Synergistic effects of biofertilizer with organic and chemical N sources in improving soil nutrient status and increasing growth and yield of wheat grown under greenhouse conditions

Biofertilizers have been identified as value-added soil amendments for improving efficiency of applied fertilizers and increasing soil fertility and crop productivity in sustainable farming system. This study explored the effect of biofertilizer (a mixture of Pseudomonas, Azospirrillium and Agrobacterium strains) supplemented with organic and mineral N fertilizers on soil properties, yield, and NPK uptake of wheat (Triticum aestivum L.) grown under greenhouse conditions. The treatments included the application of fertilizer alone or in different combinations with urea N (UN) and/or poultry manure (PM) added at various strengths. Results indicated that most of the growth characteristics were higher in treatments receiving biofertilizer supplemented with 1/2UN and full PM (200 mg N kg(-1)). However, treatments under full recommended N (200 mg N kg(-1)) or 1/2UN+full PM had similar effects. Chlorophyll contents were highest in the full UN treatment, followed by the treatment with 1/2UN+fullPM+biofertilizer. The latter significantly increased the yield and yield components of wheat compared to full UN and exhibited superiority over PM. Similarly, NPK uptake in plant shoot was highest in 1/2UN+full PM+biofertilizer compared to full UN or full PM treatments. Furthermore, our results showed that biofertilizer supplemented with PM improved soil properties, such as organic matter, NPK content and concentration of the micronutrients Fe-3 Mn, Cu and Zn. The application of biofertilizer increased the efficiency of both organic and mineral N fertilizer but alone was ineffective in increasing yield. Thus, biofertilizers could be used as value-added soil amendments by supplementing organic and low chemical fertilizer rates for improving soil fertility and sustaining crop productivity.