Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges & Opportunities
during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
treatments in cotton-based intercropping systems. The nutrient management consists of INM
(M1) comprising 75% RDF + compensation through NPS compost, Organic (M2) comprising
100% NPK dose through NPS compost, and cotton-based intercropping systems i.e. Only cotton
(S1), cotton + dhaincha (S2), cotton + sunhemp (S3), cotton + greengram (S4), cotton +
blackgram (S5). The soil is slightly alkaline in reaction (pH 7.76), low in available nitrogen
(195.17 kg N ha -1 ), low in available phosphorus (12.90 kg p ha -1 ), very high in available potash
(368.42 kg K ha -1 ) and has 8.27 mg kg -1 available sulphur and 0.52 mg kg -1 DTPA extractable
zinc.
Results
The significantly higher organic carbon (6.12 g kg -1 ) was observed with the application of 100%
nutrients through nitrophosphosulpho (NPS) compost only as compared to nutrients supplied
through integrated nutrient management (5.80 g kg -1 ) i.e. 75% RDF + 25% compensation
through NPS compost as shown in the table. While, under cotton-based intercropping systems,
cotton + dhaincha (1:1) recorded significantly highest organic carbon (6.43 g kg -1 ) followed by
cotton + sunhemp (1:1) (6.18 g kg -1 ) which was found on par with each other. The lowest
organic carbon (5.47 g kg -1 ) was noticed under sole cotton treatment.
The residual soil fertility status in respect of available nitrogen (235 kg ha -1 ), phosphorus (21.80
kg ha -1 ), potassium (412 kg ha -1 ), and sulphur (12.73 mg kg -1 ) was increased significantly due to
the application of 75 % RDF + 25% compensation through NPS compost as compared to the
application of 100% NPK dose through NPS compost (organic only) under nutrient management.
Under the treatments of cotton-based intercropping systems, the significantly higher value of
available N (242 kg ha -1 ), P (23.70 kg ha -1 ), K (418 kg ha -1 ), and S (13.30 mg kg -1 ) was recorded
in the intercropping of cotton + dhaincha (1:1) which was at par with the intercropping of cotton
+ sunhemp (1:1). The lowest available nitrogen, phosphorus, potassium and sulphur status was
recorded in the treatment of sole cotton only. The nutrient management and cotton-based
intercropping system interaction effect was found to be non-significant.
Under the nutrient management, the significantly higher soil microbial biomass carbon (210.41
mg kg -1 ), dehydrogenase activity (46.01 µg g -1 24 hr -1 ) and CO2 evolution (47.59 mg 100 -1 g soil)
were recorded in the treatment receiving 100% RDF through NPS compost as compared to the
nutrients supplied through 75 % RDF + 25% compensation through NPS compost. The
significantly highest SMBC (217.43 mg kg -1 ), dehydrogenase activity (48.91 µg g -1 24 hr -1 ) and
CO2 evolution (52.27 mg 100 -1 g soil) was observed in the intercropping treatment of cotton +
dhaincha (1:1) followed by intercropping of cotton + sunhemp (1:1) which were on par with each
other. The lowest biological properties were recorded in sole cotton.
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