Continuous grass coverage as a management practice in humid environment vineyards increases compaction and CO2 emissions but does not modify must quality

Few works have been carried out on the coupled impacts of different management practices and tractor traffic on soil properties and degradation in vineyards, grape productivity and must quality. The influence of different tillage practices (conventional tillage—CT; grass coverage in a given year—INV‐GC; tillage in a given year—INV‐T) and continuous grass coverage (CGC) on bulk density (BD), soil water content (SWC), CO2 emissions, grape yield and must quality have been investigated in a vineyard in Zagreb, Croatia. During 2017, soil properties were analysed in the 0–10 cm and 10–20 cm layers after 3, 6 and 11 tractor traffic passes. The results showed that tractor traffic increased the BD in the CGC, INV‐GC and INV‐T treatments. The BD at the 0–10 cm and 10–20 cm depths was significantly higher in CGC than in CT. During the wet year of 2017, CT and INV‐T had significantly higher SWCs than did CGC and INV‐GC. The CO2 emissions under different management practices were INV‐T (120.3 CO2 ha−1 yr−1) > CGC (111.4 CO2 ha−1 yr−1) > INV‐GC (71.7 CO2 ha−1 yr−1) > CT (51.5 kg CO2 ha−1 yr−1). The effects of soil management on must quality and grape composition measurements were also detected. Grape yield was as follows: CT (5.37 kg vine−1) > INV‐GC (4.43 kg vine−1) > CGC (4.06 kg vine−1) > INV‐T (3.87 kg vine−1). Treatments had a significant impact only on pruning weight, pH value and free amino nitrogen (FAN), whereas no significant differences were found in the cluster number per vine, mean cluster weight, sugar content and titratable acids.