土壤温湿度对玉米根系的影响

采用方形整段标本法,对河北省保定市固城镇中国气象局农业试验基地玉米（屯玉46）不同生育期的根系进行监测,同时对土壤水分、地温进行分析,研究土壤湿度、温度对玉米根系生长发育的影响。结果表明,拔节期和完熟期的根长密度在10～20 cm土层最大,分别为0.49 cm/cm³和1.98 cm/cm³,分别占0～100 cm土层总根长密度的49%和28%;抽雄期和乳熟期则是0～10 cm土层最大,分别为0.45 cm/cm³和1.17 cm/cm³,分别占0～100 cm土层总根长密度的34%和22%。对于土壤水分,50 cm土层以上,不同时期基本保持较为平缓的变化趋势,拔节期和抽雄期40～50 cm土层的水分为整层最大,分别可达18.84%和17.83%;乳熟期和完熟期为50～60 cm土层的水分最大,分别可达22.7%和22.0%。50 cm土层以上,不同生育期玉米根长密度的垂直分布均为向下递减;50 cm土层以下,乳熟期和完熟期的根长密度与土壤水分具有较为一致的变化趋势,水分较多的层次对应的根长密度较大,根系量较多。在土壤剖面中,不同生育期玉米根长密度增长量变化的垂直分布与土壤水分变化的垂直分布较为一致,无偏相关系数分别为0.38、0.9和0.7。地温越高,玉米侧根越细,温度对根系生长发育和生理活性产生一定影响。

Effect of Soil Temperature and Humidity on Different Developmental Periods of Corn Root

In order to investigate the effect of temperature and moisture on corn root growth and development, experimental field located in the large root monitoring system of Gucheng agrometeorological station, the application of minirhizotron in monitoring of the growth dynamics at milky stage and full ripe of "Tunyu46" corn root was studied, and the soil moisture and temperature were also analyzed. The results showed that: at the jointing stage, small bell mouth stage, milky stage and full ripe stage, the maximum root densities of soil layer were 34%, 22% and 28% of 100 cm soil layer, respectively. Meanwhile the maximum soil mositure was 18.8%, 17.8% and 22% of the whole total layer, respectively.The root system decrease in different development periods at 0-50 cm soil layer. Under the 50 cm soil layer, the variation trends of the root density was consistent with soil moisture at milky stage and mature stage, the root density was greater, and the root system grew faster at the more soil moisture layer. The differences of root density and soil moisture distribution trend in soil profiles were basically consistent in different development periods, and no partial correlation coefficient were 0.38, 0.9, and 0.7, respectively, The temperature affected the root growth and physiological activity.