旱地全膜覆土穴播荞麦田土壤水热及产量效应研究

Effects of whole soil-plastic mulching with hole-sowing on soil temperature,moisture and yield of buckwheat in aridlands

2015 2017 年在西北黄土高原半干旱区设全膜覆土穴播(FMS)和露地穴播(CK) 2 种种植方式,研究西北黄土高原全膜覆土穴播对旱地荞麦农田土壤水分和温度、产量及水分利用效率的影响,为寻求半干旱区荞麦高产高效的技术途径提供理论依据。结果表明, FMS 较 CK 使荞麦苗期提前 2.0~2.7 d,分枝期提前 2~3 d,现蕾期提前 0~1.7 d,而灌浆期延长 4.7~7.0 d。全膜覆土穴播(FMS)提高平水年(2015)和欠水年(2016)荞麦农田的土壤贮水量,较 CK 增加 16.9mm 和 25.59 mm,提高 2.91%和 5.79%,差异显著(P<0.05),但丰水年(2017)处理间差异不显著。在平水年和丰水年,0~25 cm 土壤平均温度 FMS 较 CK 分别增加 2.27℃和 2.20℃,但是在高温干旱年, FMS 分枝期至灌浆期明显低于 CK,全生育期内 0~25 cm 土壤平均温度 FMS 较 CK 降低。成熟期 FMS 干物质量较 CK 增加 13.46%~137.87%,叶面积指数增加 16.22%~52.55%,株高增加 12.78%~48.91%,单株粒重增加 33.39%~60.90%,籽粒饱满率提高 8.48%~9.14%。3 年全膜覆土穴播荞麦生育期 0~300 cm 土壤耗水量增加 3.89%,但差异不显著,产量增加 7.26%~95.25%,水分利用效率提高 7.59%~87.08%,差异显著(P<0.05),而且越干旱年份增产增效愈加明显。全膜覆土穴播能够提高荞麦播前土壤贮水量,降低高温时段的土壤温度,延长灌浆期,显著提高叶面积指数和生物量,促进荞麦植株发育,使得产量和水分利用效率明显升高。

To provide a theoretical basis for exploring a high-yield and high-efficiency technique for buckwheat (Fagopyrum tataricum [L.] Gaertn.) in semiarid areas of China, we carried out long-term field experiments (2015 to 2017) at the Dingxi Experiment Station of Gansu Academy of Agricultural Sciences in the Loess Plateau of northwestern China. Two planting patterns, namely whole field soil-plastic mulching with hole-sowing (FMS), and hole-sowing on bare soils (CK), were set to investigate the effects of FMS on soil temperature, moisture, yield and water use efficiency (WUE) of buckwheat. Compared with CK, FMS advanced seedling stage of buckwheat 2.0 to 2.7 days earlier, branching stage 2 to 3 days earlier, and budding stage 0 to 1.7 days earlier, and extended the filling stage 4.7 to 7.0 days longer. FMS increased soil water storage (SWS) of 0 to 300 cm layer in normal (2015) and dry years (2016) by 2.91%(16.9 mm) and 5.79%(25.59 mm)(P < 0.05), respectively. However, no significant difference was found between them in the wet year of 2017. FMS increased average soil temperature (Ts) in 0?25 cm layer by 2.27℃ and 2.20℃ in normal and wet years, respectively. While in dry year with higher temperature, FMS lowered Ts during branching to filling stages. Similarly, FMS appreciably decreased seasonal mean Ts of 0 to 25 cm layer compared with CK. At maturity, FMS increased dry matter weight (DM) by 13.46% to 137.87%, leaf area index (LAI) by 16.22% to 52.55%, plant height by 12.78% to 48.91%, grain weight per plant by 33.39% to 60.90%, and grain plumpness rates by 8.48% to 9.14%. On average,FMS increased crop water consumption in 0 to 300 cm soil layer by 3.89% during the three consecutive years, but the difference was not significant (P > 0.05). Nevertheless, FMS increased yield by 7.26% to 95.25%, and WUE by 7.59% to 87.08%(P < 0.05). The results demonstrated that the high-yield and high-efficiency of FMS were more significant during drier years. In conclusion, FMS could increase SWS prior to sowing, decrease Ts during high-temperature periods, prolong filling stage, and markedly increase LAI and DM, resulting in the promoted the development of plants, and the significantly enhanced yield and WUE of buckwheat.