Crop row spacing and its influence on the partitioning of evapotranspiration by winter-grown wheat in Northern Syria

Abstract

A study was conducted during the 1996-97 crop growth season at ICARDA in northern Syria, to investigate the influence of wheat canopy architecture on the partitioning of moisture between soil evaporation and crop transpiration, on a soil with high hydraulic conductivity. The study was conducted on the long-term two course wheat-lentil rotation trial, established on a swelling clay soil (Calcixerollic xerochrept). The wheat canopy architecture was manipulated by sowing the crop at either of two row-spacings, 0.17 or 0.30 m, both at a constant sowing rate equivalent to 120 kg ha −1 . In this study, evapotranspiration from the crop was inferred from changes in soil moisture content over time, evaporation and rainfall interception were measured daily using microlysimetry, drainage was estimated as being the difference between potential daily evapotranspiration, and the evapotranspiration estimated from the soil water deficit. Between sowing and day 80 (tillering stage), evapotranspiration was calculated to consist mainly of soil evaporation. However, after day 80, transpiration became an increasingly dominant component of evapotranspiration. For both row-spacings, cumulative evapotranspiration over the season was approximately 373 mm. In the narrow-row crop, transpiration and soil evaporation were approximately 185 mm and 183 mm of water respectively. Conversely for the wide row-spaced crop, 172 mm of water was transpired while about 205 mm of water evaporated from the soil surface. While green leaf area index did not differ between row-spacings, the architecture of the crops as a result of sowing affected solar radiation penetration such that more incident radiation was intercepted at the soil surface of the wide row-spaced crop. This is likely to have made some contribution to the elevated levels of evaporation from the soil beneath the canopy of the wide-sown crop.Abbreviations: Ep -potential evaporation measured using a Class A pan evaporation basin, Et -evapotranspiration; T -transpiration; Es -soil evaporation; P -precipitation measured at a height of 1.2 m above the ground surface; I -precipitation intercepted by the crop canopy; Pe -precipitation at the soil surface; θ v -soil volumetric moisture content.

Radiation use efficiency and yield of winter wheat under deficit irrigation in North Chin

“…Some researchers studied the effects of deficit irrigation on the evapotranspiration (Eberbach and Pala 2005), water use efficiency (Lauenroth et al 2000, Angus and Van Herwaarden 2001, Li et al 2008b) and yield (Pan et al 2003) of winter wheat; Zhang et al (1999) discussed the relationship between evapotranspiration and yield. These studies, however, have not reported the integrated effects of the deficit irrigation on the radiation use efficiency (RUE) in North China.…”

Effect of sowing techniques on the agroecological parameters of cereal crops

“…В исследованиях применялись полевой, вегетационный и лабораторный методы (Foulkes et al, 2011;Hochman et al, 2009;Naresh et al, 2012;Oyewole, Attah, 2007); свойства почв определялись по общепринятым методикам (Eberbach, Pala, 2005;Foulkes et al, 2011;Malik et al, 2009). Оценка качества посева проводилась в полупроизводственных опытах по основным предшественникам яровой пшеницы (пар, горох, пшеница) в трехкратной повторности по схеме, представленной в табл.…”

“…Среди агротехнических приемов (предшественник, обработка почвы и др.) в получении полноценных всходов зерновых немаловажное значение имеет посев (Chen et al, 2010;Eberbach, Pala, 2005;Foulkes et al, 2011;Naresh et al, 2012). Задача посева состоит в получении дружных всходов посредством оптимального использования способа, срока посева, нормы высева, глубины заделки и распределении семян, ширины междурядий (Chen et al, 2010;Liang et al, 2011;Pandey et al, 2013;Shah et al, 2006).…”

Variation in Growth, Yield and Quality of Happy Seeder Sown Wheat with Different Planting Patterns and Times of Nitrogen Application

“…Row spacing requirements of wheat depend on architecture and growth pattern of the varieties. For higher yield, higher proportion of incident radiation at the soil surface must be intercepted by the crop canopy (Eberbach and Pala, 2005). Skip planting geometry with pairs of row allow more light penetration inside plant canopy, while in solid geometry the field is more populated and there is less light penetration inside plant canopy.…”