NPK Nutrient Source Influence on Performance and Profitability of Intercropped Safflower (Carthamus tinctorius) with Fenugreek (Trigonella foenum-graecum)

Intercropping and types of fertilizers may influence the productivity and quality of crops. An experiment was carried out to assess how chemical and biological fertilizers impact the yield and economic outcomes of safflower plants grown in monoculture and intercropped with fenugreek. Six fertilizer treatments, including no fertilizer (control); 100% soil test recommended nitrogen (N) in the form of urea; nitrogen, phosphorus, and potassium (NPK) solution spray; phosphorus biofertilizer (Barvar 2 phosphate) + 100% urea; Barvar 2 phosphate + 50% urea; and Barvar 2 phosphate + NPK spray, were evaluated in a randomized complete block design (RCB) with three replications. The results indicated that safflower monocultures fertilized with urea produced significantly higher grain (332.6 g/m²) and oil yield (85.18 g/m²) than intercropped plots. The Barvar 2 phosphate + NPK treatment in monoculture and the Barvar 2 phosphate + 100% recommended urea treatment in intercrop yielded the most seeds per unit area. The foliar application of NPK fertilizer resulted in the highest biological yield (966.7 g/m²) for sole safflower. Each intercropping pattern had a land equivalent ratio (LER) higher than one. During 2021 and 2022, the most effective treatments involved using Barvar 2 phosphate fertilizer with 100% urea (LER = 2.16), as well as Barvar 2 phosphate with 50% soil test recommended urea in mixed cultivation (LER = 2.7). Furthermore, the relative yield total (RVT) values exceeded one in the mixed cropping treatments that received Barvar 2 phosphate fertilizer with 50% urea. Finally, the results indicated that combining safflower and fenugreek planting with the application of chemical and biological fertilizers effectively increased grain yield, oil yield, and oil content in safflower plants. The findings of this study pave the way for future research to explore the long-term impacts of intercropping systems on soil health and biodiversity.