垄沟集雨种植下不同降解地膜沟覆盖对农田马铃薯产量和土壤水热的影响

为筛选适宜于西北旱作区沟垄集雨系统下马铃薯生长和产量提高的降解地膜类型,于2015—2016年设置两年田间试验,以平作不覆盖为对照(CK),研究生物地膜(DS)、麻纤维地膜(DM)和液态地膜(DY)的降解特征、土壤水热效应及其对马铃薯生长、产量的影响。结果表明,两年试验期内不同类型降解地膜的降解失重率整体表现为DY>DM>DS,DY完全降解,DM和DS两年平均降解失重率达72.3%和38.3%。两年生育期平均土壤蓄水量各处理表现为DS>DM>DY≈CK,DM和DS在生育关键期(播后70 d)有效增加0~160 cm层土壤蓄水量,2015年较CK分别增加29.0%和15.6%,2016年分别增加17.8%和11.6%;而DY与CK无显著差异。与CK相比,DY在播后30~50 d土壤保温效应显著,DM 在播后0~70 d土壤增温效果尤为显著;在播后110 d各处理土壤增温效应差异不显著。土壤水分、温度与马铃薯总产量Pearson相关分析表明,播后30 d土壤水分、温度对马铃薯总产量的形成至关重要,且播后70~90 d土壤水分对总产量的影响高于土壤温度。与CK相比,DM、DS和DY的马铃薯产量2015年分别显著增加20.3%、17.4%和9.2%,2016年分别显著增加18.1%、17.0%和12.2%;DS、DM的水分利用效率2015年分别显著增加24.1%和24.5%,2016年分别显著增加23.1%和15.2%。两年马铃薯纯收益均以DM最高,较CK分别显著增加47.8%和32.4%。综上,沟垄集雨种植下可降解地膜沟覆盖能显著改善旱地土壤水热环境,提高马铃薯产量、水分利用效率和纯收益,以沟覆盖麻纤维地膜处理效果最佳。本研究结果为降解地膜覆盖种植应用于西北旱作区马铃薯农业生产提供了理论依据和技术参考。

Effects of Different Degradable Plastic Film With Furrow Mulch Under Ridge-Furrow Planting on Farmland Potato Yield and Soil Water and Heat

In order to screen the suitable types of degradable mulching film for potato growth and yield increase under the rainwater harvesting system in the northwestern dry farming area, a 2-year field experiment was conducted in 2015-2016 to determine the effect of degradable mulching films, the biodegradable film mulch (DS), hemp fiber film mulch (DM) and liquid film mulch (DY) on degradation characteristics, soil water and heat effects, potato growth and yield. The flat cropping without mulching was used as a control check (CK). The results showed that the degradation loss rate of different degradable films mulch during the two-year study period followed the order of DY>DM>DS. The DY treatment was completely degraded, and the average degradation loss rate with the DM and DS treatments reached 72.3% and 38.3%. The order of average soil water storage with all treatments during the two-year growth period was DS>DM>DY≈CK. The DM and DS treatments significantly increased the soil water storage in 0 to 160 cm layer at the critical growth period (70 d after sowing), by 29.0% and 15.6% in 2015, and by 17.8% and 11.6% in 2016, respectively, compared with CK. There was no significant difference between DY and CK treatments. The soil temperature preservation effect with DY treatment was significant after sowing 30 to 50 d, and the soil warming effect with DM treatment was particularly significant after sowing 0 to 70 d. However, no significant soil warming effect was found among the degradable film mulching treatments after sowing 110 d. Through the Pearson correlation analysis of soil water, temperature and potato total yield, it was found that soil water and temperature after sowing 30 d are critical to total yield formation of potato, while the soil moisture is higher than soil temperature after sowing 70 to 90 d. The DM, DS and DY treatments significantly increased potato yield by 20.3%, 17.4%, and 9.2% in 2015, respectively, and 18.1%, 17.0%, and 12.2% in 2016, respectively, compared to CK. The water use efficiency with the DS and DM treatments was significantly increased by 24.1% and 24.5% in 2015, respectively, and 23.1% and 15.2% in 2016, respectively, compared to CK. The DM treatment maintained the highest potato net income, which was 47.8% and 32.4% significantly higher than that of CK, respectively, in 2015 and 2016. In summary, furrow covered degradable plastic film under ridge-furrow planting could significantly improve the soil hydrothermal environment and increase potato yield, water use efficiency and net income. The effect of furrow-covered hemp fiber film was the best. This study could provide the theoretical basis and technical references for the feasibility of further application of degradable plastic film mulching planting to potato agricultural production in Northwest China.