Study On The Field Weed Diversity And Niche In The Main Potato Producing Areas In The Southern Ningxia Mountain Area

The potato is the staple crop in Ningxia.Because of its good drought resistance,strong disaster resistance,stable production and good market prospect,potato has long been the main crop in the southern mountain area of Ningxia and is the economical mainstay for the local people.In this experiment,5 administrative village fields in the southern mountain area of Ningxia were selected as experimental sites,and random sampling was adopted to set up 10 fixed sample plots in each sample.By analyzing the diversity,similarity,niche breadth value and overlap value of the weed community in potato field,and the interspecific relationship between the communities,the potato field was understood.The present situation of weeds,the composition and distribution of weed community in the field of potato in the Southern Ningxia Mountain area.The data of the number,height and coverage of the weeds were analyzed and analyzed.The results showed that the results were as follows:(1)The basic characteristics of weeds community in the study area:the proportion of annual herbage is higher than that of perennial herbs in the field weed communities in the main potato producing areas in the Southern Ningxia Mountain area,and the proportion of annual herbaceous in the community is increasing with the development of the growth period,and the years of herbaceous plants are the opposite.The occurrence of weeds in the field of potato in the early flowering period,tuber expansion period and starch accumulation period was the highest rate of potato in three different growth stages.There are 36 species of vegetation in the field of weeds in the field of potato,belonging to 33 genera of 17 families and 33 genera.There are 37 species of vegetation in the field of weeds in potato field,which belong to 34 genera of 17 families,and 33 species of vegetation in the field of weeds in the potato field,belonging to 16 families and 30 genera,which are classified as gramineaceae and Compositae.Plants occupy the highest proportion in the growth period of potatoes.The proportion of annual herbaceous herbs is higher than that of perennial herbs in the field of field weeds.With the growth period,the proportion of annual herbaceous in the community is increasing,and the proportion of perennial herbs is decreasing gradually.(2)The Shannon-Wiener index of field weeds in five experimental areas in three growing periods of potato showed significant changes,indicating that different growth stages of potato have significant influence on the diversity of weeds in the field.There was no obvious regularity of Sorenson similarity between weeds in different experimental areas during the same growing season.The analysis of field weed diversity showed that there was a good correlation between the Simpson diversity index and the Pielou evenness index of the field,and the Sorenson similarity index of the weed community in the potato field in the early flowering stage and Yangshan village was the largest,which was 0.789,and the tuber village and Yangshan village were in the period of tuber expansion.The similarity index of Sorenson in Xin Ying and three battalion towns was 0.780 and 0.778,and the similarity between Xin Ying and Yangshan was the highest at the time of starch accumulation.The similarity of the community was the highest when the block was expanded.(3)The niche breadth and niche overlap:among the weed communities in the five main potato production areas in the Southern Ningxia Mountain area,the three growth stages of the potato were the most competitive and the largest niche breadth in the three growth stages of the potato,and the field weeds were similar to the highest degree of utilization of the resources in the period of potato tuber expansion.The competitiveness is large and the niche overlap is the largest.The niche breadth and niche overlap of 12 major weeds in the field of potato field were measured by using the Levins niche breadth formula and the Pianka niche overlap index.The results showed that the niche breadth of the quinoa was the largest in the early flowering period,the width of the grass and tartary buckwheat was the smallest,and the competitiveness was weak in the community.When the tuber expanded,the niche breadth of the quinoa and the herba Herba was larger,the niche of the Elsholtzia was narrower,and the quinoa still had the most wide ecology in the period of starch accumulation.The ecological niche of the reed and reed is narrower.In terms of niche overlap,niche overlap in tuber expansion was significantly higher than that in early flowering and starch accumulation.(4)During the three growth periods,the total correlation of potato field weeds showed a positive correlation.The initial and starch accumulation period showed a significant positive correlation;the 12 dominant species were 66 species pairs,and the initial flowering period was 33 pairs,and the negative correlation species were 22 pairs.There were 4 pairs of correlation,23 pairs of positive correlation of tuber bulking period,13 pairs of negative correlation,1 pairs of significant correlation,35 pairs of positive correlation in starch accumulation period,22 pairs of negative correlation,and no significant correlation.The correlation between the three growth stages is far less than the logarithm of the species that is not significantly correlated,which indicates that there is no strong competitive relationship between most species.