Performance evaluation of high yielding soybean varieties for summer rice fallows

Abstract

The study entitled ‘Performance evaluation of high yielding soybean varieties for summer rice fallows’ was conducted at College of Agriculture, Vellayani during 2021-2023. The objective of the experiment was to assess the performance of high yielding soybean varieties under different land configurations in summer rice fallows. The field experiment was conducted at the Instructional Farm, Vellayani, during February to May 2023 in split plot design with three main plot treatments viz., broadbed and furrow (BBF) (l1), ridge and furrow (RAF) (l2) and flatbed method (l3); and six varieties viz., JS 9305 (v1), KDS 726 (v2), JS 2069 (v3), AISB 50 (v4), JS 335 (v5), Basara (v6) as sub plot treatments replicated four times. In BBF, raised beds were taken at a width of 120 cm with furrows of 15 cm width on both sides; in RAF, the ridges were made at a width of 30 cm with furrows in between and in the flatbed system, the land was levelled without any furrows on sides. Rhizobium inoculated seeds were dibbled at a spacing of 45 cm x 15 cm and the crop was managed as per the KAU Package of Practices. The results of the study revealed that the growth attributes were significantly influenced by land configuration methods and varieties. The BBF method and the variety JS 2069 produced taller plants throughout the growth stages. The highest leaf count was observed in BBF followed by RAF while KDS 726 and JS 2069 consistently produced higher leaf counts at all growth stages. Superior LAI was recorded by BBF up to 45 DAS. However, the values were comparable between l1(3.898, 3.579) and l2 (3.809, 3.434) at 60 DAS and at harvest respectively. The variety JS 2069 exhibited superior LAI (0.534, 1.810, 2.471, 4.284 respectively) at all the growth stages (15, 30, 45 DAS and at harvest) except at 60 DAS followed by KDS 726. The nodule count was higher for the variety AISB 50 (41.88) and was on par with JS 2069 (41.25), KDS 726 (40.52), and Basara (40), while JS 9305 had the lowest nodule count (35.78). Among the land configurations, BBF displayed the highest nodule fresh weight (0.850 g) while AISB 50 produced the highest nodule fresh weight (0.863 g) among the varieties tested. The varieties, AISB 50, JS 335, JS 9305, and Basara flowered early (37.73 to 40.65 days), while JS 2069 took the longest time (48.45 days), followed by KDS 726 (43.08 days). The BBF method yielded the highest pods per plant (53.36) and pod length (4.51 cm) followed by RAF (50.18 and 4.17 cm respectively). Among the varieties, JS 2069 produced the highest pod count (55.95 per plant) while JS 9305, KDS 726 and JS 2069 recorded higher pod length, pod weight and number of seeds per pod respectively. The variety JS 2069 recorded a higher pod yield per plant (31.71 g) and pod yield ha-1 (4932 kg) and was on par with KDS 726 (30.64 g, 4766 kg ha-1 ) and Basara (29.24 g, 4549 kg ha-1). AISB 50 had a lower pod count (42.95 per plant) and was on par with JS 9305 (44.98 per plant). The interaction between land configuration and varieties was found to be significant on pod weight where l3v5 recorded a higher pod weight (0.599 g). The BBF method produced the highest seed yield per plant (20.30 g) and seed yield ha-1 (2706 kg) with higher 100 seed weight (13.22 g), harvest index (HI) (0.404) and dry matter production per plant (DMP) (41.05 g). Among the varieties, JS 2069 recorded the highest seed yield per plant (24.61 g), seed yield ha-1 (3281 kg), HI (0.441) and DMP (48.94 g per plant). The haulm yield per plant and haulm yield ha-1 were found to be higher in KDS 726 (28.11 g, 4372 kg ha-1 respectively). Broad leaf weeds dominated the weed flora composition. The flatbed method had the highest weed density (19.12, 37.72, 40.72 m-2) and weed dry weight (17.74, 38.01, 53.16 g m-2) at all growth stages. Regarding quality parameters, the highest protein and oil contents were recorded for AISB 50 (41.97 %) and JS 9305 (20.10 %) respectively. The BBF method resulted in the highest N, P and K uptake (194.0, 10.55 and 123.41 kg ha-1 respectively), while the flatbed method had the lowest N, P and K uptake (150.33, 8.29, 93.04 kg ha-1 respectively). Among the varieties, JS 2069 recorded the highest N, P and K uptake (234.07, 13.43 and 156.40 kg ha-1 respectively). The BBF method resulted in a higher available N and K status while the highest available P (63.01 kg ha-1) was recorded in the flatbed method. Plants grown under the BBF method recorded a higher net income (₹82,913 ha-1) and B: C ratio (1.70) and were on par with the RAF method (₹74,579 ha-1). Among the varieties, JS 2069 registered the highest net income (₹1,11,171 ha-1) and B: C ratio (2.35). The study identified BBF as the most effective land configuration method and JS 2069 as the most suitable variety for soybean cultivation in summer rice fallows of Kerala based on growth and yield parameters. Considering the economics, either BBF or RAF method could be adopted as a suitable land configuration method for soybean cultivation in summer rice fallows. The variety JS 2069 under BBF could be identified as the most effective combination for realizing higher productivity for soybean cultivation in the summer rice fallows.