透明膜覆盖土壤太阳能消毒及其对大白菜生长的影响

Study on soil solarization with transparent plastic mulching and its effects on growth of Chinese cabbage cultivars

为了了解覆盖透明膜对土壤的增温和消毒效果，以土壤无覆膜处理为对照，研究了陕西关中地区利用透明膜覆盖进行土壤太阳能消毒期间的温度变化，及对消毒土壤上生长的4个大白菜品种产量和发病率的影响。结果表明，覆膜处理的地表及地下5，10，15和20cm的最高温度分别可达62。95，54．05，48．05，42．1和40．7℃，与对照相比，平均温度最大差值分别为12．37，10．43，9．46，7．62和7．87℃，即随土壤深度增加，覆膜处理的增温效果下降;就温度持续时间而言，在处理的30d内，处理与对照温度超过40℃的时间有极大差异，覆盖使地下5，10，15和20cm处在15：00超过40℃的时间分别为18，14，1和1d，在19：00分别为15，12，4和1d，而对照均为0d；覆膜使土壤日温差加大，晴天尤为显著，并随土层深度增加日温差递减，晴天15：00时，覆膜土壤地表及地下5，10，15和20cm处的温度分别为对照平均温度的l.41，1.40，l.31，1．23和1．29倍。消毒效果表明，处理田块生长的02杂64、北京桔红心、春晓和秦白二号4个大白菜品种生长势明显增强，毛菜产量较对照高（春晓除外），炭疽病发生率较对照显著降低，降幅达32．3％～71．1％。

To find the effect of soil temperature raised and sterillized with white plastic mulched,the pa- per studied the change of soil temperature during the whole mulched period and its effect on 4 cultivars of Chinese cabbage planted with transparent plastic mulching in Guanzhong district, Shaanxi Province. Results showed that the maximum soil temperature of surface, 5,10,15 and 20 cm depths approached 62.95,54.05, 48.05,42.1 and 40.7 ℃, respectively, with the transparent plastic mulched, the average temperature in- creased 12.37,10. 43,9.46,7.62 and 7.87 ℃, repectively, compared with the control（un-mulched）. The mulching effect was decreased with the increasing of soil depth. In terms of mulching duration, it would have much better effect in sunny days on soil temperature than that in cloudy or rainy days ; during the whole mulching period, the cumulative days of temperature higher than 40 at 5,10,15 and 20 cm soil depths were 18,14,1 and 1 d at 15：00;15,12,4 and 1 d at 19.00, separately. Mulching also increased the value of temperature difference in different soil depth,and the day temperature difference was decreased with the increasing of soil depth. At the depth of 5, 10,15 and 20 cm at 15：00 of sunny days,the soil temperature would be 1.41,1.40,1.31,1.23 and 1.29times as many as that in cloudy or rainy ted. The results showed that 4 cultivars for chunxiao） and the disease of anthrac experiment, and incidence of the disease days. After solarization, four Chinese cabbage cultivars were plan- grew vigorously in mulched field,the bio-yield improved （except nose （Colletotrichurn higginsianurn Sacc. ） was lower than control decreased by 32.3%-71.1%.