Performance, Phyto-nutritional and Bio-active substances of Sweet Pepper (Capsicum annum) in response to Soil Applied Organic and Inorganic Sources of N Fertilizers

Soil health is an important factor for producing a higher yield and obtaining good quality products. Nitrogen fertilizer is one of the most important and valuable agricultural inputs for increasing crop production.

Experiments were conducted in 2017 and 2018 in the cropping seasons to determine the performance and nutritional qualities of sweet pepper in response to organic and inorganic sources of N fertilizers.

Ten kilograms (10 kg) capacity black polythene bags were filled with topsoil and were arranged randomly on the field. Treatment combination included: - 0 NPK + 0 PM (T₁), 40 NPK + 0 PM (T₂), 32 NPK + 8 PM (T₃), 24 NPK + 16 PM (T₄), 0 NPK + 40 PM (T₅), 8 NPK + 32 PM (T₆), 16 NPK + 24 PM (T₇) and 20 NPK + 20 PM (T₈). Experiments were laid out in a completely randomized design and were replicated four times. Vegetative, flowering, and quality parameters were collected and analyzed using the GenStat Discovery, 2014 statistical analysis software. Separation of means was determined by the Duncan Multiple Range Test (DMRT) at a probability level of 5%.

Results indicated that high rates of an organic source of N fertilizer produced higher values for vegetative and yield parameters, which was similar to the sole application of inorganic fertilizer. There was no significant effect of the sole application and combined organic and inorganic sources of N fertilizer on heavy metals and nitrates accumulation, but their effects were able to increase the values for nitrites above the recommended limits as suggested by the Joint FAO/WHO Expert Committee on Food Additives.

Our results showed that 20 NPK + 20 PM is the best treatment without any health implications in the study area, which also improved the yield and, therefore, can be considered economical.