稻草和地膜覆盖对冬季茶园保温增温作用的研究

通过对稻草秸秆覆盖、地膜覆盖等不同覆盖物表层及其对应的地表最低、最高温度23d连续测定与对比分析,研究了覆盖物对地表的保温、增温作用。各测点最低温度相关系数最小为0.889,最高温度相关系数最小为0.813,均在0.01水平显著相关,表明温度场高度相关。与对照相比,稻草覆盖使地表最低温度平均提高1.2℃以上,地膜覆盖则提高0.2℃以上。天气晴好状态下,稻草覆盖的保温作用强于地膜覆盖,且与覆草厚度无关;阴雨雪天气,稻草与地膜的保温作用均显著下降,稻草覆盖的降幅小于地膜覆盖,且覆盖厚度大降幅较小。天气晴好条件下地膜覆盖可以提高地表温度,无光环境中地膜无显著增温作用;将茶园覆盖的稻草分为晴天干草、晴天湿草、阴天干草、阴天湿草4种类型,其增温效果与稻草类型有关,且强于地膜覆盖。总之,与地膜相比,稻草覆盖保温效果好,并具有一定的增温效果,无污染,材料来源丰富,更适宜于作为冬季防寒材料。

Effect of straw and plastic film mulching on warming and insulation of tea plantation in winter

Three forms of mulching (plastic film mulching, two forms of straw mulching and CK) of tea plantation were compared to learn the role of mulching in warming and insulation in winter. The continuous investigation in 23 days on the lowest and highest temperatures on the mulching materials surface and the corresponding soil surface was conducted. The lowest correlation coefficient for the lowest temperature among measuring points is 0.889 and that for the highest temperature is 0.813 - both are at 0.01 level of significance. This indicates that temperature field is highly correlated. Compared with CK, straw mulching increases the lowest temperature by 1.2 ℃, while plastic film mulching by 0.2 ℃. The insulation effect of straw mulching is more significant compared with plastic film mulching, and is independent on the straw depth in sunny days. In cloudy and rainy or snow days, insulation effect of both the straw and plastic film mulching decreases, however, the straw mulching causes less decrease which is negatively correlated with straw depth. In sunny, the plastic film mulching increases the soil surface temperature, but, in cloudy days, not significant warming effect is observed. The warming effect of straw mulching is more obvious than that of plastic film mulching, and dependent on the type of straw, which is divided into four types, dry straw in sunny day, wet straw in sunny day, dry straw in cloudy day, and wet straw in cloudy day. In summation, compared with plastic film mulching, straw mulching has a better warming and insulation effect, zero pollution and a rich origin. Straw mulching is therefore more suitable for use as a cold-resistance material in the winter.