Effect of FYM, nitrogen and phosphorus levels on productivity and economics of Kharif Sorghum

Introduction

Sorghum (Sorghum bicolor L.) is one of the most important cereal crops cultivated in semi-arid and arid regions of the world due to its drought tolerance and adaptability to marginal soils. In India, sorghum plays a vital role in ensuring food, fodder, and livelihood security, particularly in rainfed ecosystems. Despite its adaptability, productivity of sorghum remains relatively low, primarily due to imbalanced and inadequate nutrient management. Nitrogen is the most yield-limiting nutrient in sorghum, governing vegetative growth, photosynthetic efficiency, and sink development. Phosphorus is equally important for early root establishment, energy transfer, and reproductive development. Continuous reliance on chemical fertilizers, however, has resulted in declining soil organic carbon and nutrient-use efficiency. Farmyard manure (FYM) serves as a valuable organic amendment that improves soil physical, chemical, and biological properties while supplying nutrients in a slow and sustained manner. Integrated use of FYM with inorganic fertilizers has been widely advocated as a sustainable nutrient management strategy, improving crop productivity while maintaining soil health. Considering these aspects, the present investigation was undertaken to study the individual and combined effects of FYM, nitrogen, and phosphorus levels on yield parameters and economics of kharif sorghum under middle Gujarat conditions.

Materials and Methods

The field experiment was conducted during the kharif season of 2024 at the Agronomy Farm, B. A. College of Agriculture, Anand Agricultural University, Anand, Gujarat. The soil of the experimental field was loamy sand (Goradu), slightly alkaline in reaction (pH 8.35), low in organic carbon (0.46%) and available nitrogen (203.84 kg ha⁻¹), medium in available phosphorus (29.55 kg ha⁻¹), and high in available potassium (238.23 kg ha⁻¹). The experiment was laid out in a factorial randomized block design with three replications.

Treatments consisted of two FYM levels (5 and 10 t ha⁻¹), three nitrogen levels (60, 80, and 100 kg ha⁻¹), and two phosphorus levels (20 and 40 kg P₂O₅ ha⁻¹), forming twelve treatment combinations. FYM was incorporated into the soil before sowing. Nitrogen was applied in two splits, half as basal and the remaining half at 30 days after sowing (DAS), while the entire dose of phosphorus was applied basally. Sorghum variety GJ 44 was sown at a spacing of 45 cm, and all recommended agronomic practices were followed uniformly. Results and Discussion Yield Parameters (Grain yield, Straw yield and Harvest index) The yield performance of kharif sorghum as influenced by different levels of FYM, nitrogen, and phosphorus is presented in Table 1 and the interaction effects in Table 1.1. The results clearly indicated that individual application of FYM, nitrogen, and phosphorus significantly influenced grain and straw yields, whereas harvest index remained statistically non-significant across treatments.

Effect of FYM: Application of 10 t FYM ha⁻¹ (F₂) recorded significantly higher grain yield (2337 kg ha⁻¹) and straw yield (10,308 kg ha⁻¹) compared to 5 t FYM ha⁻¹ (F₁). The improvement in yield with higher FYM application can be attributed to enhanced soil physical properties, improved moisture retention, and sustained nutrient release throughout the crop growth period. FYM also stimulates microbial activity, resulting in improved mineralization and nutrient availability, particularly nitrogen and phosphorus, which ultimately enhances biomass production and yield formation. Similar yield improvements due to FYM application in sorghum have been reported by Patidar and Mali (2004) [13] , Kushwaha et al. (2014) [11] , and Jat et al. (2013) [9] .

Effect of Nitrogen:

Increasing nitrogen levels significantly increased grain and straw yields. The highest grain yield (2541 kg ha⁻¹) and straw yield (11,096 kg ha⁻¹) were recorded with 100 kg N ha⁻¹ (N₃), which was significantly superior to 60 and 80 kg N ha⁻¹. Nitrogen plays a crucial role in chlorophyll synthesis, photosynthetic activity, and vegetative growth, which enhances dry matter accumulation and translocation of assimilates towards the sink. These findings corroborate the results of Meena et al. (2012) [12] , Al-Taher et al. (2005) [1] , and Gautam et al. (2020) [6] , who also reported significant yield enhancement in sorghum with increasing nitrogen levels.

Effect of Phosphorus: Application of 40 kg P₂O₅ ha⁻¹ (P₂) significantly increased grain yield (2468 kg ha⁻¹) and straw yield (10,727 kg ha⁻¹) over 20 kg P₂O₅ ha⁻¹ (P₁). Phosphorus enhances root development, energy transfer, and reproductive growth, which improves nutrient uptake efficiency and grain formation. These results are in close agreement with those reported by Sumeria et al. (2002) [16] , Roy and Khandaker (2010) [15] , and Getinet and Atinafu (2022) [7] .

Interaction effect (N × P):

The interaction between nitrogen and phosphorus levels was found significant for grain and straw yields (Table 1.1). The treatment combination of 100 kg N ha⁻¹ + 40 kg P₂O₅ ha⁻¹ (N₃P₂) produced the highest grain yield (2793 kg ha⁻¹) and straw yield (12,083 kg ha⁻¹). The synergistic interaction suggests that adequate phosphorus availability enhances nitrogen use efficiency, resulting in improved vegetative growth, reproductive development, and assimilate partitioning. Similar synergistic effects of N and P on sorghum yield were also reported by Rashid et al. (2008) [14] , Gautam et al. (2020) [6] , and Hailu and Kedir (2022) [8] . Harvest index was not significantly influenced by FYM, nitrogen, phosphorus, or their interactions, indicating that increases in grain yield were largely proportional to total biomass production. This trend is in agreement with the findings of Donald and Hamblin (1976) [5] and Tudu et al. (2023) [17] .

Economics

Economic analysis of kharif sorghum under different nutrient management treatments is presented in Table 2, with interaction effects shown in Tables 2.1 and 2.2. The cost of cultivation increased with higher levels of FYM and fertilizers; however, higher yields resulted in increased gross and net returns.

Effect of FYM: Application of 10 t FYM ha⁻¹ recorded higher gross realization (₹111,369.67 ha⁻¹) compared to 5 t FYM ha⁻¹, though net realization was statistically at par due to the increased cost of FYM application. Consequently, the benefitcost ratio was higher with 5 t FYM ha⁻¹ (1.94), indicating better economic efficiency at lower FYM levels. Similar economic trends with FYM application were reported by Meena and Meena (2012) [12] and Bhunwal et al. (2016) [4] .

Effect of Nitrogen: Nitrogen application significantly influenced economic returns. The highest gross realization (₹120,644.28 ha⁻¹), net realization (₹63,174.28 ha⁻¹), and benefit-cost ratio (2.10) were recorded with 100 kg N ha⁻¹. Improved profitability at higher nitrogen levels was mainly due to substantial yield gains outweighing the marginal increase in fertilizer cost. These results are in line with the findings of Al-Taher et al. (2005) [1] , Meena et al. (2012) [12] , and Amiri et al. (2014) [2] .

Effect of Phosphorus: Application of 40 kg P₂O₅ ha⁻¹ resulted in significantly higher gross (₹116,969.89 ha⁻¹) and net returns (₹58,987.39 ha⁻¹) along with a higher benefit-cost ratio (2.02) compared to 20 kg P₂O₅ ha⁻¹. Enhanced economic returns under higher phosphorus levels can be attributed to improved yield performance and better nutrient use efficiency, as also reported by Arunakumari et al. (2021) [3] and Kumar et al. (2023) [10] .

Interaction effect (N × P):

The interaction between nitrogen and phosphorus levels significantly influenced gross and net realization as well as benefit-cost ratio (Tables 2 [14] , Bhunwal et al. (2016) [4] , and Hailu and Kedir (2022) [8] .

Conclusion

The present investigation clearly demonstrated that integrated nutrient management through combined application of FYM, nitrogen, and phosphorus significantly improved yield and economic returns of kharif sorghum. Application of 10 t FYM ha⁻¹ along with 100 kg N ha⁻¹ and 40 kg P₂O₅ ha⁻¹ proved superior in maximizing grain and straw yields as well as gross and net realization. However, the highest benefit-cost ratio was recorded with 5 t FYM ha⁻¹ combined with 100 kg N ha⁻¹ and 40 kg P₂O₅ ha⁻¹, indicating greater economic efficiency under moderate organic input levels. Balanced and integrated use of organic and inorganic nutrient sources thus emerges as a sustainable and profitable nutrient management strategy for sorghum cultivation under middle Gujarat agro-climatic conditions.

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