深松耕作对土壤物理性状和入渗性能的影响

为探讨深松耕作对华北平原地区土壤物理性状和水分入渗性能的影响,采用双环(APM)、入渗仪等试验材料,研究了深松(40 cm)+旋耕(PS)和仅旋耕(CK)2种耕作方式对冬小麦全生育期土壤物理性状及入渗特性的影响.结果表明:冬小麦全生育期,PS处理(0,40]cm土层土壤容重、紧实度较CK分别降低6.58%,31.29%,土壤含水率较CK增加12.11%;PS处理20,40 cm深度土壤饱和导水率较CK分别显著提高116.65%,83.69%,60 cm深度土壤饱和导水率较CK提高8.25%;PS处理土壤初始入渗速率、稳定入渗速率和累计入渗量畦灌前较CK分别提高21.52%,31.75%和11.56%,畦灌后较CK分别提高61.54%,68.42%和12.63%,差异具有统计学意义;采用4种入渗模型对入渗试验进行了比较,其中,Kositiakov入渗模型能够较好地对各处理进行拟合,决定系数R 2在0.92~0.96,得到了不同处理畦灌前后的入渗系数a和入渗指数b.研究结果可为不同耕作方式模拟畦灌过程、确定畦灌最优灌水技术参数提供参考依据.

Effects of subsoiling tillage on soil physical properties and infiltration characteristics

Subsoiling tillage(PS)is beneficial to improve soil structure and permeable capacity.To explore effects of PS on soil physical properties and soil moisture infiltration characteristics,field experiment was carried out under two conditions,namely subsoiling+PS and conventional tillage(CK),i.e.PS only,then soil bulk density,soil compaction,moisture content,saturated hydraulic conductivity and soil infiltration parameters were measured by making use of double-ring and the Aardvark Permeameter Module(APM)in various growth stages of winter wheat in North China Plain.The results show that the soil bulk density and compaction are decreased in PS treatment by 6.58%and 31.29%and the soil moisture is increased by 12.11%compared to CK in 0-40 cm soil layer in the whole growth period.The soil saturated hydraulic conductivity is significantly increased by 116.65%and 83.69%in subsoiling(20,40 cm)+PS treatments,but increased by 8.25%subsoiling(60 cm)+PS treatment in comparison with CK treatment.The soil initial,sTab.infiltration and accumulative infiltration rates are well improved by 21.52%,31.75%and 11.56%before irrigation and by 61.54%,68.42%and 12.63%after irrigation higher in subsoiling(20,40 cm)+PS treatments than that in CK treatment.The infiltration experiments are compared in terms of four infiltration models.The Kositiakov infiltration model can better fit every set of experimental data with a correlation coefficient between 0.92 and 0.96.The infiltration coefficient a and infiltration index b before and after border irrigation are obtained.The results in the paper has provided a reference for border irrigation simulation and determination of optimal technical parameters of irrigation in different tillage modes.