Microclimate and thermal indices of garden pea (Pisum Sativum L.) under poplar (Populus Deltoides Bartr.) based agroforestry system

Agroforestry is a practically feasible, scientifically and ecologically sound system that has emerged as a viable land use system for crop diversification and a way to achieve the target of bringing 33.3% of the total area under forest as against 24.6% of the current area for maintaining ecological balance (Anonymous, 2021). Modification in climatic factors viz. temperature, relative humidity and photosynthetic active radiation (PAR) has been recorded beneath the poplar canopy as compared with open field conditions (Singh et al., 2019; Bhardwaj et al., 2021). [...]the present study was conducted to analyze the microclimate modifications along with the computation of agroclimatic indices for different garden pea varieties cultivated under poplar block plantation. The current investigation was conducted at the main experimental area of the Department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana, during the rabi season 2021-22. For the computation of PAR interception (%), the incoming and outgoing radiations on top of the crop canopy and transmitted radiations at the ground surface below the crop canopy were measured: PAR interception(%) = (ProQuest: ... denotes formula omitted.) Where, IPAR = Incident solar radiation (W m'2), RPAR = Reflected solar radiations (W m-2), and TPAR = Transmitted solar radiation (W m-2) Agroclimatic indices The agroclimatic indices viz., accumulated growing degree days (GDD), accumulated photothermal units (PTU), accumulated heliothermal units (HTU) and heat use efficiency (HUE) were calculated as per the standard formulae (Gill et al., 2014).