Photosynthetic light response models for spring wheat mulching treatments in a northwestern China desert oasis

Abstract

AbstractIn the desert oasis areas of northwestern China, mulching treatments are an effective method for alleviating drought in agricultural production. Four mulching treatments of polyacrylamide (PAM), which is a water retention agent; plastic film; stones; straw; plus an unmulched control treatment were used in the field to explore their influence on soil water content (SWC), soil temperature, the net photosynthetic rate (Pn), leaf area index (LAI), and yield in spring wheat (Triticum aestivum L.). Six light response models were used to simulate the light response of wheat. A significant difference was found between straw and the control vs. the other mulching treatments in terms of grain yield and yield components of spring wheat (p < .05). Under the film treatment, the yield increased by 9.8–16.9% and the water use efficiency (WUE) increased by 20% in 2012 and 23% in 2013. Compared with PAM, stone, straw, and the control, the film mulch had the largest maximum photosynthesis and the largest rate of light adaptation. The nonrectangular hyperbolic had the smallest error and simulated the best photosynthetic light response. Compared with the control treatment, the soil temperatures were reduced by a mean of 8.5–11.3 °C and the average SWC increased by 5.5–3.2% under all mulching treatments. However, SWC had a greater effect on Pn than soil temperature during the growth season under the mulching treatments, which increased yield in this arid environment. Film mulching was the best mulching treatment for spring wheat in this desert oasis.