Utilizing comprehensive decision analysis methods to determine an optimal planting pattern and nitrogen application for winter oilseed rape

Oilseed rape is one of the most important oil crops globally.Attaining the appropriate cultivation method(planting pattern and nitrogen level)is necessary to achieve high yield,quality and resource utilization efficiency.However,the optimal method for oilseed rape varies across countries and regions.The objective of the present study was to determine an appropriate cultivation method,including planting pattern and nitrogen application,for winter oilseed rape in northwestern China.Two planting patterns:ridge film mulching and furrow planting(RFMF)and flat planting(FP),and six nitrogen(N)amounts:0(N0),60(N60),120(N120),180(N180),240(N240),and 300(N300)kg N ha–1 were applied across three growing seasons(2014–2017).Three comprehensive decision analysis methods:principal component analysis,grey correlation degree analysis and the combined entropy weight and dynamic technique for order preference by similarity to ideal solution method were used to evaluate the growth and physiological indicators,nutrient uptake,yield,quality,evapotranspiration,and water use efficiency of winter oilseed rape.Planting pattern,nitrogen amount and their interaction significantly affected the indicators aforementioned.The RFMF pattern significantly increased all indicators over the FP pattern.Application of N also markedly increased all the indicators except for seed oil content,but the yield,oil production and water use efficiency were decreased when N fertilizer exceeded 180 kg N ha–1 under FP and 240 kg N ha–1 under RFFM.The evaluation results of the three comprehensive decision analysis methods indicated that RFMF planting pattern with 240 kg N ha–1 is an appropriate cultivation method for winter oilseed rape in northwestern China.These findings are of vital significance to maximize yield,optimize quality and improve resource use efficiencies of winter oilseed rape.

Effect of low-temperature treatment on bacterial cultivation in bacterial induced mineralization

In this paper,the effect of low-temperature treatment on bacterial activity was investigated and its performance in preparing the consolidated sand was accessed.Four factors,including absorbance(OD600),p H,electric conductivity(EC)and urease activity(UA)were monitored to evaluate the bacterial activity.Moreover,the calcium carbonate yields under different bacterial solution and cementation solution volume ratios were determined.Finally,the compressive strength and microstructure of consolidated sand were investigated and the mechanism was explored by characterising the products among sand particles.The results showed that for both continuous and interval cultivation of bacteria,stable bacterial solution was harvested within the cultivation period of 30 h.Low-temperature treatment showed limited inhibition at early cultivation stage,while it had strong inhibition at middle cultivation stage.The interval cultivation improved the cultivation efficiency of bacteria.It was observed that the low-temperature preservation for a stable bacterial solution has little influence on UA before 4 days,while UA decreased seriously after its preservation time was extended to over 8 days.The optimal volume ratio of bacterial solution and substrate solution was 1:1,resulting in the highest calcium carbonate yield.The improved compressive strength of consolidated sand after 3 injections was attributed to the irregular-shaped calcite products,which coated and bonded the sand grains together.

Rapid quantitative analysis of 12 chemical constituents in wild-simulated and cultivated Astragali Radix based on UHPLC-MS

Objective:Astragali Radix(AR)is one of the most widely used traditional Chinese medicines(TCMs)for tonic,which can be divided into wild-simulated and cultivated AR according to its cultivation method.However,whether cultivated AR can replace wild-simulated AR has always been a concern.Methods:In this study,a rapid,highly sensitive and specific analytical method using ultra-high performance liquid chromatography tandem mass spectrometry(UHPLC-MS)was developed to quantitatively measure 12 chemical constituents of AR in the different cultivation methods.Results:AR samples were analyzed with a good linear regression relationship(R2,0.9983–0.9995),precisions(relative standard deviation(RSD),1.31%-2.36%),repeatability(RSD,2.65%-4.92%),stability(RSD,1.50%-4.05%),and recovery(95.13%-106.52%).Through the determination of AR samples,we found the components of favonoids in wild-simulated AR were higher than cultivated AR,the saponins in cultivated AR were higher,the ratio of saponins/favonoids in cultivated AR was higher than wildsimulated AR.Conclusion:Based on this research,it could provide guidance for the quality control of AR.