套种绿肥对茶园土壤理化性状的影响

通过田间小区试验,以不套种任何绿肥处理为对照,研究了白三叶(Trifolium repens L.)、多年生黑麦草(Lolium perenne L.)和两者混播的3种套种模式对茶园土壤理化性状及环境小气候的影响。结果表明:茶园套种绿肥有降低土壤体积质量、降低土壤紧实度、改善土壤气相和液相比例的趋势,套种绿肥可明显降低地表、5 cm、10 cm和15 cm土层温度,减小土壤温度变幅。最高温时,各土层降温效果均为:黑麦草白三叶混播。绿肥处理的土壤有机质含量、全氮含量、速效磷含量和速效钾含量较对照有所增加,增幅分别为6.67%~12.6%、0.8%~15.2%、24.1%~26.7%和6.8%~88.9%。绿肥处理与对照相比,土壤微生物数量明显增加:细菌数量、真菌数量、放线菌数量分别是对照的1.75倍~2.58倍、1.22倍~1.88倍和1.15倍~1.46倍。因此,茶园套种白三叶和套种黑麦草对土壤生态环境效应的改善和茶园土壤基本肥力的效果相对更佳,值得在生产上进一步推广应用。

Effects of Interplanting Green Manure on Soil Physico-chemical Characters in Tea Plantation

A field experiment was conducted to study the effects of interplanting green manures on soil physico-chemical characters, soil fertility and environmental microclimate in tea plantation. The treatments included none-green manure (CK), interplanting white clover (Trifolium repens L.) , interplanting perennial ryegrass (Lolium perenne L.) and clover-ryegrass mixed sowing in tea gardens. Soil samples were collected from different layers of 0–5, 5–10 and 10–15 cm and the contents of organic matter, total nitrogen and rapid available phosphorus were determined, air temperature, relative humidity and soil temperature were measured. The results showed that interplanting green manure effectively reduced soil bulk density and soil compaction, improved the ratio of soil gas phase and liquid phase, reduced soil temperatures at surface, 5 cm, 10 cm and 15 cm depths significantly, decreased the amplitude of soil temperature. While at the highest temperature, the cooling effect of each soil layer were in order of ryegrass > white clover > mixed sowing. The contents of soil organic matter, total nitrogen, available phosphorus and available potassium under green manure treatments were higher than CK, increased by 6.67%–12.6%, 0.8%–15.2%, 24.1%–26.7% and 6.8%–88.9%, respectively. Green manure treatments increased significantly soil microbial quantity compared with CK, the number of bacteria, fungi and actinomycetes were 1.75–2.58 times, 1.22–1.88 times and 1.15–1.46 times of CK, respectively. The above results proved that the good effects and application prospect of interplanting white clover or perennial ryegrass in tea gardens in improving soil fertility and environmental microclimate.