Assessment of precision levelling on water saving and crop yield in rice-based cropping systems

Abstract:

A clear trend across South Asian rice research is the growing gap between water availability and crop water demand—a gap that precision land levelling can partly close. This research compared laser-guided precision levelling (PL) with traditional farmer-levelled fields (TL) across two rice–wheat cycles (2021–22 and 2022–23) at Dr. Rajendra Prasad Central Agricultural University, Pusa, Bihar. PL reduced total irrigation water applied to rice by 20.4% (1,067 vs. 1,340 mm) while raising grain yield by 18.2% (4.87 vs. 4.12 t ha⁻¹). Water productivity improved from 3.07 to 4.56 kg grain m⁻³. In the subsequent wheat crop, PL plots maintained a 12.7% yield advantage. The benefit-cost ratio of PL was 2.18 compared with 1.74 for TL. These results confirm that one-time laser levelling generates multi-season water and yield benefits in the rice–wheat system of the eastern Indo-Gangetic Plains.