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| Analysis of Soil EC Value Dynamic and Salt Sensitivity for Facility Fruity
Vegetable |
| LI Yu-Hong, CHEN Qing* |
| （College of Resources and Environmental Science，China Agricultural University，Beijing 100193，China） |
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Abstract Abstract：The electrical conductivity（EC）of different extracts（saturated extract and 1∶5 of soil and water ratio extract）were tested，and the relationship between ECe andEC1:5 was established in this study．Therefore，the soil standardized classification ofEC1:5 was also established．Besides，the study evaluated the soil salinity dynamic of overwinter and spring facility vegetables under conventional management．The results indicated that the soil ECe and EC1:5 of facility vegetable fields showed significant and positive correlated linear relationship．Under the soil conditions at Beijing suburbs the reduction formula was EC1:5 =0.105 ECe．The critical value of soil EC1:5 at salt tolerant root layer for sensitive fruity vegetables（eggplant and pepper）
during seedling stage and the whole growing period were 0.10 dS·m -1 and 0.30 dS·m -1，respectively．And the adjustable value was between 0.30dS·m -1and 0.50 dS·m -1．For non-sensitive vegetables（tomato and cucumber）the critical value of soil EC1:5 at salt tolerant root layer during seedling stage and the whole growing period were 0.30 dS·m -1 and 0.60dS·m -1，respectively．And the adjustable value was between 0.60dS·m -1 and 0.90dS·m -1．The average soil EC1:5 value in solar greenhouse from planting to next March in over-winter season was stable between 0.30-0.34 dS·m -1，and then declined gradually till July to 0.15 dS·m -1．In the plastic shed for spring season，the soil EC at root layer declined after planting，and it was 0.29-0.30 dS·m -1 before April．It dropped to 0.20 dS·m -1 till July．According to vegetable salt tolerance index，we found that under traditional management condition，the verwinter vegetables in solar greenhouse and spring vegetables in plastic shed were easily suffered from soil salt damage．For overwinter sensitive vegetables uring the Period from seedling to next March，the soil salinity was inclined to exceed its critical value of salt tolerance．Reasonable adjustment between water and fertilizer was needed so as to control the salt damage．
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Received: 22 September 2013
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