Continuous film mulching enhances maize root growth and grain yield by improving soil aggregates characteristic in semiarid areas of China: An eight-year field experiment

Abstract AimsFilm mulching has been widely used in agricultural production in semiarid areas. While studies regarding the long-term effects of different film mulching methods on soil aggregates and stability are still lacking. MethodsIn the Loess Plateau of China, a 8-year continuous field experiment was conducted on soil aggregate and stability, and crop yield with five different film mulching treatments: (i) a control method, flat planting without mulching (CK); (ii) alternate mulching and bare rows without ridges (P); (iii) planting furrows separated by consecutive plastic film-mulched ridges (S); (iv) double ridge-furrow with full plastic film mulching (D); and (v) traditional ridge-furrow rainwater harvesting planting (R). The indexes were used to expressed soil aggregate stability by mean-weight diameter (MWD), geometric mean diameter (GMD), fractal dimension (FD), percentage of aggregate destruction (PAD) and unstable aggregates index (ELT).ResultsAfter 8 years continuous film mulching, soil quality was significantly improved. Compared with CK, mulching could decrease soil bulk density (2.96%-4.54%), and increase soil porosity (2.45%-4.00%), soil macroaggregate content (7.39%-22.92% by dry-sieving, 8.49%-21.67% by wet-sieving), soil aggregate stability and crop yield (29.98%-63.96%), especially under S and D treatments. D and S significantly improved soil structure (soil aggregate content and stability) with the increase of crop root biomass (43.59%, and 47.25%, respectively), compared with other mulching treatments. The root system characteristic parameters under S and D treatment were significantly higher than R and P, especially during 60–120 days after planting.ConclusionsOn the whole, the S treatment has a greater effect on crop yield increase and soil quality improve, and thus it was suggested as an effective mulching pattern on stimulate and stable crop yields in the Loess Plateau of China.