To investigate the effects of different drip irrigation belt layout modes on the distribution of soil phenolic acids

enzyme activities

and microorganisms in the fruit characteristics-crop intercropping system

and to preliminarily explore the relationship between soil phenolic acids and soil biological factors under intercropping drip irrigation conditions

a typical apple (Malus pumila L.)-soybean (Glycine max L.) intercropping system in the loess region of western Shanxi was used was the research object

with three types of drip irrigation belt spacing (L1

L2

L3). The spatial distribution changes of soil phenolic substances

enzyme activity

and microbial quantity under different water distributions were analyzed

and based on this

stepwise regression model was used to analyze the interrelationships among these three soil factors. The results showed that except for benzoic acid and phloroglucinol

the distance between drip irrigation belts had a significant impact on the distribution of phenolic acids (p<0.05)

and had a significant impact on the enzyme activity and the distribution of microbial population except for catalase (p<0.05). In the vertical direction

different drip irrigation belt layout modes resulted in more distribution of phenolic acids in deep soil

the number of microorganisms and some enzyme activities first decreased and then increased with the deepening of soil layer in L1 and L2 treatments; In the horizontal direction

the effects of different drip irrigation belt layout modes on the distribution of soil phenolic acids

bacteria

and fungi were consistent with the intercropping control treatment

increasing with the increase of distance from the tree. Under the condition of drip irrigation

phenolic acids except p-hydroxybenzoic acid were significantly inhibited by urease

catalase and actinomycetes

and the total amount of phenolic acids in intercropping soil was less than that in monocropping. L1 treatment had the highest soil enzyme activity and total microbial biomass

while L2 treatment had the lowest accumulation of phenolic acids in the soil. Among them

L2 treatment had a relatively high level of soil enzyme activity on the basis of the lowest accumulation of phenolic acids. Therefore

it is recommended to adopt the pattern of arrange a drip irrigation belt at intervals of one row of soybean in the fruit-crop intercropping system

improving the soil micro-ecological environment can alleviate the inhibition of allelochemicals at the same time.