中国农业科学 ›› 2017, Vol. 50 ›› Issue (18): 3561-3571.doi: 10.3864/j.issn.0578-1752.2017.18.012

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

膜下滴灌不同灌水控制下限对设施土壤团聚体分布特征的影响

马建辉,叶旭红,韩冰,李文,虞娜,范庆锋,张玉玲,邹洪涛,张玉龙   

  1. 沈阳农业大学土地与环境学院/农业部东北耕地保育重点实验室/土肥资源高效利用国家工程实验室,沈阳 110866
  • 收稿日期:2017-02-21 出版日期:2017-09-16 发布日期:2017-09-16
  • 通讯作者: 邹洪涛,E-mail:zouhongtao2001@163.com
  • 作者简介:马建辉,E-mail:JianhMa@126.com
  • 基金资助:
    国家科技支撑计划(2015BAD23B0203)、辽宁省高等学校优秀人才计划、辽宁省农业领域青年科技创新人才培养计划(2015051)

Effects of Different Controlled Irrigation Low Limits on the Size Distribution of Soil Aggregates with Drip Irrigation Under Film Mulching in a Greenhouse Soil

MA JianHui, YE XuHong, HAN Bing, LI Wen, YU Na, FAN QingFeng, ZHANG YuLing, ZOU HongTao, ZHANG YuLong   

  1. College of Land and Environment, Shenyang Agricultural University/ Northeast Key Laboratory of Conservation and Improvement of Cultivated (Shenyang), Ministry of Agricultural/National Engineering Laboratory for Efficient Utilization of Soil Fertilizer Resources, Shenyang 110866
  • Received:2017-02-21 Online:2017-09-16 Published:2017-09-16

摘要: 【目的】灌溉是设施土壤水分的主要来源,也是影响土壤结构稳定性的重要因子。探究不同灌水控制下限对设施土壤团聚体分布特征和稳定性的影响,为设施农业合理水分调控、促进设施土壤结构改善提供理论依据。【方法】选用6年膜下滴灌试验地为对象,供试作物为番茄 (Lycopersicon esculentum Mill.),种植模式为沟垄覆膜。设置了3个灌水控制下限,其土壤水吸力值分别为20、30及40 kPa(分别记为D20、D30、D40),灌水控制上限均为6 kPa。各小区以埋设深度30 cm的张力计指示土壤水分变化,确定灌水时间和灌水量。通过干筛法和湿筛法测定了土壤团聚体的组成,>0.25 mm团聚体含量(R0.25)、平均重量直径(MWD)、几何平均直径(GMD)、分形维数(D)、以及土壤结构破坏率(RDS)和不稳定团粒指数(ElT)。【结果】在0—30 cm土层,D40处理的土壤电导率(EC)、阳离子交换量(CEC)和容重都显著低于D20和D30处理(D40<D30<D20);D20处理的pH显著低于D30和D40处理(D40>D30>D20)(P<0.05)。通过干筛法和湿筛法对团聚体数量和大小的测定发现,在0—30 cm土层,土壤机械稳定性团聚体主要集中在>2和1—0.25 mm粒级(23.01%—39.98%),而水稳性团聚体主要集中在1—0.25 和0.25—0.053 mm粒级(31.08—47.27%)。在0—20 cm土层,D30处理的R0.25、平均重量直径(MWD)和几何平均直径(GMD)均高于D20和D40处理;但在20—30 cm土层,D20处理的水稳性团聚体的含量高于D30和D40处理。不同灌水控制下限下的土壤结构破坏率(RDS)和不稳定团粒指数(ElT)随土壤深度增加而增加,且RDSElT的变化规律相似。在0—20 cm土层,D30处理的土壤结构破坏率(RDS)和不稳定团粒指数(ElT)显著低于D20和D40处理(P<0.05)。但在20—30 cm 土层,D20处理的土壤结构破坏率(RDS)比D30和D40处理分别低了12.2%和16.8%。干筛下在10—20 cm 土层内,D20、D30、D40处理的分形维数最小,分别是2.13、2.08、2.19;湿筛下在10—20 cm 土层内,D40、D30、D40处理的分形维数最小,分别是2.31、1.99、2.12。结果表现出,与D20和D40处理相比,D30处理显著降低了团聚体中的分形维数(D)。【结论】在保证设施番茄产量和节约用水的条件下,将土壤水吸力30 kPa作为膜下滴灌灌水控制下限,有利于土壤结构的形成和稳定。

关键词: 设施土壤, 膜下滴灌, 灌水控制下限, 土壤团聚体

Abstract: 【Objective】 Irrigation is the main source of soil moisture and affects the soil structure stability under greenhouse condition. The objective of this paper is to explore the effects of different controlled irrigation low limits on composition and stability of soil aggregates in a greenhouse soil. Results of the study will provide a theoretical basis for reasonable water regulation and improvement soil structure.【Method】The irrigation experiments were conducted in a greenhouse at the scientific research base of Shenyang Agricultural University, China during the period from 2011 to 2016. The test crop was tomato, and the planting mode was ridge and furrow covering. Different controlled irrigation low limits were set to: 20 kPa (D20), 30 kPa (D30), 40 kPa (D40), respectively, and the irrigation allowable upper limit of them was set to 6 kPa. Soil water suctions detected by tensiometers were placed in 30 cm soil layer. The aggregates amount, macro-aggregate content (R0.25), geometric mean diameter (GMD), mean weight diameter (MWD), structure deterioration rate (RDS), unstable aggregates index (ElT)and fractal dimension (D) were examined by dry and wet sieving methods. 【Result】 In the 0-30 cm soil layer, the electrical conductivity (EC), cation exchange capacity (CEC) and soil bulk density in D40 treatment were significantly lower than those of D20 and D30 treatments (D40<D30<D20). The pH value of D20 treatment was significantly lower than that of D30 and D40 treatments (P<0.05). In the 0-30 cm soil layer, the size class of dry-stable aggregate was mainly composed of >2 mm and 1-0.25 mm (23.01%-39.98%); the size class of water-stable aggregate was mainly composed of 1-0.25 and 0.25-0.053 mm (31.08%-47.27%). In the 0-20 cm soil layer, R0.25, GMD and MWD in D30 treatment were significantly higher than those of D20 and D30 treatments. While in the 20-30 cm soil layer, the wet stable aggregate content of D20 treatment was significantly higher than that of D30 and D40 treatments (P<0.05). The soil structure deterioration rate (RDS) and unstable aggregate index (ElT) increased with soil depth under different irrigation control limits, and the variation of RDS and ElT was similar. In the 0-20 cm soil layer, the RDS and ElT of D30 treatment were significantly lower than those of D20 and D30 treatments. But in the 20-30 cm soil layer, the RDS of D20 treatment was lower than those of D20 and D30 treatments by 12.2% and 16.8%, respectively. By dry sieving, the soil fractal dimension (D) of D20, D30 and D40 in the 20-30 cm soil layer was 2.13, 2.08 and 2.19, respectively; by wet sieving, that of D20, D30 and D40 treatment in the 20-30 cm soil layer was 2.31, 1.99 and 2.12, respectively. Overall, compared with D20 and D40, D30 treatment significantly reduced the fractal dimension (D) in the aggregates.【Conclusion】 The result suggests that the 30 kPa drip irrigation treatment greatly enhanced the composition of macroaggregates and the stabilization of soil structure.

Key words: the greenhouse soil, plastic mulching and drip irrigation, lower limit of irrigation, soil aggregates