Effects of different plastic-film mulching techniques on maize (Zea mays L.) dry matter accumulation and yield

Plastic-film mulching is an effective yield-increasing technique in arid areas. Previous studies on film mulching have reported constant improvements in the techniques and understanding of the use of plastic-films in production systems. Different film mulching modes have different maize yield-increase effects in different areas. Field experiments were therefore conducted to determine the best plastic-film mulching technique in maize production for all regions. The effects of four plastic-film mulching techniques — full plastic-film mulching on double ridges and planting in catchment furrows (FF), half plastic-film mulching on double ridges and planting in catchment furrows (HF), flat planting with half plastic-film mulching (FN), and plastic-film mulching on ridge and planting in side film mulch (FS) — on leaf area, photosynthetic potential, dry matter accumulation, ear characteristics, grain yield and water use efficiency were compared with flat planting of zero-film mulching (CK). Cost-benefit analysis was also performed in the study. Results indicated that leaf area under FF and HF treatments significantly increased at the developmental stages but changed little under FN and FS treatments compared with CK. Photosynthetic potential also significantly increased at all stages of development under FF, HF and FS treatments. However, it was positively affected at the initial stages of growth and negatively affected at the later stages of growth under FN, FF and HF treatments. Maize ear length, diameter, row number and row grain number increased and as well lengthened ear barren tip. Although FN somewhat accelerated the increasing processes of ear length, diameter and row number and retarded that of ear barren tip, it had no obvious effect on row grain number. To some extent, FS improved ear length, row number and row grain number. However its effect on ear diameter and length of barren tip was not remarkable. All plastic-film mulching techniques increased ear grain number and 100-grain weight, but decreased ear number per plant. The highest grey correlation was noted between grain number per ear and grain yield, followed by 100-grain weight, and then by the number of ear per plant. Yield of FF, HF, FS and FN increased by 67.23%, 60.08%, 38.81% and 20.02%, respectively, compared with CK. Also water use efficiency of FF, HF, FS and FN increased by 66.43%, 59.54%, 38.35% and 19.63%, respectively, compared with CK. Economic benefit of FF, HF, FS and FN respectively increased by 85.51%, 69.58%, 36.37% and 18.69% over CK. The above findings suggested that FF treatment had the higher yield and economic advantage in the study area.