Effects of continuous plastic mulching on crop growth in a winter wheat-summer maize rotation system on the Loess Plateau of China

摘要

The use of plastic mulching is considered to be a primary solution to improve crop productivity in dryland farming of northwest China. However, the interaction of this management practice on cereal crop growth and environment factors is not clearly understood. Based on a three rotation cycles field experiment from 2013 to 2016, this study, based on the logistic equation, tried to quantify the impacts of continuous plastic mulching (PM) on the crop growth dynamics in a winter wheat (Triticwn aestivum L.) and summer maize (Zea mays L.) rotation system on the Loess Plateau, northwest China. The results showed that the logistic equation did well in the characterization of wheat and maize growth dynamics with its characteristic parameter (e.g., inflection points). Both in wheat and maize growth seasons, the plant height accumulation occurred earlier than the aboveground biomass accumulation. In comparison to the crop growth under the non-mulched treatment, the acceleration effects of PM treatment on the crop growth continued to be enhanced when the apical meristem was underground. For wheat, the improved soil hydrothermal conditions under the PM treatment effectively accelerated the wheat leaves' appearance and the tiller nodes development, which increased the final spike number and grain yields. For maize, because of the greater radiation and water use efficiency during the maize growth seasons, the PM treatment increased the maize kernels per spike and the thousand-seed weight, and significantly improved maize yields. Attributable to improved soil hydrothermal conditions and beneficial interactions between the crop growth and the external environment, the PM treatment significantly improved crop production and increased resource use efficiency, which may greatly contribute to the sustainability of local dryland farming.