Study On The Effects Of Different Fertilizers On The Quality Of Artemisia Selengensis And Analysis Of Obstacles Caused By Continuous Cropping

Artemisia selengensis is the specialty vegetable in Southern China. In recent years, continuous cropping, which severely restricts the Artemisia selengensis production, need to be solved urgently. To clarify the mechanism of obstacles caused by continuous cropping and to provide a reference for the cultivation, the cause of the continuous cropping obstacles was analyzed in the present research, by detecting the pH, the enzyme activities, the structure of culturable microorganisms and autotoxicity in the rhizosphere soil, and studying the effects of organic fertilizer on the growth and stem quality of Artemisia selengensis. The main results were as follows:1. According to the research on the effect of different combinations of organic fertilizer and inorganic fertilizer on the growth and stem quality of Artemisia selengensis, we found the stem soluble sugar content increased24.24%,28.36%,26.87%,20.00%compared with inorganic fertilizer (the second crop), in stem of rice-Artemisiaselengensis cropping, watermelon-Artemisia selengensis cropping,0year cropping and10continuous years croping respectively, the cellulose content reduced15.69%,18.47%,19.25%,17.37%. Suggesting the quality of Artemisia selengensis was improved by mixed fertilizer.2. The pH, enzyme activities and proportions of culturable microorganisms in the rhizosphere soils of continuous cropping Artemisia selengensis for0,5and10years were analyzed respectively. The results showed that the soil pH reduced from7.82in0year to5.86in5years and to4.72in10years. Continuous growing of Artemisia selengensis increased the activity of acid phosphatase and CAT, while the activity of sucrose and urease increased firstly, and then decreased. With the successive cropping years increased, the number of fungal flora was increased, while the cultured microbial flora aggregates and bacterial flora were reduced.3. The chemical compositions of rhizosphere soils, where Artemisia selengensis was cultivated for0,5and10years were analyzed respectively. Compared with the distilled water and the soil extract from the continuous cropping of Artemisia selengensis for0year, we found the soil extract from10years with concentration12:10significantly inhibited seed germination rates of C. coronarium and watermelon. Seventeen compounds were found in all the three extracts of soil by using GC/MS, including alkanes, alcohols, organic acids, phenols and esters. Content of tetradecanoic acid, dibutyl phthalate, hexadecanoic acid and octadecanoic acid in the soil from5years was6.76,20.64,12.45,6.23fold of that in the soil of0year namely, and content of those in the soil of10years was37.35,55.36,16.89,12.33fold of that in the soil of0year. Moreover, the obstacles caused by continuous cropping of Artemisia selengensis, to some extent, may be due to the accumulation of those four self-allelochemicals.