Nutrient management with nano urea for enhanced herbage yield and quality of fodder sorghum (Sorghum bicolor (L) Moench)

Abstract

The study entitled “Nutrient management with nano urea for enhanced herbage yield and quality of fodder sorghum (Sorghum bicolor (L.) Moench)” was conducted during the period 2022-24 at College of Agriculture, Vellayani. The main objective of the study was to evaluate the effect of different concentrations of nano urea on growth, yield, quality and economics of fodder sorghum. The field experiment was conducted at the Instructional Farm, during the period from December 2023 to February 2024. The experiment was laid out in randomized block design with 13 treatments, replicated thrice. The treatments comprised nitrogen management and foliar nutrition. The treatments were T1: 75% Recommended dose of nitrogen (RDN) + nano urea (0.2%); T2: 75% RDN + nano urea (0.4%); T3: 75% RDN + nano urea (0.6%); T4: 100% RDN + nano urea (0.2%); T5: 100% RDN + nano urea (0.4%); T6: 100% RDN + nano urea (0.6%); T7: 75% RDN + urea spray (2%); T8: 100% RDN + urea spray (2%); T9: nano urea (0.2%) alone; T10: nano urea (0.4%) alone; T11: nano urea (0.6%) alone; T12: KAU POP; T13: control (without nitrogen). The variety used for the study was CNFS-1 released from Zonal Agricultural Research Station, VC Farm, Mandya. The fertilizer recommendation followed was 60:40:20 kg NPK ha-1, along with farm yard manure (10 t ha-1). Foliar spray of nano urea and urea were done at 20 DAS and 40 DAS. All other management practices were followed as per the KAU package of practices recommendations. Nitrogen management and foliar nutrition had significant influence on the growth and yield attributes of fodder sorghum. At 30 DAS, taller plants (75.52 cm) were observed in T5 and was on par with T6. The treatment, T6 resulted in taller plants (132.41 cm and 226.62 cm) at both 45 DAS and harvest and remained on par with T5. Similarly, at 30 DAS, T6 exhibited more number of leaves per plant (6.41), leaf length (47.12 cm), leaf breadth (3.64 cm), leaf area per plant (661.68 cm2), LAI (1.44), stem diameter (11.06 mm), number of internodes per plant (5.24), length of internode (4.38 cm) and leaf: stem ratio (0.39) which was comparable with T5. Similarly, the treatment, T5 resulted in maximum number of leaves per plant (7.54 and 8.99), leaf length (63.47 cm and 89.00 cm), leaf breadth (4.69 cm and 5.61 cm) and length of internode (13.07 cm and 19.95 cm) at both 45 DAS and harvest and was on par with T6. However, higher leaf area per plant at harvest (2682.69 cm2), LAI (3.52) and number of internodes per plant (6.80) at 45 DAS were observed in T6 and remained on par with T5. The treatment, T5 resulted in more number of internodes per plant at harvest (9.67) and was on par with T6. Similarly, leaf area per plant (1586.64 cm2) at 45 DAS and stem diameter (12.94 mm and 15.19 mm) at both 45 DAS and harvest were observed in T6 and was statistically comparable with T5 and T3. Green fodder yield (32.03 t ha-1), dry fodder yield (5.81 t ha-1) and per day productivity (0.53 t ha-1 d-1) were found significantly higher in the treatment, T5 and remained on par with T6. The treatment T5 exhibited higher total chlorophyll content (1.92 mg g-1 FW and 2.83 mg g-1 FW) at both 30 DAS and 45 DAS and was statistically comparable with T6. Higher crude protein content (9.92 %) and crude protein yield (0.50 t ha-1) were observed in T5 and was on par with T6. The treatment T5 resulted in higher N content and NPK uptake which was comparable with T6. The organic carbon and available N, P and K status of soil after the experiment did not vary significantly with nitrogen management and foliar nutrition. The treatment, T5 (100 per cent RDN + nano urea 0.4 per cent) fetched higher net return of ₹ 92221 ha-1 with BCR of 2.36 and was comparable with T6. Based on the study it could be concluded that nitrogen management along with foliar application of nitrogen based formulations improved the growth, yield, quality and economics of fodder sorghum. There was an increased yield of green fodder (39. 26%) when nano urea (0.4%) was supplemented with RDF compared to urea spray (2 %). When the fertilizer level was decreased by 25 percent, growth, yield, quality parameters and net return were also found to be reduced. Thus, the result of the research work revealed that soil application of 100 per cent RDF (60:40:20 NPK kg ha-1) along with foliar spray of nano urea, 0.4 per cent each at 20 DAS and 40 DAS was beneficial for growing fodder sorghum in terms of growth, yield, quality and economics in Kerala during the rabi season.