Effects of crop rotation patterns on photosynthetic physiological parameters and yield of oilseed flax in dryland
This study aimed to investigate the impact of different crop rotation patterns and previous crops on the photosynthetic characteristics and yield of oilseed flax in a long-term field positioning experiment conducted from 2012 to 2020.Oilseed flax was selected as the primary research subject.The effects of previous crops,flax planting frequency,and continuous cropping years on leaf area index,SPAD value,photosynthetic potential,net as-similation rate,photosynthetic characteristics,and yield of flax were examined in the northwest dry farming area un-der six different crop rotation patterns:FFFF(flax → flax → flax → flax),FWPF(flax → wheat → potato →flax),FPFW(flax → potato → flax → wheat),FFWP(flax → flax → wheat → potato),FWFP(flax → wheat →flax → potato),and FWPW(flax → wheat → potato → wheat).The objective was to provide theoretical founda-tions and technical guidance for optimizing the planting system of dryland farming areas while elucidating the photo-synthetic physiological mechanisms underlying high-yield production in oilseed flax.Furthermore,the results dem-onstrated that compared with continuous cropping,crop rotation significantly increased leaf area index by 8.11%-86.49%,SPAD value by 3.54%-42.86%,and photosynthetic potential by 10.38%-76.58%in oilseed flax.The stubble biomass after wheat or potato cultivation was significantly higher than that after oilseed flax cultivation.Moreover,the planting frequencies at 25%and 50%were significantly higher than that at 100%,which also in-creased with decreasing years of continuous cropping.Meanwhile,net assimilation rate exhibited an increasing trend after budding stage.Additionally,crop rotation significantly enhanced the photosynthetic characteristics of oilseed flax,resulting in a substantial increase in net photosynthetic rate(8.26%-106.00%)and leaf water use effi-ciency(20.77%-51.84%),except for the(F)WPF treatment during the anthesis stage.Compared to continuous cropping,crop rotation significantly boosted grain yield,non-grain yield,and total biomass yield of oilseed flax at maturity stage by 29.89%-109.59%,44.60%-111.90%,and 38.98%-111.01%,respectively.In addition,four-year continuous cropping led to a significant decrease of 23.01%,30.85%,and 28.05%in grain yield,non-grain yield,and total biomass yield compared to two-year continuous cropping respectively;however,these yields increased when previous crops were replaced and flax planting frequency was reduced.Correlation analysis revealed that aboveground biomass yield and grain yield exhibited a significant positive correlation with net photosynthetic rate and transpiration rate of oilseed flax during budding and anthesis stages,but showed a significant negative correla-tion with intercellular CO2 concentration.Notably,the correlation coefficient was higher during the anthesis stage than during the budding stage.Therefore,crop rotation facilitated the development of robust individual and popula-tion-level photosynthetic capacity in oilseed flax while maintaining strong photosynthetic performance throughout its growth period.This approach led to increased accumulation of photosynthetic products resulting in improved grain yield as well as overall biological productivity for oilseed flax cultivation.Among various crop rotation patterns tested,"flax → wheat → potato → wheat"proved to be an appropriate choice.
万方数据
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