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Effects of Different Allelopathic Wheat Root Exudates on Cucumber Growth and Soil Quality

Author: MaYaFei
Tutor: WuFengZhi
School: Northeast Agricultural University
Course: Olericulture
Keywords: Cucumber Wheat Root exudates Allelopathic effect Soil enzymes Soil nutrients Soil microbial
CLC: S642.2
Type: Master's thesis
Year: 2011
Downloads: 134
Quote: 1
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Abstract

Cucumber facilities cultivated vegetable species cultivated area accounts for about 60% of the cultivation area of ??vegetables. Due to market demand and limited arable land of contradictions, as well as the cultivation of habits and economic interests driving, even as widespread, continuous cropping obstacle serious. Studies have shown that the cucumber and wheat rotation and intercropping cucumber soil micro-ecological environment will help to improve and to improve the yield and quality of cucumber. The test by studying the allelopathic effects of different varieties (lines) wheat root exudates of cucumber, screened two pairs cucumber significant differences in allelopathic wheat varieties (lines) to explore the growth of cucumber and soil ecological environment, attempt to clarify the allelopathic effect of soil ecological effect of wheat root exudates the cucumber - wheat cropping systems, and provide a theoretical basis for the establishment and promotion of a reasonable system of cultivation. The study results are as follows: 1, for the trial of 40 wheat varieties (lines) Allelopathic effects of root exudates of cucumber differences allelopathic effects of 70.25 percent of the wheat varieties (lines) root exudates of cucumber to promote Longfu 04-0348 cucumber allelopathic the promoting effect most Longfu 17 allelopathic inhibition strongest. 2, the root exudates of different allelopathic effects promote cucumber seedling root dry weight and to promote seedling height. Allelopathic promote of effect root exudates of cucumber seedlings, plant height, stem diameter, root dry weight show to promote the role; the allelopathic inhibition effect of root exudates of cucumber seedlings, plant height, stem diameter, shoot dry weight exhibit pre-suppression, anaphase promoting trend. After planting, cucumber disease was no significant change in yield. 3, the root exudates of different allelopathic effects demonstrated reduced soil pH in cucumber seedlings after the first raise, first decreased and then increased cucumber seedling soil EC value trends. The allelopathic promote the effect of wheat root exudates showed a trend to improve the cucumber seedling soil nitrogen, available phosphorus, available potassium; allelopathic inhibition effect of wheat root exudates showed decreased first improve cucumber seedling soil available nitrogen, available phosphorus content first increase, reducing the available potassium trend. Different allelopathic effect of wheat root secretion showed the first increase trend to reduce the seedlings without soil available nitrogen, available phosphorus, available potassium. Soil organic matter variation is not obvious. 4, the root exudates of different allelopathic effects demonstrated cucumber seedlings soil and seedlings soil urease activity, first decreased and then increased hydrogen peroxide activity trends. Allelopathic promote the effects of root exudates showed the first increase in reducing cucumber seedling soil and no seedlings soil neutral phosphatase activity trends; allelopathic inhibition showed small root exudates decreased first cucumber seedlings soil neutral phosphatase activity, The first increase reduced no seedlings soil neutral phosphatase activity trends. Early root exudates of different allelopathic effect on cucumber seedlings soil and seedlings soil dehydrogenase activity was significantly inhibited late improve gradually. 5, the root exudates of different allelopathic effect reduces the number of cucumber seedling soil and seedlings soil fungi. Allelopathic promotion effect of wheat root exudates to reduce the number of cucumber seedling soil actinomycetes showed trend of decreased first and then raise cucumber seedlings soil bacteria quantity of; improved no seedlings soil bacteria quantity, showing first improve reduce no seedlings soil actinomycetes bacteria number of trends. Allelopathic inhibition effect of wheat root exudates of cucumber seedlings increased the number of soil bacteria, the actinomyces trends showed the first increase to reduce of cucumber seedlings soil and seedlings soil. The Allelopathic for effects of root exudates on microbial biomass carbon impact of the law is not obvious, allelopathic inhibition effects of root exudates improve the cucumber seedling soil and seedlings microbial biomass carbon. Root exudates of different allelopathic effect showed a trend of first reduced to improve of cucumber seedling soil fungi DGGE profile bar with the number and the diversity index, no seedlings soil fungal DGGE profiles strip number and diversity index. 6, wheat interplanting different allelopathic effects, improved cucumber soil alkaline hydrolysis nitrogen, available phosphorus, available potassium, organic matter content and pH value lower EC value; improve soil urease, neutral phosphatase and dehydrogenase activity; increase the number of soil bacteria and microbial biomass. Promoting effects of interplanting allelopathic wheat, reducing the number of cucumber soil fungi, actinomyces, catalase activity as well as the number of fungal DGGE profile bands and diversity index, cucumber yield of 2.9%; interplanted allelopathic inhibitory effect of wheat to improve cucumber fungi, actinomyces reduce the activity of hydrogen peroxide, as well as the number of the fungal DGGE profile bands and diversity index, cucumber yield 25.5%.

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