Crop Yield and Growth Trait Response to Varied Nitrogen Fertilization and Pre-Planting of Cover Crops in Rice (Oryza sativa L.)

This study was performed to investigate the effect of nitrogen fertilizer levels and pre-planting of cover crops on some vegetative traits and yield of rice plants.

This was conducted over 2017-2018 and 2018-2019, at the research farm of Sari University of Agricultural Sciences and Natural Resources. The experimental design employed a three-replicated split-plot arrangement within a randomized complete block design. The main plots involved five nitrogen consumption levels (0, 120, 240, 320, and 400 kg ha-1). The sub-plots included four types of pre-planted cover crops (no cover crop, canola, bersim clover, and rye).

Based on the findings, employing berseem clover as a cover crop in pre-sowing resulted in a significantly more favorable rice yield than others. Nitrogen fertilizer at rates of 320- 400 kg ha-1 led to enhanced vegetative traits, yield, and various yield components, including leaf area index and tiller number, ultimately resulting in increased overall yield. Results revealed that planting bersim clover cover crop before planting rice, along with 320 kg ha-1 of urea fertilizer, leads to 41.5% higher yield compared to no fertilizer).).

Bersim clover stood out among the pre-planting cover crops, significantly enhancing many rice traits. Additionally, no significant difference was observed between urea fertilizer levels of 320 and 400 kg ha-1 in several measured traits. Thus, the integrated treatment of bersim clover cover crop and 320 kg ha-1 of urea fertilizer is recommended before planting rice.