Economic Feasibility of Ratoon Pigeon Pea under Different Levels of Irrigation, Fertilizers and Mulching

Pigeon pea (Cajanus cajan) is a legume crop, renowned for its adaptability to diverse agro-climatic conditions and its nutritional values. India is a dominant cultivator of pigeon pea with a contribution of 81% of the world’s total area and 79% of production. Although India is a major producer, still it imports pigeon pea from other countries (Saxena and Kanwal, 2019). Inorder to meet the demand for pigeonpea increasing the production through horizontal as well as vertical expansion is needed. Ratooning of pigeon pea has remained as an unexplored path of horizontal expansion for increasing production. Ratooning of pigeon pea effectively reduces the crop durations in comparison to main crop hence; more crops per year can be taken. The major constraints for lower production of pigeonpea is attributable to its cultivation on sub-marginal lands with low energy inputs, poor soil fertility, inadequate fertilizer applications, cultivation by small holding farmers and majority of the area is under rainfed conditions. Apart from these, several intrinsic factors such as poor source to sink relationship, inefficient translocation of nutrients, flower dropping and long duration of the crop (Ware et al., 2018; Suresh et al., 2024).
       
The availability and supply of assured irrigation, fertilizers and mulching practice would have increased the pigeon pea yield which help to overcome the constraints for higher productivity. However, these additional inputs to enhance pigeonpea yield will result in increased cost of cultivation, that determines their practical implications under farmers’ field. Drip irrigation combined with split drip fertigation had achieved higher productivity and profitability in pigeon pea cultivation (Gadade et al., 2022).
       
Ratooning practice of pigeonpea cuts down the land preparation activities which accounts for 30% of the cost of production. Adaption of technologies such as drip irrigation, fertigation and mulching which have shown promising results in pigeonpea crop may help to boost the production of ratoon crop while, conserving the resources and minimizing the costs involved. The suitability of ratooning for cultivation depends on its yield and economics of production. Since, so far the ratooning of pigeon pea and its economic feasibility is unknown. With that objective, the following study was undertaken to check its economic suitability for cultivation.

The experiment was conducted during October 2020 to February 2021 at Zonal Agriculture Research Station, GKVK, UAS, Bangalore. The research was formulated with two levels of irrigation (I₁: 0.50 CPE and I₂: 0.75 CPE), three levels of fertilizers (F₁: 100%, F₂: 75% and F₃: 50% recommended dose of fertilizers of pigeon pea) and two levels of mulching (M₀: without mulch and M₁: with mulch) under split-split plot design having 12 treatment combinations.
       
The previous crop was pruned to a uniform height of 45 cm above the ground level and in each plant three branches were retained for ratooning to avoid excessive vegetative growth. The irrigation water was applied in three days intervals up to a week before harvest through drip system on the basis of cumulative pan evaporation (CPE) values from the United States Weather Bureau (USWB) pan evaporimeter. The Recommended dose (25:50:25 kg N, P₂O₅ and K₂O ha^-1) of main crop applied to ratoon since no recommended dose of fertilizers (RDF) for rotoon crop. The fertilizers were applied in three splits at an interval of 30 days during rabi 2020 through drip fertigation. The source of nutrients were urea, di-ammonium phosphate and muriate of potash for nitrogen, phosphorous and potassium, respectively. The growth observations of the crop was recorded at 30, 60, 90 days after pruning (DAP) and at the harvest stage. The yield observations were recorded from tagged five plants and converted to hectare basis based on the number of plants per hectare. All the recorded experimental data was analyzed using a statistical F test (P=0.05) at 5% level of significance. Wherever the F test is found to be significant the critical difference (CD) was calculated and non significant data is not mentioned.

Growth attributes
 
The treatments had significant effect on the growth parameters of ratoon pigeonpea (Table 1). Among the different treatments higher amount of growth parameters such as plant height, number of branches, leaf area and dry matter accumulation was observed in higher irrigation level (0.75 CPE), fertilizer (100% RDF) and plants with mulching throughout the growth period. Among all the interactions, irrigation and fertilizers interaction significantly affected the growth parameters where higher plant height, leaf area and dry matter accumulation were recorded at 0.75 CPE irrigation level with 100% RDF.
 

       
Better growth parameters at higher irrigation level is because of better availability of moisture in the root zone which maintains better turgor pressure in the leaf leading to better cell division and expansion (Nagaraj et al., 2019) similar results found by Jadav et al., (2022) and Kumar et al., (2024). Higher availability of primary nutrients such as N, P and K in soil led to more uptake of nutrients as well as positively influenced the absorption of other nutrients under drip irrigation (Kakade et al., 2018). Mulching the crop with black polyethylene sheet maintained better moisture content, nutrient availability by virtue of reducing evaporation and soil thermal regime improved the growth (Savani et al., 2017). The complementary effect of better availability of moisture and split fertigation of nutrients enhances the uptake and contributes to the better plant growth (Praharaj and Kumar, 2012) meanwhile, reducing the deep percolation losses.
 
Yield and yield attributes
 
Irrigation, fertilizers and mulching had significant influence on the yield and yield attributes of ratoon pigeonpea (Table 2). Days to 50% flowering, number of pods per plant, number of seeds per pod, stalk yield of ratoon pigeon pea were found higher at 0.75 CPE irrigation level, 100% RDF and plants with mulchihg. Meanwhile, higher seed yield and harvest index was recorded at same irrigation and mulching levels but at 50% RDF. Among irrigation and fertilizers interactions, irrigation at 0.75 CPE with 50% RDF was observed with a higher number of pods, seed yield, and harvest index. Meanwhile, a higher amount of stalk (2490 kg ha^-1) was recorded at 0.75 CPE irrigation level with 100% RDF fertilizer level.
 

       
Drip irrigation provides optimum moisture conditions which improved the yield due to better crop growth and air-soil-water proportion maintained at 0.75 CPE throughout the crop growth stage (Jadhav et al., 2018; Kumbhar et al., 2015). Mulching with black polythene sheet effectively improves the storage of water in the rhizosphere and reduces evaporation (Dhillon, 2020) similar results were recorded by Swathi et al., (2017) and Kumar et al., (2022) in which improved the leaf area of the crop and increased the photosynthates production and their accumulation in grains under mulching.
       
The yield of the crop at different fertilizer level is greatly influenced by its interaction with irrigation levels. The lower yield at 100% RDF fertilizer level along with 0.75 CPE is because of higher diseased (pigeonpea sterility mosaic) and dead plants (non-ratooned crop) which is mainly because of the luxuriant plant growth which attracted more insects in the main crop and ratoon crop leading to lower yields (Table S1). The another probable reason for lower yield at 100% RDF at 0.75 CPE is higher vegetative growth and flower dropping which imbalances the source to sink relationship because of which lower number of pods per plants recorded resulting in lower yield (Gangana Gowdra et al., 2024).
 

 
Economics
 
Among all the twelve combinations of irrigation, fertilizers and mulching; I2F3M1 (Irrigation at 0.75 CPE, fertilizers at 50% RDF and with mulching) recorded lower cost of cultivation, higher gross returns (Rs. 43,591 ha-1), net returns (Rs. 27,698 ha^-1) and BC ratio (2.74) followed by I₂F₂M₁ (Table 3).
 

                       
The economics of the crop was mainly influenced by the yield of crop and cost of cultivation involved in it. The higher gross income and net income were recorded in I₂F₃M₁ (Irrigation at 0.75 CPE + 50% RDF + with mulching) because of higher yields which is in line with the results of (Savani et al., 2017). Another strong factor that influences the income and B:C ratio is the cost of production which was found lower in the treatment that has recorded higher yield.

Under the changing climatic situation, it is necessary to evaluate the alternate methods of cultivation to meet the needs of the growing population. Ratooning of pigeon pea in rabi under different irrigation, fertilizers, and mulching revealed that, higher irrigation (0.75 CPE), fertilizer (100% RDF) and mulching improved the growth attributes. Meanwhile, higher irrigation (0.75 CPE) with lower fertilizer (50% RDF) and mulching found suitable for receiving higher ratoon pigeon pea yield. Cultivating ratoon pigeon pea with 50% RDF at 0.75 CPE irrigation level and mulching found to be more economically feasible than the other treatment combination. The combination of treatment found with higher net returns (Rs. 27,698 ha^-1), BC ratio (2.74) and lower cost of cultivation (Rs. 15,893 ha^-1) with save of 50% fertilizer dosage.

Authors do not have any conflict to disclose regarding the publication of article.