Crop establishment and diversification strategies for intensification of rice-based cropping systems in rice-fallow areas in Odisha.

Context or problem: In the Indian state of Odisha, rice-based system productivity is poor due to: (i) low rice yield in the monsoon (wet) season (2-4 t ha-1 compared to 6-8 t ha-1 in Punjab or Haryana); and (ii) limited cropping during the post-monsoon (dry) season (59% of the wet season rice area is left fallow in the dry season). Objective: Our study identifies strategies for increasing rice-based system productivity through: (i) alternative crop establishment methods in the wet season (Dry-Direct Seeded Rice or DSR, and mechanical puddled transplanted rice or PTR-M) to traditional methods such as broadcasting followed by post-emergence tillage (locally known as beushening) and manual random puddled transplanted rice (PTR-R); (ii) to identify rice-fallow areas suitable for pulse and oilseed cultivation in the dry season; and (iii) to evaluate the performance of short-duration pulses (green gram, Vigna radiata; black gram, Vigna mungo), and oilseeds (Brassica rapa var. toria, Helianthus annuus) in rice-fallow areas in the dry season. Methods: On-farm experiments were conducted between 2017 and 2019 in three districts of Odisha (Bhadrak, Cuttack and Mayurbhanj) to evaluate DSR compared to beushening and PTR-R; and PTR-M compared to PTR-R and manual line puddled transplanted rice (PTR-L) in the wet season. The data from Landsat-8 Operational Land Imager (OLI) and Sentinel-1satellite sensors was used to identify rice-fallow areas, and the daily SMAP (Soil Moisture Active Passive) L-band soil moisture was used for mapping suitable rice-fallow areas for growing pulses and oilseeds. Short duration crops were evaluated in suitable rice-fallow areas. Results: In the wet season, DSR (range -4 to + 53%) had a significant effect on rice yield over beushening. Similarly, PTR-M consistently increased rice yield by 16-26% over PTR-R, and by 5-23% over PTR-L. In the dry season, pulse crops (green gram and black gram) performed well compared to Indian mustard under rainfed cultivation. However, under irrigated conditions, dry-season rice yield was more productive than the rice equivalent yield of green gram, black gram and sunflower. We found that 1.03 M ha (i.e., ∼50%) of total rice-fallow areas of 2.1 M ha were suitable for growing short duration green gram and black gram in the dry season. Conclusions: We conclude that system productivity and cropping intensity can be increased by adoption of DSR and PTR-M in the wet season, and growing of green gram and black gram in the dry season. Implications: Odisha state can potentially produce an additional 0.67 million tonnes pulses if suitable rice-fallow areas are brought under green gram and black gram cultivation in the dry the season.

Index for refining soil health assessment through multivariate approach under diverse agro-climatic zones in the Indo-Gangetic basin of Bihar.

A fundamental necessity in advancing sustainable crop production lies in the establishment of a reliable technique for assessing soil health. Soil health assessment is a challenge considering multiple interactions among dynamic indicators within various management strategies and agroecological contexts. Hence a study was conducted to determine the soil health variables, quantify the soil health index (SHI), and validate them with the productivity of rice (Oryza sativa L.)-wheat (Triticum aestivum L.) system for the Indo Gangetic basin of Bihar, India, under four contrasting agro-climatic zones (ACZ-I, II, IIIA & IIIB). For this study, 100 soil samples (0-15 cm) from each ACZ with a total of 400 soil samples were obtained for analyzing 20 soil health variables (soil physical, chemical, and biological properties). To identify SHI and important soil health variables, principal component analysis (PCA) was employed. Apart from specific variables, soil pH, soil organic carbon (SOC), available Zn and available water capacity (AWC) were identified as common indicators for the four ACZs. Results revealed that under the rice-wheat cropping system, ACZ-IIIB soils had a higher SHI (0.19-0.70) than other ACZs. SHI of ACZ-IIIB was significantly influenced by SOC (19.32 %), available P (10.52 %), clay (10.43 %), pH (10.80 %), and soil respiration (9.8 %). The strong relationship between SHI and system productivity of the rice-wheat (R2 = 0.79) system indicates that the selected soil health variables are representative of good soil health. It is concluded that ACZ-specific SHIs are a promising strategy for evaluating and monitoring soil health to achieve the United Nations' Sustainable Development Goal of 'zero hunger' by 2030.