关键词: 玉米, 产量, 种植方式, 垄沟集雨, 土壤水热效应, 黄土高原, 半干旱区

Abstract:

【Objective】 This experiment explored the dynamic changes of soil water and thermal environment and spring maize yield and water use efficiency in semi-arid areas of the Loess Plateau, which provided a theoretical basis for optimizing the soil water and heat environment and improving the crop yield of spring maize field in the dry farming area in central Gansu. 【Method】 The field positioning experiments were carried out in Yuzhong Agricultural Technology Promotion Center of Gansu from 2017 to 2018, which were set up 6 planting methods, including non-contoured seedbed with film mulching (WM), non-contoured seedbed with half film mulching (HM), ridge-furrow with polyethylene film and straw mulching (MRM), ridge-furrow with full film mulching (WRF), ridge-furrow with straw mulching (SM) and non-contoured seedbed without mulching (CK). Based on the experiments, the water and heat conditions of soil layers profiles in different fertility period of spring maize, phenological characteristics, yield and water use efficiency during harvest period were measured and analyzed. 【Result】 In this study, the film mulching treatment had a warming effect compared with CK, the average soil temperature during the whole growth period was 2.42 °C, while the SM showed a cooling effect with an average temperature drop of 0.36 °C, and the adjustment of soil temperature by the planting method was mainly manifested in the seedling stage, the effect of temperature regulation gradually weakened with the progress of growth period. MRM, WRF, HM and SM had significant effect on the preservation of spring maize during the whole growth period, while WM was not conducive to precipitation collection. It only had the effect of preserving in the early stage of spring maize growth, while the water consumption in the middle and later stages increased with the crop growth, and the soil moisture content was lower than that under CK. The most water consumed of spring maize was in the middle growth stage (jointing to silking), followed by the later growth stage (silking to maturity), and the least was in the early growth stage (budding to jointing), in which the water consumption of plastic film mulching was greater than straw mulching, and full film mulching was greater than half film mulching. Plastic film mulching planting method could improve biomass water use efficiency of spring maize least and middle growth stage significantly. The improvement was highest (up to 250.68%) at early growth stage of HM and at the middle stage of WRF (up to 61.30%), compared with CK. Plastic film mulching planting method resulted in increased soil temperatures and improved soil water consumption, therefore, these treatments extended the growing period for spring maize and increased the dry matter weight per plant, the final performance was the improvement of yield and water use efficiency. The most significant effect on increasing yield and water use efficiency was WRF and MRM, increased yield by 171.40% and 155.05%, respectively, and increased water use efficiency by 142.80% and 125.44%, respectively, compared with CK. 【Conclusion】 The plastic film mulched ridge and sowing furrow planting changed the soil water and thermal environment and increased dry matter accumulation in semi-arid areas of the Loess Plateau. The yield and water use efficiency of the ridge-furrow with full film mulching planting method was the best under these treatments.

Key words: maize, yield, planting methods, ridge-furrow rainwater harvesting, soil temperature and moisture, Loess Plateau, semi-arid area