Effects of ridging and mulching combined practices on proso millet growth and yield in semi-arid regions of China

The study is intended to find a more effective farming practice for improving proso millet production in semi-arid regions of China and a fast real-time method of estimating effects of ridging treatments on the growth and yield of proso millet. An experiment was conducted to investigate soil water contents (SWCs), soil temperatures, water use efficiencies (WUEs), growths and grain yields of proso millet in 2014 and 2015 in Yulin, Shaanxi, China. In the experiment, a control treatment (CK, a convention farming without mulching) and six ridging and mulching combined treatments were tested. The ridging treatments mostly improved the soil moistures, WUEs, growths and grain yields of proso millet compared with the CK. The highest grain yields of proso millet appeared in the ridging treatment with hills and furrows plastic film mulched (RHFPFM) in both of the years. Because of its beneficial effects in SWC, WUE and leaf area index (LAI), RHFPFM improved the growth of proso millet and increased its yield by 31.3%-35.3% in the experimental years. These benefits mostly intensified with the extensions of the corresponding mulched areas. The LAI was shown to have close relations with the aboveground dry matter, crop growth rate and yield of proso millet. The LAI regression formulae developed in the study would provide useful information for growth monitoring and yield estimation of proso millet in the ridging treatments. In this study, the RHFPFM was recommended as an effective farming practice for improving the growth and yield of proso millet in semi-arid regions of China.