Forage Mass and Water Use Response to Irrigation Time in North China

Abstract

Siberian wildrye grass (Elymus sibiricus L.) is the primary forage species in alpine cold areas of North China. Scheduled irrigation is an important way to increase the forage mass because of water shortage and the inconsistency between rainy season and the most intense water use period. Irrigation experiments were conducted during 2006 to 2008 to study the feasibility of applying single irrigation before winter (WI) or at the elongating stage (EI), irrigating at these two stages (WEI, in 2006-2007), and irrigating before winter with mulching straw before next reviving (WMI, only in 2008) to increase forage mass (FM) and water use effi ciency (WUE). Th e results showed that irrigation at the elongating stage played the most important role in mass and WUE increase. Th e FMs under EI achieved 6381, 6883, and 5763 kg ha −1 , increased by 66, 218, and 99%, respectively, and WUE was 1.9, 2.3, and 1.8 kg m −3 , increased by 56, 134, and 81%, respectively, compared with no irrigation treatment (NI) in 3 yr. Th e FMs under WI were increased by 40, 53, and 44%, and the WUE was increased by 30, 31, and 34%, respectively. No signifi cant FM and WUE increment under WEI were found compared with EI during 2006 to 2007. Th e FM and WUE under WMI were higher than values under EI in 2008. Th erefore, EI can achieve relatively high production and WUE of Siberian wildrye grass. If water resources at the elongating stage were defi cient, the WMI treatment might be a good choice.

Yield and Water Use of Siberian Wildrye with Ridge and Furrow Planting in Northern China

“…Plastic mulch on the ridge (MRB and MRM treatments) resulted in relatively high WUE values ranging from 15.0 to 28.8 kg ha –1 mm –1 , compared with WUE values ranging from 6.8 to 14.0 kg ha –1 mm –1 for the FB treatment. The WUE values for the FB treatment were comparable to those reported by Wang et al (2009a, 2010) for rainfed conditions, ranging from 9.0 to 13.0 kg ha –1 mm –1 . The WUE values for the MRB and MRM treatments were similar to the WUE values of 17.8 to 23.0 kg ha –1 mm –1 under a single irrigation at the stem elongation (jointing) stage reported by Wang et al (2009a, 2010) and 17.0 kg ha –1 mm –1 with full irrigation (Wang et al, 2009a).…”

“…In this study, relatively high forage yields were consistently obtained with the MRB and MRM treatments, ranging from 3990 to 6720 kg ha –1 . In comparison, the forage yield for the FB treatment was comparable to the yields reported by Wang et al (2009a, 2010), which ranged from 2160 to 3850 kg ha –1 under dryland conditions. In this study, forage yield for the MRB and MRM treatments was lower than that reported by Wang et al (2009a, 2010) with a single irrigation at the stem elongation (jointing) stage (5730–6880 kg ha –1 ) and was lower than that reported by Wang et al (2009a) under full irrigation (6490–7130 kg ha –1 ).…”

Yield and Water Use Efficiency of Non‐ and Single‐Irrigated Alfalfa with Ridge and Furrow Planting in Northern China

“…Irrigation plays an important role in increasing forage yield around the world, especially in semiarid areas (Smeal et al, 2005; Li et al, 2007). The water requirement of alfalfa ranges from 700 to 1600 mm per year (FAO, 2002; Kuslu et al, 2010), however, the mean annual precipitation ranges from 300 to 400 mm in semiarid northern China (Wang et al, 2010). Sufficient irrigation water is not available or is costly in this region, and deficit irrigation can be used to increase yield and WUE (Kang et al, 2002; Zhang et al, 2004; Fereres and Soriano, 2007).…”