Impact of fertigation levels on economics of hybrid tomato production

Introduction

Tomato (Solanum lycopersicum) is a prominent solanaceous vegetable crop extensively cultivated in India, holding a prime position among vegetables. It is a high valued crop consumed both fresh in salads and cooked in curries. Tomato has achieved significant worldwide importance and globally known as the 'love apple', 'golden apple' or 'poor man's apple'. It is a rich source of vitamins A and C, as well as potassium. The red colour is due to lycopene pigment, which acts as a potent antioxidant for reducing damage from free radicals (Ayyar, 2019) [1] . Major tomato-producing states in India include Andhra Pradesh, Madhya Pradesh, Karnataka, Gujarat, Maharashtra, Tamil Nadu, Odisha, and West Bengal. In the year 2024-25, tomato cultivation in India covered an area of 853.27 thousand hectares, producing 25,959.43 thousand tonnes with a productivity of 27.7 tonnes per hectare, indicating improved yield levels despite a slight decline in cultivated area. During the same year in Maharashtra, tomato was grown over 56.47 thousand hectares, with a production of 1,512.37 thousand tonnes and a productivity of 26.2 tonnes per hectare, reflecting better performance in terms of output and efficiency compared to earlier years. India ranks as the third largest producer and consumer of fertilizers globally. However, the nutrient consumption per hectare and fertilizer use efficiency remain notably low within the country. The primary reasons for this low efficiency include the types of fertilizers used and the application methods typically adopted by Indian farmers. Consequently, there is a clear necessity to develop an appropriate fertilizer application method that can enhance both the quantity and quality of crop yields. Fertigation is the technique of applying water-soluble solid fertilizers or liquid fertilizers directly through a drip irrigation system. In fertigation, nutrients are delivered directly into the wetted soil volume beneath the emitter, where root activity is most concentrated (Ayyar, 2019) [1] . Drip fertigation combined with mulching stands as one of the most effective management strategies, capable of significantly improving water management practices. The benefits of mulching in vegetable crop production are well-established. Mulch is essentially a protective layer of material spread over the soil surface. It enriches and safeguards the soil while creating a more favourable growing environment. Simultaneously, it acts as a barrier to moisture loss from the soil. Mulches can efficiently reduce water vapour loss, soil erosion, weed proliferation, and nutrient leaching. Mulching mitigates soil deterioration, curtails weed infestation, provides a beneficial microclimate for root development, and inhibits water evaporation. The plastic materials commonly used for mulching are polyvinyl chloride or polyethylene films, with polyethylene being the preferred choice for crop production.

Materials and Methods

A study was conducted during rabi season of 2024-25 to examine the effects of different fertigation levels on hybrid tomato production at Instructional Farm of Department of Irrigation and Drainage Engineering, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola.

Climate at Experimental Site

Akola is geographically situated between North latitudes 20°16' and 21°17', and East longitudes 76°38' and 77°38'. Akola station receives an average annual rainfall 819 mm. The climate of Akola is subtropical semi-arid, featuring three distinct seasons: a hot and dry summer from March to May, a warm and rainy monsoon from June to October, and a mild, cold winter from November to February. The temperature at Akola varies between 12.6 °C to 42.4 °C.

Details of Experimentation

The experiment was laid out in Randomized Block Design (RBD) with five treatments which include four drip fertigation levels and control treatment of which details are as given in following Table 1. Conventional application of fertilizer with 100% RDF (Soil application of basal dose of 50% N + 100% P + 100% K through fertigation at the time of transplanting and remaining 50% N in twelve equal splits at an interval of ten days)-Control Tomato seedlings (Syngenta Saaho) were transplanted in a double row with spacing of 90 cm x 60 cm on ridge.

Irrigation and Fertigation Management

Prior to transplanting, a common irrigation was provided across all plots to bring the soil to field capacity. Accounting for the use of polyethylene mulch, which conserves approximately 20% of irrigation water (Deshmukh, 2015) [3] , the water requirement for the tomato crop under drip was estimated at 80% of crop evapotranspiration (ETc). It was calculated using modified Penman-Monteith model, which is expressed as: where, ETo: Reference evapotranspiration, mmday -1 Rn: Net radiation at the crop surface, MJm -2 day -1 G: Soil heat flux density, MJm-2day -1 T: AirtemperatureaT 2 mheight,°C U2: Wind speed at 2 m height, m s -1 Es: Saturation vapour pressure, kPa ea: Actual vapour pressure, kPa ∆: Slope vapour pressure curve, kPa°C -1 γ: Psychometric constant, kPa°C -1 The values of crop coefficient used for different growth stages of tomato crop are referred from FAO 56. The crop evapotranspiration values for tomato crop is calculated by using following formula.

ETc = Kc х Eto

where, ETc = crop evapotranspiration (mm d -1 ) Kc = crop coefficient (dimensionless) ETo = reference crop evapotranspiration (mm d -1 )

Irrigation and Fertigation scheduling

To achieve optimal and efficient production, irrigation for the tomato crop was scheduled every day. The recommended fertilizer dose of 300:150:150 N:P:K kg/ha was considered. In treatments T 1 to T 4 , water soluble fertilizers (source -19:19:19 WSF complex and urea) through drip fertigation was applied in 12 equal splits at an interval of 10 days. In control treatment T 5 , basal dose of 50% N +100% P + 100% K (sources -Urea and 19:19:19 WSF complex) were given as conventional fertilization through drip fertigation at the time of transplanting and remaining 50% of N (source-Urea) was given through drip fertigation.

Yield of tomato

The yield of tomato from a net plot in every treatment was observed in every picking. The total yield of the fruit harvested from the net plot was recorded by cumulating yield per picking and expressed in kg per plot and then it is converted into quintal per hectare.

Cost economics

To compare the net returns and benefit-cost ratio, the cost economics of all treatments was worked out. For this purpose, the life period of polyvinyl chloride items was considered as 10 years and for the rest of G.I. items, and motor pump set as 25 years. Standard market rates were considered for each Item. Fixed cost, operating cost, net return, and benefit-cost ratio for each system were worked out as follows.

a) Fixed cost

Fixed cost comprised of interest on initial cost and depreciation on the system. The interest calculated on the capital was at the rate of 10 per cent per annum. The depreciation of the system was worked out by the straight-line method as follows.

(I -S) D = L where, D= Depreciation per annum I= Initial cost of system S= Salvage value @ 10% L= Expected life period of the system

Operating cost

Operating cost is the amount that is paid by the cultivator in cash throughout the cultivation period. Total operating cost comprised of operating cost of the system and interest on operating cost at the rate of twelve per cent per annum.

Total cost

Total cost comprised of fixed cost-plus operating cost. Total cost per ha was calculated for comparison on a per hectare basis.

Gross monetary return

This is worked out by considering the yield of produce and its selling price.

Benefit-cost ratio

The benefit-cost ratio was estimated by using the following formula.

Benefit-cost ratio = 𝐺𝑟𝑜𝑠𝑠 𝑟𝑒𝑡𝑢𝑟𝑛 𝑝𝑒𝑟 𝑡𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡 𝑇𝑜𝑡𝑎𝑙 𝑐𝑜𝑠𝑡 𝑝𝑒𝑟 𝑡𝑟𝑒𝑎𝑡𝑚𝑒𝑛𝑡

Results and Discussion

Water requirement of tomato Irrigation equal to 80% ETc was provided daily. The stage wise irrigation water applied is as given in Table 2. It is cleared that maximum irrigation water was required during mid stage followed by development, late stage while minimum irrigation water was required during initial stage.

Yield of Tomato

Yield of tomato during each picking was cumulated to obtain total yield of tomato and presented in Table 3.

Benefit Cost Ratio

Benefit cost ration for hybrid tomato production was estimated considering market rate of tomato as Rs.1500/qtl and presented in Table 4 and Table 5. The benefit cost ratio was observed highest for treatment T1 followed by T2, T5, T3 and T4. The minimum water use efficiency was found minimum for treatment T4.

Inference

It is suggested to implement treatment T 1 (120% RDF with 12 equal splits of RDF at interval of 10 days) for maximum yield and benefit cost ratio.

References

1. Ayyar S. Mulching and fertigation on the yield and quality of tomato. IJCS. 2019;7(4):2539-2541.
2. Saurabh A, Kumar M. Effect of different training systems, spacings and fertigation levels interactions (2 Way) on yield contributing attributes in bell pepper under protected conditions in mid hills of Himachal Pradesh. Multilogic In Science. 2018;VIII(XXVII):17-21.
3. Deshmukh PV. Response of tomato to polyethylene mulch under drip fertigation. Akola: Dr. PDKV; 2015.
4. Patell JM, Savani NG, Solia BM, Patel KK. Response of cabbage to different discharge rates, fertigation levels and lateral placements. Multilogic In Science. 2022;XII(XXXXI):192-195.
5. Navatha N, Madavi B, Madhukar Rao P, Raju B, Umareddy R. Effect of fertigation levels and frequencies on growth and yield of maize in sandy loam soil. Multilogic In Science. 2020;IX(XXXII):426-431.
6. Tayade VD, Sonkamble AM, Nagre PK, Kale VS, Wadatkar SB, Walke RD. Effect of irrigation and fertigation levels on yield and economics of watermelon (Citrullus lanatus Thunb). Multilogic In Science. 2024;XIII(XXXXVII):950-956.
7. Sharma V, Saurabh A, Ruksana, Saini D, Himanshi, Sharma P. Effect of different hybrids and fertigation levels on benefit cost ratio of cucumber (Cucumis sativus L.) under poly house conditions. Multilogic In Science. 2023;XIII(XXXXVI):640-642.