Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
N3 (75% RDF as basal and 25% through fertigation) > N1 (25% RDF as basal and 75%
through fertigation). Plots under N2 had 64, 11 and 18% higher DHA, APA and BGA,
respectively than N1. A similar trend with lower values was observed at 15-30 cm depth.
Microbial population viz., bacteria, fungi and actinomycetes was significantly affected by
tillage, residue and nutrient management practices. Population of bacteria was higher
compared to fungi and actinomycetes at both the soil depths though the counts were lower at
(15-30) cm depth as compared to upper (0-15) cm depth. Compared to CT the counts of
bacteria, fungi and actinomycetes were 51, 39 and 73% higher in RT and 41, 38 and 72%
higher in RR as compared to RB, respectively. The treatments having application of >50% of
RDF as basal (N2 and N3) had higher microbial population i.e. 40%, 60% and 70% bacteria,
fungi and actinomycetes, respectively as compared to N1.
Effect of tillage, residue and nutrient management on soil enzymes and microbial
population
Treatments
Tillage (T)
Dehydrogenase
activity
(µg TPF g -1 h -1 )
Alkaline
phosphatase
activity
(µg p-
nitrophenol
g -1 h -1 )
ß-glucosidase
activity
(µg p-
nitrophenol
g -1 h -1 )
Bacteria
(CFU x 10 10
g -1 soil)
Fungi
(CFU x
10 10 g -1
soil)
0-15 15-30 0-15 15-30 0-15 15-30 0-15 15-30 0-15 15-
30
Actinomycetes
(CFU x 10 10 g -1
soil)
0-15 15-30
CT 21.67 b 17.40 b 203.64 b 197.19 b 17.14 b 16.30 b 7.93 b 6.67 b 5.69 b 4.63 b 4.43 b 3.33 b
RT 91.37 a 85.76 a 276.27 a 268.06 a 26.50 a 25.63 a 11.20 a 10.06 a 7.92 a 7.66 a 7.66 a 7.48 a
Residue (R)
RR 43.13 b 38.61 b 227.00 b 219.45 b 20.61 b 19.73 b 7.95 b 6.78 b 5.68 b 4.64 b 4.43 b 3.41 b
RB 78.79 a 73.58 a 263.50 a 255.54 a 24.98 a 24.08 a 11.19 a 10.99 a 7.83 a 7.66 a 7.61 a 7.49 a
Nutrient (N)
N1 41.56 c 36.69 c 226.57 c 218.86 c 20.04 b 19.12 b 7.93 b 6.86 b 5.63 b 4.59 b 4.47 b 3.43 b
N2 73.24 a 68.97 a 257.26 a 249.81 a 24.61 a 23.68 a 11.17 a 10.94 a 7.87 a 7.68 a 7.59 a 7.53 a
N3 68.08 b 62.63 b 251.93 b 243.82 b 23.74 a 22.91 a 11.11 a 10.86 a 7.77 a 7.69 a 7.52 a 7.39 a
Different lower-case letters within same column show significant difference at P=0.05 as per
Duncan Multiple Range test for mean separation
Soil organic carbon content and its pools
Results showed that total SOC was increased by 12 and 17% under RT and residue retention,
respectively as compared CT and RB plots at 0-15 cm soil depths. In surface layer, active and
passive pool carbon (6.98 and 19.45 Mg C ha-1) was 14% and 18% higher in RR plots as
compared to RB, respectively after six years of continuous sugarcane cropping. Again, plots
with residue retention had 63, 34 and 15% higher labile, less labile and non-labile pools,
593 | Page Resource conservation and rainfed agriculture