Radiation interception, light extinction coefficient and leaf area index of wheat (Triticum aestivum L.) crop as influenced by row orientation and row spacing

Abstract

A field experiment was conducted at the B A College of Agriculture, Anand Agricultural University, Anand (India)(22°35’N, 72°55’E; 45.1 m MSL)during rabi (winter) season of 2003-2004 on a sandy loam soil to study the effect of row orientation and row spacing on radiation interception, Leaf Area Index and Light extinction coefficient in Wheat (Triticum aestivum L.) cv. GW-496 under two dates of sowing. The PAR values in terms of incident/incoming PAR and transmitted PAR at the field were measured after canopy development (i.e. 23 Days after sowing) at 10 day intervals at 0900-1000 h, 1200-1300 h and 1500-1600 h in a day with a Sun San Canopy Analysis System (Delta-T Devices, UK). LAI was also measured directly by the Sun Scan Canopy Analysis System at noon. The instantaneous values were averaged for that day and were converted to MJm-2 day-1. Solar radiation was recorded by a Pyranometer. The conversion of the daily solar radiation to PAR was made by employing a 0.5 fraction. Narrow NS (North-South) rows in general produced higher LAI throughout the growing season. NS row with narrow spacing was the most effective treatment in relation to the accumulated IPAR values, although the differences in the values corresponding to other treatments were not remarkable. The fluctuations in extinction coefficient (k) values were less random in NS rows than those corresponding ones for EW rows.

Modelling the impacts of climate variability on crop yields in Nigeria: performance evaluation of RegCM3-GLAM system

“…These results suggest that improvement of TE means maximization of crop production per unit of water use. Thus, manipulation of radiant energy within a crop field by an appropriate adoption of crop stand geometry, like row orientation and row spacing, can provide a means to create light‐saturated conditions for crop canopy for the purpose of efficient harvest of solar energy for agricultural production (Lunagaria and Shekh, ).…”

Unified representation of the C3, C4, and CAM photosynthetic pathways with the Photo3 model

“…o Based on Lunagaria and Shekh (2006) p Based on Bandyopadhyay et al (2003) q Based on Kerstiens (1996)…”

Improving Representation of Crop Growth and Yield in the Dynamic Land Ecosystem Model and Its Application to China

“…where ΔQ root is the daily increment in the root biomasses (g m À2 day À1 ); ptoroot is the daily accumulated root carbon (g C m À2 day À1 ); ΔC is the daily newly accumulated carbon (g C m À2 day À1 ); rho is the fraction of the carbon allocated to the root; Alloc_root is the allocation fraction of the newly accumulated carbon to the root (0-1), which is a cultivar-specific parameter in Table 1; L light is the scalar light available; W water is scalar water available; N nitrogen is the scalar available nitrogen; f(N) is a nitrogen factor that affects grain filling; LAI is the actual leaf area, which is determined by the same calculation process as that of the natural vegetation in the DLEM 2.0 version (Pan et al, 2014;Tian, 2002;; btrans is the water limitation factor on evapotranspiration, which is calculated by soil water content (Pan et al, 2014;Tian, 2002;; N leaf is the actual leaf nitrogen concentration; and N leaf_opt is the optimal leaf nitrogen concentration for photosynthesis (g N/m 2 ), which is calculated based on leaf carbon content and the minimum leaf CN ratio (CN min, leaf ; Table S1 in the supporting information; Pan et al, 2014;Tian, 2002;. The ext coef is the canopy light extinction coefficient, which is a cultivar-specific parameter in the parameter table (Table S1 in the supporting information, refer from Awal et al, 2005;Calderini et al, 1997;Dingkuhn et al, 1999;Flénet et al, 1996;Lunagaria & Shekh, 2006;Shearman et al, 2005). In the DLEM-AG2.0, nitrogen cycling is the same as that for natural vegetation in the DLEM 2.0 version (e.g., Lu et al, 2012;Ren et al, 2011;Tian, Xu, et al, 2011).…”