Effects Of Planting Row Ratio On Soil Nutrients And Bacterial Community In Potato Intercropping Vicia Faba System

Different planting patterns will change soil nutrient content and bacterial community diversity,and then affect the structure and function of farmland ecosystem,which is an important factor for high yield and high efficiency of crops.At present,there are few systematic studies on soil nutrient content and soil microbial diversity with different planting row ratios.Based on high-pass resequencing technology,this study conducted field experiments and set up three intercropping modes,namely potato and broad bean row ratio 2:2(P2B2),potato and broad bean row ratio 2:4(P2B4),and potato and broad bean row ratio 2:8(P2B8),and monoculture potato(P)and monoculture broad bean(B)were used as controls.The agronomic traits,photosynthetic indexes,nutrient contents in different soil layers,soil enzyme activities and diversity of soil bacterial community were systematically analyzed,in order to provide theoretical basis for optimizing potato planting pattern and realizing high yield and efficiency.The main research results are as follows:(1)The agronomic traits and photosynthetic indexes of the three intercropping modes showed the difference between different row ratios of c.majiensis.Under P2B2 treatment,the increase of potato plant height was the highest 10.16%,the increase of stem diameter was the lowest 10.21%,the decrease of relative chlorophyll content was the highest 14.20%,and the increase of underground dry matter was the highest 25.69%P2B8 treatment had a maximum increase of 17.92%in dry matter of potato shoot,P2B2 treatment had a minimum decrease of 0.20%in carbon dioxide concentration,a maximum decrease of 41.19%in net photosynthetic rate,and a minimum increase of 20.50%and 24.28%in stomatal conductance and transpiration rate.(2)Among the three intercropping modes,P2B8 treatment increased plant height by 13.82%and relative chlorophyll content by 19.11%.Compared with egg-bean mono-cropping,dry matter in underground and abovementid parts decreased by 1.90%and 26.83%in P2B8 treatment,and net photosynthetic rate increased by 14.20%in P2B8 treatment.P2B2 treatment had the highest increase of 48.75%in stem diameter,59.84%,167%and 9.82%in transpiration rate,stomatal conductance and intercellular co2 concentration.(3)The number of intercropping rows had significant differences in nutrient contents in different soil layers.Compared with mono-cropping potato,the contents of alkali-hydrolyzable nitrogen,nitrate chlorine,available atmosphere and available phosphorus in soil were increased and the contents of available phosphorus in soil were decreased.P2B2 treatment can significantly reduce soil temperature and increase soil water content.(4)The soil enzyme activities of different intercropping modes of Horseinggrave broad bean were the highest in P2B4 treatment,including the activities of portobase,phosphatase,sucrase and catalase.With the deepening of soil layer,the soil enzyme activities showed a decreasing trend.(5)the jingle bell’s tomb beans different planting than has remarkable effect on soil bacteria community diversity P2B8 processing OTUs and total OTUs were the lowest,relative abundance of species,the lowest diversity,distribution uniformity of the lowest,the most dominant species,soil bacterial community space distribution of the concentration,the tomb was a jingle bell constitute a significant differences with interplanting mode soil species differences.(6)The total land equivalent ratio of potato and broad bean in the three intercropping modes were all greater than 1,which had significant advantage in increasing yield and increasing the overall yield per unit area.P2B2 treatment had the highest yield of horsebell grave,increase of 17.92%,and the lowest yield of broad bean.With the increase of the number of intercropping lines,the overall yield and economic benefit continued to decrease.Taken together,the increase of broad bean interplanting rows of jingle bell tomb of agronomic traits and photosynthetic indexes advantage influence gradually reduce,a significant increase in soil gas content and enzyme activity,reduces the number of bacterial species per unit area,increase a few dominant species,decreasing overall yield and economic benefit,but were higher than monoculture jingle bell’s tomb,various processing is still in the two kinds In the marginal range of intercropping crops,the solid atmosphere advantage of broad bean can still be reflected,which provides scientific theoretical basis for further exploring the suitable planting line ratio to combine agricultural machinery and agronomy.