Rotors Wind Wall Enabled Microclimate Engineering for Enhanced Rice Leaf Morphometrics Traits, Yield and Agronomic Performance

Abstract

An exploratory investigation into the effects of unmanned aerial vehicle (UAV) airflow on microclimate engineering in rice cultivation reveals novel insights, with a specific emphasis on wind temperature and velocity dynamics during critical growth stages. This research highlights diurnal fluctuations in wind temperature and speed during the critical rice growth stages (heading, panicle and flowering). ‘Results revealed that wind wall running or UAV flying in the morning (9:00 am) produces a stable temperature of 29.31°C (σ = 0.26017) supported pollination during the heading stage’. However, by noon, increased variability caused a slight temperature drop to 29.11°C (σ = 0.26749), raising the risk of heat stress. Afternoon temperatures remained steady at 29.18°C but exhibited the highest variability (σ = 0.27663), signalling potential microclimate disruptions that could reduce grain yield. ‘Wind-speeds followed a clear diurnal pattern, rising by 33.33% from morning (1.2 m s⁻¹) to noon (1.6 m s⁻¹) and dropping by 37.5% in the afternoon’. ‘This emphasizes the importance of precise UAV operation timing, aligning rotor schedules with natural wind dynamics to achieve an 18.2% increase in crop yield and 25.8% reduction in thermal stress’. Microclimate mapping revealed significant diurnal fluctuations in wind temperature and speed, particularly around noon and afternoon, posing risks of heat and mechanical stress. During the heading stage, temperatures increased by 0.86% from morning (29.15°C) to noon (29.45°C), while wind-speeds at noon peaked at 2.0–2.5 m s⁻¹, a 100%–150% rise from morning levels. While this improved air circulation, it also introduced the risk of mechanical stress during critical pollination periods. During the heading stage, leaf shape index (LSI) remained stable with minor fluctuations (3.27–3.29), but during the panicle stage, LSI rose by 44% from morning (2.08) to noon (3.01), and then dropped by 31% in the afternoon (2.06). At the flowering stage, LSI remained steady at 3.01–3.02. Leaf number plant⁻¹ increased by 6.5% during the panicle stage, while leaf length grew by 16% at the flowering stage, highlighting the positive impact of microclimate-engineering by UAV airflow on rice growth. Leaf water content surged by 65% during the heading stage, from morning (0.40) to noon (0.66). Specific Leaf Area (SLA) was most sensitive during the panicle stage, peaking at 211.13 cm² g⁻¹ at noon, an 81.4% increase. UAV rotor airflow significantly improves microclimatic conditions during panicle and flowering stages, benefiting crop growth. Further investigation is needed to explore optimal UAV applications and understand interactions between UAV airflow, crop varieties and environmental factors.