Effects of mulching and maize cultivars on grain yield and photosynthetic characteristics in the Loess Plateau

Abstract

Millions of small farmers rely on maize (Zea mays L.) produced in the Loess Plateau of China. The purpose of this study was to find a fine maize variety in the Check Dam and to reveal the reasons for the effects of white plastic film mulch and maize varieties on crop yield and photosynthetic characteristics. Three maize cultivars (Dafeng 26 [DF], Xianyu 335 [XY], and Tianci 19 [TC]) were grown with and without plastic mulch in 2016 and 2017 in Ansai County, Shaanxi Province, China. Results showed that mulch increased grain yield by 10.5% in 2016 and 11.3% in 2017 across all cultivars. Among all cultivars, XY had the highest grain yield under both mulch and no mulch. Grain yield was significantly correlated with soil water content in the 0-20 cm layer. Soil temperature under mulch decreased with increasing soil depth. On average, mulch increased soil temperature from 0.2 to 1.9 • C over the entire growing season. Photosynthetic characteristics were directly determined for all tested maize cultivars. Grain yield was more closely related to photosynthetic rate in July (r = .828, P = .001; n = 12) than in August (r = .617, P = .032; n = 12). Moreover, grain yield was correlated with stomatal conductance and transpiration rate in July and August (r = .913-.928, P < .001; n = 12). Our findings suggest that photosynthetic characteristics were an important index affecting maize grain yield for small farmers using check dams in the Loess Plateau.