Integration of fish culture and poultry rearing in transplanted rice for nutritional security in smallholder farms

Agriculture provides livelihood for 65% of Nepal’s population contributing for 27% of its GDP. Smallholder farms constitute 60% of farming segment. Distress farming, with inadequate minimum support price, subsidies and inadequate revenue generation force 29% of the general population to be malnourished. Farming system designs with integration of animal components would augment animal protein intake of these resource-poor populations, livelihood enhancement and sustainability of production system. On-farm field experiments in 75 participating farmers fields of Nepal with integration of fish culture and poultry rearing in transplanted rice showed appreciable (a significant) increase in nutritional status and livelihoods of participating farmers.

www.nature.com/scientificreports/ status, increased economic return and reduced agrochemical input 14 . Integrating allied components with cropping system helped in effective water budgeting and better economic returns in lowland farming 15 .
Results of the studies at annamalai university, department of Agronomy with statistically laid out field experiments on Integrated Rice + Fish + Poultry Farming System comprising individual treatment plots of size 40 square meter, each with a fish trench of 1 m depth and 0.5 m width, running along the boundary of one side and a poultry cage installed at the center of each plot accommodating 4 broiler birds with wire mesh as the bottom and sides of the cages, showed that the system resulted in an increase in net income of Rs. 2,04,297 (US$ 2,701) over monocropping of rice and a cost-benefit ratio of 1:2.40 16 . This system was upscaled for adoption by farmers in four districts of the state of Tamilnadu in India and was named as Annamalai Rice + Fish + Poultry Farming System. Animal components integrated with the farming system viz., poultry and fish also enhanced the fertility level of lowland rice soil that was revealed by increased Post-harvest soil available Nitrogen, Phosphorus and Potassium 17 . This increase in soil fertility status was made possible by gradual addition of 17.7 t/ha of poultry manure, spread throughout the cropping period 18 . Integrating fish culture in rice also favoured management of weeds contributing for 20% of weed control 19,20 . Complementary weed control from rice + fish + poultry farming 21 and reduced pest incidence 18,22 have also been reported.
In Annamalai integrated farming system fish trenches running alongside any one of the border of rice fields of dimension 20 × 10 m accommodated fish polyculture comprising a stocking density of 5,000 fingerlings/ha of equal proportions of Catla, Roghu, Mrigal, Common carp and Grass carp. These fish trenches occupied 7.5% of the rice area (15 square meter), with a depth of 1 m, top width of 0.75 m and bottom width of 0.5 m. Broiler rearing is integrated in these rice fields @1 bird for every 10 square meter of rice area, using a poultry cage of floor size 1.8 × 1.2 m and 0.9 m height that accommodated 20 birds. These cages were randomly installed in the rice fields using concrete posts 2.4 m tall, 1.2 m interred inside the field, lifting the cages 1.2 m above. The broiler waste was reaching the rice field through the wire mesh bottom of the cages, and got dissolved, in the water retained in the field to a height of 5 cm, there by serving as a rice manure and feed for fish. Irrigation water that enters the field through one end and while reaching the other end with the flow served the purpose of spreading the poultry waste in the field. This design elided the laborious task of collecting the poultry waste for application to rice fields that stand apart in other conventional farming system designs, besides the purview of some wastage 17,18 .

Materials and methods
The Annamalai Rice + Fish + Poultry farming system was implemented (Table 1)  The participating 75 farmers were selected by adopting simple random sampling method.
Technological intervention/novelty. The Annamalai Rice + Fish + Poultry system differs from the conventional integrated farming system. This Annamalai model is different from conventional Rice + Fish + Poultry system demonstrated generally until now by other Agricultural Universities and Research Institutes. The conventional models have fish ponds excavated exclusively over 400 m 2 area in one acre of rice field (4,000 m 2 ). A poultry cage is installed in the fish pond and these two viz., poultry and fish components confine themselves to 400 m 2 , without directly supplementing the remaining 3,600 m 2 of rice. Further, mostly layer birds are used in the poultry component. The bird's waste that adds valuable organic manure has to be collected at the end of every farming season for application to rice. Inorganic agro inputs like pesticides and fertilizers are frequently used for rice, as rice has no direct integration with fish.
But in Annamalai Rice + Fish + Poultry model: The poultry cages are installed in the rice fields straightaway, with the help of four concrete posts 2.4 m high, 1.2 m buried inside and 1.2 m protruding above, that lifts the cage above the crop canopy. The cage bottom is of wire mesh which leaves the poultry waste to reach the rice fields directly, wherein they get dissolved in standing water and serve both as crop manure as well as fish feed.
The fish trenches that accommodate the fishes, as a permanent shelter are 1 m deep and possesses a width of 1 m at the top and 0.75 m at the bottom and they run along the side of the rice field, occupying 7.5% of the rice  The impact assessment questionnaire was prepared and the details were obtained from 75 farmers including men and women, before intervention as a baseline survey and again after intervention as final impact assessment survey.
The baseline survey and final impact assessment included annual household income in nepalese rupees (1 US$ = 121.29 NPR), house hold food intake per month with particular reference to poultry meat, fish meat, and vegetables along with farmer's blood biochemical parameters such as haemoglobin count, serum albumin, folic acid and calcium, of the individual farmers adopting the technology. The blood biochemical parameters were analyzed in nationally accredited clinical laboratories, as instructed by the sponsors of the project.
The salient observations on household diet consumption particularly poultry meat, fish meat and vegetables intake per month, blood biochemical parameters such as haemoglobin, serum albumin, folic acid and calcium levels of farmers participating were subjected to paired t-test analysis using SPSS software. The number of pairs (N) was 75.
Ethical approval. All these methods were carried out in accordance with relevant guidelines and regulations. The Experimental protocols were approved by Commercial Agriculture Alliance Human and experimental ethical committee of Nepal (No. CAA/HEC/NEPAL/03 dt. 03/10/2017). Data collection was taken up by Commercial Agriculture Alliance of Nepal after obtaining written informed consent from all subjects (Men and women, the participating farmers).

Results and discussion
Annual household income. Observation regarding annual household income is furnished in Table 2. The annual household income of the participating farming household were nepalese rupees 64,160 before the start of the intervention and the same rose to NPR 1,26,560, with the difference of NPR 62,400 that accounted to livelihood enhancement of 97%, almost double that of the baseline value. This increase is due to the revenue generated from the sale of broiler meat (180 kg of broiler meat produced from 200 m 2 of holding), fish meat (15 kg from 200 m 2 of holding) and increased rice grain yield (from the farm holdings of the participating farmers of 78 kg/2000 m 2 of rice field), coupled with displaced agrochemical cost.
Poultry meat intake. The pattern of household poultry meat intake per month observed is presented in Fig. 1. The intake pattern of farming households, participating through adoption of integrated farming system were 1.5 kg of poultry meat/month, during baseline survey i.e. before intervention. The poultry meat intake of participating households rose to 4.11 kg per month after the intervention (completion of broiler chicken rearing in the cages installed in their rice fields), with an increase by 2.74-folds. The increase in consumption of poultry meat by participating households are statistically significant as revealed by the paired t-test analysis. This is due to availability of 180 kg of poultry meat per household produced from their own fields, adopting integrated Rice + Fish + Poultry farming system. Besides, selling the major portion of meat that resulted in enhanced www.nature.com/scientificreports/ revenue generation, the farming households also were consuming some of this meat available from their own holding.
Fish meat intake. The pattern of fish meat intake by the participating farming households is given in Fig. 1.
The rate of fish meat intake per household per month was 2.17 kg before adoption of the technology and this increased to 3.52 kg with the farming households participating in technology adoption, with a 62% increase. The www.nature.com/scientificreports/ increase in consumption of fish meat by participating households are statistically significant as revealed by the paired t-test analysis.This is due to the production of fish meat from every participating farmers holding, besides the enhanced income generation from the innovative farming system adopted, that imparted better purchasing potential.
Vegetable intake. The trend of vegetable consumption as furnished in Fig. 2 also showed an increase in household consumption of vegetables per month, which is attributed to the enhanced household income that paves way for potential to buy more vegetables by the farmers adopting the technology. The increase in consumption of vegetables by participating households is statistically significant as revealed by the paired t-test analysis.
The results vividly reveal that there exists a significant difference in the consumption of poultry meat, fish meat and vegetables by those households adopting integrated farming system, between the after and before intervention scenarios. The mean values were significant at level, p = 0.01.
Blood Biochemical Parameters. The observations regarding the blood biochemical parameters viz, haemoglobin, serum albumin, folic acid and calcium levels are presented in Table 3.
It could be understood from the results that there exists a significant difference between the post and pre intervention scenarios interms of the level of blood biochemical parameters viz., haemoglobin, folic acid, serum albumin and calcium of the blood samples collected from farmers adopting integrated farming systems. The respective mean value of all the four clinical parameters were significant at level p = 0.01. The mean values of the levels of haemoglobin, folic acid, serum albumin and calcium in the Post-intervention scenarios were higher by 1.41 g/dl, 0.87 ng/ml, 0.425 g/dl and 0.375 mg/dl, respectively than the pre intervention scenario (Table 3). This significant difference is attributable to the increased poultry meat intake, fish meat intake and vegetables intake of the participating farmers in these villages, that was triggered by diversified farm production and enhanced income generation made possible by the adoption of integrated rice + fish + poultry farming system, replacing monocropping of rice.

Conclusion
The study reveals the potential of Annamalai integrated Rice + Fish + Poultry farming system designed and implemented, in enhancing the nutritional status of resource-poor rice farmers of Nepal. This integrated Rice + Fish + Poultry farming system holds scope for upscaling in similar agroceologies of all Asian countries, predominated by smallholder rice farms towards ensuring nutritional security. www.nature.com/scientificreports/