Evaluation of short-term conservation tillage systems by enzyme activity assessment

Aims: There are few studies on the effectiveness of this type of management on the soil properties of Golestan Province, the main agricultural pole in Iran. This study aims to investigate tillage types on microbial enzymes as quality indicators of Fertile soils. Materials Methods: Three types of operations which include No Tillage (NT), Minimum or Occasionally Tillage (OT or MT), and Conventional Tillage (CT) were selected. In 0-30 cm of soil depth, samples were taken with 30 replications. Microbial respiration, microbial biomass, urease, acid and alkaline phosphatase, dehydrogenase, and cellulase activity were measured. Findings: Conservation tillage (ST) which includes both MT and NT, increased acid and alkaline phosphatase by 1.6 to 2.5 times. The reverse trend for cellulase decreased from 37.5% in MT to 25% in NT. Urease and dehydrogenase increased by 14 and 18% in MT and decreased by 5.7 and 10% in NT. Microbial biomass and microbial respiration increased by 1.8 and 2.5 times in MT, and no-tillage operation decreased by 15 and 44%. Conclusion: The emphasis is on the advice of ST. However, some points related to promoting this method in agricultural lands should be considered. In short-term operation (transitional phase), MT has a better condition for enzyme activity than NT. Low enzyme activity in NT conditions may reduce the availability of nutrients and thus reduce the yield, and then extension experts should inform the Farmers.