Yield and quality of forage maize as a function of diverse irrigation regimes and biofertilizer in the west of Iran

Abstract

Maize in the west of Iran is the most important cultivation after winter cereals like wheat and barley. Applying biofertilizers is recommended strategy for improving yield and quality of silage maize, in response to challenges of water shortage and high pollution of chemical fertilizers in the region. This study aimed to assess forage yield and quality of silage maize under various irrigation regimes (optimum, 80% and 60% of water requirement), chemical fertilizer (100% and 50% of recommended dose), and vermicompost (0, 3 and 6 ton ha⁻¹) rates, in a two-year trial. Results suggested that with the optimal irrigation, using high chemical fertilizer and 6 ton ha⁻¹ vermicompost increased LAI (4.52), plant height (225 cm), chlorophyll SPAD (46.6), fresh yield (82.5 ton ha⁻¹) and dry yield (35.2 ton ha⁻¹) to the maximum extent. Vermicompost reduced the acid detergent fiber (ADF) and neutral detergent fiber (NDF) and increased relative water content (RWC), crude protein (CP) of silage maize in almost all water and fertilizer rates. In irrigation treatment by 60% of water requirement and 50% of chemical fertilizer, vermicompost at the rate 6 ton ha⁻¹ increased fresh yield by 26.26% and crude protein by 6.9%. Applying high rate of vermicompost compensated for the 50% reduction in chemical fertilizer and maintained water use efficiency (WUE) at highest value. Linear regression model showed that CP increased, whereas both ADF and NDF decreased with increasing forage yield. The findings recommend combine using of chemical and vermicompost for improving yield, WUE and quality of silage maize.

Keywords:

• Chemical fertilizer
• fiber
• protein
• vermicompost
• Zea mays L

Acknowledgements

The authors would like to thank Agricultural Resources Research and Education Center (AREEO). The authors also would like to thank Maryam Rahimi Jahangirlou, PhD student of University of Tehran in Agrotechnology for his guidance with the regression analyses.

Disclosure statement

No potential conflict of interest was reported by the authors.