness of its analysis. The KMO value of EZ, CZ and WZ were greater than p>0.50 evinced that the sampling was adequate (Table S1). Moisture content was the most crucial factor, ranged between 11.6 to 29.8% across the cane producing zones of Uttar Pradesh. The highest moisture content was retained in EZ soils followed by WZ and CZ. Value of soil pH varied from 6.12−8.80, being the highest in EZ followed by CZ and WZ, while EC value existed in normal range across the cane growing zones. Although, no definite trends were observed in SOC, Na, Pa, Ka and Sa, but were ranged between 2.0−7.90 g kg-1, 100.3−290.9 kg ha-1, 3.35−45.3 kg ha-1 and 2.48−28.1 mg kg-1, respectively. The highest mean values of Na, Pa and Ka in CZ, while as SOC and Sa were in EZ and WZ soils, respectively. Reversely, EZ soils contained highest values of Zn, Cu, Fe and Mn than CZ and WZ. The lowest value of Zn, Cu, Fe and Mn were recorded in WZ soils (Table 2).
The MBC, MBN and BSR were ranged between 68.4−498.7 µg C g-1, 0.60– 4.17 m g NH3-N kg-1 d-1and 7.06−42.0 mg CO2-Cg-1d-1 across the cane producing zones of Uttar Pradesh (Table 3). MBC, MBN and BSR were recorded maximum in WZ, which was 49.3 and 72.9%, 74.6 and 32.0% and 14.5 and 22.9% more than EZ and CZ soils, respectively. Similarly, the highest mean value of TCB, TCA and AZO were counted in WZ soils, but TCF noted maximum in EZ that was 3.48 and 83.8% greater than CZ and WZ, respectively. Reversely, FDA, β-glucosidase and urease activities were highest in CZ soils, and the lowest in EZ, while DHA was greater in EZ (Table 3). ACP and ALP were highest in WZ followed by CZ and EZ.