Chickpea (Cicer arietinum L.) is one of the major Rabi pulse crops grown predominantly in northern India. India ranks first in pulse production (27.70 mt) with an area of 3.10 m ha and productivity of 892 kg/ha (DES, 2021). India is the largest producer and consumer of chickpea in the world with an area, production and productivity of 10.17 m ha, 11.35 mt and 11.16 q/ha, respectively (DES, 2021), however, in  Bihar, chickpea is grown in an area of 0.051 m ha with total production of 0.054 m tonnes and productivity of 10.53 q/ha (DES, 2022) with the highest production share of 45.53 per cent  in country followed by pigeon pea (17.06 per cent), urdbean (13.40 per cent), mungbean (7.76 per cent), lentil (5 per cent) and field pea (5 per cent). Chickpea is a rich source of protein (24%), carbohydrates (59.6) and minerals (3.2%) and  plays an important role in vegetarian human diet  as well as its straw  as animal feed (Singh et al., 2015), which improve animals health and milk production. The per-capita availability of pulses had decreased gradually from 80 g to 42 g per capita/day (WHO) due to the higher growth rate of the population and low growth rate of production and productivity of pulses. Besides, the traditional methods of cultivation like use of old varieties with poor quality seed, no use of external inputs (fertilizer, weedicide and pesticide), broadcasting sowing with higher seed rate and biotic/abiotic stresses could be the major reasons for low productivity, that emphases the need to create awareness among the farming community to popularize the location specific improved varieties, improved technologies and package of practices  to increase the production and productivity of pulse crops.
       
In recent years, the production and productivity of chickpea has increased due to inclusion of high yielding varieties, seed treatment, line sowing, integrated pest and weed management have potential to improve productivity of chickpea (Dhillon et al., 2021). The productivity was further increased by adopting better crop management practices (Kumar, 2014). This indicates that the low yield of chickpea in farmers’ fields is mainly due to large gaps between farmers’ practices recommended improved technology. The technological gaps may be in soil fertility status and weather condition. For minimizing these gaps, the Indian Council of Agricultural Research (ICAR), New Delhi introduced cluster frontline demonstrations (CFLDs) in the year 2015 under National Food Security Mission for promotion of pulses. The main objective of CFLDs programme is to demonstrate the latest crop production and protection technologies at farmers’ field under close supervision of KVKs scientists to minimize the adoption gap. Keeping these problems under consideration, a study was conducted to improve the productivity of the chickpea by determining the yield gaps, technological gap, extension gap, technology index, technology adoption and horizontal spread at farmer’s fields in participatory mode in different selected villages of Bhagalpur district.

The investigation entitled ‘Studies on intervention of improved technology for reducing yield gap and improving productivity of chickpea in Eastern-Gangetic Plains of India’ a cluster front line demonstrations (CFLDs) was conducted by Krishi Vigyan Kendra Sabour, Bhagalpur during Rabi season from 2016-17 to 2022-2023 (7 consecutive years) in 26 villages of 8 blocks viz., Goradih, Kahalgaon, Nathnagar, Pirpainti, Sabour, Sanhaula, Shahkund and Sultanganj under Bhagalpur district that are categorized under South-Western Alluvial plain zone (zone IIIB) as per the agro climatic Zones of Bihar (Table 1). Before conducting CFLDs, a group meeting and specific training was organized at village wise and only interested farmers were purposely selected for cluster front line demonstrations. Large, medium and small holding size farmers were included in the study. Co-operative farmers group were identified based on their participation and feedback received during the preliminary survey and interactive meeting for data and opinion collections related to demonstration of improved technology. The total sum of 325 CFLD in 130 ha area under both irrigated and rainfed farming situation by the active participation of 390 farmers were conducted during seven years with involvements of improved and existing farmers’ practices. Almost the soil of the CFLDs sites was silty loam to clay loam in texture, with an average of soil pH 7.23, EC 0.28dS/m, organic carbon 0.41%, available N 168.7 kg/ha, P2O5 21.36 kg/ha and K2O 218.53 kg/ha. The meteorological data on rainfall and temperature (Min, Max) is presented in Fig 1. The major gaps between improved technologies and farmers’ practices of chickpea for low yield were identified through PRA/ preliminary discussion with selected farmers and prioritized as give in Table 2.






       
CFLDs was conducted on the basis of identified causes for low yield in integrated crop management manner as suggested by Choudhary (1999) and Venkattakumar et al. (2010). In control plots the existing farmer’s practices were followed. The significant technological critical inputs like seed of improved varieties (GNG-1581, PG-186, GCP-105 and RVG 202), Trichoderma viride, Chloropyriphos, Rhizobium and PSB culture for seed treatment, sex pheromone trap for control of r pod borer were given to selected farmers from the Krishi Vigyan Kendra, Bhagalpur under CFLDs  and remaining technological critical inputs were arranged themselves by the farmers. The details of CFLDs are given in Table 3.


       
All the technological interventions were taken as per prescribed package and practices for improved variety of chickpea. Before conducting CFLDs, specific skill trainings were organized with involving the selected farmers and local extension functionaries in their villages/KVK center regarding various aspects of improved technologies of chickpea production. In case of farmers practice(control plot), the traditional practices were followed by using existing varieties (known as desila in local name) with high seed rate (125-140 kg/ha), without Rhizobium inoculation, imbalanced use of fertilizer, no proper management of weed,  pod borer (Helicoverpa armigera) and wilt. Subsequently demonstrated crops were visited during different crop growth stages by the KVK scientists to ensure proper guidance to the farmers. Different group meeting, field visit and training programme were organised at various stages of crop to aware non-beneficiaries and beneficiaries farmers and extension personnel to witness the benefits of demonstrated technology. Finally field day was organised at demonstrated plot with involving selected farmers, other farmers of the villages and local extension functionaries to show the superiority of the technology and disseminate to message in large scale. The crops were harvested in third week of March to first week of April after maturity.
       
The yield data were collected from both the demonstration and existing farmers practice (control plot) by random crop cutting method and analyzed by using simple statistical tools. For the study, technology gap, extension gap and technology index were calculated as suggested by Samui et al. (2000) and Kumar (2014) as per formula given below:

Extension gap (q/ha) = Demonstrated yield - Farmers yield

Technology gap (q/ha) = Potential yield - Demonstrated yield

Extension gap (q/ha) = Demonstrated yield - Farmers yield



Net return (Rs./ha) =  Gross Return (Rs./ha)  - Cost of cultivation (Rs./ha)



Additional cost (Rs/ha) = Improved technology cost - Farmer practice cost

Additional return (Rs/ha) = Improved technology return - Farmers’ Practice return

Effective gains (Rs/ha) = Additional return - Additional cost

Productivity of chickpea
 
Results of 325 demonstrations of CFLDs observed in 130 ha area conducted during Rabi season from 2016-17 to 2022-2023 (7 consecutive years) in 26 villages of 8 blocks viz., Goradih, Kahalgaon, Nathnagar, Pirpainti, Sabour, Sanhaula, Shahkund and Sultanganj under Bhagalpur district (Table 4) revealed that the average yield of chickpea under improved technology of CFLDs range from 10.75 to 15.71 q/ha as compared to 9.14 to 11.32 q/ha in existing farmers’ practices (control plot). Average yield of 325 demonstrations of seven years was 13.87 q/ha from improved technology whereas; the average yield from existing farmers’ practices was 10.15 q/ha. It was also observed that the improved technology (CFLDs) increased yield from 17.61 to 53.7% (with an average of 36.53%) over farmers’ practice. It might be due to the adoption of improved high yielding varieties, seed treatment, proper weed management practices, recommended dose of fertilizers, insect pest and disease management and other agronomical practices as compared to control (existing farmers practice). The results clearly indicate the positive effects of CFLDs over the existing farmer’s practices toward enhancing the yield of chickpea. The result is also in close conformity with the findings of Mauriya et al., (2017), Singh et al., (2020) and Dhillon et al. (2021).


 
District, state and potential yield gap minimized analysis
 
It is the extent to which the yield gap at different level, i.e. district, state and potential yield levels were compensated because of the yield advantages obtained from the demonstrations of improved technology. On the basis of seven years data from 2016-17 to 2022-23 it was observed that the district yield gap was minimized from 18.85 to 59.39% with an average of 39.77%, whereas, it was from 17.36 to 32.09 with an average of 23.74% under state yield gap and from 23.00 to 46.25% with the mean of 33.82 % in potential yield gap minimization. It might be mainly due to the timely sowing of improved varieties in residual moisture with recommended seed rate, Seed treatment with Trichoderma viride, chloropyriphos and bio-fertilizers (Rhizobium and PSB cultures), balance dose of fertilizer application, timely weed management and suitable plant protection measures. The results indicated that the cluster front line demonstrations have given a good impact over the farming community of Bhagalpur district as they were motivated by the new agricultural technologies applied in the cluster front line demonstration plots. The minimized potential gap  is an indicative for adoption of  need  and situation based specific adaptive trials along with updating the scientific knowledge of production technologies among the farmers.  The similar results have also been reported by Dubey et al. (2018), Mauriya et al. (2019) and Singh et al. (2020).
 
Technology and extension gaps
               
The data presented in Table 4  reveal that the technological yield  gap for the seven years ranged from 4.60 to 9.26 kg/ha with an average of 7.13 kg/ha. The technological yield gap observed may probably be due to variation  in the soil fertility status, agronomical practices, managerial skills of individual farmer’s and the  climatic situation of the area. Since the difference between potential and demonstration yield is the technology gap, therefore, the site specific recommendations are necessary to bridge these gaps. The findings are in line with that reported by Srivastava et al., (2017).
       
The difference between demonstration yield and the existing farmers practice yield is known as extension gap. The perusal of seven years mean data indicated that the extension gap from the technological interventions through CFLD was found to be 3.72 q/ha and range from 1.61 to 5.29 q/ha (Table 4).  There is a need to motivate, aware and trained the farmers for adoption of improved technology of crop production with high yielding varieties through extension activities to narrow down the extension gap. An intensive use of the latest production technologies with high yielding varieties will subsequently change this alarming trend of galloping extension gap. These results corroborate with the results of Arunkumar et al., (2023) in groundnut.
 
Technology Index
 
The technology index generally shows the feasibility of the technology at farmers’ field. The lower value of index indicates the higher feasibility of technology. The data of Table 4 revealed that the technology index for the seven years (2016-17 to 2022-23) ranged from 23.00 to 46.25%, with an average of 33.82%. The similar finding was observed by Reager et al., (2020) in green gram.
 
Economic analysis
 
The major economic indicators viz. total cost of cultivation, gross return, net return and B:C ratio were calculated  based on prevailing market price of inputs and outputs for both the CFLD (improved technology ) and existing farmers practice during  2016-17 to 2022-23 (Table 5). On the basis of seven years average data, higher gross return (Rs. 75525/ha), net return (Rs. 48993 /ha), benefit cost ratio (2.85) and effective gain (Rs. 17376 /ha) with improved technologies demonstration in CFLDs as compared to existing farmer’s practices. The percentage increase in net return over existing farmer practice (control plot) was the highest (88.80%) in 2017-18 under chickpea variety GNG 1581. Whereas, average net return of seven years under improved technologies demonstration was 54.95% higher than existing farmer’s practices. This finding is in corroboration with the findings of Raj et al., (2013), Kumar and Mauriya (2014) and Dubey et al. (2018).

Based on seven years study, it can be concluded that the imparting group discussion, training, campaigns, field days and conducting cluster front line demonstrations on integrated crop management approaches with an improved varieties in chick pea are more effective in reducing the yield gap and increasing the production, productivity and profitability of the farmers. Further it suggests the active involvement of various agriculture line department and local extension functionaries of agriculture extension systems for adoption of the improved technologies.

All authors declare that they have no conflict of interest.