Performance of Diversified Legume Entailing Ultra High Intensity Rice based Cropping System Models for Higher Productivity, Profitability and Sustainability

Rice (Oryza sativa L.) stands first amongst all the food grain crops of the world and is the staple food of more than half of the world’s population. Rice-wheat cropping system is the most predominant cropping system in India because of its major contribution in enhancing food grain production. The continuous adoption of rice-wheat cropping system has been responsible for the declining soil fertility, emergence of multiple micronutrients deficiencies, excess emission of greenhouse gases and decline in water table (Todar et al., 2018; Shahane and Shivay, 2019). This cropping system is being practiced in 13.50 million hectare across the Indo-Gangetic Plains of South Asia, contributing more than 30% and 40% to the total rice and wheat area, respectively (Gathala et al., 2011). In view of the limited scope for horizontal expansion to augment food production, the alternative is to concentrate on vertical growth by increasing the productivity of the available land area. Intensified crop diversification would fulfill the basic needs of cereals, pulses, vegetables as well as fodder and has been recognized as an effective strategy for achieving the objectives of national food security, income growth, poverty alleviation, employment generation, judicious use of land and water resources, sustainable agricultural and environmental development. In India, more than 80% of farming community belongs to marginal and small farmers having only 32.50% of the total operational area. The income from single season field crop is hardly sufficient to sustain the small farmer’s family. The importance of highly intensive crop sequence is well recognized to sustain these farm families and to meet the growing demand of ever increasing population as well. An intensive cropping system should not only be highly productive and profitable but should also be stable over time and maintains soil fertility in present conditions taking care of soil health for future. So, intensification of crops has been envisaged as a new strategy for enhancing and stabilizing productivity. 
       
Introduction of short duration, photo-insensitive, dwarf and input responsive high yielding varieties of vegetables, pulses and fodders in sequence with rice help in achieving the purpose of identification of cropping system models. Pulses are next to cereals in terms of their economic and nutritional importance as human consumption. Pulses are described as “poor men’s meat” due to its high protein content (Abbas et al., 2011). They contain about double the amount of protein found in wheat and about three times the amount of protein in rice. The Indian Council of Medical Research (ICMR) recommends 40 g pulses man^-1 day^-1 (ICMR-NIN, 2011). However, actual availability ranges from 30-35 g pulses man^-1 day^-1 (Roy et al., 2017). Pulses continued to be an integral component of sustainable crop-production system, as these crops have ability of biological nitrogen fixation, low water requirement and capacity to withstand moisture stress conditions. These are well known for their soil fertility restoration value. Deep-rooting, leaf-shedding ability and mobilization of insoluble soil nutrients, especially phosphorus, are some of the important characteristics of pulses. To arrest the declining trend in productivity of cereal-based cropping systems, inclusion of pulses is an important alternative for improving physical, chemical and biological environment of soil. Now-a-days, vegetables are ideal choice for cash crops since they are easy to raise, provide high yields and command a higher market price than cereals and pulses whereas fodder crop is an integral part of Indian farming which is a blend of both crop and animal components. Hence, the present investigation was carried out to evaluate diversified legume entailing ultra high intensity rice based cropping system models for higher productivity, profitability and sustainability.
 

Basmati-370 rice equivalent system productivity
 
It is evident from the overall mean data (Table 1) that legume entailing ultra high intensity rice based cropping system models had a significant influence on basmati-370 rice equivalent system productivity. Among different cropping systems, treatment T₄: Rice (Pusa-1121) - Radish (CR-45) - Green onion (Nasik Red) - French bean (Anupama) - Okra (Seli special) registered significantly highest basmati-370 rice equivalent system productivity (25058.38 kg ha^-1) which was followed by treatment T₅: Rice (IET-1410) - Fenugreek (JF-07) - Knol khol (G-40) - Green onion (Nasik Red) - Dry onion (Selection-1) - Black gram (Pant U-19) (19227.92 kg ha^-1). Treatment T₅ was found statistically at par with treatment T₃ (17853.51 kg ha^-1) and treatment T₂ (15253.62 kg ha^-1) whereas significantly lowest basmati-370 rice equivalent system productivity of 8786.00 kg ha^-1 was recorded in treatment T₁: Rice (Basmati-370) - Wheat (HD-3086) - Cowpea (Lobia Super-60). This might be ascribed to the higher production potential of vegetable crops such as radish, green onion, french bean, okra, potato and knol khol along with their higher market prices were responsible for obtaining higher system productivity in terms of basmati-370 rice equivalent yield. Kachroo et al., (2014) and Tandel et al., (2014) reported similar findings in rice based cropping systems.
 


System profitability
 
Overall mean data on cost of cultivation (Table 1) reveals that highest system cost of cultivation of Rs. 525119.37 ha^-1 was incurred with treatment T₄ followed by treatments T₃ (Rs. 389296.67 ha^-1), T₅ (Rs. 372301.07 ha^-1) and T₂ (Rs. 306424.38 ha^-1) while lowest system cost of cultivation (Rs. 123094.59 ha^-1) was recorded with treatment T₁. Inclusion of green onion, french bean, okra, knol khol and potato in the cropping systems increased the cost of cultivation due to higher cost of seed/ tuber, manure and fertilizers, as well as high labour requirement for the cultivation of these crops. The results were in close agreement with Sharma et al., (2008) who reported that the highest cost of cultivation incurred in rice-potato-onion+maize relay cropping system, followed by rice-potato-onion. 
       
Among different cropping systems, significantly highest system gross returns of Rs. 981512.16 ha^-1 was recorded with treatment T₄ while treatment T₁ registered significantly lowest system gross returns (Rs. 340598.82 ha^-1). Treatment T₄ was followed by treatments T₅ (Rs. 735511.61 ha^-1), T₃ (Rs. 684194.80 ha^-1) and T₂ (Rs. 588989.14 ha^-1). Overall mean data with respect to system net returns given in Table 1 shows that significantly highest system net returns of Rs. 456392.80 ha^-1 was recorded treatment T₄ followed by treatment T₅ (Rs. 363210.54 ha^-1) and T₃ (Rs. 294898.13 ha^-1). Further, treatment T₃ was found statistically at par with treatment T₂ (Rs. 282564.76 ha^-1) whereas significantly lowest system net returns of Rs. 217504.23 ha^-1 was recorded with treatment T₁. The highest system gross and net returns might be due to higher basmati-370 rice equivalent yield of vegetable crops such as radish, green onion, french bean, okra, fenugreek and knol khol in the cropping systems which fetched higher market prices, thereby increasing the gross and net returns of cropping systems. These results were in close conformity with the findings of Jat et al., (2012) and Yadav et al., (2013). Prasad (2016) reported that vegetable based cropping systems showed more gross returns than rice-wheat cropping system. The higher net returns might be due to increasing cropping intensity of the system that enhance the production potential of the cropping systems. Similar results were reported by Mall et al., (2014) and Desai et al., (2016). Sammauria et al., (2020) reported that inclusion of vegetable crops such as onion and fenugreek in cropping systems fetched higher market prices, thus increasing net returns.
 
Soil fertility
 
The soil organic carbon is an important factor of soil fertility that plays a crucial role in maintaining sustainability of cropping systems by improving physical, chemical and biological properties of soil. The data with respect to soil organic carbon (Table 2) was not significantly influenced by legume entailing different rice based cropping system models. The soil organic carbon increased from 5.68 to 5.75 g kg^-1 under all the cropping systems as compared to their initial status. The highest soil organic carbon was recorded in treatment T₅ followed by treatment T₃, T₄ and T₂ whereas the lowest soil organic carbon was recorded with treatment T₁. This might be due to integrated application of inorganic and organic nutrients which attributed to higher contribution of biomass to the soil, accumulation of root residues and leaf shedding resulted in improvement of soil organic carbon over their parental status. Results revealed that significantly higher available nitrogen was recorded with treatment T₅ which was statistically at par with treatments T₄ and T₂ followed by treatment T₃ whereas significantly lowest available nitrogen was registered in treatment T₁. The inclusion of leguminous crops in rice based cropping systems led to addition of nitrogen in the soil through atmospheric nitrogen fixation by root nodules. The findings are in close conformity with those of Upadhyay and Vishwakarma (2014), Lakshmi et al., (2015) and Gudadhe et al., (2020). Significantly higher available phosphorus was recorded with treatment T₅ which was statistically at par with treatment T₄ while treatment T₂ recorded significantly lowest available phosphorus which was statistically at par with treatments T₃ and T₁. The lowest available phosphorus might be attributed to inclusion of potato crop in treatments T₂ and T₃ which caused lower down of available P in the soil due to heavy mining and utilization of phosphorus by the crop. The organic manures on decomposition, solubilize inorganic and organic phosphorus fractions through release of various organic acids resulting in significant increase in the available phosphorus status of soil (Ninan et al., 2013). However, treatment T₄ registered significantly higher available potassium which was found statistically at par with treatment T₂ whereas treatment T₃ recorded significantly lowest available potassium which was statistically at par with treatments T₁ and T₅. This might be due to direct addition of potassium in the accessible K pool in soil and release of potassium owing to organic matter interaction with clay. These results were in close conformity with the findings of Das et al., (2004) and Yadav et al., (2013). Kumar et al., (2012) and Kalhapure et al., (2013) reported that cropping systems including legume crops improved the availability of NPK and organic carbon.

The results obtained under two years research study revealed that cropping system Rice (Pusa-1121) - Radish (CR-45) - Green onion (Nasik Red) - French bean (Anupama) - Okra (Seli special) having 500% cropping intensity proved to more productive, profitable and remunerative as it can fetched more net returns per unit area. Therefore, farmers with adequate resources can diversify the existing cereal-cereal cropping system with rice based cropping systems diversified with including pulse, vegetable and fodder crops for obtaining higher productivity, profitability and sustainability under irrigated conditions.

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