长期滴灌施肥对荔枝根系生长及土壤pH的影响

摘要

[ Objective ] The aim was to di~uss the effects of long-term drip fertigation on root growth of L. chinensis and soil pH of different soil profile in L. chinensis orchard. [ Method] Field experiment was used. Additional fertilizer, CO( NH2 )2, KCI and MgSO4 and so on, were applied by drip fertigation system during the period of treetip in autumn, the period of flowering and the before and after the period of fruiting.Superphosphate, peanut bran and chicken manure and and on were used as basal fertilizer to furrow fertilization along the dripping line of tree crown. [ Result] The results showed that drip fertigationcould significantly improve the root growth of L. chinensis. With 6-years drip fertigation, the number of root weight, the root length and the root surface area of L. chinensis in the drip fertigation area was 2.29, 2.17 and 2.25 times respectively non-drip fertigaton area. The more root concentrated on the area from 0 cm to 40 cm depth, but there were significant difference with the root distribution between 0 -20 cm depth and 20 -40 cm depth in the drip fertigation area and non-drip fertigation area. Drip fertigation could promote deep insertion of the root system. On the condition of long-term fertigation, the L. chinensis orchard soil acidification was significant, soil pH of drip fertigation area was far lower than the that of non-drip fertigation area. Comparing to non-drip fertigation area with the i0 -20 cm soil profiles, the largest decrease of pH was 1.47. [ Conclusion ] The study can provide a theoretic basis for application and extension of drip fertigation technology in L. chinensis production.%[目的]探讨长期滴灌施肥汁荔枝(Litchi chinens)根系生长分布及荔枝园不同土层土壤pH变化的影响.[方法]采用田间试验,追肥包括CO(NH2)2、KCI和MgsO4 等,均通过滴灌施肥系统施入,主要施肥时期为每年荔枝的秋梢期、花期和结果期前后;过磷酸钙、花生麸及鸡龚等则以基肥的形式沿树冠滴水线沟施.[结果]滴灌施肥能显著促进荔枝根系的生长,增加根系与土壤的接触面积,连续6年滴灌施肥后滴灌施肥区土体中的根干重、根长、根表面积分别为非滴灌区的2.29、2.17和2.25倍.荔枝根系主要分布在0～40 cm土层,但滴灌施肥区和非滴灌区在0～20和20～40 cm土层中的根系分布存在明显的差异性,滴灌施肥更有利于根系向土壤深层生长分布.长期滴灌施肥条件下,荔枝园土壤酸化明显,与非滴灌区相比,滴灌施肥区在10～20 cm土层土壤pH的降幅最大,达到1.47个单位.[结论]该研究可为滴灌施肥技术在荔枝生产中的推广应用提供理论依据.