Hydrothermal effects on maize productivity with different planting patterns in a rainfed farmland area

Mulch planting techniques are widely used to increase the productivity of rainfed farming. However, the key resources (solar radiation, temperature, and precipitation) that affect crop production vary greatly in different dryland areas, and the best results will not be achieved if farmland planting methods are applied blindly. This study was initiated to identify the appropriate farmland planting patterns based on regional hydrothermal characteristics. Four different planting patterns were tested for several years in semiarid (2013–2018) and semi-humid (2015–2018) sites in the dryland area of northwest China: (i) ridge-furrow planting pattern where only the ridges were mulched using plastic-film (R), (ii) flat planting pattern with full plastic-film mulch (P), (iii) flat planting pattern with full straw mulch (S), and (iv) conventional tillage without mulch (control). The crop productivity and related factors were studied, i.e., air temperature, precipitation, soil moisture and soil temperature. Hydrothermal conditions significantly affected the crop productivity performance under different planting patterns. The average yield increased by 33.3 %, 73.8 %, and –10.4 % in the semi-arid area, under R, P and S, respectively, and by 17.3 %, 17.5 %, and 6.7 % in the semi-humid area. In addition, the water use efficiencies under R, P, and S was 26.8, 33.5, and 18.3 kg mm–¹ ha–¹, respectively, in the semiarid area, and 30.4, 28.8, and 27.3 kg mm–¹ ha–¹ in the semi-humid area. Redundancy analysis (RDA) showed that the soil temperature from seedling to jointing was the most important environmental factor that affected crop productivity in the semi-arid area, followed by evapotranspiration and precipitation during the growth period. The difference in crop productivity in the semi-humid area was mainly determined by precipitation during the growth period and evapotranspiration. Therefore, screening appropriate planting methods based on the major limiting factors in different regions is effective for maintaining farmland productivity.