THE EFFECT OF COMPACTION ON WATER RETENTION IN THE VINEYARD’S ROOT ZONE

Abstract

In vineyards, frequent machinery traffic between the vine rows results in spatialand temporal changes in soil structure that affect the water retention properties inthe root zone. Compaction effects on the soil water characteristic curve in the rootzone were evaluated in three vineyards of different soil types (a Cl, a ClL, and aSiL with increased sand percentage). Soil cores were collected from a) the tilledsoil on the vine-row and b) the compacted soil of ruts produced by machinerytraffic within the inter-row distance. Sampling was carried out at two depths (0-15cm and 15-30cm) and at two time intervals, the first in spring when agriculturalvehicles had accomplished 6-8 passes and the second in autumn, after ca 20 passes.The results of the first sampling in the beginning of the cultivation period revealedthat compaction increased soil bulk density of the three vineyards in both depths.Drainage pores collapsed to smaller ones while plant available water and texturalporosity increased. The effect of compaction was more pronounced on the surface(0-15 cm) of the more fine textured soils. In autumn, at the end of the cultivationperiod, it was found that the soil water retention characteristics in the vineyardsroot zone were not substantially further affected by machinery traffic. Weconcluded that machinery traffic impact on the studied properties was intense inspring when the soil in vineyards was loose from tillage before the cultivationperiod and had temporally increased moisture content which results in decreasedstrength.