The experiments were conducted on the irrigated upland of Tamil Nadu Agricultural University, Coimbatore, from 2017 to 2022. The experimental site was located at 10°12′ and 11°24′ N latitude and between 76°39′ and 77°30′ E longitude of 426.7 m above MSL. The experimental site has a tropical wet and dry climate. During the study, the mean maximum and minimum temperatures were 32.0°C and 22.8°C, respectively. Similarly, the mean morning and evening relative humidity were 84.6% and 54.1%, respectively. A total rainfall of 3,778.9 mm was recorded with 272 rainy days (Figures 1A, B). A mean sunshine hour of 6.5 and a mean evaporation of 5.9 mm were also registered during the cropping period.

The soil of the experimental field was clay loam in texture, with the underlying Periyanaikenpalayam soil series having a bulk density (mg m⁻²) of 1.24. The soil was alkaline (8.49), medium in organic carbon (0.60), medium in available N (250 kg/ha), medium in P₂O₅ (21.9 kg/ha), and high in K₂O (624 kg/ha).

The IFS model was established during 2017–2018 in a 1.0 ha area. Six components were included, viz., crop (0.85 ha) + horticulture (0.10 ha) + 2 cattles along with 2 calves in dairy (50 m²) + 12 female goats and one male goat (50 m²) + 150 numbers of poultry birds (50 m²) + kitchen garden (200 m²) + boundary planting + vermicompost (50 m²) + value addition. In addition to this, a 100 m² area was allotted for supporting activities (100 m²) (Table 1). A benchmark survey of 150 farmers from three districts (Erode, Salem, and Coimbatore) in the western zone of Tamil Nadu has been taken as the data for conventional farming systems.

The ever-increasing demand for food grain production requires crop diversification, which is essential to increasing productivity, profitability, and sustainability. In this study, a higher maize equivalent yield of 1.86 t in a 1,500 m² area was obtained from prosomillet-chillies-dhaincha (Tables 3, 4). This might be due to the rooting systems of the crops; the shallow and fibrous root systems of the prosomillet and deep root systems of the chillies enable for better uptake of nutrients from the top and bottom layers of the soil in their consecutive seasons of cropping. Prosomillet is included in the cropping system for its nutritional content and significance. At present, millet is considered an important source of energy and protein for African and Asian countries (Amadou et al., 2013), and considering its nutritional superiority and climate-resilient features of prosomillet, it can be a better climate-smart alternative to the predominant cereals (Rajasekaran et al., 2023).

Similarly, vegetable-based cropping systems like prosomillet-chillies-dhaincha will provide year-round production with additional revenue, thereby guaranteeing nutritional security (Arti et al., 2019). This result was followed by maize-sunflower-dhaincha (1.85 t.). Integration of maize-sunflower cropping in the IFS system plays a pivotal role in animal nutrition. The maize grain and sunflower oil cake produced from the cropping system can be utilized as concentrate feed for livestock and feed for poultry, thus reducing the overall cost of production via better recycling. Experiments conducted in southern Africa revealed that maize-sunflower rotation produced significantly higher yields (Thierfelder et al., 2013). Furthermore, Shanmugam and Ramamoorthy (2014) in their study concluded that the maize-sunflower cropping system in a sericulture-based integrated farming system increased the productivity of maize as well as that of sunflowers with enhanced net return and B:C ratio. Similarly, crop rotation with dhaincha significantly improved the yield. This can be attributed to the efficient and adequate nutrients supply from dhaincha biomass decomposition and the released nutrients for the crop (Sarwar et al., 2017).

The overall crop productivity of 10.78 t. recorded in 8,500 m². Similarly, Meena et al. (2022) revealed that crop diversification with multiple crops like sugarcane-ratoon and sugarcane-wheat registered a higher sugarcane equivalent yield of 26.83 t./year. Further conventional farming systems, or monocropping, resulted in lower productivity and economic returns. Monocropping with rice is less economical when compared with a diversified cropping system. This is mainly due to the fact that the cultivation of a larger number of crops on the same piece of land has a synergistic impact on each other and compensates for nutrients requirements with minimal environmental risk (Mahapatra and Behera, 2011). Based on the economics of the cropping component, the highest net return of/28,149/ha was recorded with prosomillet-chillies-dhaincha with a B:C ratio of 2.19; however, pearlmillet-cotton-dhaincha recorded a higher B:C ratio of 2.25 with a net return of/21,842/ha. In the fodder system, Bajra Napier hybrid grass, Desmanthus, and Cenchrus recorded a net return of/36,185/ha with a B:C ratio of 1.87.

The productivity of the various components in the integrated farming system was converted into maize equivalent yield (Table 5). Among the different enterprises, crop components alone recorded a higher maize equivalent yield (10.78 t./ha), followed by dairy (7.17 t./ha), goat (5.02 t./ha), vermicompost (4.14 t./ha), poultry (2.39 t./ha), boundary planting (1.18 t./ha), horticulture (1.05 t./ha), and kitchen garden (0.72 t./ha). Higher productivity was due to residue recycling, increased nutrient addition from vermicompost, and the incorporation of green manure in the summer, which improved soil fertility and subsequently increased crop productivity. A higher total rice equivalent yield of 20.83 t. was recorded due to the application of organic manures, viz., farmyard manure, vermicompost, and azolla by recycling, which might have contributed to better crop productivity in IFS (Porpavai and Marimuthu, 2018). The total productivity of the developed IFS was 162.31 t./ha, which was higher when compared with the conventional farming system (crop+horticulture+livestock) (98.27 t./ha). This result is in agreement with the findings of Goverdhan et al. (2020), who opined that integration of crop+horticulture+dairy+goat+vermicompost+backyard poultry fowl recorded higher productivity (26.58 t. of total maize equivalent yield), which was higher than conventional farming systems.

Gross return, net return, production cost, and B:C ratio were worked out as individual components in the IFS model. A total gross return of ₹689,773/- and a net return of ₹317,765/- were recorded with the IFS model. The integrated farming system, which includes crops, livestock, poultry, and fisheries, provided a net return of ₹189,069/ha/year as opposed to ₹74,552/ha/year in conventional cotton, which was 2.5 times less than the IFS system (Vinodakumar et al., 2017; Paramesh et al., 2022). This might be due to the inclusion of livestock in the system, which produced higher returns for the farmer.

Among the different components, cropping recorded a higher net return of ₹106,098/- (33.39%) (Table 6). This was followed by a goat, which recorded a net return of ₹73,479/- (23.12%), and the cost of production was lower when compared with the dairy unit. Dairy recorded a net return of ₹30,240/-. This was mainly due to reduced production costs. Expenditure was reduced in the farming system mainly due to the reduction of fodder costs since fodder was grown on the farm itself and fed to animals and birds. Besides, vermicompost produced from the waste was well utilized for the production of fodder. Maintaining goats as an allied enterprise generated year-round income for the farmers with less investment. The goat component contributed to 33.1% of the total gross income. Next to goat, vermicompost production recorded a net return of ₹39,916/-, which contributed about 12.56%. For effective utilization of resources, the animal waste from dairy and goat units, along with the unutilized feed and crop residues/and by-products was used for the production of vermicompost. This provided an excellent opportunity for organic recycling and reduced farmers' dependency on externally purchased inputs.

The IFS models with coconut + goat + cow + turkey + azolla + vermicompost recorded a higher gross return, net return, and B:C ratio compared to conventional cultivation (Thavaprakaash and Premavathi, 2019). Similarly, in the crop + dairy + poultry + vermicompost + azolla IFS model with a net return of ₹10,525/-, the dairy unit contributed a higher net income of 9.52% due to the supply of balanced nutrition by green and dry fodder produced in the system (Shankar et al., 2017). The dairy component produced a considerably higher net return of ₹79,476/- in the IFS model with crop + dairy + poultry + fishery (Singh et al., 2007). Kumara et al. (2017) and Vinodakumar and Desai (2017) reported that the IFS model in a 1-ha area with crop + horticulture + dairy (one buffalo + two HF cows) + sheep (10 + 1) + vermicompost + azolla produced a higher net return from crops (₹80,795/-), followed by horticulture (₹38,526/-), dairy (₹47,278/-), and sheep unit (₹17,876/-).

The poultry component also recorded a considerable net return of ₹22,998/-, with a share of 7.24%. This was mainly due to reduced production costs from reduced purchases of feed from outside markets. The grains such as maize, cumbu, and prosomillet obtained from the farming system are used as feed for poultry. This will create interest among the farmers in rearing poultry as a component of the IFS model. The meat and eggs obtained from the poultry unit generate additional income for the farmers. Similarly, Kumar et al. (2017) reported that the integration of crops with poultry, goats, and mushrooms was more suitable for achieving better income for the farmers.

Boundary planting, horticulture, and the kitchen garden generated a net return of ₹19,923/-, 15,506/-, and 9,605/-, respectively. Integrating horticulture, the kitchen garden, and boundary planting are the sources for increasing family income and the nutritive values of foods and fodder.

The conventional farming system with crop + horticulture + livestock in 1-ha area of the farm recorded a lower gross return (₹266,236/-), a lower net return (₹102,005/-), and a lower B:C ratio (1.62). Lower economic returns in the conventional farming system are mainly due to minimum component integration. Dey et al. (2010) and Sachinkumar et al. (2012) have reported similar findings.

On employment generation, cropping activity in the IFS model generates 175 mandays of employment, and multi-enterprise included in the farming system generates 300 mandays of employment with even distribution over the course of the year (Figure 2). Total employment generation from the IFS model was 475 mandays, which was higher when compared with the conventional farming system (232 mandays). This was primarily due to the diversified nature of the numerous activities related to various allied enterprises included in integrated farming systems, which offer a lot of employment opportunities, keep farmers and their families engaged for a longer period of time, and help to improve employment for rural poor people. Integration of cropping with different enterprises such as dairy, mushroom, and biogas recorded higher employment generation (875 mandays) (Sivamurugan, 2001). Combining crops with other enterprises such as horticulture + goat + poultry increases labor requirements, which provide scope to employ more labor throughout the year without giving breaks in the lean period as in conventional agriculture (Ravisankar et al., 2007; Kumar et al., 2012). Sharma et al. (2017) observed that crop + horticulture + kitchen garden + dairy + goat + poultry + duck + vermicompost in irrigated conditions of Chhattisgarh recorded higher employment generation for 1,033 mandays for 1.5 ha area and also in gardenland (Siddeswaran et al., 2012). This is mainly due to the diversified nature of multifarious activities related to different enterprises included in the integrated farming system.

The integrated farming system fulfills the basic family needs of cereals, pulses, oil, fruits, vegetables, and proteins through milk and meat, which improves the family income status and maintains balanced nutrition for the farm family members. It also alleviates malnutrition deficiencies in rural areas. In this study, adopting an integrated farming system (Table 7) with different components produced 1,679 kg of cereals, 1,918 kg of vegetables, 1,497 L of milk, and 300 kg of meat, which is more than sufficient for an average farm family of six members. Further production of green fodder (46,624 kg) and dry fodder (2,434 kg) was also used as feed for livestock units such as cattle and goats, which reduced the production cost considerably in livestock rearing. IFS strengthens food and nutritional security more than conventional systems. A field experiment conducted in Modipuram reported that integrating crops with dairy, fish, and boundary planting produced 3,040 kg of cereals, 289.9 kg of pulses, 4,228 L of milk, 5,560 kg of fruits, and 2,960 kg of vegetables (Panwar et al., 2019). Higher nutritional security was achieved by producing 1,738 kg of cereals, 239 kg of pulses, 283 kg of oilseeds, 5,902 L of milk, 162 kg of fruits, 1,581 kg of vegetables, 675 kg of eggs, 26,560 kg of green fodder, 3,761 kg of dry fodder, and 810 kg of fuel wood by adopting crops with dairy, horticulture, goat, poultry, and biocompost in a 1.45-ha area (Ravisankar et al., 2019).

The high utilization of agricultural chemicals in crop production produced higher GHG emissions from crop fields and other allied enterprises (Figure 3). It was demonstrated that in the integrated farming system, the highest GHG was emitted by livestock components measured at 2,480 CO₂-e (kg), followed by goats at 1,958 CO₂-e (kg) and horticultural vegetable crops and cropping systems. Among the different cropping systems, cowpea-ragi-dhaincha released a minimum of 143 CO₂-e (kg) into the atmosphere. On the contrary, prosomillet-chillies-dhaincha released a maximum of 218 CO₂-e (kg), followed by maize-sunflower-dhanicha, which released 213 CO₂-e (kg), and pearl millet-cotton-dhaincha, which released 196 CO₂-e (kg). The total sink in the IFS unit was 21,008 CO₂-e (kg), and the total GHG emission from the IFS unit was −15,118 CO₂-e (kg). Fruit trees and boundary plantations, which resulted in a negative GHG emission and a greater carbon sink in the IFS model, allow for further agricultural or enterprise intensification. The integrated farming system is considered a viable strategy to reduce greenhouse gas emissions through the adoption of suitable nutrient recycling (Barbosa et al., 2015; Sharma and Sharma, 2018). Considerably, IFS produced low greenhouse gas emissions. These results are in close conformity with the findings of Meena et al. (2022), who opined that crop + dairy + horticulture + fish pond + mushroom + poultry + kitchen garden + vermicompost + boundary planting registered negative GHG emissions. Negative (−3,175 kg CO₂ eq./ha) GHG emissions were recorded in crops with dairy, horticulture, fishery, poultry, duckery, goatery, apiary, vermicompost, biogas, liquid manure, and FYM production integration (Ravisankar et al., 2019). Perennial forages combined with cropping techniques including agroforestry, alley cropping, and intercropping provide a variety of choices for mitigating the effects of climate change by enhancing carbon sequestration and nutrient availability with better grazing management (Bell et al., 2014; Ericksson and Crane, 2018). Further border planting of trees reduces CH and CO emissions by sequestering carbon as biomass and modifying the soil environment, and the roots act as sinks of carbon (Franzluebbers et al., 2016; MacCarthy et al., 2018; Shyam et al., 2023). Therefore, it can be said that IFS is a prominent means to reduce the effects of climate change.

Although the IFS system overall is efficient, it also has certain limitations in terms of implementation and practicality. The major limitation has to be the high initial cost associated with various components of the system as well as the requirement of manpower. Furthermore, the system also needs a farm with a sizable area to accommodate all the components, which is a major barrier among small- and medium-scale farmers. The system also needs its initial operational time to become efficient and effective, and the economic stability of the farmers during this time period is also a major concern, especially for small farmers. This was further supported by the findings of Pandey et al. (2019). The availability of suitable planting materials and their combination of plants, animals, and inputs, as well as the complexities of managing, are also constraints, as mentioned in the findings of Nurcholis and Supangkat (2011) and Pushpa (2010). During the course of this study, it was understood that the limitations of the integrated farming system, although prominent, outweigh the advantages, and as the system progresses in the long run, it becomes more efficient and effective than the conventional farming system, thereby providing a stable and sustainable income for the farmers.