The effect of different fertilizer sources on qualitative characteristics of forage maize under water deficit stress conditions

To study the effect of different fertilizers on reducing the effects of water deficit stress on forage maize (KSC703), an experiment was carried out as split plots in randomized complete block design with three replications in West Azerbaijan, Iran, in 2016. Irrigation treatments including irrigation at 80% field capacity (normal irrigation) and irrigation at 50% field capacity (water deficit stress) were considered as main factor and fertilizer sources including control (water spraying), organic-biofertilizer, complete fertilizers (chemical, nano) and combined application of 50% fertilizers (organic-biofertilizer + nano, organic-biofertilizer + chemical fertilizer, chemical + nano) as sub-factor. The results of mean comparisons indicated that the highest content of photosynthetic pigments (chlorophylls-a and -b) were observed under normal irrigation conditions and combined application of 50% chemical+nano fertilizers which resulted in the highest fresh (70 t.ha-1) and dry (32 t.ha-1) forage yield. This treatment combination resulted in a 47% increase in fresh and dry forage yield compared to control fertilizer treatment. The highest proline content was obtained from nano fertilizer treatment under water deficit stress conditions. Most fertilizer treatments increased leaf potassium under both irrigation conditions. Also, application of most fertilizer treatments under normal irrigation conditions increased crude protein, dry matter digestibility, water soluble carbohydrates and crude fiber content compared to the control treatment. Based on the results of this research, combined application of 50% chemical+nano fertilizers was determined as an effective fertilizer combination under both irrigation conditions due to improvement of some quantitative and qualitative characteristics of forage maize.