Bed planted rice-wheat rotation at differential soil moisture regimes on soil hydro-physical properties, root growth, nitrogen uptake, and system productivity

摘要

Along with most widely practiced resources conserving technology zero-tillage wheat after rice, adoption of permanent beds for rice-wheat rotation is also gaining popularity. Since relatively a new approach particularly for dry-seeded rice and permanent beds for wheat, very little information is known about permanent beds on soil properties, nutrient (N) use efficiency, and system productivity. A field experiment was carried out in a Typic Haplustept soil of New Delhi, India to study the effect of permanent beds on soil hydro-physical properties, root growth, nitrogen uptake, and system productivity of irrigated rice-wheat rotation. Results revealed that direct-seeded rice followed by wheat on permanent beds irrigated at different soil water tensions (field capacity, 20 and 40 kPa) reflected a significant variation in soil hydro-physical properties, reduced total nitrogen uptake, contribution by different plant parts, and N use efficiency compared to wheat after flooded transplanted rice system. Rice root weight density at flowering was also significantly low at 0-15 cm depth but higher at 15-60 cm depth in dry-seeded rice on beds. System productivity of rice-wheat rotation was 25-33% lower in permanent beds compared to flooded transplanted system. For wider acceptability of permanent beds as a promising resource conserving technology, system productivity needs to be improved.