有机物料配合深耕混合还田快速提升砂质棕壤农业生产力的效果和机理

  【目的】  提高土壤肥力是增加作物产量的有效方式，我们尝试了不同耕作和有机肥还田方式对砂粒含量较高且贫瘠的土壤的培肥效果。  【方法】  田间试验于2018年开始，在辽宁南部砂质棕壤进行，供试作物为玉米。以常规浅翻15 cm (T15)为对照，设置了秸秆浅混还田(0—15 cm，T15+S)、深翻35 cm (T35)、秸秆深混还田(0—35 cm，T35+S)、有机肥深混还田(0—35 cm，T35+M)、秸秆有机肥深混还田(0—35 cm，T35+S+M)、免耕(NT)、免耕秸秆覆盖(NT+S)和免耕秸秆条覆盖(HT+HS)处理，共9个处理 。2020年玉米收获后，测产，同时取0—15 cm和15—30 cm土层样品，测定土壤pH、有机质和养分含量以及有机碳储量。  【结果】  试验进行3年后，在0—15 cm土层，T35+M和T35+S+M处理土壤有机质含量增幅较T15分别增加了19.2%和20.4%，而NT和T35处理则显著降低；在15—35 cm土层，T35、T35+S、T35+M和T35+S+M处理土壤有机质含量较T15分别增加了12.5%、24.5%、29.9%和35.7%。深翻和有机物料还田(T35+S、T35+M和T35+S+M)显著增加了玉米产量，与T15处理相比，3年T35+S、T35+M和T35+S+M处理玉米产量平均增加了10%、12.3%和16.4%，而浅翻处理(T15+S、NT、NT+S和HT+HS)不同程度地降低了玉米产量。T15+S、HT+HS和NT+S处理间有机质转化率无显著差异，但与T35+S处理相比平均降低了57.9%，与T35+M处理相比平均降低了78.4%。0—15 cm土壤有机质和pH对玉米产量影响显著，而在15—35 cm土层，除pH外，有机质和养分含量以及有机碳储量均对玉米产量有显著影响。  【结论】  腐熟猪粪、猪粪和玉米秸秆配合深翻混合还田可以快速提升0—35 cm土层中的土壤有机碳储量，提高有机质的转化率，是较为理想的棕壤快速培肥途径。通过提高深层土壤有机质和养分含量，提高了辽宁南部棕壤的农业生产能力。

Application of manure and straw by deep plough rapidly improves fertility and productivity of brown sandy soil

  【Objectives】  Ameliorating soil fertility is an effective way to increase crop yields, especially in soils with a coarse sandy loam.   【Methods】  We conducted a field experiment in 2018 on the brown soil in southern Liaoning, China, using nine treatments: conventional shallow tillage (0?15 cm, T15) served as the control, and conventional shallow tillage with maize straw return (T15+S), inversion tillage (0?35 cm) without or with straw return (T35 and T35+S), inversion tillage (0?35 cm) with pig manure (T35+M) and pig manure plus maize straw (T35+S+M), no tillage without or with maize straw mulching (NT and NT+S), and no tillage with maize straw ridged-mulching (HT+HS).   【Results】  Compared with T15 in the 0?15 cm soil layer, soil organic matter content was increased significantly by 19.2% and 20.4% in T35+M and T35+S+M, while NT and T35 significantly decreased. Soil organic matter content in T35, T35+S, T35+M and T35+S+M was 12.5%, 24.5%, 29.9%, and 35.7% higher than that in T15 in the 15?35 cm soil layer, respectively. In the three experimental years, maize yield showed similar trends among the different treatments, that is, inversion tillage and organic material returning significantly increased maize yield. The average maize yield in T35+S, T35+M and T35+S+M was increased by 10%, 12.3%, and 16.4% in the three experimental years, while the yield in T15+S, NT, NT+S, and HT+HS was decreased compared with T15. The increase in soil organic matter and available nutrient content were the main factors influencing maize yield and contributed significantly to it.   【Conclusions】  Inversion tillage with organic materials is a more effective way to improve soil fertility, which could enhance the agricultural productivity of brown soil in the southern part of Liaoning Province.