垄作沟覆地膜对旱地马铃薯光合特性及产量形成的影响

Effects of ridge tillage with film mulching in furrow on photosynthetic characteristics of potato and yield formation in dryland farming

为探讨垄作沟覆不同地膜对旱地马铃薯光合特性及产量形成的影响,于2018—2019年在宁夏南部山区设置垄上覆盖普通塑料地膜,沟内分别覆盖普通塑料地膜(DD)、可降解渗水地膜(DS)和麻纤维地膜(DM),以沟不覆盖为对照(CK),研究其对作物关键生育时期(播后60~120 d)土壤水分、马铃薯功能叶光合特性及产量形成的影响。结果表明,现蕾期(播后60 d)不同覆盖处理可显著提高0~100 cm层土壤贮水量,2018年以DD处理最高,2019年以DM处理最高,分别较CK显著提高11.2%和21.6%。马铃薯关键生育时期,除2019年DS处理叶面积指数较CK显著提高外,其他处理间差异均不显著;不同覆盖处理可有效提高净光合速率和蒸腾速率,其中在块茎膨大期(播后120 d)DM处理分别较CK显著提高30.0%和23.2%。2年块茎膨大期DD、DM和DS处理块茎干物质累积量平均分别较CK显著提高54.9%、50.0%和22.6%,马铃薯产量平均分别较CK增产13.2%、14.1%和5.2%,平均净收入分别增收16.3%、14.6%和4.0%,而DS处理马铃薯产量和净收益与CK相比差异均不显著。相关分析发现,土壤水分和净光合速率是影响马铃薯产量形成的主要因素。垄作沟覆普通塑料地膜(DD)与垄作沟覆麻纤维地膜(DM)处理均可改善现蕾期土壤水分,从而促进马铃薯光合和产量的提高。因此,垄作沟覆麻纤维地膜与垄作沟覆普通塑料地膜的增产增收效果相当,具有部分替代普通塑料地膜的优势。

To investigate the effects of ridge tillage with film mulching in furrow on photosynthetic characteristics and yield for-mation of potato in dry land,field experiment was conducted from 2018 to 2019 in mountain area of south Ningxia.Ridges were covered with common plastic film in all treatments,while different furrow treatments were mulched with common plastic film(DD),degradable permeable mulch film(DS),and bast fiber film(DM),and no mulching furrows was used as the control check(CK).The effects of ridge tillage with film mulching in furrow on soil moisture,photosynthetic characteristics of potato functional leaves and yield formation during the key growth period(60-120 days after sowing)were investigated and compared.The results showed that the different mulching treatments could significantly increase soil water storage in 0-100 cm layer during potato squaring stage(60 days after sowing).DD treatment was the highest in 2018 and DM treatment was the highest in 2019,which significantly increased by 11.2%and 21.6%than CK,respectively.In the key growth periods of potato,leaf area index of DS treatment was significantly higher than that of CK in 2019,but there was no significant difference among the other treatments.Different mulching treatments could increase the net photosynthetic rate and transpiration rate,while DM treatment significantly increased the net photosynthetic rate and transpiration rate by 30.0%and 23.2%in the tuber swelling stage(120 days after sowing),compared with CK,respectively.The average tuber dry matter accumulation with DD,DM and DS treatments in the 2-year tuber swelling stage was significantly increased by 54.9%,50.0%,and 22.6%.During the 2-year experiments,the average potato yield with DD,DM and DS treatments was increased by 13.2%,14.1%,and 5.2%,the average net income was increased by 16.3%,14.6%and 4.0%,respectively,compared with CK,while the differences in potato yield and net income were not signifi-cant between DS and CK.Correlation analysis showed that soil moisture and net photosynthetic rate were the main factors affect-ing potato yield formation.The treatments of ridge tillage with common plastic film mulching in furrow(DD)and ridge tillage with bast fiber film mulching in furrow(DM)could improve soil moisture at squaring stage,thus promoting the increase of potato photosynthesis and yield.Therefore,ridge tillage with bast fiber film mulching in furrow had the same effect of increasing yield and income as ridge tillage with common plastic film mulching in furrow,and it had the advantage of partially replacing common plastic mulching.